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mariadb/sql/sql_prepare.cc
unknown eaf34dd8e3 Port of cursors to be pushed into 5.0 tree: 
- client side part is simple and may be considered stable
- server side part now just joggles with THD state to save execution
  state and has no additional locking wisdom.
  Lot's of it are to be rewritten.


include/mysql.h:
  Cursor patch to push into the main tree, client library part (considered 
  stable):
  - new statement attribute STMT_ATTR_CURSOR_TYPE
  - MYSQL_STMT::flags to store statement cursor type
  - MYSQL_STMT::server_status to store server status (i. e. if the server
  was able to open a cursor for this query).
include/mysql_com.h:
  Cursor patch to push into the main tree, client library part (considered 
  stable):
  - new COMmand, COM_FETCH, to fetch K rows from read-only cursor.
    By design should support scrollable cursors as well.
  - a few new server statuses:
    SERVER_STATUS_CURSOR_EXISTS is sent by server in reply to COM_EXECUTE,
    when cursor was successfully opened for this query
    SERVER_STATUS_LAST_ROW_SENT is sent along with the last row to prevent one
    more round trip just for finding out that all rows were fetched from 
    this cursor (this is server mem savier also).
  - and finally, all possible values of STMT_ATTR_CURSOR_TYPE, 
    while now we support only CURSORT_TYPE_NO_CURSOR and 
    CURSOR_TYPE_READ_ONLY
libmysql/libmysql.c:
  Cursor patch to push into the main tree, client library part (considered 
  stable):
  - simple additions to mysql_stmt_fetch implementation to read data 
    from an opened cursor: we can read up to iteration count rows per
    one request; read rows are buffered in the same way as rows of
    mysql_stmt_store_result.
  - now send stmt->flags to server to let him now if we wish to have 
    a cursor for this statement.
  - support for setting/getting statement cursor type.
libmysqld/examples/Makefile.am:
  Testing cursors was originally implemented in C++. Now when these tests
  go into client_test, it's time to convert it to C++ as well.
libmysqld/lib_sql.cc:
  - cleanup: send_fields flags are now named.
sql/ha_innodb.cc:
  - cleanup: send_fields flags are now named.
sql/mysql_priv.h:
  - cursors support: declaration for server-side handler of COM_FETCH
sql/protocol.cc:
  - cleanup: send_fields flags are now named.
  - we can't anymore assert that field_types[field_pos] is sensible:
    if we have COM_EXCUTE(stmt1), COM_EXECUTE(stmt2), COM_FETCH(stmt1)
    field_types[field_pos] will point to fields of stmt2.
sql/protocol.h:
  - cleanup: send_fields flag_s_ are now named.
sql/protocol_cursor.cc:
  - cleanup: send_fields flags are now named.
sql/repl_failsafe.cc:
  - cleanup: send_fields flags are now named.
sql/slave.cc:
  - cleanup: send_fields flags are now named.
sql/sp.cc:
  - cleanup: send_fields flags are now named.
sql/sp_head.cc:
  - cleanup: send_fields flags are now named.
sql/sql_acl.cc:
  - cleanup: send_fields flags are now named.
sql/sql_class.cc:
  - cleanup: send_fields flags are now named.
sql/sql_class.h:
  - cleanup: send_fields flags are now named.
sql/sql_error.cc:
  - cleanup: send_fields flags are now named.
sql/sql_handler.cc:
  - cleanup: send_fields flags are now named.
sql/sql_help.cc:
  - cleanup: send_fields flags are now named.
sql/sql_parse.cc:
  Server side support for cursors:
  - handle COM_FETCH
  - enforce assumption that whenever we free thd->free_list, 
    we reset it to zero. This way it's much easier to handle free_list
    in prepared statements implementation.
sql/sql_prepare.cc:
  Server side support for cursors:
  - implementation of mysql_stmt_fetch (fetch some rows from open cursor).
  - management of cursors memory is quite tricky now.
  - execute_stmt can't be reused anymore in mysql_stmt_execute and 
    mysql_sql_stmt_execute
sql/sql_repl.cc:
  - cleanup: send_fields flags are now named.
sql/sql_select.cc:
  Server side support for cursors:
  - implementation of Cursor::open, Cursor::fetch (buggy when it comes to
    non-equi joins), cursor cleanups.
  - -4 -3 -0 constants indicating return value of sub_select and end_send are
    to be renamed to something more readable:
    it turned out to be not so simple, so it should come with the other patch.
sql/sql_select.h:
  Server side support for cursors:
  - declaration of Cursor class.
  - JOIN::fetch_limit contains runtime value of rows fetched via cursor.
sql/sql_show.cc:
  - cleanup: send_fields flags are now named.
sql/sql_table.cc:
  - cleanup: send_fields flags are now named.
sql/sql_union.cc:
  - if there was a cursor, don't cleanup unit: we'll need it to fetch
    the rest of the rows.
tests/Makefile.am:
  Now client_test is in C++.
tests/client_test.cc:
  A few elementary tests for cursors.
BitKeeper/etc/ignore:
  Added libmysqld/examples/client_test.cc to the ignore list
2004-08-03 03:32:21 -07:00

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/* Copyright (C) 1995-2002 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; either version 2 of the License, or
(at your option) any later version.
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 */
/**********************************************************************
This file contains the implementation of prepare and executes.
Prepare:
- Server gets the query from client with command 'COM_PREPARE';
in the following format:
[COM_PREPARE:1] [query]
- Parse the query and recognize any parameter markers '?' and
store its information list in lex->param_list
- Allocate a new statement for this prepare; and keep this in
'thd->prepared_statements' pool.
