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b3c2bc8cc44ebcc1ecd486baaf6d231807d44ef8
mariadb/sql/sql_base.cc
antony@pcg5ppc.xiphis.org 3b95727600 Merge anubis.xiphis.org:/usr/home/antony/work/mysql-5.1-engines 
into  anubis.xiphis.org:/usr/home/antony/work/mysql-5.1-engines.merge
2007-10-19 13:06:37 -07:00

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/* Copyright (C) 2000-2006 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Basic functions needed by many modules */
#include "mysql_priv.h"
#include "sql_select.h"
#include "sp_head.h"
#include "sp.h"
#include "sql_trigger.h"
#include <m_ctype.h>
#include <my_dir.h>
#include <hash.h>
#ifdef __WIN__
#include <io.h>
#endif
#define FLAGSTR(S,F) ((S) & (F) ? #F " " : "")
/**
This internal handler is used to trap internally
errors that can occur when executing open table
during the prelocking phase.
*/
class Prelock_error_handler : public Internal_error_handler
{
public:
Prelock_error_handler()
: m_handled_errors(0), m_unhandled_errors(0)
{}
virtual ~Prelock_error_handler() {}
virtual bool handle_error(uint sql_errno,
MYSQL_ERROR::enum_warning_level level,
THD *thd);
bool safely_trapped_errors();
private:
int m_handled_errors;
int m_unhandled_errors;
};
bool
Prelock_error_handler::handle_error(uint sql_errno,
MYSQL_ERROR::enum_warning_level /* level */,
THD * /* thd */)
{
if (sql_errno == ER_NO_SUCH_TABLE)
{
m_handled_errors++;
return TRUE;
}
m_unhandled_errors++;
return FALSE;
}
bool Prelock_error_handler::safely_trapped_errors()
{
/*
If m_unhandled_errors != 0, something else, unanticipated, happened,
so the error is not trapped but returned to the caller.
Multiple ER_NO_SUCH_TABLE can be raised in case of views.
*/
return ((m_handled_errors > 0) && (m_unhandled_errors == 0));
}
/**
@defgroup Data_Dictionary Data Dictionary
@{
*/
TABLE *unused_tables; /* Used by mysql_test */
HASH open_cache; /* Used by mysql_test */
static HASH table_def_cache;
static TABLE_SHARE *oldest_unused_share, end_of_unused_share;
static pthread_mutex_t LOCK_table_share;
static bool table_def_inited= 0;
static int open_unireg_entry(THD *thd, TABLE *entry, TABLE_LIST *table_list,
const char *alias,
char *cache_key, uint cache_key_length,
MEM_ROOT *mem_root, uint flags);
static void free_cache_entry(TABLE *entry);
static bool open_new_frm(THD *thd, TABLE_SHARE *share, const char *alias,
uint db_stat, uint prgflag,
uint ha_open_flags, TABLE *outparam,
TABLE_LIST *table_desc, MEM_ROOT *mem_root);
static void close_old_data_files(THD *thd, TABLE *table, bool morph_locks,
bool send_refresh);
static bool
has_two_write_locked_tables_with_auto_increment(TABLE_LIST *tables);
extern "C" uchar *table_cache_key(const uchar *record, size_t *length,
my_bool not_used __attribute__((unused)))
{
TABLE *entry=(TABLE*) record;
*length= entry->s->table_cache_key.length;
return (uchar*) entry->s->table_cache_key.str;
}
bool table_cache_init(void)
{
return hash_init(&open_cache, &my_charset_bin, table_cache_size+16,
0, 0, table_cache_key,
(hash_free_key) free_cache_entry, 0) != 0;
}
void table_cache_free(void)
{
DBUG_ENTER("table_cache_free");
if (table_def_inited)
{
close_cached_tables((THD*) 0,0,(TABLE_LIST*) 0);
if (!open_cache.records) // Safety first
hash_free(&open_cache);
}
DBUG_VOID_RETURN;
}
uint cached_open_tables(void)
{
return open_cache.records;
}
#ifdef EXTRA_DEBUG
static void check_unused(void)
{
uint count= 0, open_files= 0, idx= 0;
TABLE *cur_link,*start_link;
if ((start_link=cur_link=unused_tables))
{
do
{
if (cur_link != cur_link->next->prev || cur_link != cur_link->prev->next)
{
DBUG_PRINT("error",("Unused_links aren't linked properly")); /* purecov: inspected */
return; /* purecov: inspected */
}
} while (count++ < open_cache.records &&
(cur_link=cur_link->next) != start_link);
if (cur_link != start_link)
{
DBUG_PRINT("error",("Unused_links aren't connected")); /* purecov: inspected */
}
}
for (idx=0 ; idx < open_cache.records ; idx++)
{
TABLE *entry=(TABLE*) hash_element(&open_cache,idx);
if (!entry->in_use)
count--;
if (entry->file)
open_files++;
}
if (count != 0)
{
DBUG_PRINT("error",("Unused_links doesn't match open_cache: diff: %d", /* purecov: inspected */
count)); /* purecov: inspected */
}
#ifdef NOT_SAFE_FOR_REPAIR
/*
check that open cache and table definition cache has same number of
aktive tables
*/
count= 0;
for (idx=0 ; idx < table_def_cache.records ; idx++)
{
TABLE_SHARE *entry= (TABLE_SHARE*) hash_element(&table_def_cache,idx);
count+= entry->ref_count;
}
if (count != open_files)
{
DBUG_PRINT("error", ("table_def ref_count: %u open_cache: %u",
count, open_files));
DBUG_ASSERT(count == open_files);
}
#endif
}
#else
#define check_unused()
#endif
/*
Create a table cache key
SYNOPSIS
create_table_def_key()
thd Thread handler
key Create key here (must be of size MAX_DBKEY_LENGTH)
table_list Table definition
tmp_table Set if table is a tmp table
IMPLEMENTATION
The table cache_key is created from:
db_name + \0
table_name + \0
if the table is a tmp table, we add the following to make each tmp table
unique on the slave:
4 bytes for master thread id
4 bytes pseudo thread id
RETURN
Length of key
*/
uint create_table_def_key(THD *thd, char *key, TABLE_LIST *table_list,
bool tmp_table)
{
uint key_length= (uint) (strmov(strmov(key, table_list->db)+1,
table_list->table_name)-key)+1;
if (tmp_table)
{
int4store(key + key_length, thd->server_id);
int4store(key + key_length + 4, thd->variables.pseudo_thread_id);
key_length+= TMP_TABLE_KEY_EXTRA;
}
return key_length;
}
/*****************************************************************************
Functions to handle table definition cach (TABLE_SHARE)
*****************************************************************************/
extern "C" uchar *table_def_key(const uchar *record, size_t *length,
my_bool not_used __attribute__((unused)))
{
TABLE_SHARE *entry=(TABLE_SHARE*) record;
*length= entry->table_cache_key.length;
return (uchar*) entry->table_cache_key.str;
}
static void table_def_free_entry(TABLE_SHARE *share)
{
DBUG_ENTER("table_def_free_entry");
if (share->prev)
{
/* remove from old_unused_share list */
pthread_mutex_lock(&LOCK_table_share);
*share->prev= share->next;
share->next->prev= share->prev;
pthread_mutex_unlock(&LOCK_table_share);
}
free_table_share(share);
DBUG_VOID_RETURN;
}
bool table_def_init(void)
{
table_def_inited= 1;
pthread_mutex_init(&LOCK_table_share, MY_MUTEX_INIT_FAST);
oldest_unused_share= &end_of_unused_share;
end_of_unused_share.prev= &oldest_unused_share;
return hash_init(&table_def_cache, &my_charset_bin, table_def_size,
0, 0, table_def_key,
(hash_free_key) table_def_free_entry, 0) != 0;
}
void table_def_free(void)
{
DBUG_ENTER("table_def_free");
if (table_def_inited)
{
table_def_inited= 0;
pthread_mutex_destroy(&LOCK_table_share);
hash_free(&table_def_cache);
}
DBUG_VOID_RETURN;
}
uint cached_table_definitions(void)
{
return table_def_cache.records;
}
/*
Get TABLE_SHARE for a table.
get_table_share()
thd Thread handle
table_list Table that should be opened
key Table cache key
key_length Length of key
db_flags Flags to open_table_def():
OPEN_VIEW
error out: Error code from open_table_def()
IMPLEMENTATION
Get a table definition from the table definition cache.
If it doesn't exist, create a new from the table definition file.
NOTES
We must have wrlock on LOCK_open when we come here
(To be changed later)
RETURN
0 Error
# Share for table
*/
TABLE_SHARE *get_table_share(THD *thd, TABLE_LIST *table_list, char *key,
uint key_length, uint db_flags, int *error)
{
TABLE_SHARE *share;
DBUG_ENTER("get_table_share");
*error= 0;
/* Read table definition from cache */
if ((share= (TABLE_SHARE*) hash_search(&table_def_cache,(uchar*) key,
key_length)))
goto found;
if (!(share= alloc_table_share(table_list, key, key_length)))
{
#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
pthread_mutex_unlock(&LOCK_open);
#endif
DBUG_RETURN(0);
}
#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
// We need a write lock to be able to add a new entry
pthread_mutex_unlock(&LOCK_open);
pthread_mutex_lock(&LOCK_open);
/* Check that another thread didn't insert the same table in between */
if ((old_share= hash_search(&table_def_cache, (uchar*) key, key_length)))
{
(void) pthread_mutex_lock(&share->mutex);
free_table_share(share);
share= old_share;
goto found;
}
#endif
/*
Lock mutex to be able to read table definition from file without
conflicts
*/
(void) pthread_mutex_lock(&share->mutex);
/*
We assign a new table id under the protection of the LOCK_open and
the share's own mutex. We do this insted of creating a new mutex
and using it for the sole purpose of serializing accesses to a
static variable, we assign the table id here. We assign it to the
share before inserting it into the table_def_cache to be really
sure that it cannot be read from the cache without having a table
id assigned.
CAVEAT. This means that the table cannot be used for
binlogging/replication purposes, unless get_table_share() has been
called directly or indirectly.
*/
assign_new_table_id(share);
if (my_hash_insert(&table_def_cache, (uchar*) share))
{
#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
pthread_mutex_unlock(&LOCK_open);
(void) pthread_mutex_unlock(&share->mutex);
#endif
free_table_share(share);
DBUG_RETURN(0); // return error
}
#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
pthread_mutex_unlock(&LOCK_open);
#endif
if (open_table_def(thd, share, db_flags))
{
#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
/*
No such table or wrong table definition file
Lock first the table cache and then the mutex.
This will ensure that no other thread is using the share
structure.
*/
(void) pthread_mutex_unlock(&share->mutex);
(void) pthread_mutex_lock(&LOCK_open);
(void) pthread_mutex_lock(&share->mutex);
#endif
*error= share->error;
(void) hash_delete(&table_def_cache, (uchar*) share);
DBUG_RETURN(0);
}
share->ref_count++; // Mark in use
DBUG_PRINT("exit", ("share: 0x%lx ref_count: %u",
(ulong) share, share->ref_count));
(void) pthread_mutex_unlock(&share->mutex);
DBUG_RETURN(share);
found:
/*
We found an existing table definition. Return it if we didn't get
an error when reading the table definition from file.
*/
/* We must do a lock to ensure that the structure is initialized */
(void) pthread_mutex_lock(&share->mutex);
#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
pthread_mutex_unlock(&LOCK_open);
#endif
if (share->error)
{
/* Table definition contained an error */
open_table_error(share, share->error, share->open_errno, share->errarg);
(void) pthread_mutex_unlock(&share->mutex);
DBUG_RETURN(0);
}
if (share->is_view && !(db_flags & OPEN_VIEW))
{
open_table_error(share, 1, ENOENT, 0);
(void) pthread_mutex_unlock(&share->mutex);
DBUG_RETURN(0);
}
if (!share->ref_count++ && share->prev)
{
/*
Share was not used before and it was in the old_unused_share list
Unlink share from this list
*/
DBUG_PRINT("info", ("Unlinking from not used list"));
pthread_mutex_lock(&LOCK_table_share);
*share->prev= share->next;
share->next->prev= share->prev;
share->next= 0;
share->prev= 0;
pthread_mutex_unlock(&LOCK_table_share);
}
(void) pthread_mutex_unlock(&share->mutex);
/* Free cache if too big */
while (table_def_cache.records > table_def_size &&
oldest_unused_share->next)
{
pthread_mutex_lock(&oldest_unused_share->mutex);
VOID(hash_delete(&table_def_cache, (uchar*) oldest_unused_share));
}
DBUG_PRINT("exit", ("share: 0x%lx ref_count: %u",
(ulong) share, share->ref_count));
DBUG_RETURN(share);
}
/*
Get a table share. If it didn't exist, try creating it from engine
For arguments and return values, see get_table_from_share()
*/
static TABLE_SHARE
*get_table_share_with_create(THD *thd, TABLE_LIST *table_list,
char *key, uint key_length,
uint db_flags, int *error)
{
TABLE_SHARE *share;
int tmp;
DBUG_ENTER("get_table_share_with_create");
if ((share= get_table_share(thd, table_list, key, key_length,
db_flags, error)) ||
thd->net.last_errno != ER_NO_SUCH_TABLE)
DBUG_RETURN(share);
/* Table didn't exist. Check if some engine can provide it */
if ((tmp= ha_create_table_from_engine(thd, table_list->db,
table_list->table_name)) < 0)
{
/*
No such table in any engine.
Hide "Table doesn't exist" errors if table belong to view
*/
if (table_list->belong_to_view)
{
TABLE_LIST *view= table_list->belong_to_view;
thd->clear_error();
my_error(ER_VIEW_INVALID, MYF(0),
view->view_db.str, view->view_name.str);
}
DBUG_RETURN(0);
}
if (tmp)
{
/* Give right error message */
thd->clear_error();
DBUG_PRINT("error", ("Discovery of %s/%s failed", table_list->db,
table_list->table_name));
my_printf_error(ER_UNKNOWN_ERROR,
"Failed to open '%-.64s', error while "
"unpacking from engine",
MYF(0), table_list->table_name);
DBUG_RETURN(0);
}
/* Table existed in engine. Let's open it */
mysql_reset_errors(thd, 1); // Clear warnings
thd->clear_error(); // Clear error message
DBUG_RETURN(get_table_share(thd, table_list, key, key_length,
db_flags, error));
}
/*
Mark that we are not using table share anymore.
SYNOPSIS
release_table_share()
share Table share
release_type How the release should be done:
RELEASE_NORMAL
- Release without checking
RELEASE_WAIT_FOR_DROP
- Don't return until we get a signal that the
table is deleted or the thread is killed.
IMPLEMENTATION
If ref_count goes to zero and (we have done a refresh or if we have
already too many open table shares) then delete the definition.
If type == RELEASE_WAIT_FOR_DROP then don't return until we get a signal
that the table is deleted or the thread is killed.
*/
void release_table_share(TABLE_SHARE *share, enum release_type type)
{
bool to_be_deleted= 0;
DBUG_ENTER("release_table_share");
DBUG_PRINT("enter",
("share: 0x%lx table: %s.%s ref_count: %u version: %lu",
(ulong) share, share->db.str, share->table_name.str,
share->ref_count, share->version));
safe_mutex_assert_owner(&LOCK_open);
pthread_mutex_lock(&share->mutex);
if (!--share->ref_count)
{
if (share->version != refresh_version)
to_be_deleted=1;
else
{
/* Link share last in used_table_share list */
DBUG_PRINT("info",("moving share to unused list"));
DBUG_ASSERT(share->next == 0);
pthread_mutex_lock(&LOCK_table_share);
share->prev= end_of_unused_share.prev;
*end_of_unused_share.prev= share;
end_of_unused_share.prev= &share->next;
share->next= &end_of_unused_share;
pthread_mutex_unlock(&LOCK_table_share);
to_be_deleted= (table_def_cache.records > table_def_size);
}
}
if (to_be_deleted)
{
DBUG_PRINT("info", ("Deleting share"));
hash_delete(&table_def_cache, (uchar*) share);
DBUG_VOID_RETURN;
}
pthread_mutex_unlock(&share->mutex);
DBUG_VOID_RETURN;
#ifdef WAITING_FOR_TABLE_DEF_CACHE_STAGE_3
if (to_be_deleted)
{
/*
We must try again with new locks as we must get LOCK_open
before share->mutex
*/
pthread_mutex_unlock(&share->mutex);
pthread_mutex_lock(&LOCK_open);
pthread_mutex_lock(&share->mutex);
if (!share->ref_count)
{ // No one is using this now
TABLE_SHARE *name_lock;
if (share->replace_with_name_lock && (name_lock=get_name_lock(share)))
{
/*
This code is execured when someone does FLUSH TABLES while on has
locked tables.
*/
(void) hash_search(&def_cache,(uchar*) key,key_length);
hash_replace(&def_cache, def_cache.current_record,(uchar*) name_lock);
}
else
{
/* Remove table definition */
hash_delete(&def_cache,(uchar*) share);
}
pthread_mutex_unlock(&LOCK_open);
free_table_share(share);
}
else
{
pthread_mutex_unlock(&LOCK_open);
if (type == RELEASE_WAIT_FOR_DROP)
wait_for_table(share, "Waiting for close");
else
pthread_mutex_unlock(&share->mutex);
}
}
else if (type == RELEASE_WAIT_FOR_DROP)
wait_for_table(share, "Waiting for close");
else
pthread_mutex_unlock(&share->mutex);
#endif
}
/*
Check if table definition exits in cache
SYNOPSIS
get_cached_table_share()
db Database name
table_name Table name
RETURN
0 Not cached
# TABLE_SHARE for table
*/
TABLE_SHARE *get_cached_table_share(const char *db, const char *table_name)
{
char key[NAME_LEN*2+2];
TABLE_LIST table_list;
uint key_length;
safe_mutex_assert_owner(&LOCK_open);
table_list.db= (char*) db;
table_list.table_name= (char*) table_name;
key_length= create_table_def_key((THD*) 0, key, &table_list, 0);
return (TABLE_SHARE*) hash_search(&table_def_cache,(uchar*) key, key_length);
}
/*
Close file handle, but leave the table in the table cache
SYNOPSIS
close_handle_and_leave_table_as_lock()
table Table handler
NOTES
By leaving the table in the table cache, it disallows any other thread
to open the table
thd->killed will be set if we run out of memory
*/
void close_handle_and_leave_table_as_lock(TABLE *table)
{
TABLE_SHARE *share, *old_share= table->s;
char *key_buff;
MEM_ROOT *mem_root= &table->mem_root;
DBUG_ENTER("close_handle_and_leave_table_as_lock");
DBUG_ASSERT(table->db_stat);
/*
Make a local copy of the table share and free the current one.
This has to be done to ensure that the table share is removed from
the table defintion cache as soon as the last instance is removed
*/
if (multi_alloc_root(mem_root,
&share, sizeof(*share),
&key_buff, old_share->table_cache_key.length,
NULL))
{
bzero((char*) share, sizeof(*share));
share->set_table_cache_key(key_buff, old_share->table_cache_key.str,
old_share->table_cache_key.length);
share->tmp_table= INTERNAL_TMP_TABLE; // for intern_close_table()
}
table->file->close();
table->db_stat= 0; // Mark file closed
release_table_share(table->s, RELEASE_NORMAL);
table->s= share;
DBUG_VOID_RETURN;
}
/*
Create a list for all open tables matching SQL expression
SYNOPSIS
list_open_tables()
thd Thread THD
wild SQL like expression
NOTES
One gets only a list of tables for which one has any kind of privilege.
db and table names are allocated in result struct, so one doesn't need
a lock on LOCK_open when traversing the return list.
RETURN VALUES
NULL Error (Probably OOM)
# Pointer to list of names of open tables.
*/
OPEN_TABLE_LIST *list_open_tables(THD *thd, const char *db, const char *wild)
{
int result = 0;
OPEN_TABLE_LIST **start_list, *open_list;
TABLE_LIST table_list;
DBUG_ENTER("list_open_tables");
VOID(pthread_mutex_lock(&LOCK_open));
bzero((char*) &table_list,sizeof(table_list));
start_list= &open_list;
open_list=0;
for (uint idx=0 ; result == 0 && idx < open_cache.records; idx++)
{
OPEN_TABLE_LIST *table;
TABLE *entry=(TABLE*) hash_element(&open_cache,idx);
TABLE_SHARE *share= entry->s;
if (db && my_strcasecmp(system_charset_info, db, share->db.str))
continue;
if (wild && wild_compare(share->table_name.str, wild, 0))
continue;
/* Check if user has SELECT privilege for any column in the table */
table_list.db= share->db.str;
table_list.table_name= share->table_name.str;
table_list.grant.privilege=0;
if (check_table_access(thd,SELECT_ACL | EXTRA_ACL,&table_list,1))
continue;
/* need to check if we haven't already listed it */
for (table= open_list ; table ; table=table->next)
{
if (!strcmp(table->table, share->table_name.str) &&
!strcmp(table->db, share->db.str))
{
if (entry->in_use)
table->in_use++;
if (entry->locked_by_name)
table->locked++;
break;
}
}
if (table)
continue;
if (!(*start_list = (OPEN_TABLE_LIST *)
sql_alloc(sizeof(**start_list)+share->table_cache_key.length)))
{
open_list=0; // Out of memory
break;
}
strmov((*start_list)->table=
strmov(((*start_list)->db= (char*) ((*start_list)+1)),
share->db.str)+1,
share->table_name.str);
(*start_list)->in_use= entry->in_use ? 1 : 0;
(*start_list)->locked= entry->locked_by_name ? 1 : 0;
start_list= &(*start_list)->next;
*start_list=0;
}
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(open_list);
}
/*****************************************************************************
* Functions to free open table cache
****************************************************************************/
void intern_close_table(TABLE *table)
{ // Free all structures
DBUG_ENTER("intern_close_table");
free_io_cache(table);
delete table->triggers;
if (table->file) // Not true if name lock
VOID(closefrm(table, 1)); // close file
DBUG_VOID_RETURN;
}
/*
Remove table from the open table cache
SYNOPSIS
free_cache_entry()
table Table to remove
NOTE
We need to have a lock on LOCK_open when calling this
*/
static void free_cache_entry(TABLE *table)
{
DBUG_ENTER("free_cache_entry");
intern_close_table(table);
if (!table->in_use)
{
table->next->prev=table->prev; /* remove from used chain */
table->prev->next=table->next;
if (table == unused_tables)
{
unused_tables=unused_tables->next;
if (table == unused_tables)
unused_tables=0;
}
check_unused(); // consisty check
}
my_free((uchar*) table,MYF(0));
DBUG_VOID_RETURN;
}
/* Free resources allocated by filesort() and read_record() */
void free_io_cache(TABLE *table)
{
DBUG_ENTER("free_io_cache");
if (table->sort.io_cache)
{
close_cached_file(table->sort.io_cache);
my_free((uchar*) table->sort.io_cache,MYF(0));
table->sort.io_cache=0;
}
DBUG_VOID_RETURN;
}
/*
Close all tables which aren't in use by any thread
THD can be NULL, but then if_wait_for_refresh must be FALSE
and tables must be NULL.
*/
bool close_cached_tables(THD *thd, bool if_wait_for_refresh,
TABLE_LIST *tables, bool have_lock)
{
bool result=0;
DBUG_ENTER("close_cached_tables");
DBUG_ASSERT(thd || (!if_wait_for_refresh && !tables));
if (!have_lock)
VOID(pthread_mutex_lock(&LOCK_open));
if (!tables)
{
refresh_version++; // Force close of open tables
while (unused_tables)
{
#ifdef EXTRA_DEBUG
if (hash_delete(&open_cache,(uchar*) unused_tables))
printf("Warning: Couldn't delete open table from hash\n");
#else
VOID(hash_delete(&open_cache,(uchar*) unused_tables));
#endif
}
/* Free table shares */
while (oldest_unused_share->next)
{
pthread_mutex_lock(&oldest_unused_share->mutex);
VOID(hash_delete(&table_def_cache, (uchar*) oldest_unused_share));
}
}
else
{
bool found=0;
for (TABLE_LIST *table= tables; table; table= table->next_local)
{
if (remove_table_from_cache(thd, table->db, table->table_name,
RTFC_OWNED_BY_THD_FLAG))
found=1;
}
if (!found)
if_wait_for_refresh=0; // Nothing to wait for
}
#ifndef EMBEDDED_LIBRARY
if (!tables)
kill_delayed_threads();
#endif
if (if_wait_for_refresh)
{
/*
If there is any table that has a lower refresh_version, wait until
this is closed (or this thread is killed) before returning
*/
thd->mysys_var->current_mutex= &LOCK_open;
thd->mysys_var->current_cond= &COND_refresh;
thd->proc_info="Flushing tables";
close_old_data_files(thd,thd->open_tables,1,1);
mysql_ha_flush(thd, tables, MYSQL_HA_REOPEN_ON_USAGE | MYSQL_HA_FLUSH_ALL,
TRUE);
bool found=1;
/* Wait until all threads has closed all the tables we had locked */
DBUG_PRINT("info",
("Waiting for other threads to close their open tables"));
while (found && ! thd->killed)
{
found=0;
for (uint idx=0 ; idx < open_cache.records ; idx++)
{
TABLE *table=(TABLE*) hash_element(&open_cache,idx);
/*
Note that we wait here only for tables which are actually open, and
not for placeholders with TABLE::open_placeholder set. Waiting for
latter will cause deadlock in the following scenario, for example:
conn1: lock table t1 write;
conn2: lock table t2 write;
conn1: flush tables;
conn2: flush tables;
It also does not make sense to wait for those of placeholders that
are employed by CREATE TABLE as in this case table simply does not
exist yet.
*/
if (table->needs_reopen_or_name_lock() && table->db_stat)
{
found=1;
DBUG_PRINT("signal", ("Waiting for COND_refresh"));
pthread_cond_wait(&COND_refresh,&LOCK_open);
break;
}
}
}
/*
No other thread has the locked tables open; reopen them and get the
old locks. This should always succeed (unless some external process
has removed the tables)
*/
thd->in_lock_tables=1;
result=reopen_tables(thd,1,1);
thd->in_lock_tables=0;
/* Set version for table */
for (TABLE *table=thd->open_tables; table ; table= table->next)
table->s->version= refresh_version;
}
if (!have_lock)
VOID(pthread_mutex_unlock(&LOCK_open));
if (if_wait_for_refresh)
{
pthread_mutex_lock(&thd->mysys_var->mutex);
thd->mysys_var->current_mutex= 0;
thd->mysys_var->current_cond= 0;
thd->proc_info=0;
pthread_mutex_unlock(&thd->mysys_var->mutex);
}
DBUG_RETURN(result);
}
/*
Close all tables which match specified connection string or
if specified string is NULL, then any table with a connection string.