- Without executing the query, return back to client the total
number of parameters along with result-set metadata information
(if any) in the following format:
[STMT_ID:4]
[Column_count:2]
[Param_count:2]
[Columns meta info] (if Column_count > 0)
[Params meta info] (if Param_count > 0 ) (TODO : 4.1.1)
Prepare-execute:
- Server gets the command 'COM_EXECUTE' to execute the
previously prepared query. If there is any param markers; then client
will send the data in the following format:
[COM_EXECUTE:1]
[STMT_ID:4]
[NULL_BITS:(param_count+7)/8)]
[TYPES_SUPPLIED_BY_CLIENT(0/1):1]
[[length]data]
[[length]data] .. [[length]data].
(Note: Except for string/binary types; all other types will not be
supplied with length field)
- Replace the param items with this new data. If it is a first execute
or types altered by client; then setup the conversion routines.
- Execute the query without re-parsing and send back the results
to client
Long data handling:
- Server gets the long data in pieces with command type 'COM_LONG_DATA'.
- The packet recieved will have the format as:
[COM_LONG_DATA:1][STMT_ID:4][parameter_number:2][data]
- data from the packet is appended to long data value buffer for this
placeholder.
- It's up to the client to check for read data ended. The server doesn't
care; and also server doesn't notify to the client that it got the
data or not; if there is any error; then during execute; the error
will be returned
***********************************************************************/
#include "mysql_priv.h"
#include "sql_acl.h"
#include "sql_select.h" // for JOIN
#include <m_ctype.h> // for isspace()
#include "sp_head.h"
#ifdef EMBEDDED_LIBRARY
/* include MYSQL_BIND headers */
#include <mysql.h>
#else
#include <mysql_com.h>
#endif
/******************************************************************************
Prepared_statement: statement which can contain placeholders
******************************************************************************/
class Prepared_statement: public Statement
{
public:
THD *thd;
Item_param **param_array;
uint param_count;
uint last_errno;
char last_error[MYSQL_ERRMSG_SIZE];
bool get_longdata_error;
#ifndef EMBEDDED_LIBRARY
bool (*set_params)(Prepared_statement *st, uchar *data, uchar *data_end,
uchar *read_pos, String *expanded_query);
#else
bool (*set_params_data)(Prepared_statement *st, String *expanded_query);
#endif
bool (*set_params_from_vars)(Prepared_statement *stmt,
List<LEX_STRING>& varnames,
String *expanded_query);
public:
Prepared_statement(THD *thd_arg);
virtual ~Prepared_statement();
void setup_set_params();
virtual Statement::Type type() const;
};
static void execute_stmt(THD *thd, Prepared_statement *stmt,
String *expanded_query);
/******************************************************************************
Implementation
******************************************************************************/
inline bool is_param_null(const uchar *pos, ulong param_no)
{
return pos[param_no/8] & (1 << (param_no & 7));
}
enum { STMT_QUERY_LOG_LENGTH= 8192 };
enum enum_send_error { DONT_SEND_ERROR= 0, SEND_ERROR };
/*
Seek prepared statement in statement map by id: returns zero if statement
was not found, pointer otherwise.
*/
static Prepared_statement *
find_prepared_statement(THD *thd, ulong id, const char *where,
enum enum_send_error se)
{
Statement *stmt= thd->stmt_map.find(id);
if (stmt == 0 || stmt->type() != Statement::PREPARED_STATEMENT)
{
char llbuf[22];
my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), 22, llstr(id, llbuf), where);
if (se == SEND_ERROR)
send_error(thd);
return 0;
}
return (Prepared_statement *) stmt;
}
/*
Send prepared stmt info to client after prepare
*/
#ifndef EMBEDDED_LIBRARY
static bool send_prep_stmt(Prepared_statement *stmt, uint columns)
{
NET *net= &stmt->thd->net;
char buff[9];
buff[0]= 0; /* OK packet indicator */
int4store(buff+1, stmt->id);
int2store(buff+5, columns);
int2store(buff+7, stmt->param_count);
/*
Send types and names of placeholders to the client
XXX: fix this nasty upcast from List<Item_param> to List<Item>
*/
return my_net_write(net, buff, sizeof(buff)) ||
(stmt->param_count &&
stmt->thd->protocol_simple.send_fields((List<Item> *)
&stmt->lex->param_list,
Protocol::SEND_EOF)) ||
net_flush(net);
return 0;
}
#else
static bool send_prep_stmt(Prepared_statement *stmt,
uint columns __attribute__((unused)))
{
THD *thd= stmt->thd;
thd->client_stmt_id= stmt->id;
thd->client_param_count= stmt->param_count;
thd->net.last_errno= 0;
return 0;
}
#endif /*!EMBEDDED_LIBRARY*/
/*
Read the length of the parameter data and return back to
caller by positing the pointer to param data.
*/
#ifndef EMBEDDED_LIBRARY
static ulong get_param_length(uchar **packet, ulong len)
{
reg1 uchar *pos= *packet;
if (len < 1)
return 0;
if (*pos < 251)
{
(*packet)++;
return (ulong) *pos;
}
if (len < 3)
return 0;
if (*pos == 252)
{
(*packet)+=3;
return (ulong) uint2korr(pos+1);
}
if (len < 4)
return 0;
if (*pos == 253)
{
(*packet)+=4;
return (ulong) uint3korr(pos+1);
}
if (len < 5)
return 0;
(*packet)+=9; // Must be 254 when here
/*
In our client-server protocol all numbers bigger than 2^24
stored as 8 bytes with uint8korr. Here we always know that
parameter length is less than 2^4 so don't look at the second
4 bytes. But still we need to obey the protocol hence 9 in the
assignment above.
*/
return (ulong) uint4korr(pos+1);
}
#else
#define get_param_length(packet, len) len
#endif /*!EMBEDDED_LIBRARY*/
/*
Data conversion routines
SYNOPSIS
set_param_xx()
param parameter item
pos input data buffer
len length of data in the buffer
All these functions read the data from pos, convert it to requested type
and assign to param; pos is advanced to predefined length.