*/
bool close_cached_connection_tables(THD *thd, bool if_wait_for_refresh,
LEX_STRING *connection, bool have_lock)
{
uint idx;
TABLE_LIST tmp, *tables= NULL;
bool result= FALSE;
DBUG_ENTER("close_cached_connections");
DBUG_ASSERT(thd);
bzero(&tmp, sizeof(TABLE_LIST));
if (!have_lock)
VOID(pthread_mutex_lock(&LOCK_open));
for (idx= 0; idx < table_def_cache.records; idx++)
{
TABLE_SHARE *share= (TABLE_SHARE *) hash_element(&table_def_cache, idx);
/* Ignore if table is not open or does not have a connect_string */
if (!share->connect_string.length || !share->ref_count)
continue;
/* Compare the connection string */
if (connection &&
(connection->length > share->connect_string.length ||
(connection->length < share->connect_string.length &&
(share->connect_string.str[connection->length] != '/' &&
share->connect_string.str[connection->length] != '\\')) ||
strncasecmp(connection->str, share->connect_string.str,
connection->length)))
continue;
/* close_cached_tables() only uses these elements */
tmp.db= share->db.str;
tmp.table_name= share->table_name.str;
tmp.next_local= tables;
tables= (TABLE_LIST *) memdup_root(thd->mem_root, (char*)&tmp,
sizeof(TABLE_LIST));
}
if (tables)
result= close_cached_tables(thd, FALSE, tables, TRUE);
if (!have_lock)
VOID(pthread_mutex_unlock(&LOCK_open));
if (if_wait_for_refresh)
{
pthread_mutex_lock(&thd->mysys_var->mutex);
thd->mysys_var->current_mutex= 0;
thd->mysys_var->current_cond= 0;
thd->proc_info=0;
pthread_mutex_unlock(&thd->mysys_var->mutex);
}
DBUG_RETURN(result);
}
/*
Mark all tables in the list which were used by current substatement
as free for reuse.
SYNOPSIS
mark_used_tables_as_free_for_reuse()
thd - thread context
table - head of the list of tables
DESCRIPTION
Marks all tables in the list which were used by current substatement
(they are marked by its query_id) as free for reuse.
NOTE
The reason we reset query_id is that it's not enough to just test
if table->query_id != thd->query_id to know if a table is in use.
For example
SELECT f1_that_uses_t1() FROM t1;
In f1_that_uses_t1() we will see one instance of t1 where query_id is
set to query_id of original query.
*/
static void mark_used_tables_as_free_for_reuse(THD *thd, TABLE *table)
{
for (; table ; table= table->next)
{
if (table->query_id == thd->query_id)
{
table->query_id= 0;
table->file->ha_reset();
}
}
}
/*
Close all tables used by the current substatement, or all tables
used by this thread if we are on the upper level.
SYNOPSIS
close_thread_tables()
thd Thread handler
lock_in_use Set to 1 (0 = default) if caller has a lock on
LOCK_open
skip_derived Set to 1 (0 = default) if we should not free derived
tables.
stopper When closing tables from thd->open_tables(->next)*,
don't close/remove tables starting from stopper.
IMPLEMENTATION
Unlocks tables and frees derived tables.
Put all normal tables used by thread in free list.
When in prelocked mode it will only close/mark as free for reuse
tables opened by this substatement, it will also check if we are
closing tables after execution of complete query (i.e. we are on
upper level) and will leave prelocked mode if needed.
*/
void close_thread_tables(THD *thd, bool lock_in_use, bool skip_derived)
{
bool found_old_table;
prelocked_mode_type prelocked_mode= thd->prelocked_mode;
DBUG_ENTER("close_thread_tables");
/*
We are assuming here that thd->derived_tables contains ONLY derived
tables for this substatement. i.e. instead of approach which uses
query_id matching for determining which of the derived tables belong
to this substatement we rely on the ability of substatements to
save/restore thd->derived_tables during their execution.
TODO: Probably even better approach is to simply associate list of
derived tables with (sub-)statement instead of thread and destroy
them at the end of its execution.
*/
if (thd->derived_tables && !skip_derived)
{
TABLE *table, *next;
/*
Close all derived tables generated in queries like
SELECT * FROM (SELECT * FROM t1)
*/
for (table= thd->derived_tables ; table ; table= next)
{
next= table->next;
free_tmp_table(thd, table);
}
thd->derived_tables= 0;
}
if (prelocked_mode)
{
/*
Mark all temporary tables used by this substatement as free for reuse.
*/
mark_used_tables_as_free_for_reuse(thd, thd->temporary_tables);
}
if (thd->locked_tables || prelocked_mode)
{
/*
Let us commit transaction for statement. Since in 5.0 we only have
one statement transaction and don't allow several nested statement
transactions this call will do nothing if we are inside of stored
function or trigger (i.e. statement transaction is already active and
does not belong to statement for which we do close_thread_tables()).
TODO: This should be fixed in later releases.
*/
ha_commit_stmt(thd);
/* Ensure we are calling ha_reset() for all used tables */
mark_used_tables_as_free_for_reuse(thd, thd->open_tables);
/* We are under simple LOCK TABLES so should not do anything else. */
if (!prelocked_mode || !thd->lex->requires_prelocking())
DBUG_VOID_RETURN;
/*
We are in prelocked mode, so we have to leave it now with doing
implicit UNLOCK TABLES if need.
*/
DBUG_PRINT("info",("thd->prelocked_mode= NON_PRELOCKED"));
thd->prelocked_mode= NON_PRELOCKED;
if (prelocked_mode == PRELOCKED_UNDER_LOCK_TABLES)
DBUG_VOID_RETURN;
thd->lock= thd->locked_tables;
thd->locked_tables= 0;
/* Fallthrough */
}
if (thd->lock)
{
/*
For RBR we flush the pending event just before we unlock all the
tables. This means that we are at the end of a topmost
statement, so we ensure that the STMT_END_F flag is set on the
pending event. For statements that are *inside* stored
functions, the pending event will not be flushed: that will be
handled either before writing a query log event (inside
binlog_query()) or when preparing a pending event.
*/
thd->binlog_flush_pending_rows_event(TRUE);
mysql_unlock_tables(thd, thd->lock);
thd->lock=0;
}
/*
assume handlers auto-commit (if some doesn't - transaction handling
in MySQL should be redesigned to support it; it's a big change,
and it's not worth it - better to commit explicitly only writing
transactions, read-only ones should better take care of themselves.
saves some work in 2pc too)
see also sql_parse.cc - dispatch_command()
*/
if (!(thd->state_flags & Open_tables_state::BACKUPS_AVAIL))
bzero(&thd->transaction.stmt, sizeof(thd->transaction.stmt));
if (!thd->active_transaction())
thd->transaction.xid_state.xid.null();
if (!lock_in_use)
VOID(pthread_mutex_lock(&LOCK_open));
DBUG_PRINT("info", ("thd->open_tables: 0x%lx", (long) thd->open_tables));
found_old_table= 0;
while (thd->open_tables)
found_old_table|= close_thread_table(thd, &thd->open_tables);
thd->some_tables_deleted=0;
/* Free tables to hold down open files */
while (open_cache.records > table_cache_size && unused_tables)
VOID(hash_delete(&open_cache,(uchar*) unused_tables)); /* purecov: tested */
check_unused();
if (found_old_table)
{
/* Tell threads waiting for refresh that something has happened */
broadcast_refresh();
}
if (!lock_in_use)
VOID(pthread_mutex_unlock(&LOCK_open));
/* VOID(pthread_sigmask(SIG_SETMASK,&thd->signals,NULL)); */
if (prelocked_mode == PRELOCKED)
{
/*
If we are here then we are leaving normal prelocked mode, so it is
good idea to turn off OPTION_TABLE_LOCK flag.
*/
DBUG_ASSERT(thd->lex->requires_prelocking());
thd->options&= ~(ulong) (OPTION_TABLE_LOCK);
}
DBUG_VOID_RETURN;
}
/* move one table to free list */
bool close_thread_table(THD *thd, TABLE **table_ptr)
{
bool found_old_table= 0;
TABLE *table= *table_ptr;
DBUG_ENTER("close_thread_table");
DBUG_ASSERT(table->key_read == 0);
DBUG_ASSERT(!table->file || table->file->inited == handler::NONE);
*table_ptr=table->next;
if (table->needs_reopen_or_name_lock() ||
thd->version != refresh_version || !table->db_stat)
{
VOID(hash_delete(&open_cache,(uchar*) table));
found_old_table=1;
}
else
{
/*
Open placeholders have TABLE::db_stat set to 0, so they should be
handled by the first alternative.
*/
DBUG_ASSERT(!table->open_placeholder);
/* Free memory and reset for next loop */
table->file->ha_reset();
table->in_use=0;
if (unused_tables)
{
table->next=unused_tables; /* Link in last */
table->prev=unused_tables->prev;
unused_tables->prev=table;
table->prev->next=table;
}
else
unused_tables=table->next=table->prev=table;
}
DBUG_RETURN(found_old_table);
}
/* close_temporary_tables' internal, 4 is due to uint4korr definition */
static inline uint tmpkeyval(THD *thd, TABLE *table)
{
return uint4korr(table->s->table_cache_key.str + table->s->table_cache_key.length - 4);
}
/*
Close all temporary tables created by 'CREATE TEMPORARY TABLE' for thread
creates one DROP TEMPORARY TABLE binlog event for each pseudo-thread
*/
void close_temporary_tables(THD *thd)
{
TABLE *table;
TABLE *next;
TABLE *prev_table;
/* Assume thd->options has OPTION_QUOTE_SHOW_CREATE */
bool was_quote_show= TRUE;
LINT_INIT(next);
if (!thd->temporary_tables)
return;
if (!mysql_bin_log.is_open() || thd->current_stmt_binlog_row_based)
{
TABLE *tmp_next;
for (table= thd->temporary_tables; table; table= tmp_next)
{
tmp_next= table->next;
close_temporary(table, 1, 1);
}
thd->temporary_tables= 0;
return;
}
/* Better add "if exists", in case a RESET MASTER has been done */
const char stub[]= "DROP /*!40005 TEMPORARY */ TABLE IF EXISTS ";
uint stub_len= sizeof(stub) - 1;
char buf[256];
String s_query= String(buf, sizeof(buf), system_charset_info);
bool found_user_tables= FALSE;
memcpy(buf, stub, stub_len);
/*
Insertion sort of temp tables by pseudo_thread_id to build ordered list
of sublists of equal pseudo_thread_id
*/
for (prev_table= thd->temporary_tables, table= prev_table->next;
table;
prev_table= table, table= table->next)
{
TABLE *prev_sorted /* same as for prev_table */, *sorted;
if (is_user_table(table))
{
if (!found_user_tables)
found_user_tables= true;
for (prev_sorted= NULL, sorted= thd->temporary_tables; sorted != table;
prev_sorted= sorted, sorted= sorted->next)
{
if (!is_user_table(sorted) ||
tmpkeyval(thd, sorted) > tmpkeyval(thd, table))
{
/* move into the sorted part of the list from the unsorted */
prev_table->next= table->next;
table->next= sorted;
if (prev_sorted)
{
prev_sorted->next= table;
}
else
{
thd->temporary_tables= table;
}
table= prev_table;
break;
}
}
}
}
/* We always quote db,table names though it is slight overkill */
if (found_user_tables &&
!(was_quote_show= test(thd->options & OPTION_QUOTE_SHOW_CREATE)))
{
thd->options |= OPTION_QUOTE_SHOW_CREATE;
}
/* scan sorted tmps to generate sequence of DROP */
for (table= thd->temporary_tables; table; table= next)
{
if (is_user_table(table))
{
my_thread_id save_pseudo_thread_id= thd->variables.pseudo_thread_id;
/* Set pseudo_thread_id to be that of the processed table */
thd->variables.pseudo_thread_id= tmpkeyval(thd, table);
/*
Loop forward through all tables within the sublist of
common pseudo_thread_id to create single DROP query.
*/
for (s_query.length(stub_len);
table && is_user_table(table) &&
tmpkeyval(thd, table) == thd->variables.pseudo_thread_id;
table= next)
{
/*
We are going to add 4 ` around the db/table names and possible more
due to special characters in the names
*/
append_identifier(thd, &s_query, table->s->db.str, strlen(table->s->db.str));
s_query.append('.');
append_identifier(thd, &s_query, table->s->table_name.str,
strlen(table->s->table_name.str));
s_query.append(',');
next= table->next;
close_temporary(table, 1, 1);
}
thd->clear_error();
CHARSET_INFO *cs_save= thd->variables.character_set_client;
thd->variables.character_set_client= system_charset_info;
Query_log_event qinfo(thd, s_query.ptr(),
s_query.length() - 1 /* to remove trailing ',' */,
0, FALSE);
thd->variables.character_set_client= cs_save;
/*
Imagine the thread had created a temp table, then was doing a
SELECT, and the SELECT was killed. Then it's not clever to
mark the statement above as "killed", because it's not really
a statement updating data, and there are 99.99% chances it
will succeed on slave. If a real update (one updating a
persistent table) was killed on the master, then this real
update will be logged with error_code=killed, rightfully
causing the slave to stop.
*/
qinfo.error_code= 0;
mysql_bin_log.write(&qinfo);
thd->variables.pseudo_thread_id= save_pseudo_thread_id;
}
else
{
next= table->next;
close_temporary(table, 1, 1);
}
}
if (!was_quote_show)
thd->options&= ~OPTION_QUOTE_SHOW_CREATE; /* restore option */
thd->temporary_tables=0;
}
/*
Find table in list.
SYNOPSIS
find_table_in_list()
table Pointer to table list
offset Offset to which list in table structure to use
db_name Data base name
table_name Table name
NOTES:
This is called by find_table_in_local_list() and
find_table_in_global_list().
RETURN VALUES
NULL Table not found
# Pointer to found table.
*/
TABLE_LIST *find_table_in_list(TABLE_LIST *table,
TABLE_LIST *TABLE_LIST::*link,
const char *db_name,
const char *table_name)
{
for (; table; table= table->*link )
{
if ((table->table == 0 || table->table->s->tmp_table == NO_TMP_TABLE) &&
strcmp(table->db, db_name) == 0 &&
strcmp(table->table_name, table_name) == 0)
break;
}
return table;
}
/*
Test that table is unique (It's only exists once in the table list)
SYNOPSIS
unique_table()
thd thread handle
table table which should be checked
table_list list of tables
check_alias whether to check tables' aliases
NOTE: to exclude derived tables from check we use following mechanism:
a) during derived table processing set THD::derived_tables_processing
b) JOIN::prepare set SELECT::exclude_from_table_unique_test if
THD::derived_tables_processing set. (we can't use JOIN::execute
because for PS we perform only JOIN::prepare, but we can't set this
flag in JOIN::prepare if we are not sure that we are in derived table
processing loop, because multi-update call fix_fields() for some its
items (which mean JOIN::prepare for subqueries) before unique_table
call to detect which tables should be locked for write).
c) unique_table skip all tables which belong to SELECT with
SELECT::exclude_from_table_unique_test set.
Also SELECT::exclude_from_table_unique_test used to exclude from check
tables of main SELECT of multi-delete and multi-update
We also skip tables with TABLE_LIST::prelocking_placeholder set,
because we want to allow SELECTs from them, and their modification
will rise the error anyway.
TODO: when we will have table/view change detection we can do this check
only once for PS/SP
RETURN
found duplicate
0 if table is unique
*/
TABLE_LIST* unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list,
bool check_alias)
{
TABLE_LIST *res;
const char *d_name, *t_name, *t_alias;
DBUG_ENTER("unique_table");
DBUG_PRINT("enter", ("table alias: %s", table->alias));
/*
If this function called for query which update table (INSERT/UPDATE/...)
then we have in table->table pointer to TABLE object which we are
updating even if it is VIEW so we need TABLE_LIST of this TABLE object
to get right names (even if lower_case_table_names used).
If this function called for CREATE command that we have not opened table
(table->table equal to 0) and right names is in current TABLE_LIST
object.
*/
if (table->table)
{
/* temporary table is always unique */
if (table->table && table->table->s->tmp_table != NO_TMP_TABLE)
DBUG_RETURN(0);
table= table->find_underlying_table(table->table);
/*
as far as we have table->table we have to find real TABLE_LIST of
it in underlying tables
*/
DBUG_ASSERT(table);
}
d_name= table->db;
t_name= table->table_name;
t_alias= table->alias;
DBUG_PRINT("info", ("real table: %s.%s", d_name, t_name));
for (;;)
{
if (((! (res= find_table_in_global_list(table_list, d_name, t_name))) &&
(! (res= mysql_lock_have_duplicate(thd, table, table_list)))) ||
((!res->table || res->table != table->table) &&
(!check_alias || !(lower_case_table_names ?
my_strcasecmp(files_charset_info, t_alias, res->alias) :
strcmp(t_alias, res->alias))) &&
res->select_lex && !res->select_lex->exclude_from_table_unique_test &&
!res->prelocking_placeholder))
break;
/*
If we found entry of this table or table of SELECT which already
processed in derived table or top select of multi-update/multi-delete
(exclude_from_table_unique_test) or prelocking placeholder.
*/
table_list= res->next_global;
DBUG_PRINT("info",
("found same copy of table or table which we should skip"));
}
DBUG_RETURN(res);
}
/*
Issue correct error message in case we found 2 duplicate tables which
prevent some update operation
SYNOPSIS
update_non_unique_table_error()
update table which we try to update
operation name of update operation
duplicate duplicate table which we found
NOTE:
here we hide view underlying tables if we have them
*/
void update_non_unique_table_error(TABLE_LIST *update,
const char *operation,
TABLE_LIST *duplicate)
{
update= update->top_table();
duplicate= duplicate->top_table();
if (!update->view || !duplicate->view ||
update->view == duplicate->view ||
update->view_name.length != duplicate->view_name.length ||
update->view_db.length != duplicate->view_db.length ||
my_strcasecmp(table_alias_charset,
update->view_name.str, duplicate->view_name.str) != 0 ||
my_strcasecmp(table_alias_charset,
update->view_db.str, duplicate->view_db.str) != 0)
{
/*
it is not the same view repeated (but it can be parts of the same copy
of view), so we have to hide underlying tables.
*/
if (update->view)
{
/* Issue the ER_NON_INSERTABLE_TABLE error for an INSERT */
if (update->view == duplicate->view)
my_error(!strncmp(operation, "INSERT", 6) ?
ER_NON_INSERTABLE_TABLE : ER_NON_UPDATABLE_TABLE, MYF(0),
update->alias, operation);
else
my_error(ER_VIEW_PREVENT_UPDATE, MYF(0),
(duplicate->view ? duplicate->alias : update->alias),
operation, update->alias);
return;
}
if (duplicate->view)
{
my_error(ER_VIEW_PREVENT_UPDATE, MYF(0), duplicate->alias, operation,
update->alias);
return;
}
}
my_error(ER_UPDATE_TABLE_USED, MYF(0), update->alias);
}
TABLE *find_temporary_table(THD *thd, const char *db, const char *table_name)
{
TABLE_LIST table_list;
table_list.db= (char*) db;
table_list.table_name= (char*) table_name;
return find_temporary_table(thd, &table_list);
}
TABLE *find_temporary_table(THD *thd, TABLE_LIST *table_list)
{
char key[MAX_DBKEY_LENGTH];
uint key_length;
TABLE *table;
DBUG_ENTER("find_temporary_table");
DBUG_PRINT("enter", ("table: '%s'.'%s'",
table_list->db, table_list->table_name));
key_length= create_table_def_key(thd, key, table_list, 1);
for (table=thd->temporary_tables ; table ; table= table->next)
{
if (table->s->table_cache_key.length == key_length &&
!memcmp(table->s->table_cache_key.str, key, key_length))
{
DBUG_PRINT("info",
("Found table. server_id: %u pseudo_thread_id: %lu",
(uint) thd->server_id,
(ulong) thd->variables.pseudo_thread_id));
DBUG_RETURN(table);
}
}
DBUG_RETURN(0); // Not a temporary table
}
/**
Drop a temporary table.
Try to locate the table in the list of thd->temporary_tables.
If the table is found:
- if the table is in thd->locked_tables, unlock it and
remove it from the list of locked tables. Currently only transactional
temporary tables are present in the locked_tables list.
- Close the temporary table, remove its .FRM
- remove the table from the list of temporary tables
This function is used to drop user temporary tables, as well as
internal tables created in CREATE TEMPORARY TABLE ... SELECT
or ALTER TABLE. Even though part of the work done by this function
is redundant when the table is internal, as long as we
link both internal and user temporary tables into the same
thd->temporary_tables list, it's impossible to tell here whether
we're dealing with an internal or a user temporary table.
@retval TRUE the table was not found in the list of temporary tables
of this thread
@retval FALSE the table was found and dropped successfully.
*/
bool close_temporary_table(THD *thd, TABLE_LIST *table_list)
{
TABLE *table;
if (!(table= find_temporary_table(thd, table_list)))
return 1;
/*
If LOCK TABLES list is not empty and contains this table,
unlock the table and remove the table from this list.
*/
mysql_lock_remove(thd, thd->locked_tables, table, FALSE);
close_temporary_table(thd, table, 1, 1);
return 0;
}
/*
unlink from thd->temporary tables and close temporary table
*/
void close_temporary_table(THD *thd, TABLE *table,
bool free_share, bool delete_table)
{
if (table->prev)
{
table->prev->next= table->next;
if (table->prev->next)
table->next->prev= table->prev;
}
else
{
/* removing the item from the list */
DBUG_ASSERT(table == thd->temporary_tables);
/*
slave must reset its temporary list pointer to zero to exclude
passing non-zero value to end_slave via rli->save_temporary_tables
when no temp tables opened, see an invariant below.
*/
thd->temporary_tables= table->next;
if (thd->temporary_tables)
table->next->prev= 0;
}
if (thd->slave_thread)
{
/* natural invariant of temporary_tables */
DBUG_ASSERT(slave_open_temp_tables || !thd->temporary_tables);
slave_open_temp_tables--;
}
close_temporary(table, free_share, delete_table);
}
/*
Close and delete a temporary table
NOTE
This dosn't unlink table from thd->temporary
If this is needed, use close_temporary_table()
*/
void close_temporary(TABLE *table, bool free_share, bool delete_table)
{
handlerton *table_type= table->s->db_type();
DBUG_ENTER("close_temporary");
free_io_cache(table);
closefrm(table, 0);
if (delete_table)
rm_temporary_table(table_type, table->s->path.str);
if (free_share)
{
free_table_share(table->s);
my_free((char*) table,MYF(0));
}
DBUG_VOID_RETURN;
}
/*
Used by ALTER TABLE when the table is a temporary one. It changes something
only if the ALTER contained a RENAME clause (otherwise, table_name is the old
name).
Prepares a table cache key, which is the concatenation of db, table_name and
thd->slave_proxy_id, separated by '\0'.
*/
bool rename_temporary_table(THD* thd, TABLE *table, const char *db,
const char *table_name)
{
char *key;
uint key_length;
TABLE_SHARE *share= table->s;
TABLE_LIST table_list;
DBUG_ENTER("rename_temporary_table");
if (!(key=(char*) alloc_root(&share->mem_root, MAX_DBKEY_LENGTH)))
DBUG_RETURN(1); /* purecov: inspected */
table_list.db= (char*) db;
table_list.table_name= (char*) table_name;
key_length= create_table_def_key(thd, key, &table_list, 1);
share->set_table_cache_key(key, key_length);
DBUG_RETURN(0);
}
/* move table first in unused links */
static void relink_unused(TABLE *table)
{
if (table != unused_tables)
{
table->prev->next=table->next; /* Remove from unused list */
table->next->prev=table->prev;
table->next=unused_tables; /* Link in unused tables */
table->prev=unused_tables->prev;
unused_tables->prev->next=table;
unused_tables->prev=table;
unused_tables=table;
check_unused();
}
}
/**
@brief Remove all instances of table from thread's open list and
table cache.
@param thd Thread context
@param find Table to remove
@param unlock TRUE - free all locks on tables removed that are
done with LOCK TABLES
FALSE - otherwise
@note When unlock parameter is FALSE or current thread doesn't have
any tables locked with LOCK TABLES tables are assumed to be
not locked (for example already unlocked).
*/
void unlink_open_table(THD *thd, TABLE *find, bool unlock)
{
char key[MAX_DBKEY_LENGTH];
uint key_length= find->s->table_cache_key.length;
TABLE *list, **prev, *next;
DBUG_ENTER("unlink_open_table");
safe_mutex_assert_owner(&LOCK_open);
list= thd->open_tables;
prev= &thd->open_tables;
memcpy(key, find->s->table_cache_key.str, key_length);
for (; list ; list=next)
{
next=list->next;
if (list->s->table_cache_key.length == key_length &&
!memcmp(list->s->table_cache_key.str, key, key_length))
{
if (unlock && thd->locked_tables)
mysql_lock_remove(thd, thd->locked_tables, list, TRUE);
VOID(hash_delete(&open_cache,(uchar*) list)); // Close table
}
else
{
*prev=list; // put in use list
prev= &list->next;
}
}
*prev=0;
// Notify any 'refresh' threads
broadcast_refresh();
DBUG_VOID_RETURN;
}
/**
@brief Auxiliary routine which closes and drops open table.
@param thd Thread handle
@param table TABLE object for table to be dropped
@param db_name Name of database for this table
@param table_name Name of this table
@note This routine assumes that table to be closed is open only
by calling thread so we needn't wait until other threads
will close the table. Also unless called under implicit or
explicit LOCK TABLES mode it assumes that table to be
dropped is already unlocked. In the former case it will
also remove lock on the table. But one should not rely on
this behaviour as it may change in future.
Currently, however, this function is never called for a
table that was locked with LOCK TABLES.
*/
void drop_open_table(THD *thd, TABLE *table, const char *db_name,
const char *table_name)
{
if (table->s->tmp_table)
close_temporary_table(thd, table, 1, 1);
else
{
handlerton *table_type= table->s->db_type();
VOID(pthread_mutex_lock(&LOCK_open));
/*
unlink_open_table() also tells threads waiting for refresh or close
that something has happened.
*/
unlink_open_table(thd, table, FALSE);
quick_rm_table(table_type, db_name, table_name, 0);
VOID(pthread_mutex_unlock(&LOCK_open));
}
}
/*
Wait for condition but allow the user to send a kill to mysqld
SYNOPSIS
wait_for_condition()
thd Thread handler
mutex mutex that is currently hold that is associated with condition
Will be unlocked on return
cond Condition to wait for
*/
void wait_for_condition(THD *thd, pthread_mutex_t *mutex, pthread_cond_t *cond)
{
/* Wait until the current table is up to date */
const char *proc_info;
thd->mysys_var->current_mutex= mutex;
thd->mysys_var->current_cond= cond;
proc_info=thd->proc_info;
thd->proc_info="Waiting for table";
DBUG_ENTER("wait_for_condition");
if (!thd->killed)
(void) pthread_cond_wait(cond, mutex);
/*
We must unlock mutex first to avoid deadlock becasue conditions are
sent to this thread by doing locks in the following order:
lock(mysys_var->mutex)
lock(mysys_var->current_mutex)
One by effect of this that one can only use wait_for_condition with
condition variables that are guranteed to not disapper (freed) even if this
mutex is unlocked
*/
pthread_mutex_unlock(mutex);
pthread_mutex_lock(&thd->mysys_var->mutex);
thd->mysys_var->current_mutex= 0;
thd->mysys_var->current_cond= 0;
thd->proc_info= proc_info;
pthread_mutex_unlock(&thd->mysys_var->mutex);
DBUG_VOID_RETURN;
}
/*
Open table which is already name-locked by this thread.
SYNOPSIS
reopen_name_locked_table()
thd Thread handle
table_list TABLE_LIST object for table to be open, TABLE_LIST::table
member should point to TABLE object which was used for
name-locking.
link_in TRUE - if TABLE object for table to be opened should be
linked into THD::open_tables list.
FALSE - placeholder used for name-locking is already in
this list so we only need to preserve TABLE::next
pointer.
NOTE
This function assumes that its caller already acquired LOCK_open mutex.