Make a note that the NULL handling is examined at first execution
(i.e. when input types altered) and for all subsequent executions
we don't read any values for this.
RETURN VALUE
none
*/
static void set_param_tiny(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 1)
return;
#endif
int8 value= (int8) **pos;
param->set_int(param->unsigned_flag ? (longlong) ((uint8) value) :
(longlong) value, 4);
*pos+= 1;
}
static void set_param_short(Item_param *param, uchar **pos, ulong len)
{
int16 value;
#ifndef EMBEDDED_LIBRARY
if (len < 2)
return;
value= sint2korr(*pos);
#else
shortget(value, *pos);
#endif
param->set_int(param->unsigned_flag ? (longlong) ((uint16) value) :
(longlong) value, 6);
*pos+= 2;
}
static void set_param_int32(Item_param *param, uchar **pos, ulong len)
{
int32 value;
#ifndef EMBEDDED_LIBRARY
if (len < 4)
return;
value= sint4korr(*pos);
#else
longget(value, *pos);
#endif
param->set_int(param->unsigned_flag ? (longlong) ((uint32) value) :
(longlong) value, 11);
*pos+= 4;
}
static void set_param_int64(Item_param *param, uchar **pos, ulong len)
{
longlong value;
#ifndef EMBEDDED_LIBRARY
if (len < 8)
return;
value= (longlong) sint8korr(*pos);
#else
longlongget(value, *pos);
#endif
param->set_int(value, 21);
*pos+= 8;
}
static void set_param_float(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 4)
return;
#endif
float data;
float4get(data,*pos);
param->set_double((double) data);
*pos+= 4;
}
static void set_param_double(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 8)
return;
#endif
double data;
float8get(data,*pos);
param->set_double((double) data);
*pos+= 8;
}
#ifndef EMBEDDED_LIBRARY
static void set_param_time(Item_param *param, uchar **pos, ulong len)
{
ulong length;
uint day;
if ((length= get_param_length(pos, len)) >= 8)
{
uchar *to= *pos;
TIME tm;
tm.neg= (bool) to[0];
day= (uint) sint4korr(to+1);
/*
Note, that though ranges of hour, minute and second are not checked
here we rely on them being < 256: otherwise
we'll get buffer overflow in make_{date,time} functions,
which are called when time value is converted to string.
*/
tm.hour= (uint) to[5] + day * 24;
tm.minute= (uint) to[6];
tm.second= (uint) to[7];
tm.second_part= (length > 8) ? (ulong) sint4korr(to+8) : 0;
if (tm.hour > 838)
{
/* TODO: add warning 'Data truncated' here */
tm.hour= 838;
tm.minute= 59;
tm.second= 59;
}
tm.day= tm.year= tm.month= 0;
param->set_time(&tm, MYSQL_TIMESTAMP_TIME,
MAX_TIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
*pos+= length;
}
static void set_param_datetime(Item_param *param, uchar **pos, ulong len)
{
uint length;
if ((length= get_param_length(pos, len)) >= 4)
{
uchar *to= *pos;
TIME tm;
tm.neg= 0;
tm.year= (uint) sint2korr(to);
tm.month= (uint) to[2];
tm.day= (uint) to[3];
/*
Note, that though ranges of hour, minute and second are not checked
here we rely on them being < 256: otherwise
we'll get buffer overflow in make_{date,time} functions.
*/
if (length > 4)
{
tm.hour= (uint) to[4];
tm.minute= (uint) to[5];
tm.second= (uint) to[6];
}
else
tm.hour= tm.minute= tm.second= 0;
tm.second_part= (length > 7) ? (ulong) sint4korr(to+7) : 0;
param->set_time(&tm, MYSQL_TIMESTAMP_DATETIME,
MAX_DATETIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
*pos+= length;
}
static void set_param_date(Item_param *param, uchar **pos, ulong len)
{
ulong length;
if ((length= get_param_length(pos, len)) >= 4)
{
uchar *to= *pos;
TIME tm;
/*
Note, that though ranges of hour, minute and second are not checked
here we rely on them being < 256: otherwise
we'll get buffer overflow in make_{date,time} functions.
*/
tm.year= (uint) sint2korr(to);
tm.month= (uint) to[2];
tm.day= (uint) to[3];
tm.hour= tm.minute= tm.second= 0;
tm.second_part= 0;
tm.neg= 0;
param->set_time(&tm, MYSQL_TIMESTAMP_DATE,
MAX_DATE_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
*pos+= length;
}
#else/*!EMBEDDED_LIBRARY*/
void set_param_time(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME *to= (MYSQL_TIME*)*pos;
param->set_time(to, MYSQL_TIMESTAMP_TIME,
MAX_TIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
void set_param_datetime(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME *to= (MYSQL_TIME*)*pos;
param->set_time(to, MYSQL_TIMESTAMP_DATETIME,
MAX_DATETIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
void set_param_date(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME *to= (MYSQL_TIME*)*pos;
param->set_time(to, MYSQL_TIMESTAMP_DATE,
MAX_DATE_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
#endif /*!EMBEDDED_LIBRARY*/
static void set_param_str(Item_param *param, uchar **pos, ulong len)
{
ulong length= get_param_length(pos, len);
param->set_str((const char *)*pos, length);
*pos+= length;
}
#undef get_param_length
static void setup_one_conversion_function(THD *thd, Item_param *param,
uchar param_type)
{
switch (param_type) {
case MYSQL_TYPE_TINY:
param->set_param_func= set_param_tiny;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_SHORT:
param->set_param_func= set_param_short;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_LONG:
param->set_param_func= set_param_int32;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_LONGLONG:
param->set_param_func= set_param_int64;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_FLOAT:
param->set_param_func= set_param_float;
param->item_type= Item::REAL_ITEM;
param->item_result_type= REAL_RESULT;
break;
case MYSQL_TYPE_DOUBLE:
param->set_param_func= set_param_double;
param->item_type= Item::REAL_ITEM;
param->item_result_type= REAL_RESULT;
break;
case MYSQL_TYPE_TIME:
param->set_param_func= set_param_time;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
case MYSQL_TYPE_DATE:
param->set_param_func= set_param_date;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
case MYSQL_TYPE_DATETIME:
case MYSQL_TYPE_TIMESTAMP:
param->set_param_func= set_param_datetime;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
case MYSQL_TYPE_TINY_BLOB:
case MYSQL_TYPE_MEDIUM_BLOB:
case MYSQL_TYPE_LONG_BLOB:
case MYSQL_TYPE_BLOB:
param->set_param_func= set_param_str;
param->value.cs_info.character_set_client= &my_charset_bin;
param->value.cs_info.final_character_set_of_str_value= &my_charset_bin;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
default:
/*
The client library ensures that we won't get any other typecodes
except typecodes above and typecodes for string types. Marking
label as 'default' lets us to handle malformed packets as well.