RETURN VALUE
FALSE - Success
TRUE - Error
*/
bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list, bool link_in)
{
TABLE *table= table_list->table;
TABLE_SHARE *share;
char *table_name= table_list->table_name;
TABLE orig_table;
DBUG_ENTER("reopen_name_locked_table");
safe_mutex_assert_owner(&LOCK_open);
if (thd->killed || !table)
DBUG_RETURN(TRUE);
orig_table= *table;
if (open_unireg_entry(thd, table, table_list, table_name,
table->s->table_cache_key.str,
table->s->table_cache_key.length, thd->mem_root, 0))
{
intern_close_table(table);
/*
If there was an error during opening of table (for example if it
does not exist) '*table' object can be wiped out. To be able
properly release name-lock in this case we should restore this
object to its original state.
*/
*table= orig_table;
DBUG_RETURN(TRUE);
}
share= table->s;
/*
We want to prevent other connections from opening this table until end
of statement as it is likely that modifications of table's metadata are
not yet finished (for example CREATE TRIGGER have to change .TRG file,
or we might want to drop table if CREATE TABLE ... SELECT fails).
This also allows us to assume that no other connection will sneak in
before we will get table-level lock on this table.
*/
share->version=0;
table->in_use = thd;
check_unused();
if (link_in)
{
table->next= thd->open_tables;
thd->open_tables= table;
}
else
{
/*
TABLE object should be already in THD::open_tables list so we just
need to set TABLE::next correctly.
*/
table->next= orig_table.next;
}
table->tablenr=thd->current_tablenr++;
table->used_fields=0;
table->const_table=0;
table->null_row= table->maybe_null= table->force_index= 0;
table->status=STATUS_NO_RECORD;
DBUG_RETURN(FALSE);
}
/**
@brief Create and insert into table cache placeholder for table
which will prevent its opening (or creation) (a.k.a lock
table name).
@param thd Thread context
@param key Table cache key for name to be locked
@param key_length Table cache key length
@return Pointer to TABLE object used for name locking or 0 in
case of failure.
*/
TABLE *table_cache_insert_placeholder(THD *thd, const char *key,
uint key_length)
{
TABLE *table;
TABLE_SHARE *share;
char *key_buff;
DBUG_ENTER("table_cache_insert_placeholder");
safe_mutex_assert_owner(&LOCK_open);
/*
Create a table entry with the right key and with an old refresh version
Note that we must use my_multi_malloc() here as this is freed by the
table cache
*/
if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL),
&table, sizeof(*table),
&share, sizeof(*share),
&key_buff, key_length,
NULL))
DBUG_RETURN(NULL);
table->s= share;
share->set_table_cache_key(key_buff, key, key_length);
share->tmp_table= INTERNAL_TMP_TABLE; // for intern_close_table
table->in_use= thd;
table->locked_by_name=1;
if (my_hash_insert(&open_cache, (uchar*)table))
{
my_free((uchar*) table, MYF(0));
DBUG_RETURN(NULL);
}
DBUG_RETURN(table);
}
/**
@brief Obtain an exclusive name lock on the table if it is not cached
in the table cache.
@param thd Thread context
@param db Name of database
@param table_name Name of table
@param[out] table Out parameter which is either:
- set to NULL if table cache contains record for
the table or
- set to point to the TABLE instance used for
name-locking.
@note This function takes into account all records for table in table
cache, even placeholders used for name-locking. This means that
'table' parameter can be set to NULL for some situations when
table does not really exist.
@retval TRUE Error occured (OOM)
@retval FALSE Success. 'table' parameter set according to above rules.
*/
bool lock_table_name_if_not_cached(THD *thd, const char *db,
const char *table_name, TABLE **table)
{
char key[MAX_DBKEY_LENGTH];
uint key_length;
DBUG_ENTER("lock_table_name_if_not_cached");
key_length= (uint)(strmov(strmov(key, db) + 1, table_name) - key) + 1;
VOID(pthread_mutex_lock(&LOCK_open));
if (hash_search(&open_cache, (uchar *)key, key_length))
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_PRINT("info", ("Table is cached, name-lock is not obtained"));
*table= 0;
DBUG_RETURN(FALSE);
}
if (!(*table= table_cache_insert_placeholder(thd, key, key_length)))
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(TRUE);
}
(*table)->open_placeholder= 1;
(*table)->next= thd->open_tables;
thd->open_tables= *table;
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(FALSE);
}
/**
@brief Check that table exists in table definition cache, on disk
or in some storage engine.
@param thd Thread context
@param table Table list element
@param[out] exists Out parameter which is set to TRUE if table
exists and to FALSE otherwise.
@note This function assumes that caller owns LOCK_open mutex.
It also assumes that the fact that there are no name-locks
on the table was checked beforehand.
@note If there is no .FRM file for the table but it exists in one
of engines (e.g. it was created on another node of NDB cluster)
this function will fetch and create proper .FRM file for it.
@retval TRUE Some error occured
@retval FALSE No error. 'exists' out parameter set accordingly.
*/
bool check_if_table_exists(THD *thd, TABLE_LIST *table, bool *exists)
{
char path[FN_REFLEN];
int rc;
DBUG_ENTER("check_if_table_exists");
safe_mutex_assert_owner(&LOCK_open);
*exists= TRUE;
if (get_cached_table_share(table->db, table->table_name))
DBUG_RETURN(FALSE);
build_table_filename(path, sizeof(path) - 1, table->db, table->table_name,
reg_ext, 0);
if (!access(path, F_OK))
DBUG_RETURN(FALSE);
/* .FRM file doesn't exist. Check if some engine can provide it. */
rc= ha_create_table_from_engine(thd, table->db, table->table_name);
if (rc < 0)
{
/* Table does not exists in engines as well. */
*exists= FALSE;
DBUG_RETURN(FALSE);
}
else if (!rc)
{
/* Table exists in some engine and .FRM for it was created. */
DBUG_RETURN(FALSE);
}
else /* (rc > 0) */
{
my_printf_error(ER_UNKNOWN_ERROR, "Failed to open '%-.64s', error while "
"unpacking from engine", MYF(0), table->table_name);
DBUG_RETURN(TRUE);
}
}
/*
Open a table.
SYNOPSIS
open_table()
thd Thread context.
table_list Open first table in list.
refresh INOUT Pointer to memory that will be set to 1 if
we need to close all tables and reopen them.
If this is a NULL pointer, then the table is not
put in the thread-open-list.
flags Bitmap of flags to modify how open works:
MYSQL_LOCK_IGNORE_FLUSH - Open table even if
someone has done a flush or namelock on it.
No version number checking is done.
MYSQL_OPEN_TEMPORARY_ONLY - Open only temporary
table not the base table or view.
IMPLEMENTATION
Uses a cache of open tables to find a table not in use.
If table list element for the table to be opened has "create" flag
set and table does not exist, this function will automatically insert
a placeholder for exclusive name lock into the open tables cache and
will return the TABLE instance that corresponds to this placeholder.
RETURN
NULL Open failed. If refresh is set then one should close
all other tables and retry the open.
# Success. Pointer to TABLE object for open table.
*/
TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
bool *refresh, uint flags)
{
reg1 TABLE *table;
char key[MAX_DBKEY_LENGTH];
uint key_length;
char *alias= table_list->alias;
HASH_SEARCH_STATE state;
DBUG_ENTER("open_table");
/* find a unused table in the open table cache */
if (refresh)
*refresh=0;
/* an open table operation needs a lot of the stack space */
if (check_stack_overrun(thd, STACK_MIN_SIZE_FOR_OPEN, (uchar *)&alias))
DBUG_RETURN(0);
if (thd->killed)
DBUG_RETURN(0);
key_length= (create_table_def_key(thd, key, table_list, 1) -
TMP_TABLE_KEY_EXTRA);
/*
Unless requested otherwise, try to resolve this table in the list
of temporary tables of this thread. In MySQL temporary tables
are always thread-local and "shadow" possible base tables with the
same name. This block implements the behaviour.
TODO: move this block into a separate function.
*/
if (!table_list->skip_temporary)
{
for (table= thd->temporary_tables; table ; table=table->next)
{
if (table->s->table_cache_key.length == key_length +
TMP_TABLE_KEY_EXTRA &&
!memcmp(table->s->table_cache_key.str, key,
key_length + TMP_TABLE_KEY_EXTRA))
{
/*
We're trying to use the same temporary table twice in a query.
Right now we don't support this because a temporary table
is always represented by only one TABLE object in THD, and
it can not be cloned. Emit an error for an unsupported behaviour.
*/
if (table->query_id == thd->query_id ||
thd->prelocked_mode && table->query_id)
{
DBUG_PRINT("error",
("query_id: %lu server_id: %u pseudo_thread_id: %lu",
(ulong) table->query_id, (uint) thd->server_id,
(ulong) thd->variables.pseudo_thread_id));
my_error(ER_CANT_REOPEN_TABLE, MYF(0), table->alias);
DBUG_RETURN(0);
}
table->query_id= thd->query_id;
table->clear_query_id= 1;
thd->thread_specific_used= TRUE;
DBUG_PRINT("info",("Using temporary table"));
goto reset;
}
}
}
if (flags & MYSQL_OPEN_TEMPORARY_ONLY)
{
my_error(ER_NO_SUCH_TABLE, MYF(0), table_list->db, table_list->table_name);
DBUG_RETURN(0);
}
/*
The table is not temporary - if we're in pre-locked or LOCK TABLES
mode, let's try to find the requested table in the list of pre-opened
and locked tables. If the table is not there, return an error - we can't
open not pre-opened tables in pre-locked/LOCK TABLES mode.
TODO: move this block into a separate function.
*/
if (thd->locked_tables || thd->prelocked_mode)
{ // Using table locks
TABLE *best_table= 0;
int best_distance= INT_MIN;
bool check_if_used= thd->prelocked_mode &&
((int) table_list->lock_type >=
(int) TL_WRITE_ALLOW_WRITE);
for (table=thd->open_tables; table ; table=table->next)
{
if (table->s->table_cache_key.length == key_length &&
!memcmp(table->s->table_cache_key.str, key, key_length))
{
if (check_if_used && table->query_id &&
table->query_id != thd->query_id)
{
/*
If we are in stored function or trigger we should ensure that
we won't change table that is already used by calling statement.
So if we are opening table for writing, we should check that it
is not already open by some calling stamement.
*/
my_error(ER_CANT_UPDATE_USED_TABLE_IN_SF_OR_TRG, MYF(0),
table->s->table_name.str);
DBUG_RETURN(0);
}
if (!my_strcasecmp(system_charset_info, table->alias, alias) &&
table->query_id != thd->query_id && /* skip tables already used */
!(thd->prelocked_mode && table->query_id))
{
int distance= ((int) table->reginfo.lock_type -
(int) table_list->lock_type);
/*
Find a table that either has the exact lock type requested,
or has the best suitable lock. In case there is no locked
table that has an equal or higher lock than requested,
we us the closest matching lock to be able to produce an error
message about wrong lock mode on the table. The best_table
is changed if bd < 0 <= d or bd < d < 0 or 0 <= d < bd.
distance < 0 - No suitable lock found
distance > 0 - we have lock mode higher then we require
distance == 0 - we have lock mode exactly which we need
*/
if (best_distance < 0 && distance > best_distance ||
distance >= 0 && distance < best_distance)
{
best_distance= distance;
best_table= table;
if (best_distance == 0 && !check_if_used)
{
/*
If we have found perfect match and we don't need to check that
table is not used by one of calling statements (assuming that
we are inside of function or trigger) we can finish iterating
through open tables list.
*/
break;
}
}
}
}
}
if (best_table)
{
table= best_table;
table->query_id= thd->query_id;
DBUG_PRINT("info",("Using locked table"));
goto reset;
}
/*
Is this table a view and not a base table?
(it is work around to allow to open view with locked tables,
real fix will be made after definition cache will be made)
*/
{
char path[FN_REFLEN];
enum legacy_db_type not_used;
build_table_filename(path, sizeof(path) - 1,
table_list->db, table_list->table_name, reg_ext, 0);
if (mysql_frm_type(thd, path, &not_used) == FRMTYPE_VIEW)
{
/*
Will not be used (because it's VIEW) but has to be passed.
Also we will not free it (because it is a stack variable).
*/
TABLE tab;
table= &tab;
VOID(pthread_mutex_lock(&LOCK_open));
if (!open_unireg_entry(thd, table, table_list, alias,
key, key_length, mem_root, 0))
{
DBUG_ASSERT(table_list->view != 0);
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(0); // VIEW
}
VOID(pthread_mutex_unlock(&LOCK_open));
}
}
/*
No table in the locked tables list. In case of explicit LOCK TABLES
this can happen if a user did not include the able into the list.
In case of pre-locked mode locked tables list is generated automatically,
so we may only end up here if the table did not exist when
locked tables list was created.
*/
if (thd->prelocked_mode == PRELOCKED)
my_error(ER_NO_SUCH_TABLE, MYF(0), table_list->db, table_list->alias);
else
my_error(ER_TABLE_NOT_LOCKED, MYF(0), alias);
DBUG_RETURN(0);
}
/*
Non pre-locked/LOCK TABLES mode, and the table is not temporary:
this is the normal use case.
Now we should:
- try to find the table in the table cache.
- if one of the discovered TABLE instances is name-locked
(table->s->version == 0) or some thread has started FLUSH TABLES
(refresh_version > table->s->version), back off -- we have to wait
until no one holds a name lock on the table.
- if there is no such TABLE in the name cache, read the table definition
and insert it into the cache.
We perform all of the above under LOCK_open which currently protects
the open cache (also known as table cache) and table definitions stored
on disk.
*/
VOID(pthread_mutex_lock(&LOCK_open));
/*
If it's the first table from a list of tables used in a query,
remember refresh_version (the version of open_cache state).
If the version changes while we're opening the remaining tables,
we will have to back off, close all the tables opened-so-far,
and try to reopen them.
Note: refresh_version is currently changed only during FLUSH TABLES.
*/
if (!thd->open_tables)
thd->version=refresh_version;
else if ((thd->version != refresh_version) &&
! (flags & MYSQL_LOCK_IGNORE_FLUSH))
{
/* Someone did a refresh while thread was opening tables */
if (refresh)
*refresh=1;
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(0);
}
/*
In order for the back off and re-start process to work properly,
handler tables having old versions (due to FLUSH TABLES or pending
name-lock) MUST be closed. This is specially important if a name-lock
is pending for any table of the handler_tables list, otherwise a
deadlock may occur.
*/
if (thd->handler_tables)
mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE, TRUE);
/*
Actually try to find the table in the open_cache.
The cache may contain several "TABLE" instances for the same
physical table. The instances that are currently "in use" by
some thread have their "in_use" member != NULL.
There is no good reason for having more than one entry in the
hash for the same physical table, except that we use this as
an implicit "pending locks queue" - see
wait_for_locked_table_names for details.
*/
for (table= (TABLE*) hash_first(&open_cache, (uchar*) key, key_length,
&state);
table && table->in_use ;
table= (TABLE*) hash_next(&open_cache, (uchar*) key, key_length,
&state))
{
/*
Here we flush tables marked for flush.
Normally, table->s->version contains the value of
refresh_version from the moment when this table was
(re-)opened and added to the cache.
If since then we did (or just started) FLUSH TABLES
statement, refresh_version has been increased.
For "name-locked" TABLE instances, table->s->version is set
to 0 (see lock_table_name for details).
In case there is a pending FLUSH TABLES or a name lock, we
need to back off and re-start opening tables.
If we do not back off now, we may dead lock in case of lock
order mismatch with some other thread:
c1: name lock t1; -- sort of exclusive lock
c2: open t2; -- sort of shared lock
c1: name lock t2; -- blocks
c2: open t1; -- blocks
*/
if (table->needs_reopen_or_name_lock())
{
DBUG_PRINT("note",
("Found table '%s.%s' with different refresh version",
table_list->db, table_list->table_name));
if (flags & MYSQL_LOCK_IGNORE_FLUSH)
{
/* Force close at once after usage */
thd->version= table->s->version;
continue;
}
/* Avoid self-deadlocks by detecting self-dependencies. */
if (table->open_placeholder && table->in_use == thd)
{
VOID(pthread_mutex_unlock(&LOCK_open));
my_error(ER_UPDATE_TABLE_USED, MYF(0), table->s->table_name.str);
DBUG_RETURN(0);
}
/*
Back off, part 1: mark the table as "unused" for the
purpose of name-locking by setting table->db_stat to 0. Do
that only for the tables in this thread that have an old
table->s->version (this is an optimization (?)).
table->db_stat == 0 signals wait_for_locked_table_names
that the tables in question are not used any more. See
table_is_used call for details.
Notice that HANDLER tables were already taken care of by
the earlier call to mysql_ha_flush() in this same critical
section.
*/
close_old_data_files(thd,thd->open_tables,0,0);
/*
Back-off part 2: try to avoid "busy waiting" on the table:
if the table is in use by some other thread, we suspend
and wait till the operation is complete: when any
operation that juggles with table->s->version completes,
it broadcasts COND_refresh condition variable.
If 'old' table we met is in use by current thread we return
without waiting since in this situation it's this thread
which is responsible for broadcasting on COND_refresh
(and this was done already in close_old_data_files()).
Good example of such situation is when we have statement
that needs two instances of table and FLUSH TABLES comes
after we open first instance but before we open second
instance.
*/
if (table->in_use != thd)
{
/* wait_for_conditionwill unlock LOCK_open for us */
wait_for_condition(thd, &LOCK_open, &COND_refresh);
}
else
{
VOID(pthread_mutex_unlock(&LOCK_open));
}
/*
There is a refresh in progress for this table.
Signal the caller that it has to try again.
*/
if (refresh)
*refresh=1;
DBUG_RETURN(0);
}
}
if (table)
{
/* Unlink the table from "unused_tables" list. */
if (table == unused_tables)
{ // First unused
unused_tables=unused_tables->next; // Remove from link
if (table == unused_tables)
unused_tables=0;
}
table->prev->next=table->next; /* Remove from unused list */
table->next->prev=table->prev;
table->in_use= thd;
}
else
{
/* Insert a new TABLE instance into the open cache */
int error;
/* Free cache if too big */
while (open_cache.records > table_cache_size && unused_tables)
VOID(hash_delete(&open_cache,(uchar*) unused_tables)); /* purecov: tested */
if (table_list->create)
{
bool exists;
if (check_if_table_exists(thd, table_list, &exists))
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(NULL);
}
if (!exists)
{
/*
Table to be created, so we need to create placeholder in table-cache.
*/
if (!(table= table_cache_insert_placeholder(thd, key, key_length)))
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(NULL);
}
/*
Link placeholder to the open tables list so it will be automatically
removed once tables are closed. Also mark it so it won't be ignored
by other trying to take name-lock.
*/
table->open_placeholder= 1;
table->next= thd->open_tables;
thd->open_tables= table;
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(table);
}
/* Table exists. Let us try to open it. */
}
/* make a new table */
if (!(table=(TABLE*) my_malloc(sizeof(*table),MYF(MY_WME))))
{
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(NULL);
}
error= open_unireg_entry(thd, table, table_list, alias, key, key_length,
mem_root, (flags & OPEN_VIEW_NO_PARSE));
if (error > 0)
{
my_free((uchar*)table, MYF(0));
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(NULL);
}
if (table_list->view || error < 0)
{
/*
VIEW not really opened, only frm were read.
Set 1 as a flag here
*/
if (error < 0)
table_list->view= (st_lex*)1;
my_free((uchar*)table, MYF(0));
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(0); // VIEW
}
DBUG_PRINT("info", ("inserting table 0x%lx into the cache", (long) table));
VOID(my_hash_insert(&open_cache,(uchar*) table));
}
check_unused(); // Debugging call
VOID(pthread_mutex_unlock(&LOCK_open));
if (refresh)
{
table->next=thd->open_tables; /* Link into simple list */
thd->open_tables=table;
}
table->reginfo.lock_type=TL_READ; /* Assume read */
reset:
DBUG_ASSERT(table->s->ref_count > 0 || table->s->tmp_table != NO_TMP_TABLE);
if (thd->lex->need_correct_ident())
table->alias_name_used= my_strcasecmp(table_alias_charset,
table->s->table_name.str, alias);
/* Fix alias if table name changes */
if (strcmp(table->alias, alias))
{
uint length=(uint) strlen(alias)+1;
table->alias= (char*) my_realloc((char*) table->alias, length,
MYF(MY_WME));
memcpy((char*) table->alias, alias, length);
}
/* These variables are also set in reopen_table() */
table->tablenr=thd->current_tablenr++;
table->used_fields=0;
table->const_table=0;
table->null_row= table->maybe_null= table->force_index= 0;
table->status=STATUS_NO_RECORD;
table->insert_values= 0;
table->fulltext_searched= 0;
table->file->ft_handler= 0;
/* Catch wrong handling of the auto_increment_field_not_null. */
DBUG_ASSERT(!table->auto_increment_field_not_null);
table->auto_increment_field_not_null= FALSE;
if (table->timestamp_field)
table->timestamp_field_type= table->timestamp_field->get_auto_set_type();
table->pos_in_table_list= table_list;
table_list->updatable= 1; // It is not derived table nor non-updatable VIEW
table->clear_column_bitmaps();
DBUG_ASSERT(table->key_read == 0);
DBUG_RETURN(table);
}
TABLE *find_locked_table(THD *thd, const char *db,const char *table_name)
{
char key[MAX_DBKEY_LENGTH];
uint key_length=(uint) (strmov(strmov(key,db)+1,table_name)-key)+1;
for (TABLE *table=thd->open_tables; table ; table=table->next)
{
if (table->s->table_cache_key.length == key_length &&
!memcmp(table->s->table_cache_key.str, key, key_length))
return table;
}
return(0);
}
/*
Reopen an table because the definition has changed.
SYNOPSIS
reopen_table()
table Table object
NOTES
The data file for the table is already closed and the share is released
The table has a 'dummy' share that mainly contains database and table name.
RETURN
0 ok
1 error. The old table object is not changed.
*/
bool reopen_table(TABLE *table)
{
TABLE tmp;
bool error= 1;
Field **field;
uint key,part;
TABLE_LIST table_list;
THD *thd= table->in_use;
DBUG_ENTER("reopen_table");
DBUG_ASSERT(table->s->ref_count == 0);
DBUG_ASSERT(!table->sort.io_cache);
#ifdef EXTRA_DEBUG
if (table->db_stat)
sql_print_error("Table %s had a open data handler in reopen_table",
table->alias);
#endif
bzero((char*) &table_list, sizeof(TABLE_LIST));
table_list.db= table->s->db.str;
table_list.table_name= table->s->table_name.str;
table_list.table= table;
if (wait_for_locked_table_names(thd, &table_list))
DBUG_RETURN(1); // Thread was killed
if (open_unireg_entry(thd, &tmp, &table_list,
table->alias,
table->s->table_cache_key.str,
table->s->table_cache_key.length,
thd->mem_root, 0))
goto end;
/* This list copies variables set by open_table */
tmp.tablenr= table->tablenr;
tmp.used_fields= table->used_fields;
tmp.const_table= table->const_table;
tmp.null_row= table->null_row;
tmp.maybe_null= table->maybe_null;
tmp.status= table->status;
tmp.s->table_map_id= table->s->table_map_id;
/* Get state */
tmp.in_use= thd;
tmp.reginfo.lock_type=table->reginfo.lock_type;
tmp.grant= table->grant;
/* Replace table in open list */
tmp.next= table->next;
tmp.prev= table->prev;
delete table->triggers;
if (table->file)
VOID(closefrm(table, 1)); // close file, free everything
*table= tmp;
table->default_column_bitmaps();
table->file->change_table_ptr(table, table->s);
DBUG_ASSERT(table->alias != 0);
for (field=table->field ; *field ; field++)
{
(*field)->table= (*field)->orig_table= table;
(*field)->table_name= &table->alias;
}
for (key=0 ; key < table->s->keys ; key++)
{
for (part=0 ; part < table->key_info[key].usable_key_parts ; part++)
table->key_info[key].key_part[part].field->table= table;
}
if (table->triggers)
table->triggers->set_table(table);
broadcast_refresh();
error=0;
end:
DBUG_RETURN(error);
}
/**
@brief Close all instances of a table open by this thread and replace
them with exclusive name-locks.
@param thd Thread context
@param db Database name for the table to be closed
@param table_name Name of the table to be closed
@note This function assumes that if we are not under LOCK TABLES,
then there is only one table open and locked. This means that
the function probably has to be adjusted before it can be used
anywhere outside ALTER TABLE.
*/
void close_data_files_and_morph_locks(THD *thd, const char *db,
const char *table_name)
{
TABLE *table;
DBUG_ENTER("close_data_files_and_morph_locks");
safe_mutex_assert_owner(&LOCK_open);
if (thd->lock)
{
/*
If we are not under LOCK TABLES we should have only one table
open and locked so it makes sense to remove the lock at once.
*/
mysql_unlock_tables(thd, thd->lock);
thd->lock= 0;
}
/*
Note that open table list may contain a name-lock placeholder
for target table name if we process ALTER TABLE ... RENAME.
So loop below makes sense even if we are not under LOCK TABLES.
*/
for (table=thd->open_tables; table ; table=table->next)
{
if (!strcmp(table->s->table_name.str, table_name) &&
!strcmp(table->s->db.str, db))
{
if (thd->locked_tables)
mysql_lock_remove(thd, thd->locked_tables, table, TRUE);
table->open_placeholder= 1;
close_handle_and_leave_table_as_lock(table);
}
}
DBUG_VOID_RETURN;
}
/**
@brief Reopen all tables with closed data files.
@param thd Thread context
@param get_locks Should we get locks after reopening tables ?
@param in_refresh Are we in FLUSH TABLES ? TODO: It seems that
we can remove this parameter.
@note Since this function can't properly handle prelocking and
create placeholders it should be used in very special
situations like FLUSH TABLES or ALTER TABLE. In general
case one should just repeat open_tables()/lock_tables()
combination when one needs tables to be reopened (for
example see open_and_lock_tables()).
@note One should have lock on LOCK_open when calling this.
@return FALSE in case of success, TRUE - otherwise.
*/
bool reopen_tables(THD *thd,bool get_locks,bool in_refresh)
{
TABLE *table,*next,**prev;
TABLE **tables,**tables_ptr; // For locks
bool error=0, not_used;
DBUG_ENTER("reopen_tables");
if (!thd->open_tables)
DBUG_RETURN(0);
safe_mutex_assert_owner(&LOCK_open);
if (get_locks)
{
/* The ptr is checked later */
uint opens=0;
for (table= thd->open_tables; table ; table=table->next)
opens++;
tables= (TABLE**) my_alloca(sizeof(TABLE*)*opens);
}
else
tables= &thd->open_tables;
tables_ptr =tables;
prev= &thd->open_tables;
for (table=thd->open_tables; table ; table=next)
{
uint db_stat=table->db_stat;
next=table->next;
if (!tables || (!db_stat && reopen_table(table)))
{
my_error(ER_CANT_REOPEN_TABLE, MYF(0), table->alias);
VOID(hash_delete(&open_cache,(uchar*) table));
error=1;
}
else
{
*prev= table;
prev= &table->next;
if (get_locks && !db_stat)
*tables_ptr++= table; // need new lock on this
if (in_refresh)
{
table->s->version=0;
table->open_placeholder= 0;
}
}
}
if (tables != tables_ptr) // Should we get back old locks
{
MYSQL_LOCK *lock;
/* We should always get these locks */
thd->some_tables_deleted=0;
if ((lock= mysql_lock_tables(thd, tables, (uint) (tables_ptr - tables),
0, &not_used)))
{
thd->locked_tables=mysql_lock_merge(thd->locked_tables,lock);
}
else
error=1;
}
if (get_locks && tables)
{
my_afree((uchar*) tables);
}
broadcast_refresh();
*prev=0;
DBUG_RETURN(error);
}
/**
@brief Close handlers for tables in list, but leave the TABLE structure
intact so that we can re-open these quickly.