*/
{
CHARSET_INFO *fromcs= thd->variables.character_set_client;
CHARSET_INFO *tocs= thd->variables.collation_connection;
uint32 dummy_offset;
param->value.cs_info.character_set_client= fromcs;
/*
Setup source and destination character sets so that they
are different only if conversion is necessary: this will
make later checks easier.
*/
param->value.cs_info.final_character_set_of_str_value=
String::needs_conversion(0, fromcs, tocs, &dummy_offset) ?
tocs : fromcs;
param->set_param_func= set_param_str;
/*
Exact value of max_length is not known unless data is converted to
charset of connection, so we have to set it later.
*/
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
}
}
param->param_type= (enum enum_field_types) param_type;
}
#ifndef EMBEDDED_LIBRARY
/*
Update the parameter markers by reading data from client packet
and if binary/update log is set, generate the valid query.
*/
static bool insert_params_withlog(Prepared_statement *stmt, uchar *null_array,
uchar *read_pos, uchar *data_end,
String *query)
{
THD *thd= stmt->thd;
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
uint32 length= 0;
String str;
const String *res;
DBUG_ENTER("insert_params_withlog");
if (query->copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (is_param_null(null_array, it - begin))
param->set_null();
else
{
if (read_pos >= data_end)
DBUG_RETURN(1);
param->set_param_func(param, &read_pos, data_end - read_pos);
}
}
res= param->query_val_str(&str);
if (param->convert_str_value(thd))
DBUG_RETURN(1); /* out of memory */
if (query->replace(param->pos_in_query+length, 1, *res))
DBUG_RETURN(1);
length+= res->length()-1;
}
DBUG_RETURN(0);
}
static bool insert_params(Prepared_statement *stmt, uchar *null_array,
uchar *read_pos, uchar *data_end,
String *expanded_query)
{
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
DBUG_ENTER("insert_params");
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (is_param_null(null_array, it - begin))
param->set_null();
else
{
if (read_pos >= data_end)
DBUG_RETURN(1);
param->set_param_func(param, &read_pos, data_end - read_pos);
}
}
if (param->convert_str_value(stmt->thd))
DBUG_RETURN(1); /* out of memory */
}
DBUG_RETURN(0);
}
static bool setup_conversion_functions(Prepared_statement *stmt,
uchar **data, uchar *data_end)
{
/* skip null bits */
uchar *read_pos= *data + (stmt->param_count+7) / 8;
DBUG_ENTER("setup_conversion_functions");
if (*read_pos++) //types supplied / first execute
{
/*
First execute or types altered by the client, setup the
conversion routines for all parameters (one time)
*/
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
THD *thd= stmt->thd;
for (; it < end; ++it)
{
ushort typecode;
const uint signed_bit= 1 << 15;
if (read_pos >= data_end)
DBUG_RETURN(1);
typecode= sint2korr(read_pos);
read_pos+= 2;
(**it).unsigned_flag= test(typecode & signed_bit);
setup_one_conversion_function(thd, *it, (uchar) (typecode & ~signed_bit));
}
}
*data= read_pos;
DBUG_RETURN(0);
}
#else
static bool emb_insert_params(Prepared_statement *stmt, String *expanded_query)
{
THD *thd= stmt->thd;
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
MYSQL_BIND *client_param= stmt->thd->client_params;
DBUG_ENTER("emb_insert_params");
for (; it < end; ++it, ++client_param)
{
Item_param *param= *it;
setup_one_conversion_function(thd, param, client_param->buffer_type);
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (*client_param->is_null)
param->set_null();
else
{
uchar *buff= (uchar*) client_param->buffer;
param->set_param_func(param, &buff,
client_param->length ?
*client_param->length :
client_param->buffer_length);
}
}
if (param->convert_str_value(thd))
DBUG_RETURN(1); /* out of memory */
}
DBUG_RETURN(0);
}
static bool emb_insert_params_withlog(Prepared_statement *stmt, String *query)
{
THD *thd= stmt->thd;
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
MYSQL_BIND *client_param= thd->client_params;
String str;
const String *res;
uint32 length= 0;
DBUG_ENTER("emb_insert_params_withlog");
if (query->copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (; it < end; ++it, ++client_param)
{
Item_param *param= *it;
setup_one_conversion_function(thd, param, client_param->buffer_type);
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (*client_param->is_null)
param->set_null();
else
{
uchar *buff= (uchar*)client_param->buffer;
param->set_param_func(param, &buff,
client_param->length ?