@param thd Thread context
@param table Head of the list of TABLE objects
@param morph_locks TRUE - remove locks which we have on tables being closed
but ensure that no DML or DDL will sneak in before
we will re-open the table (i.e. temporarily morph
our table-level locks into name-locks).
FALSE - otherwise
@param send_refresh Should we awake waiters even if we didn't close any tables?
*/
void close_old_data_files(THD *thd, TABLE *table, bool morph_locks,
bool send_refresh)
{
bool found= send_refresh;
DBUG_ENTER("close_old_data_files");
for (; table ; table=table->next)
{
/*
Reopen marked for flush.
*/
if (table->needs_reopen_or_name_lock())
{
found=1;
if (table->db_stat)
{
if (morph_locks)
{
/*
Wake up threads waiting for table-level lock on this table
so they won't sneak in when we will temporarily remove our
lock on it. This will also give them a chance to close their
instances of this table.
*/
mysql_lock_abort(thd, table, TRUE);
mysql_lock_remove(thd, thd->locked_tables, table, TRUE);
/*
We want to protect the table from concurrent DDL operations
(like RENAME TABLE) until we will re-open and re-lock it.
*/
table->open_placeholder= 1;
}
close_handle_and_leave_table_as_lock(table);
}
else if (table->open_placeholder)
{
/*
We come here only in close-for-back-off scenario. So we have to
"close" create placeholder here to avoid deadlocks (for example,
in case of concurrent execution of CREATE TABLE t1 SELECT * FROM t2
and RENAME TABLE t2 TO t1). In close-for-re-open scenario we will
probably want to let it stay.
*/
DBUG_ASSERT(!morph_locks);
table->open_placeholder= 0;
}
}
}
if (found)
broadcast_refresh();
DBUG_VOID_RETURN;
}
/*
Wait until all threads has closed the tables in the list
We have also to wait if there is thread that has a lock on this table even
if the table is closed
*/
bool table_is_used(TABLE *table, bool wait_for_name_lock)
{
DBUG_ENTER("table_is_used");
do
{
char *key= table->s->table_cache_key.str;
uint key_length= table->s->table_cache_key.length;
DBUG_PRINT("loop", ("table_name: %s", table->alias));
HASH_SEARCH_STATE state;
for (TABLE *search= (TABLE*) hash_first(&open_cache, (uchar*) key,
key_length, &state);
search ;
search= (TABLE*) hash_next(&open_cache, (uchar*) key,
key_length, &state))
{
DBUG_PRINT("info", ("share: 0x%lx "
"open_placeholder: %d locked_by_name: %d "
"db_stat: %u version: %lu",
(ulong) search->s,
search->open_placeholder, search->locked_by_name,
search->db_stat,
search->s->version));
if (search->in_use == table->in_use)
continue; // Name locked by this thread
/*
We can't use the table under any of the following conditions:
- There is an name lock on it (Table is to be deleted or altered)
- If we are in flush table and we didn't execute the flush
- If the table engine is open and it's an old version
(We must wait until all engines are shut down to use the table)
*/
if ( (search->locked_by_name && wait_for_name_lock) ||
(search->is_name_opened() && search->needs_reopen_or_name_lock()))
DBUG_RETURN(1);
}
} while ((table=table->next));
DBUG_RETURN(0);
}
/* Wait until all used tables are refreshed */
bool wait_for_tables(THD *thd)
{
bool result;
DBUG_ENTER("wait_for_tables");
thd->proc_info="Waiting for tables";
pthread_mutex_lock(&LOCK_open);
while (!thd->killed)
{
thd->some_tables_deleted=0;
close_old_data_files(thd,thd->open_tables,0,dropping_tables != 0);
mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE, TRUE);
if (!table_is_used(thd->open_tables,1))
break;
(void) pthread_cond_wait(&COND_refresh,&LOCK_open);
}
if (thd->killed)
result= 1; // aborted
else
{
/* Now we can open all tables without any interference */
thd->proc_info="Reopen tables";
thd->version= refresh_version;
result=reopen_tables(thd,0,0);
}
pthread_mutex_unlock(&LOCK_open);
thd->proc_info=0;
DBUG_RETURN(result);
}
/*
drop tables from locked list
SYNOPSIS
drop_locked_tables()
thd Thread thandler
db Database
table_name Table name
INFORMATION
This is only called on drop tables
The TABLE object for the dropped table is unlocked but still kept around
as a name lock, which means that the table will be available for other
thread as soon as we call unlock_table_names().
If there is multiple copies of the table locked, all copies except
the first, which acts as a name lock, is removed.
RETURN
# If table existed, return table
0 Table was not locked
*/
TABLE *drop_locked_tables(THD *thd,const char *db, const char *table_name)
{
TABLE *table,*next,**prev, *found= 0;
prev= &thd->open_tables;
DBUG_ENTER("drop_locked_tables");
for (table= thd->open_tables; table ; table=next)
{
next=table->next;
if (!strcmp(table->s->table_name.str, table_name) &&
!strcmp(table->s->db.str, db))
{
mysql_lock_remove(thd, thd->locked_tables, table, TRUE);
if (!found)
{
found= table;
/* Close engine table, but keep object around as a name lock */
if (table->db_stat)
{
table->db_stat= 0;
table->file->close();
}
}
else
{
/* We already have a name lock, remove copy */
VOID(hash_delete(&open_cache,(uchar*) table));
}
}
else
{
*prev=table;
prev= &table->next;
}
}
*prev=0;
if (found)
broadcast_refresh();
if (thd->locked_tables && thd->locked_tables->table_count == 0)
{
my_free((uchar*) thd->locked_tables,MYF(0));
thd->locked_tables=0;
}
DBUG_RETURN(found);
}
/*
If we have the table open, which only happens when a LOCK TABLE has been
done on the table, change the lock type to a lock that will abort all
other threads trying to get the lock.
*/
void abort_locked_tables(THD *thd,const char *db, const char *table_name)
{
TABLE *table;
for (table= thd->open_tables; table ; table= table->next)
{
if (!strcmp(table->s->table_name.str, table_name) &&
!strcmp(table->s->db.str, db))
{
mysql_lock_abort(thd,table, TRUE);
break;
}
}
}
/*
Function to assign a new table map id to a table share.
PARAMETERS
share - Pointer to table share structure
DESCRIPTION
We are intentionally not checking that share->mutex is locked
since this function should only be called when opening a table
share and before it is entered into the table_def_cache (meaning
that it cannot be fetched by another thread, even accidentally).
PRE-CONDITION(S)
share is non-NULL
The LOCK_open mutex is locked
POST-CONDITION(S)
share->table_map_id is given a value that with a high certainty is
not used by any other table (the only case where a table id can be
reused is on wrap-around, which means more than 4 billion table
shares open at the same time).
share->table_map_id is not ~0UL.
*/
void assign_new_table_id(TABLE_SHARE *share)
{
static ulong last_table_id= ~0UL;
DBUG_ENTER("assign_new_table_id");
/* Preconditions */
DBUG_ASSERT(share != NULL);
safe_mutex_assert_owner(&LOCK_open);
ulong tid= ++last_table_id; /* get next id */
/*
There is one reserved number that cannot be used. Remember to
change this when 6-byte global table id's are introduced.
*/
if (unlikely(tid == ~0UL))
tid= ++last_table_id;
share->table_map_id= tid;
DBUG_PRINT("info", ("table_id=%lu", tid));
/* Post conditions */
DBUG_ASSERT(share->table_map_id != ~0UL);
DBUG_VOID_RETURN;
}
/*
Load a table definition from file and open unireg table
SYNOPSIS
open_unireg_entry()
thd Thread handle
entry Store open table definition here
table_list TABLE_LIST with db, table_name & belong_to_view
alias Alias name
cache_key Key for share_cache
cache_key_length length of cache_key
mem_root temporary mem_root for parsing
flags the OPEN_VIEW_NO_PARSE flag to be passed to
openfrm()/open_new_frm()
NOTES
Extra argument for open is taken from thd->open_options
One must have a lock on LOCK_open when calling this function
RETURN
0 ok
# Error
*/
static int open_unireg_entry(THD *thd, TABLE *entry, TABLE_LIST *table_list,
const char *alias,
char *cache_key, uint cache_key_length,
MEM_ROOT *mem_root, uint flags)
{
int error;
TABLE_SHARE *share;
uint discover_retry_count= 0;
DBUG_ENTER("open_unireg_entry");
safe_mutex_assert_owner(&LOCK_open);
retry:
if (!(share= get_table_share_with_create(thd, table_list, cache_key,
cache_key_length,
OPEN_VIEW |
table_list->i_s_requested_object,
&error)))
DBUG_RETURN(1);
if (share->is_view)
{
if (table_list->i_s_requested_object & OPEN_TABLE_ONLY)
goto err;
/* Open view */
error= (int) open_new_frm(thd, share, alias,
(uint) (HA_OPEN_KEYFILE | HA_OPEN_RNDFILE |
HA_GET_INDEX | HA_TRY_READ_ONLY),
READ_KEYINFO | COMPUTE_TYPES | EXTRA_RECORD |
(flags & OPEN_VIEW_NO_PARSE),
thd->open_options, entry, table_list,
mem_root);
if (error)
goto err;
/* TODO: Don't free this */
release_table_share(share, RELEASE_NORMAL);
DBUG_RETURN((flags & OPEN_VIEW_NO_PARSE)? -1 : 0);
}
if (table_list->i_s_requested_object & OPEN_VIEW_ONLY)
goto err;
while ((error= open_table_from_share(thd, share, alias,
(uint) (HA_OPEN_KEYFILE |
HA_OPEN_RNDFILE |
HA_GET_INDEX |
HA_TRY_READ_ONLY),
(READ_KEYINFO | COMPUTE_TYPES |
EXTRA_RECORD),
thd->open_options, entry, FALSE)))
{
if (error == 7) // Table def changed
{
share->version= 0; // Mark share as old
if (discover_retry_count++) // Retry once
goto err;
/*
TODO:
Here we should wait until all threads has released the table.
For now we do one retry. This may cause a deadlock if there
is other threads waiting for other tables used by this thread.
Proper fix would be to if the second retry failed:
- Mark that table def changed
- Return from open table
- Close all tables used by this thread
- Start waiting that the share is released
- Retry by opening all tables again
*/
if (ha_create_table_from_engine(thd, table_list->db,
table_list->table_name))
goto err;
/*
TO BE FIXED
To avoid deadlock, only wait for release if no one else is
using the share.
*/
if (share->ref_count != 1)
goto err;
/* Free share and wait until it's released by all threads */
release_table_share(share, RELEASE_WAIT_FOR_DROP);
if (!thd->killed)
{
mysql_reset_errors(thd, 1); // Clear warnings
thd->clear_error(); // Clear error message
goto retry;
}
DBUG_RETURN(1);
}
if (!entry->s || !entry->s->crashed)
goto err;
// Code below is for repairing a crashed file
if ((error= lock_table_name(thd, table_list, TRUE)))
{
if (error < 0)
goto err;
if (wait_for_locked_table_names(thd, table_list))
{
unlock_table_name(thd, table_list);
goto err;
}
}
pthread_mutex_unlock(&LOCK_open);
thd->clear_error(); // Clear error message
error= 0;
if (open_table_from_share(thd, share, alias,
(uint) (HA_OPEN_KEYFILE | HA_OPEN_RNDFILE |
HA_GET_INDEX |
HA_TRY_READ_ONLY),
READ_KEYINFO | COMPUTE_TYPES | EXTRA_RECORD,
ha_open_options | HA_OPEN_FOR_REPAIR,
entry, FALSE) || ! entry->file ||
(entry->file->is_crashed() && entry->file->check_and_repair(thd)))
{
/* Give right error message */
thd->clear_error();
my_error(ER_NOT_KEYFILE, MYF(0), share->table_name.str, my_errno);
sql_print_error("Couldn't repair table: %s.%s", share->db.str,
share->table_name.str);
if (entry->file)
closefrm(entry, 0);
error=1;
}
else
thd->clear_error(); // Clear error message
pthread_mutex_lock(&LOCK_open);
unlock_table_name(thd, table_list);
if (error)
goto err;
break;
}
if (Table_triggers_list::check_n_load(thd, share->db.str,
share->table_name.str, entry, 0))
{
closefrm(entry, 0);
goto err;
}
/*
If we are here, there was no fatal error (but error may be still
unitialized).
*/
if (unlikely(entry->file->implicit_emptied))
{
entry->file->implicit_emptied= 0;
if (mysql_bin_log.is_open())
{
char *query, *end;
uint query_buf_size= 20 + share->db.length + share->table_name.length +1;
if ((query= (char*) my_malloc(query_buf_size,MYF(MY_WME))))
{
/* this DELETE FROM is needed even with row-based binlogging */
end = strxmov(strmov(query, "DELETE FROM `"),
share->db.str,"`.`",share->table_name.str,"`", NullS);
thd->binlog_query(THD::STMT_QUERY_TYPE,
query, (ulong)(end-query), FALSE, FALSE);
my_free(query, MYF(0));
}
else
{
/*
As replication is maybe going to be corrupted, we need to warn the
DBA on top of warning the client (which will automatically be done
because of MYF(MY_WME) in my_malloc() above).
*/
sql_print_error("When opening HEAP table, could not allocate memory "
"to write 'DELETE FROM `%s`.`%s`' to the binary log",
table_list->db, table_list->table_name);
delete entry->triggers;
closefrm(entry, 0);
goto err;
}
}
}
DBUG_RETURN(0);
err:
release_table_share(share, RELEASE_NORMAL);
DBUG_RETURN(1);
}
/*
Open all tables in list
SYNOPSIS
open_tables()
thd - thread handler
start - list of tables in/out
counter - number of opened tables will be return using this parameter
flags - bitmap of flags to modify how the tables will be open:
MYSQL_LOCK_IGNORE_FLUSH - open table even if someone has
done a flush or namelock on it.
NOTE
Unless we are already in prelocked mode, this function will also precache
all SP/SFs explicitly or implicitly (via views and triggers) used by the
query and add tables needed for their execution to table list. If resulting
tables list will be non empty it will mark query as requiring precaching.
Prelocked mode will be enabled for such query during lock_tables() call.
If query for which we are opening tables is already marked as requiring
prelocking it won't do such precaching and will simply reuse table list
which is already built.
RETURN
0 - OK
-1 - error
*/
int open_tables(THD *thd, TABLE_LIST **start, uint *counter, uint flags)
{
TABLE_LIST *tables;
bool refresh;
int result=0;
MEM_ROOT new_frm_mem;
/* Also used for indicating that prelocking is need */
TABLE_LIST **query_tables_last_own;
bool safe_to_ignore_table;
DBUG_ENTER("open_tables");
/*
temporary mem_root for new .frm parsing.
TODO: variables for size
*/
init_alloc_root(&new_frm_mem, 8024, 8024);
thd->current_tablenr= 0;
restart:
*counter= 0;
query_tables_last_own= 0;
thd->proc_info="Opening tables";
/*
If we are not already executing prelocked statement and don't have
statement for which table list for prelocking is already built, let
us cache routines and try to build such table list.
*/
if (!thd->prelocked_mode && !thd->lex->requires_prelocking() &&
thd->lex->uses_stored_routines())
{
bool first_no_prelocking, need_prelocking;
TABLE_LIST **save_query_tables_last= thd->lex->query_tables_last;
DBUG_ASSERT(thd->lex->query_tables == *start);
sp_get_prelocking_info(thd, &need_prelocking, &first_no_prelocking);
if (sp_cache_routines_and_add_tables(thd, thd->lex, first_no_prelocking))
{
/*
Serious error during reading stored routines from mysql.proc table.
Something's wrong with the table or its contents, and an error has
been emitted; we must abort.
*/
result= -1;
goto err;
}
else if (need_prelocking)
{
query_tables_last_own= save_query_tables_last;
*start= thd->lex->query_tables;
}
}
/*
For every table in the list of tables to open, try to find or open
a table.
*/
for (tables= *start; tables ;tables= tables->next_global)
{
safe_to_ignore_table= FALSE;
/*
Ignore placeholders for derived tables. After derived tables
processing, link to created temporary table will be put here.
If this is derived table for view then we still want to process
routines used by this view.
*/
if (tables->derived)
{
if (tables->view)
goto process_view_routines;
continue;
}
/*
If this TABLE_LIST object is a placeholder for an information_schema
table, create a temporary table to represent the information_schema
table in the query. Do not fill it yet - will be filled during
execution.
*/
if (tables->schema_table)
{
if (!mysql_schema_table(thd, thd->lex, tables))
continue;
DBUG_RETURN(-1);
}
(*counter)++;
/*
Not a placeholder: must be a base table or a view, and the table is
not opened yet. Try to open the table.
*/
if (!tables->table)
{
if (tables->prelocking_placeholder)
{
/*
For the tables added by the pre-locking code, attempt to open
the table but fail silently if the table does not exist.
The real failure will occur when/if a statement attempts to use
that table.
*/
Prelock_error_handler prelock_handler;
thd->push_internal_handler(& prelock_handler);
tables->table= open_table(thd, tables, &new_frm_mem, &refresh, flags);
thd->pop_internal_handler();
safe_to_ignore_table= prelock_handler.safely_trapped_errors();
}
else
tables->table= open_table(thd, tables, &new_frm_mem, &refresh, flags);
}
if (!tables->table)
{
free_root(&new_frm_mem, MYF(MY_KEEP_PREALLOC));
if (tables->view)
{
/* VIEW placeholder */
(*counter)--;
/*
tables->next_global list consists of two parts:
1) Query tables and underlying tables of views.
2) Tables used by all stored routines that this statement invokes on
execution.
We need to know where the bound between these two parts is. If we've
just opened a view, which was the last table in part #1, and it
has added its base tables after itself, adjust the boundary pointer
accordingly.
*/
if (query_tables_last_own == &(tables->next_global) &&
tables->view->query_tables)
query_tables_last_own= tables->view->query_tables_last;
/*
Let us free memory used by 'sroutines' hash here since we never
call destructor for this LEX.
*/
hash_free(&tables->view->sroutines);
goto process_view_routines;
}
if (refresh) // Refresh in progress
{
/*
We have met name-locked or old version of table. Now we have
to close all tables which are not up to date. We also have to
throw away set of prelocked tables (and thus close tables from
this set that were open by now) since it possible that one of
tables which determined its content was changed.
Instead of implementing complex/non-robust logic mentioned
above we simply close and then reopen all tables.
In order to prepare for recalculation of set of prelocked tables
we pretend that we have finished calculation which we were doing
currently.
*/
if (query_tables_last_own)
thd->lex->mark_as_requiring_prelocking(query_tables_last_own);
close_tables_for_reopen(thd, start);
goto restart;
}
if (safe_to_ignore_table)
{
DBUG_PRINT("info", ("open_table: ignoring table '%s'.'%s'",
tables->db, tables->alias));
continue;
}
result= -1; // Fatal error
break;
}
else
{
/*
If we are not already in prelocked mode and extended table list is not
yet built and we have trigger for table being opened then we should
cache all routines used by its triggers and add their tables to
prelocking list.
If we lock table for reading we won't update it so there is no need to
process its triggers since they never will be activated.
*/
if (!thd->prelocked_mode && !thd->lex->requires_prelocking() &&
tables->table->triggers &&
tables->lock_type >= TL_WRITE_ALLOW_WRITE)
{
if (!query_tables_last_own)
query_tables_last_own= thd->lex->query_tables_last;
if (sp_cache_routines_and_add_tables_for_triggers(thd, thd->lex,
tables))
{
/*
Serious error during reading stored routines from mysql.proc table.
Something's wrong with the table or its contents, and an error has
been emitted; we must abort.
*/
result= -1;
goto err;
}
}
free_root(&new_frm_mem, MYF(MY_KEEP_PREALLOC));
}
if (tables->lock_type != TL_UNLOCK && ! thd->locked_tables)
tables->table->reginfo.lock_type= tables->lock_type == TL_WRITE_DEFAULT ?
thd->update_lock_default : tables->lock_type;
tables->table->grant= tables->grant;
process_view_routines:
/*
Again we may need cache all routines used by this view and add
tables used by them to table list.
*/
if (tables->view && !thd->prelocked_mode &&
!thd->lex->requires_prelocking() &&
tables->view->uses_stored_routines())
{
/* We have at least one table in TL here. */
if (!query_tables_last_own)
query_tables_last_own= thd->lex->query_tables_last;
if (sp_cache_routines_and_add_tables_for_view(thd, thd->lex, tables))
{
/*
Serious error during reading stored routines from mysql.proc table.
Something is wrong with the table or its contents, and an error has
been emitted; we must abort.
*/
result= -1;
goto err;
}
}
}
err:
thd->proc_info=0;
free_root(&new_frm_mem, MYF(0)); // Free pre-alloced block
if (query_tables_last_own)
thd->lex->mark_as_requiring_prelocking(query_tables_last_own);
DBUG_RETURN(result);
}
/*
Check that lock is ok for tables; Call start stmt if ok
SYNOPSIS
check_lock_and_start_stmt()
thd Thread handle
table_list Table to check
lock_type Lock used for table
RETURN VALUES
0 ok
1 error
*/
static bool check_lock_and_start_stmt(THD *thd, TABLE *table,
thr_lock_type lock_type)
{
int error;
DBUG_ENTER("check_lock_and_start_stmt");
if ((int) lock_type >= (int) TL_WRITE_ALLOW_READ &&
(int) table->reginfo.lock_type < (int) TL_WRITE_ALLOW_READ)
{
my_error(ER_TABLE_NOT_LOCKED_FOR_WRITE, MYF(0),table->alias);
DBUG_RETURN(1);
}
if ((error=table->file->start_stmt(thd, lock_type)))
{
table->file->print_error(error,MYF(0));
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
/*
Open and lock one table
SYNOPSIS
open_ltable()
thd Thread handler
table_list Table to open is first table in this list
lock_type Lock to use for open
lock_flags Flags passed to mysql_lock_table
NOTE
This function don't do anything like SP/SF/views/triggers analysis done
in open_tables(). It is intended for opening of only one concrete table.
And used only in special contexts.
RETURN VALUES
table Opened table
0 Error
If ok, the following are also set:
table_list->lock_type lock_type
table_list->table table
*/
TABLE *open_ltable(THD *thd, TABLE_LIST *table_list, thr_lock_type lock_type,
uint lock_flags)
{
TABLE *table;
bool refresh;
DBUG_ENTER("open_ltable");
thd->proc_info="Opening table";
thd->current_tablenr= 0;
/* open_ltable can be used only for BASIC TABLEs */
table_list->required_type= FRMTYPE_TABLE;
while (!(table= open_table(thd, table_list, thd->mem_root, &refresh, 0)) &&
refresh)
;
if (table)
{
table_list->lock_type= lock_type;
table_list->table= table;
table->grant= table_list->grant;
if (thd->locked_tables)
{
if (check_lock_and_start_stmt(thd, table, lock_type))
table= 0;
}
else
{
DBUG_ASSERT(thd->lock == 0); // You must lock everything at once
if ((table->reginfo.lock_type= lock_type) != TL_UNLOCK)
if (! (thd->lock= mysql_lock_tables(thd, &table_list->table, 1,
lock_flags, &refresh)))
table= 0;
}
}
thd->proc_info=0;
DBUG_RETURN(table);
}
/*
Open all tables in list and locks them for read without derived
tables processing.
SYNOPSIS
simple_open_n_lock_tables()
thd - thread handler
tables - list of tables for open&locking
RETURN
0 - ok
-1 - error
NOTE
The lock will automaticaly be freed by close_thread_tables()
*/
int simple_open_n_lock_tables(THD *thd, TABLE_LIST *tables)
{
uint counter;
bool need_reopen;
DBUG_ENTER("simple_open_n_lock_tables");
for ( ; ; )
{
if (open_tables(thd, &tables, &counter, 0))
DBUG_RETURN(-1);
if (!lock_tables(thd, tables, counter, &need_reopen))
break;
if (!need_reopen)
DBUG_RETURN(-1);
close_tables_for_reopen(thd, &tables);
}
DBUG_RETURN(0);
}
/*
Open all tables in list, locks them and process derived tables
tables processing.
SYNOPSIS
open_and_lock_tables()
thd - thread handler
tables - list of tables for open&locking
RETURN
FALSE - ok
TRUE - error
NOTE
The lock will automaticaly be freed by close_thread_tables()
*/
bool open_and_lock_tables(THD *thd, TABLE_LIST *tables)
{
uint counter;
bool need_reopen;
DBUG_ENTER("open_and_lock_tables");
for ( ; ; )
{
if (open_tables(thd, &tables, &counter, 0))
DBUG_RETURN(-1);
if (!lock_tables(thd, tables, counter, &need_reopen))
break;
if (!need_reopen)
DBUG_RETURN(-1);
close_tables_for_reopen(thd, &tables);
}
if (mysql_handle_derived(thd->lex, &mysql_derived_prepare) ||
(thd->fill_derived_tables() &&
mysql_handle_derived(thd->lex, &mysql_derived_filling)))
DBUG_RETURN(TRUE); /* purecov: inspected */
DBUG_RETURN(0);
}
/*
Open all tables in list and process derived tables
SYNOPSIS
open_normal_and_derived_tables
thd - thread handler
tables - list of tables for open
flags - bitmap of flags to modify how the tables will be open:
MYSQL_LOCK_IGNORE_FLUSH - open table even if someone has
done a flush or namelock on it.
RETURN
FALSE - ok
TRUE - error
NOTE
This is to be used on prepare stage when you don't read any
data from the tables.
*/
bool open_normal_and_derived_tables(THD *thd, TABLE_LIST *tables, uint flags)
{
uint counter;
DBUG_ENTER("open_normal_and_derived_tables");
DBUG_ASSERT(!thd->fill_derived_tables());
if (open_tables(thd, &tables, &counter, flags) ||
mysql_handle_derived(thd->lex, &mysql_derived_prepare))
DBUG_RETURN(TRUE); /* purecov: inspected */
DBUG_RETURN(0);
}
/*
Mark all real tables in the list as free for reuse.
SYNOPSIS
mark_real_tables_as_free_for_reuse()
thd - thread context
table - head of the list of tables
DESCRIPTION
Marks all real tables in the list (i.e. not views, derived
or schema tables) as free for reuse.
*/
static void mark_real_tables_as_free_for_reuse(TABLE_LIST *table)
{
for (; table; table= table->next_global)
if (!table->placeholder())
table->table->query_id= 0;
}
/**
Decide on logging format to use for the statement.
Compute the capabilities vector for the involved storage engines
and mask out the flags for the binary log. Right now, the binlog
flags only include the capabilities of the storage engines, so this
is safe.
We now have three alternatives that prevent the statement from
being loggable:
1. If there are no capabilities left (all flags are clear) it is
not possible to log the statement at all, so we roll back the
statement and report an error.
2. Statement mode is set, but the capabilities indicate that
statement format is not possible.
3. Row mode is set, but the capabilities indicate that row
format is not possible.
4. Statement is unsafe, but the capabilities indicate that row
format is not possible.
If we are in MIXED mode, we then decide what logging format to use:
1. If the statement is unsafe, row-based logging is used.
2. If statement-based logging is not possible, row-based logging is
used.