*client_param->length :
client_param->buffer_length);
}
}
res= param->query_val_str(&str);
if (param->convert_str_value(thd))
DBUG_RETURN(1); /* out of memory */
if (query->replace(param->pos_in_query+length, 1, *res))
DBUG_RETURN(1);
length+= res->length()-1;
}
DBUG_RETURN(0);
}
#endif /*!EMBEDDED_LIBRARY*/
/*
Set prepared statement parameters from user variables.
SYNOPSIS
insert_params_from_vars()
stmt Statement
varnames List of variables. Caller must ensure that number of variables
in the list is equal to number of statement parameters
query Ignored
*/
static bool insert_params_from_vars(Prepared_statement *stmt,
List<LEX_STRING>& varnames,
String *query __attribute__((unused)))
{
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
user_var_entry *entry;
LEX_STRING *varname;
List_iterator<LEX_STRING> var_it(varnames);
DBUG_ENTER("insert_params_from_vars");
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
varname= var_it++;
entry= (user_var_entry*)hash_search(&stmt->thd->user_vars,
(byte*) varname->str,
varname->length);
if (param->set_from_user_var(stmt->thd, entry) ||
param->convert_str_value(stmt->thd))
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
/*
Do the same as insert_params_from_vars but also construct query text for
binary log.
SYNOPSIS
insert_params_from_vars()
stmt Statement
varnames List of variables. Caller must ensure that number of variables
in the list is equal to number of statement parameters
query The query with parameter markers replaced with their values
*/
static bool insert_params_from_vars_with_log(Prepared_statement *stmt,
List<LEX_STRING>& varnames,
String *query)
{
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
user_var_entry *entry;
LEX_STRING *varname;
DBUG_ENTER("insert_params_from_vars");
List_iterator<LEX_STRING> var_it(varnames);
String str;
uint32 length= 0;
if (query->copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
varname= var_it++;
if (get_var_with_binlog(stmt->thd, *varname, &entry))
DBUG_RETURN(1);
DBUG_ASSERT(entry);
if (param->set_from_user_var(stmt->thd, entry))
DBUG_RETURN(1);
/* Insert @'escaped-varname' instead of parameter in the query */
char *buf, *ptr;
str.length(0);
if (str.reserve(entry->name.length*2+3))
DBUG_RETURN(1);
buf= str.c_ptr_quick();
ptr= buf;
*ptr++= '@';
*ptr++= '\'';
ptr+=
escape_string_for_mysql(&my_charset_utf8_general_ci,
ptr, entry->name.str, entry->name.length);
*ptr++= '\'';
str.length(ptr - buf);
if (param->convert_str_value(stmt->thd))
DBUG_RETURN(1); /* out of memory */
if (query->replace(param->pos_in_query+length, 1, str))
DBUG_RETURN(1);
length+= str.length()-1;
}
DBUG_RETURN(0);
}
/*
Validate INSERT statement:
SYNOPSIS
mysql_test_insert()
stmt prepared statemen handler
tables global/local table list
RETURN VALUE
0 ok
1 error, sent to the client
-1 error, not sent to client
*/
static int mysql_test_insert(Prepared_statement *stmt,
TABLE_LIST *table_list,
List<Item> &fields,
List<List_item> &values_list,
List<Item> &update_fields,
List<Item> &update_values,
enum_duplicates duplic)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
List_iterator_fast<List_item> its(values_list);
List_item *values;
int res= -1;
my_bool update= (lex->value_list.elements ? UPDATE_ACL : 0);
DBUG_ENTER("mysql_test_insert");
if ((res= insert_precheck(thd, table_list, update)))
DBUG_RETURN(res);
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (open_and_lock_tables(thd, table_list))
{
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(-1);
}
if ((values= its++))
{
uint value_count;
ulong counter= 0;
if ((res= mysql_prepare_insert(thd, table_list, table_list->table,
fields, values, update_fields,
update_values, duplic)))
goto error;
value_count= values->elements;
its.rewind();
while ((values= its++))
{
counter++;
if (values->elements != value_count)
{
my_printf_error(ER_WRONG_VALUE_COUNT_ON_ROW,
ER(ER_WRONG_VALUE_COUNT_ON_ROW),
MYF(0), counter);
goto error;
}
if (setup_fields(thd, 0, table_list, *values, 0, 0, 0))
goto error;
}
}
res= 0;
error:
lex->unit.cleanup();
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(res);
}
/*
Validate UPDATE statement
SYNOPSIS
mysql_test_update()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_update(Prepared_statement *stmt,
TABLE_LIST *table_list)
{
int res;
THD *thd= stmt->thd;
SELECT_LEX *select= &stmt->lex->select_lex;
DBUG_ENTER("mysql_test_update");
if ((res= update_precheck(thd, table_list)))
DBUG_RETURN(res);
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (open_and_lock_tables(thd, table_list))
res= -1;
else
{
if (!(res= mysql_prepare_update(thd, table_list,
&select->where,
select->order_list.elements,
(ORDER *) select->order_list.first)))
{
if (setup_fields(thd, 0, table_list,
select->item_list, 1, 0, 0) ||
setup_fields(thd, 0, table_list,
stmt->lex->value_list, 0, 0, 0))
res= -1;
}
stmt->lex->unit.cleanup();
}
thd->free_temporary_memory_pool_for_ps_preparing();
/* TODO: here we should send types of placeholders to the client. */
DBUG_RETURN(res);
}
/*
Validate DELETE statement
SYNOPSIS
mysql_test_delete()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_delete(Prepared_statement *stmt,
TABLE_LIST *table_list)
{
int res;
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
DBUG_ENTER("mysql_test_delete");
if ((res= delete_precheck(thd, table_list)))
DBUG_RETURN(res);
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (open_and_lock_tables(thd, table_list))
res= -1;
else
{
res= mysql_prepare_delete(thd, table_list, &lex->select_lex.where);
lex->unit.cleanup();
}
thd->free_temporary_memory_pool_for_ps_preparing();
/* TODO: here we should send types of placeholders to the client. */
DBUG_RETURN(res);
}
/*
Validate SELECT statement.