3. Otherwise, statement-based logging is used.
@param thd Client thread
@param tables Tables involved in the query
*/
int decide_logging_format(THD *thd, TABLE_LIST *tables)
{
if (mysql_bin_log.is_open() && (thd->options & OPTION_BIN_LOG))
{
handler::Table_flags flags_some_set= handler::Table_flags();
handler::Table_flags flags_all_set= ~handler::Table_flags();
my_bool multi_engine= FALSE;
void* prev_ht= NULL;
for (TABLE_LIST *table= tables; table; table= table->next_global)
{
if (!table->placeholder() && table->lock_type >= TL_WRITE_ALLOW_WRITE)
{
ulonglong const flags= table->table->file->ha_table_flags();
DBUG_PRINT("info", ("table: %s; ha_table_flags: %s%s",
table->table_name,
FLAGSTR(flags, HA_BINLOG_STMT_CAPABLE),
FLAGSTR(flags, HA_BINLOG_ROW_CAPABLE)));
if (prev_ht && prev_ht != table->table->file->ht)
multi_engine= TRUE;
prev_ht= table->table->file->ht;
flags_all_set &= flags;
flags_some_set |= flags;
}
}
DBUG_PRINT("info", ("flags_all_set: %s%s",
FLAGSTR(flags_all_set, HA_BINLOG_STMT_CAPABLE),
FLAGSTR(flags_all_set, HA_BINLOG_ROW_CAPABLE)));
DBUG_PRINT("info", ("flags_some_set: %s%s",
FLAGSTR(flags_some_set, HA_BINLOG_STMT_CAPABLE),
FLAGSTR(flags_some_set, HA_BINLOG_ROW_CAPABLE)));
DBUG_PRINT("info", ("thd->variables.binlog_format: %ld",
thd->variables.binlog_format));
DBUG_PRINT("info", ("multi_engine: %s",
multi_engine ? "TRUE" : "FALSE"));
int error= 0;
if (flags_all_set == 0)
{
my_error((error= ER_BINLOG_LOGGING_IMPOSSIBLE), MYF(0),
"Statement cannot be logged to the binary log in"
" row-based nor statement-based format");
}
else if (thd->variables.binlog_format == BINLOG_FORMAT_STMT &&
(flags_all_set & HA_BINLOG_STMT_CAPABLE) == 0)
{
my_error((error= ER_BINLOG_LOGGING_IMPOSSIBLE), MYF(0),
"Statement-based format required for this statement,"
" but not allowed by this combination of engines");
}
else if ((thd->variables.binlog_format == BINLOG_FORMAT_ROW ||
thd->lex->is_stmt_unsafe()) &&
(flags_all_set & HA_BINLOG_ROW_CAPABLE) == 0)
{
my_error((error= ER_BINLOG_LOGGING_IMPOSSIBLE), MYF(0),
"Row-based format required for this statement,"
" but not allowed by this combination of engines");
}
/*
If more than one engine is involved in the statement and at
least one is doing it's own logging (is *self-logging*), the
statement cannot be logged atomically, so we generate an error
rather than allowing the binlog to become corrupt.
*/
if (multi_engine &&
(flags_some_set & HA_HAS_OWN_BINLOGGING))
{
error= ER_BINLOG_LOGGING_IMPOSSIBLE;
my_error(error, MYF(0),
"Statement cannot be written atomically since more"
" than one engine involved and at least one engine"
" is self-logging");
}
DBUG_PRINT("info", ("error: %d", error));
if (error)
{
ha_rollback_stmt(thd);
return -1;
}
/*
We switch to row-based format if we are in mixed mode and one of
the following are true:
1. If the statement is unsafe
2. If statement format cannot be used
Observe that point to cannot be decided before the tables
involved in a statement has been checked, i.e., we cannot put
this code in reset_current_stmt_binlog_row_based(), it has to be
here.
*/
if (thd->lex->is_stmt_unsafe() ||
(flags_all_set & HA_BINLOG_STMT_CAPABLE) == 0)
{
thd->set_current_stmt_binlog_row_based_if_mixed();
}
}
return 0;
}
/*
Lock all tables in list
SYNOPSIS
lock_tables()
thd Thread handler
tables Tables to lock
count Number of opened tables
need_reopen Out parameter which if TRUE indicates that some
tables were dropped or altered during this call
and therefore invoker should reopen tables and
try to lock them once again (in this case
lock_tables() will also return error).
NOTES
You can't call lock_tables twice, as this would break the dead-lock-free
handling thr_lock gives us. You most always get all needed locks at
once.
If query for which we are calling this function marked as requring
prelocking, this function will do implicit LOCK TABLES and change
thd::prelocked_mode accordingly.
RETURN VALUES
0 ok
-1 Error
*/
int lock_tables(THD *thd, TABLE_LIST *tables, uint count, bool *need_reopen)
{
TABLE_LIST *table;
DBUG_ENTER("lock_tables");
/*
We can't meet statement requiring prelocking if we already
in prelocked mode.
*/
DBUG_ASSERT(!thd->prelocked_mode || !thd->lex->requires_prelocking());
*need_reopen= FALSE;
if (!tables && !thd->lex->requires_prelocking())
DBUG_RETURN(decide_logging_format(thd, tables));
/*
We need this extra check for thd->prelocked_mode because we want to avoid
attempts to lock tables in substatements. Checking for thd->locked_tables
is not enough in some situations. For example for SP containing
"drop table t3; create temporary t3 ..; insert into t3 ...;"
thd->locked_tables may be 0 after drop tables, and without this extra
check insert will try to lock temporary table t3, that will lead
to memory leak...
*/
if (!thd->locked_tables && !thd->prelocked_mode)
{
DBUG_ASSERT(thd->lock == 0); // You must lock everything at once
TABLE **start,**ptr;
uint lock_flag= MYSQL_LOCK_NOTIFY_IF_NEED_REOPEN;
if (!(ptr=start=(TABLE**) thd->alloc(sizeof(TABLE*)*count)))
DBUG_RETURN(-1);
for (table= tables; table; table= table->next_global)
{
if (!table->placeholder())
*(ptr++)= table->table;
}
/* We have to emulate LOCK TABLES if we are statement needs prelocking. */
if (thd->lex->requires_prelocking())
{
thd->in_lock_tables=1;
thd->options|= OPTION_TABLE_LOCK;
/*
If we have >= 2 different tables to update with auto_inc columns,
statement-based binlogging won't work. We can solve this problem in
mixed mode by switching to row-based binlogging:
*/
if (thd->variables.binlog_format == BINLOG_FORMAT_MIXED &&
has_two_write_locked_tables_with_auto_increment(tables))
{
thd->lex->set_stmt_unsafe();
thd->set_current_stmt_binlog_row_based_if_mixed();
}
}
if (! (thd->lock= mysql_lock_tables(thd, start, (uint) (ptr - start),
lock_flag, need_reopen)))
{
if (thd->lex->requires_prelocking())
{
thd->options&= ~(ulong) (OPTION_TABLE_LOCK);
thd->in_lock_tables=0;
}
DBUG_RETURN(-1);
}
if (thd->lex->requires_prelocking() &&
thd->lex->sql_command != SQLCOM_LOCK_TABLES)
{
TABLE_LIST *first_not_own= thd->lex->first_not_own_table();
/*
We just have done implicit LOCK TABLES, and now we have
to emulate first open_and_lock_tables() after it.
Note that "LOCK TABLES" can also be marked as requiring prelocking
(e.g. if one locks view which uses functions). We should not emulate
such open_and_lock_tables() in this case. We also should not set
THD::prelocked_mode or first close_thread_tables() call will do
"UNLOCK TABLES".
*/
thd->locked_tables= thd->lock;
thd->lock= 0;
thd->in_lock_tables=0;
for (table= tables; table != first_not_own; table= table->next_global)
{
if (!table->placeholder())
{
table->table->query_id= thd->query_id;
if (check_lock_and_start_stmt(thd, table->table, table->lock_type))
{
ha_rollback_stmt(thd);
mysql_unlock_tables(thd, thd->locked_tables);
thd->locked_tables= 0;
thd->options&= ~(ulong) (OPTION_TABLE_LOCK);
DBUG_RETURN(-1);
}
}
}
/*
Let us mark all tables which don't belong to the statement itself,
and was marked as occupied during open_tables() as free for reuse.
*/
mark_real_tables_as_free_for_reuse(first_not_own);
DBUG_PRINT("info",("prelocked_mode= PRELOCKED"));
thd->prelocked_mode= PRELOCKED;
}
}
else
{
TABLE_LIST *first_not_own= thd->lex->first_not_own_table();
for (table= tables; table != first_not_own; table= table->next_global)
{
if (!table->placeholder() &&
check_lock_and_start_stmt(thd, table->table, table->lock_type))
{
ha_rollback_stmt(thd);
DBUG_RETURN(-1);
}
}
/*
If we are under explicit LOCK TABLES and our statement requires
prelocking, we should mark all "additional" tables as free for use
and enter prelocked mode.
*/
if (thd->lex->requires_prelocking())
{
mark_real_tables_as_free_for_reuse(first_not_own);
DBUG_PRINT("info", ("thd->prelocked_mode= PRELOCKED_UNDER_LOCK_TABLES"));
thd->prelocked_mode= PRELOCKED_UNDER_LOCK_TABLES;
}
}
DBUG_RETURN(decide_logging_format(thd, tables));
}
/*
Prepare statement for reopening of tables and recalculation of set of
prelocked tables.
SYNOPSIS
close_tables_for_reopen()
thd in Thread context
tables in/out List of tables which we were trying to open and lock
*/
void close_tables_for_reopen(THD *thd, TABLE_LIST **tables)
{
/*
If table list consists only from tables from prelocking set, table list
for new attempt should be empty, so we have to update list's root pointer.
*/
if (thd->lex->first_not_own_table() == *tables)
*tables= 0;
thd->lex->chop_off_not_own_tables();
sp_remove_not_own_routines(thd->lex);
for (TABLE_LIST *tmp= *tables; tmp; tmp= tmp->next_global)
tmp->table= 0;
mark_used_tables_as_free_for_reuse(thd, thd->temporary_tables);
close_thread_tables(thd);
}
/*
Open a single table without table caching and don't set it in open_list
SYNPOSIS
open_temporary_table()
thd Thread object
path Path (without .frm)
db database
table_name Table name
link_in_list 1 if table should be linked into thd->temporary_tables
NOTES:
Used by alter_table to open a temporary table and when creating
a temporary table with CREATE TEMPORARY ...
RETURN
0 Error
# TABLE object
*/
TABLE *open_temporary_table(THD *thd, const char *path, const char *db,
const char *table_name, bool link_in_list)
{
TABLE *tmp_table;
TABLE_SHARE *share;
char cache_key[MAX_DBKEY_LENGTH], *saved_cache_key, *tmp_path;
uint key_length;
TABLE_LIST table_list;
DBUG_ENTER("open_temporary_table");
DBUG_PRINT("enter",
("table: '%s'.'%s' path: '%s' server_id: %u "
"pseudo_thread_id: %lu",
db, table_name, path,
(uint) thd->server_id, (ulong) thd->variables.pseudo_thread_id));
table_list.db= (char*) db;
table_list.table_name= (char*) table_name;
/* Create the cache_key for temporary tables */
key_length= create_table_def_key(thd, cache_key, &table_list, 1);
if (!(tmp_table= (TABLE*) my_malloc(sizeof(*tmp_table) + sizeof(*share) +
strlen(path)+1 + key_length,
MYF(MY_WME))))
DBUG_RETURN(0); /* purecov: inspected */
share= (TABLE_SHARE*) (tmp_table+1);
tmp_path= (char*) (share+1);
saved_cache_key= strmov(tmp_path, path)+1;
memcpy(saved_cache_key, cache_key, key_length);
init_tmp_table_share(share, saved_cache_key, key_length,
strend(saved_cache_key)+1, tmp_path);
if (open_table_def(thd, share, 0) ||
open_table_from_share(thd, share, table_name,
(uint) (HA_OPEN_KEYFILE | HA_OPEN_RNDFILE |
HA_GET_INDEX),
READ_KEYINFO | COMPUTE_TYPES | EXTRA_RECORD,
ha_open_options,
tmp_table, FALSE))
{
/* No need to lock share->mutex as this is not needed for tmp tables */
free_table_share(share);
my_free((char*) tmp_table,MYF(0));
DBUG_RETURN(0);
}
tmp_table->reginfo.lock_type= TL_WRITE; // Simulate locked
share->tmp_table= (tmp_table->file->has_transactions() ?
TRANSACTIONAL_TMP_TABLE : NON_TRANSACTIONAL_TMP_TABLE);
if (link_in_list)
{
/* growing temp list at the head */
tmp_table->next= thd->temporary_tables;
if (tmp_table->next)
tmp_table->next->prev= tmp_table;
thd->temporary_tables= tmp_table;
thd->temporary_tables->prev= 0;
if (thd->slave_thread)
slave_open_temp_tables++;
}
tmp_table->pos_in_table_list= 0;
DBUG_RETURN(tmp_table);
}
bool rm_temporary_table(handlerton *base, char *path)
{
bool error=0;
handler *file;
char *ext;
DBUG_ENTER("rm_temporary_table");
strmov(ext= strend(path), reg_ext);
if (my_delete(path,MYF(0)))
error=1; /* purecov: inspected */
*ext= 0; // remove extension
file= get_new_handler((TABLE_SHARE*) 0, current_thd->mem_root, base);
if (file && file->delete_table(path))
{
error=1;
sql_print_warning("Could not remove temporary table: '%s', error: %d",
path, my_errno);
}
delete file;
DBUG_RETURN(error);
}
/*****************************************************************************
* The following find_field_in_XXX procedures implement the core of the
* name resolution functionality. The entry point to resolve a column name in a
* list of tables is 'find_field_in_tables'. It calls 'find_field_in_table_ref'
* for each table reference. In turn, depending on the type of table reference,
* 'find_field_in_table_ref' calls one of the 'find_field_in_XXX' procedures
* below specific for the type of table reference.
******************************************************************************/
/* Special Field pointers as return values of find_field_in_XXX functions. */
Field *not_found_field= (Field*) 0x1;
Field *view_ref_found= (Field*) 0x2;
#define WRONG_GRANT (Field*) -1
static void update_field_dependencies(THD *thd, Field *field, TABLE *table)
{
DBUG_ENTER("update_field_dependencies");
if (thd->mark_used_columns != MARK_COLUMNS_NONE)
{
MY_BITMAP *current_bitmap, *other_bitmap;
/*
We always want to register the used keys, as the column bitmap may have
been set for all fields (for example for view).
*/
table->covering_keys.intersect(field->part_of_key);
table->merge_keys.merge(field->part_of_key);
if (thd->mark_used_columns == MARK_COLUMNS_READ)
{
current_bitmap= table->read_set;
other_bitmap= table->write_set;
}
else
{
current_bitmap= table->write_set;
other_bitmap= table->read_set;
}
if (bitmap_fast_test_and_set(current_bitmap, field->field_index))
{
if (thd->mark_used_columns == MARK_COLUMNS_WRITE)
{
DBUG_PRINT("warning", ("Found duplicated field"));
thd->dup_field= field;
}
else
{
DBUG_PRINT("note", ("Field found before"));
}
DBUG_VOID_RETURN;
}
if (table->get_fields_in_item_tree)
field->flags|= GET_FIXED_FIELDS_FLAG;
table->used_fields++;
}
else if (table->get_fields_in_item_tree)
field->flags|= GET_FIXED_FIELDS_FLAG;
DBUG_VOID_RETURN;
}
/*
Find a field by name in a view that uses merge algorithm.
SYNOPSIS
find_field_in_view()
thd thread handler
table_list view to search for 'name'
name name of field
length length of name
item_name name of item if it will be created (VIEW)
ref expression substituted in VIEW should be passed
using this reference (return view_ref_found)
register_tree_change TRUE if ref is not stack variable and we
need register changes in item tree
RETURN
0 field is not found
view_ref_found found value in VIEW (real result is in *ref)
# pointer to field - only for schema table fields
*/
static Field *
find_field_in_view(THD *thd, TABLE_LIST *table_list,
const char *name, uint length,
const char *item_name, Item **ref,
bool register_tree_change)
{
DBUG_ENTER("find_field_in_view");
DBUG_PRINT("enter",
("view: '%s', field name: '%s', item name: '%s', ref 0x%lx",
table_list->alias, name, item_name, (ulong) ref));
Field_iterator_view field_it;
field_it.set(table_list);
Query_arena *arena= 0, backup;
DBUG_ASSERT(table_list->schema_table_reformed ||
(ref != 0 && table_list->view != 0));
for (; !field_it.end_of_fields(); field_it.next())
{
if (!my_strcasecmp(system_charset_info, field_it.name(), name))
{
// in PS use own arena or data will be freed after prepare
if (register_tree_change && thd->stmt_arena->is_stmt_prepare_or_first_sp_execute())
arena= thd->activate_stmt_arena_if_needed(&backup);
/*
create_item() may, or may not create a new Item, depending on
the column reference. See create_view_field() for details.
*/
Item *item= field_it.create_item(thd);
if (arena)
thd->restore_active_arena(arena, &backup);
if (!item)
DBUG_RETURN(0);
/*
*ref != NULL means that *ref contains the item that we need to
replace. If the item was aliased by the user, set the alias to
the replacing item.
We need to set alias on both ref itself and on ref real item.
*/
if (*ref && !(*ref)->is_autogenerated_name)
{
item->set_name((*ref)->name, (*ref)->name_length,
system_charset_info);
item->real_item()->set_name((*ref)->name, (*ref)->name_length,
system_charset_info);
}
if (register_tree_change)
thd->change_item_tree(ref, item);
else
*ref= item;
DBUG_RETURN((Field*) view_ref_found);
}
}
DBUG_RETURN(0);
}
/*
Find field by name in a NATURAL/USING join table reference.
SYNOPSIS
find_field_in_natural_join()
thd [in] thread handler
table_ref [in] table reference to search
name [in] name of field
length [in] length of name
ref [in/out] if 'name' is resolved to a view field, ref is
set to point to the found view field
register_tree_change [in] TRUE if ref is not stack variable and we
need register changes in item tree
actual_table [out] the original table reference where the field
belongs - differs from 'table_list' only for
NATURAL/USING joins
DESCRIPTION
Search for a field among the result fields of a NATURAL/USING join.
Notice that this procedure is called only for non-qualified field
names. In the case of qualified fields, we search directly the base
tables of a natural join.
RETURN
NULL if the field was not found
WRONG_GRANT if no access rights to the found field
# Pointer to the found Field
*/
static Field *
find_field_in_natural_join(THD *thd, TABLE_LIST *table_ref, const char *name,
uint length, Item **ref, bool register_tree_change,
TABLE_LIST **actual_table)
{
List_iterator_fast<Natural_join_column>
field_it(*(table_ref->join_columns));
Natural_join_column *nj_col, *curr_nj_col;
Field *found_field;
Query_arena *arena, backup;
DBUG_ENTER("find_field_in_natural_join");
DBUG_PRINT("enter", ("field name: '%s', ref 0x%lx",
name, (ulong) ref));
DBUG_ASSERT(table_ref->is_natural_join && table_ref->join_columns);
DBUG_ASSERT(*actual_table == NULL);
LINT_INIT(arena);
LINT_INIT(found_field);
for (nj_col= NULL, curr_nj_col= field_it++; curr_nj_col;
curr_nj_col= field_it++)
{
if (!my_strcasecmp(system_charset_info, curr_nj_col->name(), name))
{
if (nj_col)
{
my_error(ER_NON_UNIQ_ERROR, MYF(0), name, thd->where);
DBUG_RETURN(NULL);
}
nj_col= curr_nj_col;
}
}
if (!nj_col)
DBUG_RETURN(NULL);
if (nj_col->view_field)
{
Item *item;
LINT_INIT(arena);
if (register_tree_change)
arena= thd->activate_stmt_arena_if_needed(&backup);
/*
create_item() may, or may not create a new Item, depending on the
column reference. See create_view_field() for details.
*/
item= nj_col->create_item(thd);
/*
*ref != NULL means that *ref contains the item that we need to
replace. If the item was aliased by the user, set the alias to
the replacing item.
We need to set alias on both ref itself and on ref real item.
*/
if (*ref && !(*ref)->is_autogenerated_name)
{
item->set_name((*ref)->name, (*ref)->name_length,
system_charset_info);
item->real_item()->set_name((*ref)->name, (*ref)->name_length,
system_charset_info);
}
if (register_tree_change && arena)
thd->restore_active_arena(arena, &backup);
if (!item)
DBUG_RETURN(NULL);
DBUG_ASSERT(nj_col->table_field == NULL);
if (nj_col->table_ref->schema_table_reformed)
{
/*
Translation table items are always Item_fields and fixed
already('mysql_schema_table' function). So we can return
->field. It is used only for 'show & where' commands.
*/
DBUG_RETURN(((Item_field*) (nj_col->view_field->item))->field);
}
if (register_tree_change)
thd->change_item_tree(ref, item);
else
*ref= item;
found_field= (Field*) view_ref_found;
}
else
{
/* This is a base table. */
DBUG_ASSERT(nj_col->view_field == NULL);
DBUG_ASSERT(nj_col->table_ref->table == nj_col->table_field->table);
found_field= nj_col->table_field;
update_field_dependencies(thd, found_field, nj_col->table_ref->table);
}
*actual_table= nj_col->table_ref;
DBUG_RETURN(found_field);
}
/*
Find field by name in a base table or a view with temp table algorithm.
SYNOPSIS
find_field_in_table()
thd thread handler
table table where to search for the field
name name of field
length length of name
allow_rowid do allow finding of "_rowid" field?
cached_field_index_ptr cached position in field list (used to speedup
lookup for fields in prepared tables)
RETURN
0 field is not found
# pointer to field
*/
Field *
find_field_in_table(THD *thd, TABLE *table, const char *name, uint length,
bool allow_rowid, uint *cached_field_index_ptr)
{
Field **field_ptr, *field;
uint cached_field_index= *cached_field_index_ptr;
DBUG_ENTER("find_field_in_table");
DBUG_PRINT("enter", ("table: '%s', field name: '%s'", table->alias, name));
/* We assume here that table->field < NO_CACHED_FIELD_INDEX = UINT_MAX */
if (cached_field_index < table->s->fields &&
!my_strcasecmp(system_charset_info,
table->field[cached_field_index]->field_name, name))
field_ptr= table->field + cached_field_index;
else if (table->s->name_hash.records)
{
field_ptr= (Field**) hash_search(&table->s->name_hash, (uchar*) name,
length);
if (field_ptr)
{
/*
field_ptr points to field in TABLE_SHARE. Convert it to the matching
field in table
*/
field_ptr= (table->field + (field_ptr - table->s->field));
}
}
else
{
if (!(field_ptr= table->field))
DBUG_RETURN((Field *)0);
for (; *field_ptr; ++field_ptr)
if (!my_strcasecmp(system_charset_info, (*field_ptr)->field_name, name))
break;
}
if (field_ptr && *field_ptr)
{
*cached_field_index_ptr= field_ptr - table->field;
field= *field_ptr;
}
else
{
if (!allow_rowid ||
my_strcasecmp(system_charset_info, name, "_rowid") ||
table->s->rowid_field_offset == 0)
DBUG_RETURN((Field*) 0);
field= table->field[table->s->rowid_field_offset-1];
}
update_field_dependencies(thd, field, table);
DBUG_RETURN(field);
}
/*
Find field in a table reference.
SYNOPSIS
find_field_in_table_ref()
thd [in] thread handler
table_list [in] table reference to search
name [in] name of field
length [in] field length of name
item_name [in] name of item if it will be created (VIEW)
db_name [in] optional database name that qualifies the
table_name [in] optional table name that qualifies the field
ref [in/out] if 'name' is resolved to a view field, ref
is set to point to the found view field
check_privileges [in] check privileges
allow_rowid [in] do allow finding of "_rowid" field?
cached_field_index_ptr [in] cached position in field list (used to
speedup lookup for fields in prepared tables)
register_tree_change [in] TRUE if ref is not stack variable and we
need register changes in item tree
actual_table [out] the original table reference where the field
belongs - differs from 'table_list' only for
NATURAL_USING joins.
DESCRIPTION
Find a field in a table reference depending on the type of table
reference. There are three types of table references with respect
to the representation of their result columns:
- an array of Field_translator objects for MERGE views and some
information_schema tables,
- an array of Field objects (and possibly a name hash) for stored
tables,
- a list of Natural_join_column objects for NATURAL/USING joins.
This procedure detects the type of the table reference 'table_list'
and calls the corresponding search routine.
RETURN
0 field is not found
view_ref_found found value in VIEW (real result is in *ref)
# pointer to field
*/
Field *
find_field_in_table_ref(THD *thd, TABLE_LIST *table_list,
const char *name, uint length,
const char *item_name, const char *db_name,
const char *table_name, Item **ref,
bool check_privileges, bool allow_rowid,
uint *cached_field_index_ptr,
bool register_tree_change, TABLE_LIST **actual_table)
{
Field *fld;
DBUG_ENTER("find_field_in_table_ref");
DBUG_ASSERT(table_list->alias);
DBUG_ASSERT(name);
DBUG_ASSERT(item_name);
DBUG_PRINT("enter",
("table: '%s' field name: '%s' item name: '%s' ref 0x%lx",
table_list->alias, name, item_name, (ulong) ref));
/*
Check that the table and database that qualify the current field name
are the same as the table reference we are going to search for the field.
Exclude from the test below nested joins because the columns in a
nested join generally originate from different tables. Nested joins
also have no table name, except when a nested join is a merge view
or an information schema table.
We include explicitly table references with a 'field_translation' table,
because if there are views over natural joins we don't want to search
inside the view, but we want to search directly in the view columns
which are represented as a 'field_translation'.
TODO: Ensure that table_name, db_name and tables->db always points to
something !
*/
if (/* Exclude nested joins. */
(!table_list->nested_join ||
/* Include merge views and information schema tables. */
table_list->field_translation) &&
/*
Test if the field qualifiers match the table reference we plan
to search.
*/
table_name && table_name[0] &&
(my_strcasecmp(table_alias_charset, table_list->alias, table_name) ||
(db_name && db_name[0] && table_list->db && table_list->db[0] &&
strcmp(db_name, table_list->db))))
DBUG_RETURN(0);
*actual_table= NULL;
if (table_list->field_translation)
{
/* 'table_list' is a view or an information schema table. */
if ((fld= find_field_in_view(thd, table_list, name, length, item_name, ref,
register_tree_change)))
*actual_table= table_list;
}
else if (!table_list->nested_join)
{
/* 'table_list' is a stored table. */
DBUG_ASSERT(table_list->table);
if ((fld= find_field_in_table(thd, table_list->table, name, length,
allow_rowid,
cached_field_index_ptr)))
*actual_table= table_list;
}
else
{
/*
'table_list' is a NATURAL/USING join, or an operand of such join that
is a nested join itself.
If the field name we search for is qualified, then search for the field
in the table references used by NATURAL/USING the join.
*/
if (table_name && table_name[0])
{
List_iterator<TABLE_LIST> it(table_list->nested_join->join_list);
TABLE_LIST *table;
while ((table= it++))
{
if ((fld= find_field_in_table_ref(thd, table, name, length, item_name,
db_name, table_name, ref,
check_privileges, allow_rowid,
cached_field_index_ptr,
register_tree_change, actual_table)))
DBUG_RETURN(fld);
}
DBUG_RETURN(0);
}
/*
Non-qualified field, search directly in the result columns of the
natural join. The condition of the outer IF is true for the top-most
natural join, thus if the field is not qualified, we will search
directly the top-most NATURAL/USING join.