In case of success, if this query is not EXPLAIN, send column list info
back to client.
SYNOPSIS
mysql_test_select()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_select(Prepared_statement *stmt,
TABLE_LIST *tables, bool text_protocol)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX_UNIT *unit= &lex->unit;
DBUG_ENTER("mysql_test_select");
#ifndef NO_EMBEDDED_ACCESS_CHECKS
ulong privilege= lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL;
if (tables)
{
if (check_table_access(thd, privilege, tables,0))
DBUG_RETURN(1);
}
else if (check_access(thd, privilege, any_db,0,0,0))
DBUG_RETURN(1);
#endif
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (open_and_lock_tables(thd, tables))
{
send_error(thd);
goto err;
}
thd->used_tables= 0; // Updated by setup_fields
// JOIN::prepare calls
if (unit->prepare(thd, 0, 0))
{
send_error(thd);
goto err_prep;
}
if (lex->describe)
{
if (!text_protocol && send_prep_stmt(stmt, 0))
goto err_prep;
unit->cleanup();
}
else
{
if (!text_protocol)
{
if (send_prep_stmt(stmt, lex->select_lex.item_list.elements) ||
thd->protocol_simple.send_fields(&lex->select_lex.item_list,
Protocol::SEND_EOF)
#ifndef EMBEDDED_LIBRARY
|| net_flush(&thd->net)
#endif
)
goto err_prep;
}
unit->cleanup();
}
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(0);
err_prep:
unit->cleanup();
err:
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(1);
}
/*
Validate and prepare for execution DO statement expressions
SYNOPSIS
mysql_test_do_fields()
stmt prepared statemen handler
tables list of tables queries
values list of expressions
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_do_fields(Prepared_statement *stmt,
TABLE_LIST *tables,
List<Item> *values)
{
DBUG_ENTER("mysql_test_do_fields");
THD *thd= stmt->thd;
int res= 0;
if (tables && (res= check_table_access(thd, SELECT_ACL, tables, 0)))
DBUG_RETURN(res);
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (tables && (res= open_and_lock_tables(thd, tables)))
{
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(res);
}
res= setup_fields(thd, 0, 0, *values, 0, 0, 0);
stmt->lex->unit.cleanup();
thd->free_temporary_memory_pool_for_ps_preparing();
if (res)
DBUG_RETURN(-1);
DBUG_RETURN(0);
}
/*
Validate and prepare for execution SET statement expressions
SYNOPSIS
mysql_test_set_fields()
stmt prepared statemen handler
tables list of tables queries
values list of expressions
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_set_fields(Prepared_statement *stmt,
TABLE_LIST *tables,
List<set_var_base> *var_list)
{
DBUG_ENTER("mysql_test_set_fields");
List_iterator_fast<set_var_base> it(*var_list);
THD *thd= stmt->thd;
set_var_base *var;
int res= 0;
if (tables && (res= check_table_access(thd, SELECT_ACL, tables, 0)))
DBUG_RETURN(res);
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (tables && (res= open_and_lock_tables(thd, tables)))
goto error;
while ((var= it++))
{
if (var->light_check(thd))
{
stmt->lex->unit.cleanup();
res= -1;
goto error;
}
}
error:
stmt->lex->unit.cleanup();
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(res);
}
/*
Check internal SELECT of the prepared command
SYNOPSIS
select_like_statement_test()
stmt - prepared table handler
tables - global list of tables
specific_prepare - function of command specific prepare
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int select_like_statement_test(Prepared_statement *stmt,
TABLE_LIST *tables,
int (*specific_prepare)(THD *thd))
{
DBUG_ENTER("select_like_statement_test");
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
int res= 0;
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
*/
thd->allocate_temporary_memory_pool_for_ps_preparing();
if (tables && (res= open_and_lock_tables(thd, tables)))
goto end;
if (specific_prepare && (res= (*specific_prepare)(thd)))
goto end;
thd->used_tables= 0; // Updated by setup_fields
// JOIN::prepare calls
if (lex->unit.prepare(thd, 0, 0))
{
res= thd->net.report_error ? -1 : 1;
}
end:
lex->unit.cleanup();
thd->free_temporary_memory_pool_for_ps_preparing();
DBUG_RETURN(res);
}
/*
Validate and prepare for execution CREATE TABLE statement
SYNOPSIS
mysql_test_create_table()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_create_table(Prepared_statement *stmt)
{
DBUG_ENTER("mysql_test_create_table");
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX *select_lex= &lex->select_lex;
int res= 0;
/* Skip first table, which is the table we are creating */
bool link_to_local;
TABLE_LIST *create_table= lex->unlink_first_table(&link_to_local);
TABLE_LIST *tables= lex->query_tables;
if (!(res= create_table_precheck(thd, tables, create_table)) &&
select_lex->item_list.elements)
{
select_lex->resolve_mode= SELECT_LEX::SELECT_MODE;
res= select_like_statement_test(stmt, tables, 0);
select_lex->resolve_mode= SELECT_LEX::NOMATTER_MODE;
}
/* put tables back for PS rexecuting */
lex->link_first_table_back(create_table, link_to_local);
DBUG_RETURN(res);
}
/*
Validate and prepare for execution multi update statement
SYNOPSIS
mysql_test_multiupdate()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_multiupdate(Prepared_statement *stmt,