*/
fld= find_field_in_natural_join(thd, table_list, name, length, ref,
register_tree_change, actual_table);
}
if (fld)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/* Check if there are sufficient access rights to the found field. */
if (check_privileges &&
check_column_grant_in_table_ref(thd, *actual_table, name, length))
fld= WRONG_GRANT;
else
#endif
if (thd->mark_used_columns != MARK_COLUMNS_NONE)
{
/*
Get rw_set correct for this field so that the handler
knows that this field is involved in the query and gets
retrieved/updated
*/
Field *field_to_set= NULL;
if (fld == view_ref_found)
{
Item *it= (*ref)->real_item();
if (it->type() == Item::FIELD_ITEM)
field_to_set= ((Item_field*)it)->field;
else
{
if (thd->mark_used_columns == MARK_COLUMNS_READ)
it->walk(&Item::register_field_in_read_map, 1, (uchar *) 0);
}
}
else
field_to_set= fld;
if (field_to_set)
{
TABLE *table= field_to_set->table;
if (thd->mark_used_columns == MARK_COLUMNS_READ)
bitmap_set_bit(table->read_set, field_to_set->field_index);
else
bitmap_set_bit(table->write_set, field_to_set->field_index);
}
}
}
DBUG_RETURN(fld);
}
/*
Find field in table, no side effects, only purpose is to check for field
in table object and get reference to the field if found.
SYNOPSIS
find_field_in_table_sef()
table table where to find
name Name of field searched for
RETURN
0 field is not found
# pointer to field
*/
Field *find_field_in_table_sef(TABLE *table, const char *name)
{
Field **field_ptr;
if (table->s->name_hash.records)
{
field_ptr= (Field**)hash_search(&table->s->name_hash,(uchar*) name,
strlen(name));
if (field_ptr)
{
/*
field_ptr points to field in TABLE_SHARE. Convert it to the matching
field in table
*/
field_ptr= (table->field + (field_ptr - table->s->field));
}
}
else
{
if (!(field_ptr= table->field))
return (Field *)0;
for (; *field_ptr; ++field_ptr)
if (!my_strcasecmp(system_charset_info, (*field_ptr)->field_name, name))
break;
}
if (field_ptr)
return *field_ptr;
else
return (Field *)0;
}
/*
Find field in table list.
SYNOPSIS
find_field_in_tables()
thd pointer to current thread structure
item field item that should be found
first_table list of tables to be searched for item
last_table end of the list of tables to search for item. If NULL
then search to the end of the list 'first_table'.
ref if 'item' is resolved to a view field, ref is set to
point to the found view field
report_error Degree of error reporting:
- IGNORE_ERRORS then do not report any error
- IGNORE_EXCEPT_NON_UNIQUE report only non-unique
fields, suppress all other errors
- REPORT_EXCEPT_NON_UNIQUE report all other errors
except when non-unique fields were found
- REPORT_ALL_ERRORS
check_privileges need to check privileges
register_tree_change TRUE if ref is not a stack variable and we
to need register changes in item tree
RETURN VALUES
0 If error: the found field is not unique, or there are
no sufficient access priviliges for the found field,
or the field is qualified with non-existing table.
not_found_field The function was called with report_error ==
(IGNORE_ERRORS || IGNORE_EXCEPT_NON_UNIQUE) and a
field was not found.
view_ref_found View field is found, item passed through ref parameter
found field If a item was resolved to some field
*/
Field *
find_field_in_tables(THD *thd, Item_ident *item,
TABLE_LIST *first_table, TABLE_LIST *last_table,
Item **ref, find_item_error_report_type report_error,
bool check_privileges, bool register_tree_change)
{
Field *found=0;
const char *db= item->db_name;
const char *table_name= item->table_name;
const char *name= item->field_name;
uint length=(uint) strlen(name);
char name_buff[NAME_LEN+1];
TABLE_LIST *cur_table= first_table;
TABLE_LIST *actual_table;
bool allow_rowid;
if (!table_name || !table_name[0])
{
table_name= 0; // For easier test
db= 0;
}
allow_rowid= table_name || (cur_table && !cur_table->next_local);
if (item->cached_table)
{
/*
This shortcut is used by prepared statements. We assume that
TABLE_LIST *first_table is not changed during query execution (which
is true for all queries except RENAME but luckily RENAME doesn't
use fields...) so we can rely on reusing pointer to its member.
With this optimization we also miss case when addition of one more
field makes some prepared query ambiguous and so erroneous, but we
accept this trade off.
*/
TABLE_LIST *table_ref= item->cached_table;
/*
The condition (table_ref->view == NULL) ensures that we will call
find_field_in_table even in the case of information schema tables
when table_ref->field_translation != NULL.
*/
if (table_ref->table && !table_ref->view)
found= find_field_in_table(thd, table_ref->table, name, length,
TRUE, &(item->cached_field_index));
else
found= find_field_in_table_ref(thd, table_ref, name, length, item->name,
NULL, NULL, ref, check_privileges,
TRUE, &(item->cached_field_index),
register_tree_change,
&actual_table);
if (found)
{
if (found == WRONG_GRANT)
return (Field*) 0;
/*
Only views fields should be marked as dependent, not an underlying
fields.
*/
if (!table_ref->belong_to_view)
{
SELECT_LEX *current_sel= thd->lex->current_select;
SELECT_LEX *last_select= table_ref->select_lex;
/*
If the field was an outer referencee, mark all selects using this
sub query as dependent on the outer query
*/
if (current_sel != last_select)
mark_select_range_as_dependent(thd, last_select, current_sel,
found, *ref, item);
}
return found;
}
}
if (db && lower_case_table_names)
{
/*
convert database to lower case for comparison.
We can't do this in Item_field as this would change the
'name' of the item which may be used in the select list
*/
strmake(name_buff, db, sizeof(name_buff)-1);
my_casedn_str(files_charset_info, name_buff);
db= name_buff;
}
if (last_table)
last_table= last_table->next_name_resolution_table;
for (; cur_table != last_table ;
cur_table= cur_table->next_name_resolution_table)
{
Field *cur_field= find_field_in_table_ref(thd, cur_table, name, length,
item->name, db, table_name, ref,
check_privileges,
allow_rowid,
&(item->cached_field_index),
register_tree_change,
&actual_table);
if (cur_field)
{
if (cur_field == WRONG_GRANT)
{
if (thd->lex->sql_command != SQLCOM_SHOW_FIELDS)
return (Field*) 0;
thd->clear_error();
cur_field= find_field_in_table_ref(thd, cur_table, name, length,
item->name, db, table_name, ref,
false,
allow_rowid,
&(item->cached_field_index),
register_tree_change,
&actual_table);
if (cur_field)
{
Field *nf=new Field_null(NULL,0,Field::NONE,
cur_field->field_name,
&my_charset_bin);
nf->init(cur_table->table);
cur_field= nf;
}
}
/*
Store the original table of the field, which may be different from
cur_table in the case of NATURAL/USING join.
*/
item->cached_table= (!actual_table->cacheable_table || found) ?
0 : actual_table;
DBUG_ASSERT(thd->where);
/*
If we found a fully qualified field we return it directly as it can't
have duplicates.
*/
if (db)
return cur_field;
if (found)
{
if (report_error == REPORT_ALL_ERRORS ||
report_error == IGNORE_EXCEPT_NON_UNIQUE)
my_error(ER_NON_UNIQ_ERROR, MYF(0),
table_name ? item->full_name() : name, thd->where);
return (Field*) 0;
}
found= cur_field;
}
}
if (found)
return found;
/*
If the field was qualified and there were no tables to search, issue
an error that an unknown table was given. The situation is detected
as follows: if there were no tables we wouldn't go through the loop
and cur_table wouldn't be updated by the loop increment part, so it
will be equal to the first table.
*/
if (table_name && (cur_table == first_table) &&
(report_error == REPORT_ALL_ERRORS ||
report_error == REPORT_EXCEPT_NON_UNIQUE))
{
char buff[NAME_LEN*2+1];
if (db && db[0])
{
strxnmov(buff,sizeof(buff)-1,db,".",table_name,NullS);
table_name=buff;
}
my_error(ER_UNKNOWN_TABLE, MYF(0), table_name, thd->where);
}
else
{
if (report_error == REPORT_ALL_ERRORS ||
report_error == REPORT_EXCEPT_NON_UNIQUE)
my_error(ER_BAD_FIELD_ERROR, MYF(0), item->full_name(), thd->where);
else
found= not_found_field;
}
return found;
}
/*
Find Item in list of items (find_field_in_tables analog)
TODO
is it better return only counter?
SYNOPSIS
find_item_in_list()
find Item to find
items List of items
counter To return number of found item
report_error
REPORT_ALL_ERRORS report errors, return 0 if error
REPORT_EXCEPT_NOT_FOUND Do not report 'not found' error and
return not_found_item, report other errors,
return 0
IGNORE_ERRORS Do not report errors, return 0 if error
resolution Set to the resolution type if the item is found
(it says whether the item is resolved
against an alias name,
or as a field name without alias,
or as a field hidden by alias,
or ignoring alias)
RETURN VALUES
0 Item is not found or item is not unique,
error message is reported
not_found_item Function was called with
report_error == REPORT_EXCEPT_NOT_FOUND and
item was not found. No error message was reported
found field
*/
/* Special Item pointer to serve as a return value from find_item_in_list(). */
Item **not_found_item= (Item**) 0x1;
Item **
find_item_in_list(Item *find, List<Item> &items, uint *counter,
find_item_error_report_type report_error,
enum_resolution_type *resolution)
{
List_iterator<Item> li(items);
Item **found=0, **found_unaliased= 0, *item;
const char *db_name=0;
const char *field_name=0;
const char *table_name=0;
bool found_unaliased_non_uniq= 0;
/*
true if the item that we search for is a valid name reference
(and not an item that happens to have a name).
*/
bool is_ref_by_name= 0;
uint unaliased_counter;
LINT_INIT(unaliased_counter); // Dependent on found_unaliased
*resolution= NOT_RESOLVED;
is_ref_by_name= (find->type() == Item::FIELD_ITEM ||
find->type() == Item::REF_ITEM);
if (is_ref_by_name)
{
field_name= ((Item_ident*) find)->field_name;
table_name= ((Item_ident*) find)->table_name;
db_name= ((Item_ident*) find)->db_name;
}
for (uint i= 0; (item=li++); i++)
{
if (field_name && item->real_item()->type() == Item::FIELD_ITEM)
{
Item_ident *item_field= (Item_ident*) item;
/*
In case of group_concat() with ORDER BY condition in the QUERY
item_field can be field of temporary table without item name
(if this field created from expression argument of group_concat()),
=> we have to check presence of name before compare
*/
if (!item_field->name)
continue;
if (table_name)
{
/*
If table name is specified we should find field 'field_name' in
table 'table_name'. According to SQL-standard we should ignore
aliases in this case.
Since we should NOT prefer fields from the select list over
other fields from the tables participating in this select in
case of ambiguity we have to do extra check outside this function.
We use strcmp for table names and database names as these may be
case sensitive. In cases where they are not case sensitive, they
are always in lower case.
item_field->field_name and item_field->table_name can be 0x0 if
item is not fix_field()'ed yet.
*/
if (item_field->field_name && item_field->table_name &&
!my_strcasecmp(system_charset_info, item_field->field_name,
field_name) &&
!strcmp(item_field->table_name, table_name) &&
(!db_name || (item_field->db_name &&
!strcmp(item_field->db_name, db_name))))
{
if (found_unaliased)
{
if ((*found_unaliased)->eq(item, 0))
continue;
/*
Two matching fields in select list.
We already can bail out because we are searching through
unaliased names only and will have duplicate error anyway.
*/
if (report_error != IGNORE_ERRORS)
my_error(ER_NON_UNIQ_ERROR, MYF(0),
find->full_name(), current_thd->where);
return (Item**) 0;
}
found_unaliased= li.ref();
unaliased_counter= i;
*resolution= RESOLVED_IGNORING_ALIAS;
if (db_name)
break; // Perfect match
}
}
else
{
int fname_cmp= my_strcasecmp(system_charset_info,
item_field->field_name,
field_name);
if (!my_strcasecmp(system_charset_info,
item_field->name,field_name))
{
/*
If table name was not given we should scan through aliases
and non-aliased fields first. We are also checking unaliased
name of the field in then next else-if, to be able to find
instantly field (hidden by alias) if no suitable alias or
non-aliased field was found.
*/
if (found)
{
if ((*found)->eq(item, 0))
continue; // Same field twice
if (report_error != IGNORE_ERRORS)
my_error(ER_NON_UNIQ_ERROR, MYF(0),
find->full_name(), current_thd->where);
return (Item**) 0;
}
found= li.ref();
*counter= i;
*resolution= fname_cmp ? RESOLVED_AGAINST_ALIAS:
RESOLVED_WITH_NO_ALIAS;
}
else if (!fname_cmp)
{
/*
We will use non-aliased field or react on such ambiguities only if
we won't be able to find aliased field.
Again if we have ambiguity with field outside of select list
we should prefer fields from select list.
*/
if (found_unaliased)
{
if ((*found_unaliased)->eq(item, 0))
continue; // Same field twice
found_unaliased_non_uniq= 1;
}
found_unaliased= li.ref();
unaliased_counter= i;
}
}
}
else if (!table_name)
{
if (is_ref_by_name && find->name && item->name &&
!my_strcasecmp(system_charset_info,item->name,find->name))
{
found= li.ref();
*counter= i;
*resolution= RESOLVED_AGAINST_ALIAS;
break;
}
else if (find->eq(item,0))
{
found= li.ref();
*counter= i;
*resolution= RESOLVED_IGNORING_ALIAS;
break;
}
}
}
if (!found)
{
if (found_unaliased_non_uniq)
{
if (report_error != IGNORE_ERRORS)
my_error(ER_NON_UNIQ_ERROR, MYF(0),
find->full_name(), current_thd->where);
return (Item **) 0;
}
if (found_unaliased)
{
found= found_unaliased;
*counter= unaliased_counter;
*resolution= RESOLVED_BEHIND_ALIAS;
}
}
if (found)
return found;
if (report_error != REPORT_EXCEPT_NOT_FOUND)
{
if (report_error == REPORT_ALL_ERRORS)
my_error(ER_BAD_FIELD_ERROR, MYF(0),
find->full_name(), current_thd->where);
return (Item **) 0;
}
else
return (Item **) not_found_item;
}
/*
Test if a string is a member of a list of strings.
SYNOPSIS
test_if_string_in_list()
find the string to look for
str_list a list of strings to be searched
DESCRIPTION
Sequentially search a list of strings for a string, and test whether
the list contains the same string.
RETURN
TRUE if find is in str_list
FALSE otherwise
*/
static bool
test_if_string_in_list(const char *find, List<String> *str_list)
{
List_iterator<String> str_list_it(*str_list);
String *curr_str;
size_t find_length= strlen(find);
while ((curr_str= str_list_it++))
{
if (find_length != curr_str->length())
continue;
if (!my_strcasecmp(system_charset_info, find, curr_str->ptr()))
return TRUE;
}
return FALSE;
}
/*
Create a new name resolution context for an item so that it is
being resolved in a specific table reference.
SYNOPSIS
set_new_item_local_context()
thd pointer to current thread
item item for which new context is created and set
table_ref table ref where an item showld be resolved
DESCRIPTION
Create a new name resolution context for an item, so that the item
is resolved only the supplied 'table_ref'.
RETURN
FALSE if all OK
TRUE otherwise
*/
static bool
set_new_item_local_context(THD *thd, Item_ident *item, TABLE_LIST *table_ref)
{
Name_resolution_context *context;
if (!(context= new (thd->mem_root) Name_resolution_context))
return TRUE;
context->init();
context->first_name_resolution_table=
context->last_name_resolution_table= table_ref;
item->context= context;
return FALSE;
}
/*
Find and mark the common columns of two table references.
SYNOPSIS
mark_common_columns()
thd [in] current thread
table_ref_1 [in] the first (left) join operand
table_ref_2 [in] the second (right) join operand
using_fields [in] if the join is JOIN...USING - the join columns,
if NATURAL join, then NULL
found_using_fields [out] number of fields from the USING clause that were
found among the common fields
DESCRIPTION
The procedure finds the common columns of two relations (either
tables or intermediate join results), and adds an equi-join condition
to the ON clause of 'table_ref_2' for each pair of matching columns.
If some of table_ref_XXX represents a base table or view, then we
create new 'Natural_join_column' instances for each column
reference and store them in the 'join_columns' of the table
reference.
IMPLEMENTATION
The procedure assumes that store_natural_using_join_columns() was
called for the previous level of NATURAL/USING joins.
RETURN
TRUE error when some common column is non-unique, or out of memory
FALSE OK
*/
static bool
mark_common_columns(THD *thd, TABLE_LIST *table_ref_1, TABLE_LIST *table_ref_2,
List<String> *using_fields, uint *found_using_fields)
{
Field_iterator_table_ref it_1, it_2;
Natural_join_column *nj_col_1, *nj_col_2;
Query_arena *arena, backup;
bool result= TRUE;
bool first_outer_loop= TRUE;
/*
Leaf table references to which new natural join columns are added
if the leaves are != NULL.
*/
TABLE_LIST *leaf_1= (table_ref_1->nested_join &&
!table_ref_1->is_natural_join) ?
NULL : table_ref_1;
TABLE_LIST *leaf_2= (table_ref_2->nested_join &&
!table_ref_2->is_natural_join) ?
NULL : table_ref_2;
DBUG_ENTER("mark_common_columns");
DBUG_PRINT("info", ("operand_1: %s operand_2: %s",
table_ref_1->alias, table_ref_2->alias));
*found_using_fields= 0;
arena= thd->activate_stmt_arena_if_needed(&backup);
for (it_1.set(table_ref_1); !it_1.end_of_fields(); it_1.next())
{
bool found= FALSE;
const char *field_name_1;
/* true if field_name_1 is a member of using_fields */
bool is_using_column_1;
if (!(nj_col_1= it_1.get_or_create_column_ref(leaf_1)))
goto err;
field_name_1= nj_col_1->name();
is_using_column_1= using_fields &&
test_if_string_in_list(field_name_1, using_fields);
DBUG_PRINT ("info", ("field_name_1=%s.%s",
nj_col_1->table_name() ? nj_col_1->table_name() : "",
field_name_1));
/*
Find a field with the same name in table_ref_2.
Note that for the second loop, it_2.set() will iterate over
table_ref_2->join_columns and not generate any new elements or
lists.
*/
nj_col_2= NULL;
for (it_2.set(table_ref_2); !it_2.end_of_fields(); it_2.next())
{
Natural_join_column *cur_nj_col_2;
const char *cur_field_name_2;
if (!(cur_nj_col_2= it_2.get_or_create_column_ref(leaf_2)))
goto err;
cur_field_name_2= cur_nj_col_2->name();
DBUG_PRINT ("info", ("cur_field_name_2=%s.%s",
cur_nj_col_2->table_name() ?
cur_nj_col_2->table_name() : "",
cur_field_name_2));
/*
Compare the two columns and check for duplicate common fields.
A common field is duplicate either if it was already found in
table_ref_2 (then found == TRUE), or if a field in table_ref_2
was already matched by some previous field in table_ref_1
(then cur_nj_col_2->is_common == TRUE).
Note that it is too early to check the columns outside of the
USING list for ambiguity because they are not actually "referenced"
here. These columns must be checked only on unqualified reference
by name (e.g. in SELECT list).
*/
if (!my_strcasecmp(system_charset_info, field_name_1, cur_field_name_2))
{
DBUG_PRINT ("info", ("match c1.is_common=%d", nj_col_1->is_common));
if (cur_nj_col_2->is_common ||
(found && (!using_fields || is_using_column_1)))
{
my_error(ER_NON_UNIQ_ERROR, MYF(0), field_name_1, thd->where);
goto err;
}
nj_col_2= cur_nj_col_2;
found= TRUE;
}
}
if (first_outer_loop && leaf_2)
{
/*
Make sure that the next inner loop "knows" that all columns
are materialized already.
*/
leaf_2->is_join_columns_complete= TRUE;
first_outer_loop= FALSE;
}
if (!found)
continue; // No matching field
/*
field_1 and field_2 have the same names. Check if they are in the USING
clause (if present), mark them as common fields, and add a new
equi-join condition to the ON clause.
*/
if (nj_col_2 && (!using_fields ||is_using_column_1))
{
Item *item_1= nj_col_1->create_item(thd);
Item *item_2= nj_col_2->create_item(thd);
Field *field_1= nj_col_1->field();
Field *field_2= nj_col_2->field();
Item_ident *item_ident_1, *item_ident_2;
Item_func_eq *eq_cond;
if (!item_1 || !item_2)
goto err; // out of memory
/*
The following assert checks that the two created items are of
type Item_ident.
*/
DBUG_ASSERT(!thd->lex->current_select->no_wrap_view_item);
/*
In the case of no_wrap_view_item == 0, the created items must be
of sub-classes of Item_ident.
*/
DBUG_ASSERT(item_1->type() == Item::FIELD_ITEM ||
item_1->type() == Item::REF_ITEM);
DBUG_ASSERT(item_2->type() == Item::FIELD_ITEM ||
item_2->type() == Item::REF_ITEM);
/*
We need to cast item_1,2 to Item_ident, because we need to hook name
resolution contexts specific to each item.
*/
item_ident_1= (Item_ident*) item_1;
item_ident_2= (Item_ident*) item_2;
/*
Create and hook special name resolution contexts to each item in the
new join condition . We need this to both speed-up subsequent name
resolution of these items, and to enable proper name resolution of
the items during the execute phase of PS.
*/
if (set_new_item_local_context(thd, item_ident_1, nj_col_1->table_ref) ||
set_new_item_local_context(thd, item_ident_2, nj_col_2->table_ref))
goto err;
if (!(eq_cond= new Item_func_eq(item_ident_1, item_ident_2)))
goto err; /* Out of memory. */
/*
Add the new equi-join condition to the ON clause. Notice that
fix_fields() is applied to all ON conditions in setup_conds()
so we don't do it here.
*/
add_join_on((table_ref_1->outer_join & JOIN_TYPE_RIGHT ?
table_ref_1 : table_ref_2),
eq_cond);
nj_col_1->is_common= nj_col_2->is_common= TRUE;
DBUG_PRINT ("info", ("%s.%s and %s.%s are common",
nj_col_1->table_name() ?
nj_col_1->table_name() : "",
nj_col_1->name(),
nj_col_2->table_name() ?
nj_col_2->table_name() : "",
nj_col_2->name()));
if (field_1)
{
TABLE *table_1= nj_col_1->table_ref->table;
/* Mark field_1 used for table cache. */
bitmap_set_bit(table_1->read_set, field_1->field_index);
table_1->covering_keys.intersect(field_1->part_of_key);
table_1->merge_keys.merge(field_1->part_of_key);
}
if (field_2)
{
TABLE *table_2= nj_col_2->table_ref->table;
/* Mark field_2 used for table cache. */
bitmap_set_bit(table_2->read_set, field_2->field_index);
table_2->covering_keys.intersect(field_2->part_of_key);
table_2->merge_keys.merge(field_2->part_of_key);
}
if (using_fields != NULL)
++(*found_using_fields);
}
}
if (leaf_1)
leaf_1->is_join_columns_complete= TRUE;
/*
Everything is OK.
Notice that at this point there may be some column names in the USING
clause that are not among the common columns. This is an SQL error and
we check for this error in store_natural_using_join_columns() when
(found_using_fields < length(join_using_fields)).
*/
result= FALSE;
err:
if (arena)
thd->restore_active_arena(arena, &backup);
DBUG_RETURN(result);
}
/*
Materialize and store the row type of NATURAL/USING join.
SYNOPSIS
store_natural_using_join_columns()
thd current thread
natural_using_join the table reference of the NATURAL/USING join
table_ref_1 the first (left) operand (of a NATURAL/USING join).
table_ref_2 the second (right) operand (of a NATURAL/USING join).
using_fields if the join is JOIN...USING - the join columns,
if NATURAL join, then NULL
found_using_fields number of fields from the USING clause that were
found among the common fields
DESCRIPTION
Iterate over the columns of both join operands and sort and store
all columns into the 'join_columns' list of natural_using_join
where the list is formed by three parts:
part1: The coalesced columns of table_ref_1 and table_ref_2,
sorted according to the column order of the first table.
part2: The other columns of the first table, in the order in
which they were defined in CREATE TABLE.
part3: The other columns of the second table, in the order in
which they were defined in CREATE TABLE.
Time complexity - O(N1+N2), where Ni = length(table_ref_i).
IMPLEMENTATION
The procedure assumes that mark_common_columns() has been called
for the join that is being processed.
RETURN
TRUE error: Some common column is ambiguous
FALSE OK
*/
static bool
store_natural_using_join_columns(THD *thd, TABLE_LIST *natural_using_join,
TABLE_LIST *table_ref_1,
TABLE_LIST *table_ref_2,
List<String> *using_fields,
uint found_using_fields)
{
Field_iterator_table_ref it_1, it_2;
Natural_join_column *nj_col_1, *nj_col_2;
Query_arena *arena, backup;
bool result= TRUE;
List<Natural_join_column> *non_join_columns;
DBUG_ENTER("store_natural_using_join_columns");
DBUG_ASSERT(!natural_using_join->join_columns);
arena= thd->activate_stmt_arena_if_needed(&backup);
if (!(non_join_columns= new List<Natural_join_column>) ||
!(natural_using_join->join_columns= new List<Natural_join_column>))
goto err;
/* Append the columns of the first join operand. */
for (it_1.set(table_ref_1); !it_1.end_of_fields(); it_1.next())
{
nj_col_1= it_1.get_natural_column_ref();
if (nj_col_1->is_common)
{
natural_using_join->join_columns->push_back(nj_col_1);
/* Reset the common columns for the next call to mark_common_columns. */
nj_col_1->is_common= FALSE;
}
else
non_join_columns->push_back(nj_col_1);
}
/*
Check that all columns in the USING clause are among the common
columns. If this is not the case, report the first one that was
not found in an error.
*/
if (using_fields && found_using_fields < using_fields->elements)
{
String *using_field_name;
List_iterator_fast<String> using_fields_it(*using_fields);
while ((using_field_name= using_fields_it++))
{
const char *using_field_name_ptr= using_field_name->c_ptr();
List_iterator_fast<Natural_join_column>
it(*(natural_using_join->join_columns));
Natural_join_column *common_field;
for (;;)
{
/* If reached the end of fields, and none was found, report error. */
if (!(common_field= it++))
{
my_error(ER_BAD_FIELD_ERROR, MYF(0), using_field_name_ptr,
current_thd->where);
goto err;
}
if (!my_strcasecmp(system_charset_info,
common_field->name(), using_field_name_ptr))
break; // Found match
}
}
}
/* Append the non-equi-join columns of the second join operand. */
for (it_2.set(table_ref_2); !it_2.end_of_fields(); it_2.next())
{
nj_col_2= it_2.get_natural_column_ref();
if (!nj_col_2->is_common)
non_join_columns->push_back(nj_col_2);
else
{
/* Reset the common columns for the next call to mark_common_columns. */
nj_col_2->is_common= FALSE;
}
}
if (non_join_columns->elements > 0)
natural_using_join->join_columns->concat(non_join_columns);
natural_using_join->is_join_columns_complete= TRUE;
result= FALSE;
err:
if (arena)
thd->restore_active_arena(arena, &backup);
DBUG_RETURN(result);
}
/*
Precompute and store the row types of the top-most NATURAL/USING joins.
SYNOPSIS
store_top_level_join_columns()
thd current thread
table_ref nested join or table in a FROM clause
left_neighbor neighbor table reference to the left of table_ref at the
same level in the join tree
right_neighbor neighbor table reference to the right of table_ref at the
same level in the join tree
DESCRIPTION
The procedure performs a post-order traversal of a nested join tree
and materializes the row types of NATURAL/USING joins in a
bottom-up manner until it reaches the TABLE_LIST elements that
represent the top-most NATURAL/USING joins. The procedure should be
applied to each element of SELECT_LEX::top_join_list (i.e. to each
top-level element of the FROM clause).
IMPLEMENTATION
Notice that the table references in the list nested_join->join_list
are in reverse order, thus when we iterate over it, we are moving
from the right to the left in the FROM clause.
RETURN
TRUE Error
FALSE OK
*/
static bool
store_top_level_join_columns(THD *thd, TABLE_LIST *table_ref,
TABLE_LIST *left_neighbor,
TABLE_LIST *right_neighbor)
{
Query_arena *arena, backup;
bool result= TRUE;
DBUG_ENTER("store_top_level_join_columns");
arena= thd->activate_stmt_arena_if_needed(&backup);
/* Call the procedure recursively for each nested table reference. */
if (table_ref->nested_join)
{
List_iterator_fast<TABLE_LIST> nested_it(table_ref->nested_join->join_list);
TABLE_LIST *same_level_left_neighbor= nested_it++;
TABLE_LIST *same_level_right_neighbor= NULL;
/* Left/right-most neighbors, possibly at higher levels in the join tree. */
TABLE_LIST *real_left_neighbor, *real_right_neighbor;
while (same_level_left_neighbor)
{
TABLE_LIST *cur_table_ref= same_level_left_neighbor;
same_level_left_neighbor= nested_it++;
/*
The order of RIGHT JOIN operands is reversed in 'join list' to
transform it into a LEFT JOIN. However, in this procedure we need
the join operands in their lexical order, so below we reverse the
join operands. Notice that this happens only in the first loop,
and not in the second one, as in the second loop
same_level_left_neighbor == NULL.
This is the correct behavior, because the second loop sets
cur_table_ref reference correctly after the join operands are
swapped in the first loop.
*/
if (same_level_left_neighbor &&
cur_table_ref->outer_join & JOIN_TYPE_RIGHT)
{
/* This can happen only for JOIN ... ON. */
DBUG_ASSERT(table_ref->nested_join->join_list.elements == 2);
swap_variables(TABLE_LIST*, same_level_left_neighbor, cur_table_ref);
}
/*
Pick the parent's left and right neighbors if there are no immediate
neighbors at the same level.
*/
real_left_neighbor= (same_level_left_neighbor) ?
same_level_left_neighbor : left_neighbor;
real_right_neighbor= (same_level_right_neighbor) ?
same_level_right_neighbor : right_neighbor;
if (cur_table_ref->nested_join &&
store_top_level_join_columns(thd, cur_table_ref,
real_left_neighbor, real_right_neighbor))
goto err;
same_level_right_neighbor= cur_table_ref;
}
}
/*
If this is a NATURAL/USING join, materialize its result columns and
convert to a JOIN ... ON.
*/
if (table_ref->is_natural_join)
{
DBUG_ASSERT(table_ref->nested_join &&
table_ref->nested_join->join_list.elements == 2);
List_iterator_fast<TABLE_LIST> operand_it(table_ref->nested_join->join_list);
/*
Notice that the order of join operands depends on whether table_ref
represents a LEFT or a RIGHT join. In a RIGHT join, the operands are
in inverted order.
*/
TABLE_LIST *table_ref_2= operand_it++; /* Second NATURAL join operand.*/
TABLE_LIST *table_ref_1= operand_it++; /* First NATURAL join operand. */
List<String> *using_fields= table_ref->join_using_fields;
uint found_using_fields;
/*
The two join operands were interchanged in the parser, change the order
back for 'mark_common_columns'.
*/
if (table_ref_2->outer_join & JOIN_TYPE_RIGHT)
swap_variables(TABLE_LIST*, table_ref_1, table_ref_2);
if (mark_common_columns(thd, table_ref_1, table_ref_2,
using_fields, &found_using_fields))
goto err;
/*
Swap the join operands back, so that we pick the columns of the second
one as the coalesced columns. In this way the coalesced columns are the
same as of an equivalent LEFT JOIN.
*/
if (table_ref_1->outer_join & JOIN_TYPE_RIGHT)
swap_variables(TABLE_LIST*, table_ref_1, table_ref_2);
if (store_natural_using_join_columns(thd, table_ref, table_ref_1,
table_ref_2, using_fields,
found_using_fields))
goto err;
/*
Change NATURAL JOIN to JOIN ... ON. We do this for both operands
because either one of them or the other is the one with the
natural join flag because RIGHT joins are transformed into LEFT,
and the two tables may be reordered.
*/
table_ref_1->natural_join= table_ref_2->natural_join= NULL;
/* Add a TRUE condition to outer joins that have no common columns. */
if (table_ref_2->outer_join &&
!table_ref_1->on_expr && !table_ref_2->on_expr)
table_ref_2->on_expr= new Item_int((longlong) 1,1); /* Always true. */
/* Change this table reference to become a leaf for name resolution. */
if (left_neighbor)
{
TABLE_LIST *last_leaf_on_the_left;
last_leaf_on_the_left= left_neighbor->last_leaf_for_name_resolution();
last_leaf_on_the_left->next_name_resolution_table= table_ref;
}
if (right_neighbor)
{
TABLE_LIST *first_leaf_on_the_right;
first_leaf_on_the_right= right_neighbor->first_leaf_for_name_resolution();
table_ref->next_name_resolution_table= first_leaf_on_the_right;
}
else
table_ref->next_name_resolution_table= NULL;
}
result= FALSE; /* All is OK. */
err:
if (arena)
thd->restore_active_arena(arena, &backup);
DBUG_RETURN(result);
}
/*
Compute and store the row types of the top-most NATURAL/USING joins
in a FROM clause.
SYNOPSIS
setup_natural_join_row_types()
thd current thread
from_clause list of top-level table references in a FROM clause
DESCRIPTION
Apply the procedure 'store_top_level_join_columns' to each of the
top-level table referencs of the FROM clause. Adjust the list of tables
for name resolution - context->first_name_resolution_table to the
top-most, lef-most NATURAL/USING join.
IMPLEMENTATION
Notice that the table references in 'from_clause' are in reverse
order, thus when we iterate over it, we are moving from the right
to the left in the FROM clause.
RETURN
TRUE Error
FALSE OK
*/
static bool setup_natural_join_row_types(THD *thd,
List<TABLE_LIST> *from_clause,
Name_resolution_context *context)
{
thd->where= "from clause";
if (from_clause->elements == 0)
return FALSE; /* We come here in the case of UNIONs. */
List_iterator_fast<TABLE_LIST> table_ref_it(*from_clause);
TABLE_LIST *table_ref; /* Current table reference. */
/* Table reference to the left of the current. */
TABLE_LIST *left_neighbor;
/* Table reference to the right of the current. */
TABLE_LIST *right_neighbor= NULL;
/* Note that tables in the list are in reversed order */
for (left_neighbor= table_ref_it++; left_neighbor ; )
{
table_ref= left_neighbor;
left_neighbor= table_ref_it++;
/* For stored procedures do not redo work if already done. */
if (context->select_lex->first_execution)
{
if (store_top_level_join_columns(thd, table_ref,
left_neighbor, right_neighbor))
return TRUE;
if (left_neighbor)
{
TABLE_LIST *first_leaf_on_the_right;
first_leaf_on_the_right= table_ref->first_leaf_for_name_resolution();
left_neighbor->next_name_resolution_table= first_leaf_on_the_right;
}
}
right_neighbor= table_ref;
}
/*
Store the top-most, left-most NATURAL/USING join, so that we start
the search from that one instead of context->table_list. At this point
right_neighbor points to the left-most top-level table reference in the
FROM clause.
*/
DBUG_ASSERT(right_neighbor);
context->first_name_resolution_table=
right_neighbor->first_leaf_for_name_resolution();
return FALSE;
}
/****************************************************************************
** Expand all '*' in given fields
****************************************************************************/
int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
List<Item> *sum_func_list,
uint wild_num)
{
if (!wild_num)
return(0);
Item *item;
List_iterator<Item> it(fields);
Query_arena *arena, backup;
DBUG_ENTER("setup_wild");
/*
Don't use arena if we are not in prepared statements or stored procedures
For PS/SP we have to use arena to remember the changes
*/
arena= thd->activate_stmt_arena_if_needed(&backup);
thd->lex->current_select->cur_pos_in_select_list= 0;
while (wild_num && (item= it++))
{
if (item->type() == Item::FIELD_ITEM &&
((Item_field*) item)->field_name &&
((Item_field*) item)->field_name[0] == '*' &&
!((Item_field*) item)->field)
{
uint elem= fields.elements;
bool any_privileges= ((Item_field *) item)->any_privileges;
Item_subselect *subsel= thd->lex->current_select->master_unit()->item;
if (subsel &&
subsel->substype() == Item_subselect::EXISTS_SUBS)
{
/*
It is EXISTS(SELECT * ...) and we can replace * by any constant.
Item_int do not need fix_fields() because it is basic constant.
*/
it.replace(new Item_int("Not_used", (longlong) 1,
MY_INT64_NUM_DECIMAL_DIGITS));
}
else if (insert_fields(thd, ((Item_field*) item)->context,
((Item_field*) item)->db_name,
((Item_field*) item)->table_name, &it,
any_privileges))
{
if (arena)
thd->restore_active_arena(arena, &backup);
DBUG_RETURN(-1);
}
if (sum_func_list)
{
/*
sum_func_list is a list that has the fields list as a tail.
Because of this we have to update the element count also for this
list after expanding the '*' entry.
*/
sum_func_list->elements+= fields.elements - elem;
}
wild_num--;
}
else
thd->lex->current_select->cur_pos_in_select_list++;
}
thd->lex->current_select->cur_pos_in_select_list= UNDEF_POS;
if (arena)
{
/* make * substituting permanent */
SELECT_LEX *select_lex= thd->lex->current_select;
select_lex->with_wild= 0;
select_lex->item_list= fields;
thd->restore_active_arena(arena, &backup);
}
DBUG_RETURN(0);
}
/****************************************************************************
** Check that all given fields exists and fill struct with current data
****************************************************************************/
bool setup_fields(THD *thd, Item **ref_pointer_array,
List<Item> &fields, enum_mark_columns mark_used_columns,
List<Item> *sum_func_list, bool allow_sum_func)
{
reg2 Item *item;
enum_mark_columns save_mark_used_columns= thd->mark_used_columns;
nesting_map save_allow_sum_func= thd->lex->allow_sum_func;
List_iterator<Item> it(fields);
bool save_is_item_list_lookup;
DBUG_ENTER("setup_fields");
thd->mark_used_columns= mark_used_columns;
DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
if (allow_sum_func)
thd->lex->allow_sum_func|= 1 << thd->lex->current_select->nest_level;
thd->where= THD::DEFAULT_WHERE;
save_is_item_list_lookup= thd->lex->current_select->is_item_list_lookup;
thd->lex->current_select->is_item_list_lookup= 0;
/*
To prevent fail on forward lookup we fill it with zerows,
then if we got pointer on zero after find_item_in_list we will know
that it is forward lookup.
There is other way to solve problem: fill array with pointers to list,
but it will be slower.
TODO: remove it when (if) we made one list for allfields and
ref_pointer_array
*/
if (ref_pointer_array)
bzero(ref_pointer_array, sizeof(Item *) * fields.elements);
Item **ref= ref_pointer_array;
thd->lex->current_select->cur_pos_in_select_list= 0;
while ((item= it++))
{
if (!item->fixed && item->fix_fields(thd, it.ref()) ||
(item= *(it.ref()))->check_cols(1))
{
thd->lex->current_select->is_item_list_lookup= save_is_item_list_lookup;
thd->lex->allow_sum_func= save_allow_sum_func;
thd->mark_used_columns= save_mark_used_columns;
DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
DBUG_RETURN(TRUE); /* purecov: inspected */
}
if (ref)
*(ref++)= item;
if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM &&
sum_func_list)
item->split_sum_func(thd, ref_pointer_array, *sum_func_list);
thd->used_tables|= item->used_tables();
thd->lex->current_select->cur_pos_in_select_list++;
}
thd->lex->current_select->is_item_list_lookup= save_is_item_list_lookup;
thd->lex->current_select->cur_pos_in_select_list= UNDEF_POS;
thd->lex->allow_sum_func= save_allow_sum_func;
thd->mark_used_columns= save_mark_used_columns;
DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
DBUG_RETURN(test(thd->net.report_error));
}
/*
make list of leaves of join table tree
SYNOPSIS
make_leaves_list()
list pointer to pointer on list first element
tables table list
RETURN pointer on pointer to next_leaf of last element
*/
TABLE_LIST **make_leaves_list(TABLE_LIST **list, TABLE_LIST *tables)
{
for (TABLE_LIST *table= tables; table; table= table->next_local)
{
if (table->merge_underlying_list)
{
DBUG_ASSERT(table->view &&
table->effective_algorithm == VIEW_ALGORITHM_MERGE);
list= make_leaves_list(list, table->merge_underlying_list);
}
else
{
*list= table;
list= &table->next_leaf;
}
}
return list;
}
/*
prepare tables
SYNOPSIS
setup_tables()
thd Thread handler
context name resolution contest to setup table list there
from_clause Top-level list of table references in the FROM clause
tables Table list (select_lex->table_list)
leaves List of join table leaves list (select_lex->leaf_tables)
refresh It is onle refresh for subquery
select_insert It is SELECT ... INSERT command
NOTE
Check also that the 'used keys' and 'ignored keys' exists and set up the
table structure accordingly.
Create a list of leaf tables. For queries with NATURAL/USING JOINs,
compute the row types of the top most natural/using join table references
and link these into a list of table references for name resolution.
This has to be called for all tables that are used by items, as otherwise
table->map is not set and all Item_field will be regarded as const items.
RETURN
FALSE ok; In this case *map will includes the chosen index
TRUE error
*/
bool setup_tables(THD *thd, Name_resolution_context *context,
List<TABLE_LIST> *from_clause, TABLE_LIST *tables,
TABLE_LIST **leaves, bool select_insert)
{
uint tablenr= 0;
DBUG_ENTER("setup_tables");
DBUG_ASSERT ((select_insert && !tables->next_name_resolution_table) || !tables ||
(context->table_list && context->first_name_resolution_table));
/*
this is used for INSERT ... SELECT.
For select we setup tables except first (and its underlying tables)
*/
TABLE_LIST *first_select_table= (select_insert ?
tables->next_local:
0);
if (!(*leaves))
make_leaves_list(leaves, tables);
TABLE_LIST *table_list;
for (table_list= *leaves;
table_list;
table_list= table_list->next_leaf, tablenr++)
{
TABLE *table= table_list->table;
table->pos_in_table_list= table_list;
if (first_select_table &&
table_list->top_table() == first_select_table)
{
/* new counting for SELECT of INSERT ... SELECT command */
first_select_table= 0;
tablenr= 0;
}
setup_table_map(table, table_list, tablenr);
if (table_list->process_index_hints(table))
DBUG_RETURN(1);
}
if (tablenr > MAX_TABLES)
{
my_error(ER_TOO_MANY_TABLES,MYF(0),MAX_TABLES);
DBUG_RETURN(1);
}
for (table_list= tables;
table_list;
table_list= table_list->next_local)
{
if (table_list->merge_underlying_list)
{
DBUG_ASSERT(table_list->view &&
table_list->effective_algorithm == VIEW_ALGORITHM_MERGE);
Query_arena *arena= thd->stmt_arena, backup;
bool res;
if (arena->is_conventional())
arena= 0; // For easier test
else
thd->set_n_backup_active_arena(arena, &backup);
res= table_list->setup_underlying(thd);
if (arena)
thd->restore_active_arena(arena, &backup);
if (res)
DBUG_RETURN(1);
}
}
/* Precompute and store the row types of NATURAL/USING joins. */
if (setup_natural_join_row_types(thd, from_clause, context))
DBUG_RETURN(1);
DBUG_RETURN(0);
}
/*
prepare tables and check access for the view tables
SYNOPSIS
setup_tables_and_check_view_access()
thd Thread handler
context name resolution contest to setup table list there
from_clause Top-level list of table references in the FROM clause
tables Table list (select_lex->table_list)
conds Condition of current SELECT (can be changed by VIEW)
leaves List of join table leaves list (select_lex->leaf_tables)
refresh It is onle refresh for subquery
select_insert It is SELECT ... INSERT command
want_access what access is needed
NOTE
a wrapper for check_tables that will also check the resulting
table leaves list for access to all the tables that belong to a view
RETURN
FALSE ok; In this case *map will include the chosen index
TRUE error
*/
bool setup_tables_and_check_access(THD *thd,
Name_resolution_context *context,
List<TABLE_LIST> *from_clause,
TABLE_LIST *tables,
TABLE_LIST **leaves,
bool select_insert,
ulong want_access_first,
ulong want_access)
{
TABLE_LIST *leaves_tmp= NULL;
bool first_table= true;
if (setup_tables(thd, context, from_clause, tables,
&leaves_tmp, select_insert))
return TRUE;
if (leaves)
*leaves= leaves_tmp;
for (; leaves_tmp; leaves_tmp= leaves_tmp->next_leaf)
{
if (leaves_tmp->belong_to_view &&
check_single_table_access(thd, first_table ? want_access_first :
want_access, leaves_tmp, FALSE))
{
tables->hide_view_error(thd);
return TRUE;
}
first_table= 0;
}
return FALSE;
}
/*
Create a key_map from a list of index names
SYNOPSIS
get_key_map_from_key_list()
map key_map to fill in
table Table
index_list List of index names
RETURN
0 ok; In this case *map will includes the choosed index
1 error
*/
bool get_key_map_from_key_list(key_map *map, TABLE *table,
List<String> *index_list)
{
List_iterator_fast<String> it(*index_list);
String *name;
uint pos;
map->clear_all();
while ((name=it++))
{
if (table->s->keynames.type_names == 0 ||
(pos= find_type(&table->s->keynames, name->ptr(),
name->length(), 1)) <=
0)
{
my_error(ER_KEY_DOES_NOT_EXITS, MYF(0), name->c_ptr(),
table->pos_in_table_list->alias);
map->set_all();
return 1;
}
map->set_bit(pos-1);
}
return 0;
}
/*
Drops in all fields instead of current '*' field
SYNOPSIS
insert_fields()
thd Thread handler
context Context for name resolution
db_name Database name in case of 'database_name.table_name.*'
table_name Table name in case of 'table_name.*'
it Pointer to '*'
any_privileges 0 If we should ensure that we have SELECT privileges
for all columns
1 If any privilege is ok
RETURN
0 ok 'it' is updated to point at last inserted
1 error. Error message is generated but not sent to client
*/
bool
insert_fields(THD *thd, Name_resolution_context *context, const char *db_name,
const char *table_name, List_iterator<Item> *it,
bool any_privileges)
{
Field_iterator_table_ref field_iterator;
bool found;
char name_buff[NAME_LEN+1];
DBUG_ENTER("insert_fields");
DBUG_PRINT("arena", ("stmt arena: 0x%lx", (ulong)thd->stmt_arena));
if (db_name && lower_case_table_names)
{
/*
convert database to lower case for comparison
We can't do this in Item_field as this would change the
'name' of the item which may be used in the select list
*/
strmake(name_buff, db_name, sizeof(name_buff)-1);
my_casedn_str(files_charset_info, name_buff);
db_name= name_buff;
}
found= FALSE;
/*
If table names are qualified, then loop over all tables used in the query,
else treat natural joins as leaves and do not iterate over their underlying
tables.
*/
for (TABLE_LIST *tables= (table_name ? context->table_list :
context->first_name_resolution_table);
tables;
tables= (table_name ? tables->next_local :
tables->next_name_resolution_table)
)
{
Field *field;
TABLE *table= tables->table;
DBUG_ASSERT(tables->is_leaf_for_name_resolution());
if (table_name && my_strcasecmp(table_alias_charset, table_name,
tables->alias) ||
(db_name && strcmp(tables->db,db_name)))
continue;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/* Ensure that we have access rights to all fields to be inserted. */
if (!((table && (table->grant.privilege & SELECT_ACL) ||
tables->view && (tables->grant.privilege & SELECT_ACL))) &&
!any_privileges)
{
field_iterator.set(tables);
if (check_grant_all_columns(thd, SELECT_ACL, field_iterator.grant(),
field_iterator.db_name(),
field_iterator.table_name(),
&field_iterator))
DBUG_RETURN(TRUE);
}
#endif
/*
Update the tables used in the query based on the referenced fields. For
views and natural joins this update is performed inside the loop below.
*/
if (table)
thd->used_tables|= table->map;
/*
Initialize a generic field iterator for the current table reference.
Notice that it is guaranteed that this iterator will iterate over the
fields of a single table reference, because 'tables' is a leaf (for
name resolution purposes).
*/
field_iterator.set(tables);
for (; !field_iterator.end_of_fields(); field_iterator.next())
{
Item *item;
if (!(item= field_iterator.create_item(thd)))
DBUG_RETURN(TRUE);
if (!found)
{
found= TRUE;
it->replace(item); /* Replace '*' with the first found item. */
}
else
it->after(item); /* Add 'item' to the SELECT list. */
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/*
Set privilege information for the fields of newly created views.
We have that (any_priviliges == TRUE) if and only if we are creating
a view. In the time of view creation we can't use the MERGE algorithm,
therefore if 'tables' is itself a view, it is represented by a
temporary table. Thus in this case we can be sure that 'item' is an
Item_field.
*/
if (any_privileges)
{
DBUG_ASSERT(tables->field_translation == NULL && table ||
tables->is_natural_join);
DBUG_ASSERT(item->type() == Item::FIELD_ITEM);
Item_field *fld= (Item_field*) item;
const char *field_table_name= field_iterator.table_name();
if (!tables->schema_table &&
!(fld->have_privileges=
(get_column_grant(thd, field_iterator.grant(),
field_iterator.db_name(),
field_table_name, fld->field_name) &
VIEW_ANY_ACL)))
{
my_error(ER_COLUMNACCESS_DENIED_ERROR, MYF(0), "ANY",
thd->security_ctx->priv_user,
thd->security_ctx->host_or_ip,
fld->field_name, field_table_name);
DBUG_RETURN(TRUE);
}
}
#endif
if ((field= field_iterator.field()))
{
/* Mark fields as used to allow storage engine to optimze access */
bitmap_set_bit(field->table->read_set, field->field_index);
if (table)
{
table->covering_keys.intersect(field->part_of_key);
table->merge_keys.merge(field->part_of_key);
}
if (tables->is_natural_join)
{
TABLE *field_table;
/*
In this case we are sure that the column ref will not be created
because it was already created and stored with the natural join.
*/
Natural_join_column *nj_col;
if (!(nj_col= field_iterator.get_natural_column_ref()))
DBUG_RETURN(TRUE);
DBUG_ASSERT(nj_col->table_field);
field_table= nj_col->table_ref->table;
if (field_table)
{
thd->used_tables|= field_table->map;
field_table->covering_keys.intersect(field->part_of_key);
field_table->merge_keys.merge(field->part_of_key);
field_table->used_fields++;
}
}
}
else
thd->used_tables|= item->used_tables();
thd->lex->current_select->cur_pos_in_select_list++;
}
/*
In case of stored tables, all fields are considered as used,
while in the case of views, the fields considered as used are the
ones marked in setup_tables during fix_fields of view columns.
For NATURAL joins, used_tables is updated in the IF above.
*/
if (table)
table->used_fields= table->s->fields;
}
if (found)
DBUG_RETURN(FALSE);
/*
TODO: in the case when we skipped all columns because there was a
qualified '*', and all columns were coalesced, we have to give a more
meaningful message than ER_BAD_TABLE_ERROR.
*/
if (!table_name)
my_message(ER_NO_TABLES_USED, ER(ER_NO_TABLES_USED), MYF(0));
else
my_error(ER_BAD_TABLE_ERROR, MYF(0), table_name);
DBUG_RETURN(TRUE);
}
/*
Fix all conditions and outer join expressions.
SYNOPSIS
setup_conds()
thd thread handler
tables list of tables for name resolving (select_lex->table_list)
leaves list of leaves of join table tree (select_lex->leaf_tables)
conds WHERE clause
DESCRIPTION
TODO
RETURN
TRUE if some error occured (e.g. out of memory)
FALSE if all is OK
*/
int setup_conds(THD *thd, TABLE_LIST *tables, TABLE_LIST *leaves,
COND **conds)
{
SELECT_LEX *select_lex= thd->lex->current_select;
Query_arena *arena= thd->stmt_arena, backup;
TABLE_LIST *table= NULL; // For HP compilers
/*
it_is_update set to TRUE when tables of primary SELECT_LEX (SELECT_LEX
which belong to LEX, i.e. most up SELECT) will be updated by
INSERT/UPDATE/LOAD
NOTE: using this condition helps to prevent call of prepare_check_option()
from subquery of VIEW, because tables of subquery belongs to VIEW
(see condition before prepare_check_option() call)
*/
bool it_is_update= (select_lex == &thd->lex->select_lex) &&
thd->lex->which_check_option_applicable();
bool save_is_item_list_lookup= select_lex->is_item_list_lookup;
select_lex->is_item_list_lookup= 0;
DBUG_ENTER("setup_conds");
if (select_lex->conds_processed_with_permanent_arena ||
arena->is_conventional())
arena= 0; // For easier test
thd->mark_used_columns= MARK_COLUMNS_READ;
DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
select_lex->cond_count= 0;
select_lex->between_count= 0;
select_lex->max_equal_elems= 0;
for (table= tables; table; table= table->next_local)
{
if (table->prepare_where(thd, conds, FALSE))
goto err_no_arena;
}
if (*conds)
{
thd->where="where clause";
if (!(*conds)->fixed && (*conds)->fix_fields(thd, conds) ||
(*conds)->check_cols(1))
goto err_no_arena;
}
/*
Apply fix_fields() to all ON clauses at all levels of nesting,
including the ones inside view definitions.
*/
for (table= leaves; table; table= table->next_leaf)
{
TABLE_LIST *embedded; /* The table at the current level of nesting. */
TABLE_LIST *embedding= table; /* The parent nested table reference. */
do
{
embedded= embedding;
if (embedded->on_expr)
{
/* Make a join an a expression */
thd->where="on clause";
if (!embedded->on_expr->fixed &&
embedded->on_expr->fix_fields(thd, &embedded->on_expr) ||
embedded->on_expr->check_cols(1))
goto err_no_arena;
select_lex->cond_count++;
}
embedding= embedded->embedding;
}
while (embedding &&
embedding->nested_join->join_list.head() == embedded);
/* process CHECK OPTION */
if (it_is_update)
{
TABLE_LIST *view= table->top_table();
if (view->effective_with_check)
{
if (view->prepare_check_option(thd))
goto err_no_arena;
thd->change_item_tree(&table->check_option, view->check_option);
}
}
}
if (!thd->stmt_arena->is_conventional())
{
/*
We are in prepared statement preparation code => we should store
WHERE clause changing for next executions.
We do this ON -> WHERE transformation only once per PS/SP statement.