TABLE_LIST *tables)
{
int res;
if ((res= multi_update_precheck(stmt->thd, tables)))
return res;
return select_like_statement_test(stmt, tables, &mysql_multi_update_prepare);
}
/*
Validate and prepare for execution multi delete statement
SYNOPSIS
mysql_test_multidelete()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_multidelete(Prepared_statement *stmt,
TABLE_LIST *tables)
{
int res;
stmt->thd->lex->current_select= &stmt->thd->lex->select_lex;
if (add_item_to_list(stmt->thd, new Item_null()))
return -1;
uint fake_counter;
if ((res= multi_delete_precheck(stmt->thd, tables, &fake_counter)))
return res;
return select_like_statement_test(stmt, tables, &mysql_multi_delete_prepare);
}
/*
Validate and prepare for execution INSERT ... SELECT statement
SYNOPSIS
mysql_test_insert_select()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_insert_select(Prepared_statement *stmt,
TABLE_LIST *tables)
{
int res;
LEX *lex= stmt->lex;
if ((res= insert_select_precheck(stmt->thd, tables)))
return res;
TABLE_LIST *first_local_table=
(TABLE_LIST *)lex->select_lex.table_list.first;
DBUG_ASSERT(first_local_table != 0);
/* Skip first table, which is the table we are inserting in */
lex->select_lex.table_list.first= (byte*) first_local_table->next_local;
/*
insert/replace from SELECT give its SELECT_LEX for SELECT,
and item_list belong to SELECT
*/
lex->select_lex.resolve_mode= SELECT_LEX::SELECT_MODE;
res= select_like_statement_test(stmt, tables, &mysql_insert_select_prepare);
/* revert changes*/
lex->select_lex.table_list.first= (byte*) first_local_table;
lex->select_lex.resolve_mode= SELECT_LEX::INSERT_MODE;
return res;
}
/*
Send the prepare query results back to client
SYNOPSIS
send_prepare_results()
stmt prepared statement
RETURN VALUE
0 success
1 error, sent to client
*/
static int send_prepare_results(Prepared_statement *stmt, bool text_protocol)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX *select_lex= &lex->select_lex;
TABLE_LIST *tables;
enum enum_sql_command sql_command= lex->sql_command;
int res= 0;
DBUG_ENTER("send_prepare_results");
DBUG_PRINT("enter",("command: %d, param_count: %ld",
sql_command, stmt->param_count));
lex->first_lists_tables_same();
tables= lex->query_tables;
switch (sql_command) {
case SQLCOM_REPLACE:
case SQLCOM_INSERT:
res= mysql_test_insert(stmt, tables, lex->field_list,
lex->many_values,
select_lex->item_list, lex->value_list,
(lex->value_list.elements ?
DUP_UPDATE : lex->duplicates));
break;
case SQLCOM_UPDATE:
res= mysql_test_update(stmt, tables);
break;
case SQLCOM_DELETE:
res= mysql_test_delete(stmt, tables);
break;
case SQLCOM_SELECT:
if ((res= mysql_test_select(stmt, tables, text_protocol)))
goto error;
/* Statement and field info has already been sent */
DBUG_RETURN(0);
case SQLCOM_CREATE_TABLE:
res= mysql_test_create_table(stmt);
break;
case SQLCOM_DO:
res= mysql_test_do_fields(stmt, tables, lex->insert_list);
break;
case SQLCOM_SET_OPTION:
res= mysql_test_set_fields(stmt, tables, &lex->var_list);
break;
case SQLCOM_DELETE_MULTI:
res= mysql_test_multidelete(stmt, tables);
break;
case SQLCOM_UPDATE_MULTI:
res= mysql_test_multiupdate(stmt, tables);
break;
case SQLCOM_INSERT_SELECT:
res= mysql_test_insert_select(stmt, tables);
break;
case SQLCOM_SHOW_DATABASES:
case SQLCOM_SHOW_PROCESSLIST:
case SQLCOM_SHOW_STORAGE_ENGINES:
case SQLCOM_SHOW_PRIVILEGES:
case SQLCOM_SHOW_COLUMN_TYPES:
case SQLCOM_SHOW_STATUS:
case SQLCOM_SHOW_VARIABLES:
case SQLCOM_SHOW_LOGS:
case SQLCOM_SHOW_TABLES:
case SQLCOM_SHOW_OPEN_TABLES:
case SQLCOM_SHOW_CHARSETS:
case SQLCOM_SHOW_COLLATIONS:
case SQLCOM_SHOW_FIELDS:
case SQLCOM_SHOW_KEYS:
case SQLCOM_SHOW_CREATE_DB:
case SQLCOM_SHOW_GRANTS:
case SQLCOM_DROP_TABLE:
case SQLCOM_RENAME_TABLE:
case SQLCOM_ALTER_TABLE:
case SQLCOM_COMMIT:
case SQLCOM_CREATE_INDEX:
case SQLCOM_DROP_INDEX:
case SQLCOM_ROLLBACK:
case SQLCOM_TRUNCATE:
break;
default:
/*
All other is not supported yet
*/
res= -1;
my_error(ER_UNSUPPORTED_PS, MYF(0));
goto error;
}
if (res == 0)
DBUG_RETURN(text_protocol? 0 : send_prep_stmt(stmt, 0));
error:
if (res < 0)
send_error(thd,thd->killed_errno());
DBUG_RETURN(1);
}
/*
Initialize array of parameters in statement from LEX.
(We need to have quick access to items by number in mysql_stmt_get_longdata).
This is to avoid using malloc/realloc in the parser.
*/
static bool init_param_array(Prepared_statement *stmt)
{
LEX *lex= stmt->lex;
if ((stmt->param_count= lex->param_list.elements))
{
Item_param **to;
List_iterator<Item_param> param_iterator(lex->param_list);
/* Use thd->mem_root as it points at statement mem_root */
stmt->param_array= (Item_param **)
alloc_root(&stmt->thd->mem_root,
sizeof(Item_param*) * stmt->param_count);
if (!stmt->param_array)
{
send_error(stmt->thd, ER_OUT_OF_RESOURCES);
return 1;
}
for (to= stmt->param_array;
to < stmt->param_array + stmt->param_count;
++to)
{
*to= param_iterator++;
}
}
return 0;
}
/*
Given a query string with parameter markers, create a Prepared Statement
from it and send PS info back to the client.