*/
select_lex->where= *conds;
select_lex->conds_processed_with_permanent_arena= 1;
}
thd->lex->current_select->is_item_list_lookup= save_is_item_list_lookup;
DBUG_RETURN(test(thd->net.report_error));
err_no_arena:
select_lex->is_item_list_lookup= save_is_item_list_lookup;
DBUG_RETURN(1);
}
/******************************************************************************
** Fill a record with data (for INSERT or UPDATE)
** Returns : 1 if some field has wrong type
******************************************************************************/
/*
Fill fields with given items.
SYNOPSIS
fill_record()
thd thread handler
fields Item_fields list to be filled
values values to fill with
ignore_errors TRUE if we should ignore errors
NOTE
fill_record() may set table->auto_increment_field_not_null and a
caller should make sure that it is reset after their last call to this
function.
RETURN
FALSE OK
TRUE error occured
*/
static bool
fill_record(THD * thd, List<Item> &fields, List<Item> &values,
bool ignore_errors)
{
List_iterator_fast<Item> f(fields),v(values);
Item *value, *fld;
Item_field *field;
TABLE *table= 0;
DBUG_ENTER("fill_record");
/*
Reset the table->auto_increment_field_not_null as it is valid for
only one row.
*/
if (fields.elements)
{
/*
On INSERT or UPDATE fields are checked to be from the same table,
thus we safely can take table from the first field.
*/
fld= (Item_field*)f++;
if (!(field= fld->filed_for_view_update()))
{
my_error(ER_NONUPDATEABLE_COLUMN, MYF(0), fld->name);
goto err;
}
table= field->field->table;
table->auto_increment_field_not_null= FALSE;
f.rewind();
}
while ((fld= f++))
{
if (!(field= fld->filed_for_view_update()))
{
my_error(ER_NONUPDATEABLE_COLUMN, MYF(0), fld->name);
goto err;
}
value=v++;
Field *rfield= field->field;
table= rfield->table;
if (rfield == table->next_number_field)
table->auto_increment_field_not_null= TRUE;
if ((value->save_in_field(rfield, 0) < 0) && !ignore_errors)
{
my_message(ER_UNKNOWN_ERROR, ER(ER_UNKNOWN_ERROR), MYF(0));
goto err;
}
}
DBUG_RETURN(thd->net.report_error);
err:
if (table)
table->auto_increment_field_not_null= FALSE;
DBUG_RETURN(TRUE);
}
/*
Fill fields in list with values from the list of items and invoke
before triggers.
SYNOPSIS
fill_record_n_invoke_before_triggers()
thd thread context
fields Item_fields list to be filled
values values to fill with
ignore_errors TRUE if we should ignore errors
triggers object holding list of triggers to be invoked
event event type for triggers to be invoked
NOTE
This function assumes that fields which values will be set and triggers
to be invoked belong to the same table, and that TABLE::record[0] and
record[1] buffers correspond to new and old versions of row respectively.
RETURN
FALSE OK
TRUE error occured
*/
bool
fill_record_n_invoke_before_triggers(THD *thd, List<Item> &fields,
List<Item> &values, bool ignore_errors,
Table_triggers_list *triggers,
enum trg_event_type event)
{
return (fill_record(thd, fields, values, ignore_errors) ||
triggers && triggers->process_triggers(thd, event,
TRG_ACTION_BEFORE, TRUE));
}
/*
Fill field buffer with values from Field list
SYNOPSIS
fill_record()
thd thread handler
ptr pointer on pointer to record
values list of fields
ignore_errors TRUE if we should ignore errors
NOTE
fill_record() may set table->auto_increment_field_not_null and a
caller should make sure that it is reset after their last call to this
function.
RETURN
FALSE OK
TRUE error occured
*/
bool
fill_record(THD *thd, Field **ptr, List<Item> &values, bool ignore_errors)
{
List_iterator_fast<Item> v(values);
Item *value;
TABLE *table= 0;
DBUG_ENTER("fill_record");
Field *field;
/*
Reset the table->auto_increment_field_not_null as it is valid for
only one row.
*/
if (*ptr)
{
/*
On INSERT or UPDATE fields are checked to be from the same table,
thus we safely can take table from the first field.
*/
table= (*ptr)->table;
table->auto_increment_field_not_null= FALSE;
}
while ((field = *ptr++) && !thd->net.report_error)
{
value=v++;
table= field->table;
if (field == table->next_number_field)
table->auto_increment_field_not_null= TRUE;
if (value->save_in_field(field, 0) < 0)
goto err;
}
DBUG_RETURN(thd->net.report_error);
err:
if (table)
table->auto_increment_field_not_null= FALSE;
DBUG_RETURN(TRUE);
}
/*
Fill fields in array with values from the list of items and invoke
before triggers.
SYNOPSIS
fill_record_n_invoke_before_triggers()
thd thread context
ptr NULL-ended array of fields to be filled
values values to fill with
ignore_errors TRUE if we should ignore errors
triggers object holding list of triggers to be invoked
event event type for triggers to be invoked
NOTE
This function assumes that fields which values will be set and triggers
to be invoked belong to the same table, and that TABLE::record[0] and
record[1] buffers correspond to new and old versions of row respectively.
RETURN
FALSE OK
TRUE error occured
*/
bool
fill_record_n_invoke_before_triggers(THD *thd, Field **ptr,
List<Item> &values, bool ignore_errors,
Table_triggers_list *triggers,
enum trg_event_type event)
{
return (fill_record(thd, ptr, values, ignore_errors) ||
triggers && triggers->process_triggers(thd, event,
TRG_ACTION_BEFORE, TRUE));
}
my_bool mysql_rm_tmp_tables(void)
{
uint i, idx;
char filePath[FN_REFLEN], *tmpdir, filePathCopy[FN_REFLEN];
MY_DIR *dirp;
FILEINFO *file;
TABLE_SHARE share;
THD *thd;
DBUG_ENTER("mysql_rm_tmp_tables");
if (!(thd= new THD))
DBUG_RETURN(1);
thd->thread_stack= (char*) &thd;
thd->store_globals();
for (i=0; i<=mysql_tmpdir_list.max; i++)
{
tmpdir=mysql_tmpdir_list.list[i];
/* See if the directory exists */
if (!(dirp = my_dir(tmpdir,MYF(MY_WME | MY_DONT_SORT))))
continue;
/* Remove all SQLxxx tables from directory */
for (idx=0 ; idx < (uint) dirp->number_off_files ; idx++)
{
file=dirp->dir_entry+idx;
/* skiping . and .. */
if (file->name[0] == '.' && (!file->name[1] ||
(file->name[1] == '.' && !file->name[2])))
continue;
if (!bcmp((uchar*) file->name, (uchar*) tmp_file_prefix,
tmp_file_prefix_length))
{
char *ext= fn_ext(file->name);
uint ext_len= strlen(ext);
uint filePath_len= my_snprintf(filePath, sizeof(filePath),
"%s%c%s", tmpdir, FN_LIBCHAR,
file->name);
if (!bcmp((uchar*) reg_ext, (uchar*) ext, ext_len))
{
handler *handler_file= 0;
/* We should cut file extention before deleting of table */
memcpy(filePathCopy, filePath, filePath_len - ext_len);
filePathCopy[filePath_len - ext_len]= 0;
init_tmp_table_share(&share, "", 0, "", filePathCopy);
if (!open_table_def(thd, &share, 0) &&
((handler_file= get_new_handler(&share, thd->mem_root,
share.db_type()))))
{
handler_file->delete_table(filePathCopy);
delete handler_file;
}
free_table_share(&share);
}
/*
File can be already deleted by tmp_table.file->delete_table().
So we hide error messages which happnes during deleting of these
files(MYF(0)).
*/
VOID(my_delete(filePath, MYF(0)));
}
}
my_dirend(dirp);
}
delete thd;
my_pthread_setspecific_ptr(THR_THD, 0);
DBUG_RETURN(0);
}
/*****************************************************************************
unireg support functions
*****************************************************************************/
/*
Invalidate any cache entries that are for some DB
SYNOPSIS
remove_db_from_cache()
db Database name. This will be in lower case if
lower_case_table_name is set
NOTE:
We can't use hash_delete when looping hash_elements. We mark them first
and afterwards delete those marked unused.
*/
void remove_db_from_cache(const char *db)
{
for (uint idx=0 ; idx < open_cache.records ; idx++)
{
TABLE *table=(TABLE*) hash_element(&open_cache,idx);
if (!strcmp(table->s->db.str, db))
{
table->s->version= 0L; /* Free when thread is ready */
if (!table->in_use)
relink_unused(table);
}
}
while (unused_tables && !unused_tables->s->version)
VOID(hash_delete(&open_cache,(uchar*) unused_tables));
}
/*
free all unused tables
NOTE
This is called by 'handle_manager' when one wants to periodicly flush
all not used tables.
*/
void flush_tables()
{
(void) pthread_mutex_lock(&LOCK_open);
while (unused_tables)
hash_delete(&open_cache,(uchar*) unused_tables);
(void) pthread_mutex_unlock(&LOCK_open);
}
/*
Mark all entries with the table as deleted to force an reopen of the table
The table will be closed (not stored in cache) by the current thread when
close_thread_tables() is called.
PREREQUISITES
Lock on LOCK_open()
RETURN
0 This thread now have exclusive access to this table and no other thread
can access the table until close_thread_tables() is called.
1 Table is in use by another thread
*/
bool remove_table_from_cache(THD *thd, const char *db, const char *table_name,
uint flags)
{
char key[MAX_DBKEY_LENGTH];
uint key_length;
TABLE *table;
TABLE_SHARE *share;
bool result= 0, signalled= 0;
DBUG_ENTER("remove_table_from_cache");
DBUG_PRINT("enter", ("Table: '%s.%s' flags: %u", db, table_name, flags));
key_length=(uint) (strmov(strmov(key,db)+1,table_name)-key)+1;
for (;;)
{
HASH_SEARCH_STATE state;
result= signalled= 0;
for (table= (TABLE*) hash_first(&open_cache, (uchar*) key, key_length,
&state);
table;
table= (TABLE*) hash_next(&open_cache, (uchar*) key, key_length,
&state))
{
THD *in_use;
table->s->version=0L; /* Free when thread is ready */
if (!(in_use=table->in_use))
{
DBUG_PRINT("info",("Table was not in use"));
relink_unused(table);
}
else if (in_use != thd)
{
DBUG_PRINT("info", ("Table was in use by other thread"));
/*
Mark that table is going to be deleted from cache. This will
force threads that are in mysql_lock_tables() (but not yet
in thr_multi_lock()) to abort it's locks, close all tables and retry
*/
in_use->some_tables_deleted= 1;
if (table->is_name_opened())
{
DBUG_PRINT("info", ("Found another active instance of the table"));
result=1;
}
/* Kill delayed insert threads */
if ((in_use->system_thread & SYSTEM_THREAD_DELAYED_INSERT) &&
! in_use->killed)
{
in_use->killed= THD::KILL_CONNECTION;
pthread_mutex_lock(&in_use->mysys_var->mutex);
if (in_use->mysys_var->current_cond)
{
pthread_mutex_lock(in_use->mysys_var->current_mutex);
signalled= 1;
pthread_cond_broadcast(in_use->mysys_var->current_cond);
pthread_mutex_unlock(in_use->mysys_var->current_mutex);
}
pthread_mutex_unlock(&in_use->mysys_var->mutex);
}
/*
Now we must abort all tables locks used by this thread
as the thread may be waiting to get a lock for another table
*/
for (TABLE *thd_table= in_use->open_tables;
thd_table ;
thd_table= thd_table->next)
{
if (thd_table->db_stat) // If table is open
signalled|= mysql_lock_abort_for_thread(thd, thd_table);
}
}
else
{
DBUG_PRINT("info", ("Table was in use by current thread. db_stat: %u",
table->db_stat));
result= result || (flags & RTFC_OWNED_BY_THD_FLAG);
}
}
while (unused_tables && !unused_tables->s->version)
VOID(hash_delete(&open_cache,(uchar*) unused_tables));
DBUG_PRINT("info", ("Removing table from table_def_cache"));
/* Remove table from table definition cache if it's not in use */
if ((share= (TABLE_SHARE*) hash_search(&table_def_cache,(uchar*) key,
key_length)))
{
DBUG_PRINT("info", ("share version: %lu ref_count: %u",
share->version, share->ref_count));
share->version= 0; // Mark for delete
if (share->ref_count == 0)
{
pthread_mutex_lock(&share->mutex);
VOID(hash_delete(&table_def_cache, (uchar*) share));
}
}
if (result && (flags & RTFC_WAIT_OTHER_THREAD_FLAG))
{
/*
Signal any thread waiting for tables to be freed to
reopen their tables
*/
broadcast_refresh();
DBUG_PRINT("info", ("Waiting for refresh signal"));
if (!(flags & RTFC_CHECK_KILLED_FLAG) || !thd->killed)
{
dropping_tables++;
if (likely(signalled))
(void) pthread_cond_wait(&COND_refresh, &LOCK_open);
else
{
struct timespec abstime;
/*
It can happen that another thread has opened the
table but has not yet locked any table at all. Since
it can be locked waiting for a table that our thread
has done LOCK TABLE x WRITE on previously, we need to
ensure that the thread actually hears our signal
before we go to sleep. Thus we wait for a short time
and then we retry another loop in the
remove_table_from_cache routine.
*/
set_timespec(abstime, 10);
pthread_cond_timedwait(&COND_refresh, &LOCK_open, &abstime);
}
dropping_tables--;
continue;
}
}
break;
}
DBUG_RETURN(result);
}
int setup_ftfuncs(SELECT_LEX *select_lex)
{
List_iterator<Item_func_match> li(*(select_lex->ftfunc_list)),
lj(*(select_lex->ftfunc_list));
Item_func_match *ftf, *ftf2;
while ((ftf=li++))
{
if (ftf->fix_index())
return 1;
lj.rewind();
while ((ftf2=lj++) != ftf)
{
if (ftf->eq(ftf2,1) && !ftf2->master)
ftf2->master=ftf;
}
}
return 0;
}
int init_ftfuncs(THD *thd, SELECT_LEX *select_lex, bool no_order)
{
if (select_lex->ftfunc_list->elements)
{
List_iterator<Item_func_match> li(*(select_lex->ftfunc_list));
Item_func_match *ifm;
DBUG_PRINT("info",("Performing FULLTEXT search"));
thd->proc_info="FULLTEXT initialization";
while ((ifm=li++))
ifm->init_search(no_order);
}
return 0;
}
/*
open new .frm format table
SYNOPSIS
open_new_frm()
THD thread handler
path path to .frm file (without extension)
alias alias for table
db database
table_name name of table
db_stat open flags (for example ->OPEN_KEYFILE|HA_OPEN_RNDFILE..)
can be 0 (example in ha_example_table)
prgflag READ_ALL etc..
ha_open_flags HA_OPEN_ABORT_IF_LOCKED etc..
outparam result table
table_desc TABLE_LIST descriptor
mem_root temporary MEM_ROOT for parsing
*/
static bool
open_new_frm(THD *thd, TABLE_SHARE *share, const char *alias,
uint db_stat, uint prgflag,
uint ha_open_flags, TABLE *outparam, TABLE_LIST *table_desc,
MEM_ROOT *mem_root)
{
LEX_STRING pathstr;
File_parser *parser;
char path[FN_REFLEN];
DBUG_ENTER("open_new_frm");
/* Create path with extension */
pathstr.length= (uint) (strxmov(path, share->normalized_path.str, reg_ext,
NullS)- path);
pathstr.str= path;
if ((parser= sql_parse_prepare(&pathstr, mem_root, 1)))
{
if (is_equal(&view_type, parser->type()))
{
if (table_desc == 0 || table_desc->required_type == FRMTYPE_TABLE)
{
my_error(ER_WRONG_OBJECT, MYF(0), share->db.str, share->table_name.str,
"BASE TABLE");
goto err;
}
if (mysql_make_view(thd, parser, table_desc,
(prgflag & OPEN_VIEW_NO_PARSE)))
goto err;
}
else
{
/* only VIEWs are supported now */
my_error(ER_FRM_UNKNOWN_TYPE, MYF(0), share->path, parser->type()->str);
goto err;
}
DBUG_RETURN(0);
}
err:
bzero(outparam, sizeof(TABLE)); // do not run repair
DBUG_RETURN(1);
}
bool is_equal(const LEX_STRING *a, const LEX_STRING *b)
{
return a->length == b->length && !strncmp(a->str, b->str, a->length);
}
/*
SYNOPSIS
abort_and_upgrade_lock()
lpt Parameter passing struct
All parameters passed through the ALTER_PARTITION_PARAM_TYPE object
RETURN VALUE
0
DESCRIPTION
Remember old lock level (for possible downgrade later on), abort all
waiting threads and ensure that all keeping locks currently are
completed such that we own the lock exclusively and no other interaction
is ongoing.
thd Thread object
table Table object
db Database name
table_name Table name
old_lock_level Old lock level
*/
int abort_and_upgrade_lock(ALTER_PARTITION_PARAM_TYPE *lpt)
{
uint flags= RTFC_WAIT_OTHER_THREAD_FLAG | RTFC_CHECK_KILLED_FLAG;
DBUG_ENTER("abort_and_upgrade_locks");
lpt->old_lock_type= lpt->table->reginfo.lock_type;
VOID(pthread_mutex_lock(&LOCK_open));
mysql_lock_abort(lpt->thd, lpt->table, TRUE);
VOID(remove_table_from_cache(lpt->thd, lpt->db, lpt->table_name, flags));
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(0);
}
/*
SYNOPSIS
close_open_tables_and_downgrade()
RESULT VALUES
NONE
DESCRIPTION
We need to ensure that any thread that has managed to open the table
but not yet encountered our lock on the table is also thrown out to
ensure that no threads see our frm changes premature to the final
version. The intermediate versions are only meant for use after a
crash and later REPAIR TABLE.
We also downgrade locks after the upgrade to WRITE_ONLY
*/
void close_open_tables_and_downgrade(ALTER_PARTITION_PARAM_TYPE *lpt)
{
VOID(pthread_mutex_lock(&LOCK_open));
remove_table_from_cache(lpt->thd, lpt->db, lpt->table_name,
RTFC_WAIT_OTHER_THREAD_FLAG);
VOID(pthread_mutex_unlock(&LOCK_open));
mysql_lock_downgrade_write(lpt->thd, lpt->table, lpt->old_lock_type);
}
/*
SYNOPSIS
mysql_wait_completed_table()
lpt Parameter passing struct
my_table My table object
All parameters passed through the ALTER_PARTITION_PARAM object
RETURN VALUES
TRUE Failure
FALSE Success
DESCRIPTION
We have changed the frm file and now we want to wait for all users of
the old frm to complete before proceeding to ensure that no one
remains that uses the old frm definition.
Start by ensuring that all users of the table will be removed from cache
once they are done. Then abort all that have stumbled on locks and
haven't been started yet.
thd Thread object
table Table object
db Database name
table_name Table name
*/
void mysql_wait_completed_table(ALTER_PARTITION_PARAM_TYPE *lpt, TABLE *my_table)
{
char key[MAX_DBKEY_LENGTH];
uint key_length;
TABLE *table;
DBUG_ENTER("mysql_wait_completed_table");
key_length=(uint) (strmov(strmov(key,lpt->db)+1,lpt->table_name)-key)+1;
VOID(pthread_mutex_lock(&LOCK_open));
HASH_SEARCH_STATE state;
for (table= (TABLE*) hash_first(&open_cache,(uchar*) key,key_length,
&state) ;
table;
table= (TABLE*) hash_next(&open_cache,(uchar*) key,key_length,
&state))
{
THD *in_use= table->in_use;
table->s->version= 0L;
if (!in_use)
{
relink_unused(table);
}
else
{
/* Kill delayed insert threads */
if ((in_use->system_thread & SYSTEM_THREAD_DELAYED_INSERT) &&
! in_use->killed)
{
in_use->killed= THD::KILL_CONNECTION;
pthread_mutex_lock(&in_use->mysys_var->mutex);
if (in_use->mysys_var->current_cond)
{
pthread_mutex_lock(in_use->mysys_var->current_mutex);
pthread_cond_broadcast(in_use->mysys_var->current_cond);
pthread_mutex_unlock(in_use->mysys_var->current_mutex);
}
pthread_mutex_unlock(&in_use->mysys_var->mutex);
}
/*
Now we must abort all tables locks used by this thread
as the thread may be waiting to get a lock for another table
*/
for (TABLE *thd_table= in_use->open_tables;
thd_table ;
thd_table= thd_table->next)
{
if (thd_table->db_stat) // If table is open
mysql_lock_abort_for_thread(lpt->thd, thd_table);
}
}
}
/*
We start by removing all unused objects from the cache and marking
those in use for removal after completion. Now we also need to abort
all that are locked and are not progressing due to being locked
by our lock. We don't upgrade our lock here.
*/
mysql_lock_abort(lpt->thd, my_table, FALSE);
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_VOID_RETURN;
}
/*
Tells if two (or more) tables have auto_increment columns and we want to
lock those tables with a write lock.
SYNOPSIS
has_two_write_locked_tables_with_auto_increment
tables Table list
NOTES:
Call this function only when you have established the list of all tables
which you'll want to update (including stored functions, triggers, views
inside your statement).
RETURN
0 No
1 Yes
*/
static bool
has_two_write_locked_tables_with_auto_increment(TABLE_LIST *tables)
{
char *first_table_name= NULL, *first_db;
LINT_INIT(first_db);
for (TABLE_LIST *table= tables; table; table= table->next_global)
{
/* we must do preliminary checks as table->table may be NULL */
if (!table->placeholder() &&
table->table->found_next_number_field &&
(table->lock_type >= TL_WRITE_ALLOW_WRITE))
{
if (first_table_name == NULL)
{
first_table_name= table->table_name;
first_db= table->db;
DBUG_ASSERT(first_db);
}
else if (strcmp(first_db, table->db) ||
strcmp(first_table_name, table->table_name))
return 1;
}
}
return 0;
}
/*
Open and lock system tables for read.
SYNOPSIS
open_system_tables_for_read()
thd Thread context.
table_list List of tables to open.
backup Pointer to Open_tables_state instance where
information about currently open tables will be
saved, and from which will be restored when we will
end work with system tables.
NOTES
Thanks to restrictions which we put on opening and locking of
system tables for writing, we can open and lock them for reading
even when we already have some other tables open and locked. One
must call close_system_tables() to close systems tables opened
with this call.
RETURN
FALSE Success
TRUE Error
*/
bool
open_system_tables_for_read(THD *thd, TABLE_LIST *table_list,
Open_tables_state *backup)
{
DBUG_ENTER("open_system_tables_for_read");
thd->reset_n_backup_open_tables_state(backup);
uint count= 0;
bool not_used;
for (TABLE_LIST *tables= table_list; tables; tables= tables->next_global)
{
TABLE *table= open_table(thd, tables, thd->mem_root, &not_used,
MYSQL_LOCK_IGNORE_FLUSH);
if (!table)
goto error;
DBUG_ASSERT(table->s->table_category == TABLE_CATEGORY_SYSTEM);
table->use_all_columns();
table->reginfo.lock_type= tables->lock_type;
tables->table= table;
count++;
}
{
TABLE **list= (TABLE**) thd->alloc(sizeof(TABLE*) * count);
TABLE **ptr= list;
for (TABLE_LIST *tables= table_list; tables; tables= tables->next_global)
*(ptr++)= tables->table;
thd->lock= mysql_lock_tables(thd, list, count,
MYSQL_LOCK_IGNORE_FLUSH, &not_used);
}
if (thd->lock)
DBUG_RETURN(FALSE);
error:
close_system_tables(thd, backup);
DBUG_RETURN(TRUE);
}
/*
Close system tables, opened with open_system_tables_for_read().
SYNOPSIS
close_system_tables()
thd Thread context
backup Pointer to Open_tables_state instance which holds
information about tables which were open before we
decided to access system tables.
*/
void
close_system_tables(THD *thd, Open_tables_state *backup)
{
close_thread_tables(thd);
thd->restore_backup_open_tables_state(backup);
}
/*
Open and lock one system table for update.
SYNOPSIS
open_system_table_for_update()
thd Thread context.
one_table Table to open.
NOTES
Table opened with this call should closed using close_thread_tables().
RETURN
0 Error
# Pointer to TABLE object of system table
*/
TABLE *
open_system_table_for_update(THD *thd, TABLE_LIST *one_table)
{
DBUG_ENTER("open_system_table_for_update");
TABLE *table= open_ltable(thd, one_table, one_table->lock_type, 0);
if (table)
{
DBUG_ASSERT(table->s->table_category == TABLE_CATEGORY_SYSTEM);
table->use_all_columns();
}
DBUG_RETURN(table);
}
/**
Open a performance schema table.
Opening such tables is performed internally in the server
implementation, and is a 'nested' open, since some tables
might be already opened by the current thread.
The thread context before this call is saved, and is restored
when calling close_performance_schema_table().
@param thd The current thread
@param one_table Performance schema table to open
@param backup [out] Temporary storage used to save the thread context
*/
TABLE *
open_performance_schema_table(THD *thd, TABLE_LIST *one_table,
Open_tables_state *backup)
{
uint flags= ( MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK |
MYSQL_LOCK_IGNORE_GLOBAL_READ_ONLY |
MYSQL_LOCK_IGNORE_FLUSH |
MYSQL_LOCK_PERF_SCHEMA);
TABLE *table;
/* Save value that is changed in mysql_lock_tables() */
ulonglong save_utime_after_lock= thd->utime_after_lock;
DBUG_ENTER("open_performance_schema_table");
thd->reset_n_backup_open_tables_state(backup);
if ((table= open_ltable(thd, one_table, one_table->lock_type, flags)))
{
DBUG_ASSERT(table->s->table_category == TABLE_CATEGORY_PERFORMANCE);
/* Make sure all columns get assigned to a default value */
table->use_all_columns();
table->no_replicate= 1;
/*
Don't set automatic timestamps as we may want to use time of logging,
not from query start
*/
table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET;
}
else
{
/*
If error in mysql_lock_tables(), open_ltable doesn't close the
table. Thread kill during mysql_lock_tables() is such error. But
open tables cannot be accepted when restoring the open tables
state.
*/
if (thd->killed)
close_thread_tables(thd);
thd->restore_backup_open_tables_state(backup);
}
thd->utime_after_lock= save_utime_after_lock;
DBUG_RETURN(table);
}
/**
Close a performance schema table.
The last table opened by open_performance_schema_table()
is closed, then the thread context is restored.
@param thd The current thread
@param backup [in] the context to restore.
*/
void close_performance_schema_table(THD *thd, Open_tables_state *backup)
{
bool found_old_table;
/*
If open_performance_schema_table() fails,
this function should not be called.
*/
DBUG_ASSERT(thd->lock != NULL);
/*
Note:
We do not create explicitly a separate transaction for the
performance table I/O, but borrow the current transaction.
lock + unlock will autocommit the change done in the
performance schema table: this is the expected result.
The current transaction should not be affected by this code.
TODO: Note that if a transactional engine is used for log tables,
this code will need to be revised, as a separate transaction
might be needed.
*/
mysql_unlock_tables(thd, thd->lock);
thd->lock= 0;
pthread_mutex_lock(&LOCK_open);
found_old_table= false;
while (thd->open_tables)
found_old_table|= close_thread_table(thd, &thd->open_tables);
if (found_old_table)
broadcast_refresh();
pthread_mutex_unlock(&LOCK_open);
thd->restore_backup_open_tables_state(backup);
}
/**
@} (end of group Data_Dictionary)
*/
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