SYNOPSIS
mysql_stmt_prepare()
packet query to be prepared
packet_length query string length, including ignored trailing NULL or
quote char.
name NULL or statement name. For unnamed statements binary PS
protocol is used, for named statements text protocol is
used.
RETURN
0 OK, statement prepared successfully
other Error
NOTES
This function parses the query and sends the total number of parameters
and resultset metadata information back to client (if any), without
executing the query i.e. without any log/disk writes. This allows the
queries to be re-executed without re-parsing during execute.
If parameter markers are found in the query, then store the information
using Item_param along with maintaining a list in lex->param_array, so
that a fast and direct retrieval can be made without going through all
field items.
*/
int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
LEX_STRING *name)
{
LEX *lex;
Prepared_statement *stmt= new Prepared_statement(thd);
int error;
DBUG_ENTER("mysql_stmt_prepare");
DBUG_PRINT("prep_query", ("%s", packet));
if (stmt == 0)
{
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
if (name)
{
stmt->name.length= name->length;
if (!(stmt->name.str= memdup_root(&stmt->mem_root, (char*)name->str,
name->length)))
{
delete stmt;
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
}
if (thd->stmt_map.insert(stmt))
{
delete stmt;
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
thd->stmt_backup.set_statement(thd);
thd->stmt_backup.set_item_arena(thd);
thd->set_statement(stmt);
thd->set_item_arena(stmt);
if (alloc_query(thd, packet, packet_length))
{
stmt->set_statement(thd);
stmt->set_item_arena(thd);
thd->set_statement(&thd->stmt_backup);
thd->set_item_arena(&thd->stmt_backup);
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
mysql_log.write(thd, COM_PREPARE, "%s", packet);
thd->current_arena= stmt;
mysql_init_query(thd, (uchar *) thd->query, thd->query_length);
lex= thd->lex;
lex->safe_to_cache_query= 0;
error= yyparse((void *)thd) || thd->is_fatal_error ||
init_param_array(stmt) ||
send_prepare_results(stmt, test(name));
/* restore to WAIT_PRIOR: QUERY_PRIOR is set inside alloc_query */
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),WAIT_PRIOR);
if (error && thd->lex->sphead)
{
if (lex != thd->lex)
thd->lex->sphead->restore_lex(thd);
delete thd->lex->sphead;
thd->lex->sphead= NULL;
}
lex_end(lex);
stmt->set_statement(thd);
stmt->set_item_arena(thd);
thd->set_statement(&thd->stmt_backup);
thd->set_item_arena(&thd->stmt_backup);
thd->current_arena= 0;
if (error)
{
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
stmt= NULL;
/* error is sent inside yyparse/send_prepare_results */
}
else
{
stmt->setup_set_params();
SELECT_LEX *sl= stmt->lex->all_selects_list;
/*
Save WHERE clause pointers, because they may be changed during query
optimisation.
*/
for (; sl; sl= sl->next_select_in_list())
sl->prep_where= sl->where;
}
DBUG_RETURN(!stmt);
}
/* Reinit statement before execution */
void reset_stmt_for_execute(THD *thd, LEX *lex)
{
SELECT_LEX *sl= lex->all_selects_list;
if (lex->empty_field_list_on_rset)
{
lex->field_list.empty();
lex->empty_field_list_on_rset= 0;
}
for (; sl; sl= sl->next_select_in_list())
{
if (!sl->first_execution)
{
/* remove option which was put by mysql_explain_union() */
sl->options&= ~SELECT_DESCRIBE;
/*
Copy WHERE clause pointers to avoid damaging they by optimisation
*/
if (sl->prep_where)
{
sl->where= sl->prep_where->copy_andor_structure(thd);
sl->where->cleanup();
}
DBUG_ASSERT(sl->join == 0);
ORDER *order;
/* Fix GROUP list */
for (order= (ORDER *)sl->group_list.first; order; order= order->next)
order->item= &order->item_ptr;
/* Fix ORDER list */
for (order= (ORDER *)sl->order_list.first; order; order= order->next)
order->item= &order->item_ptr;
}
{
TABLE_LIST *tables= (TABLE_LIST *)sl->table_list.first;
if (tables)
tables->setup_is_done= 0;
}
{
SELECT_LEX_UNIT *unit= sl->master_unit();
unit->unclean();
unit->types.empty();
/* for derived tables & PS (which can't be reset by Item_subquery) */
unit->reinit_exec_mechanism();
}
}
/*
TODO: When the new table structure is ready, then have a status bit
to indicate the table is altered, and re-do the setup_*
and open the tables back.
*/
for (TABLE_LIST *tables= lex->query_tables;
tables;
tables= tables->next_global)
{
/*
Reset old pointers to TABLEs: they are not valid since the tables
were closed in the end of previous prepare or execute call.
*/
tables->table= 0;
}
lex->current_select= &lex->select_lex;
}
/*
Clears parameters from data left from previous execution or long data
SYNOPSIS
reset_stmt_params()
stmt - prepared statement for which parameters should be reset
*/
static void reset_stmt_params(Prepared_statement *stmt)
{
Item_param **item= stmt->param_array;
Item_param **end= item + stmt->param_count;
for (;item < end ; ++item)
(**item).reset();
}
/*
Executes previously prepared query.
If there is any parameters, then replace markers with the data supplied
from client, and then execute the query.
SYNOPSIS
mysql_stmt_execute()
thd Current thread
packet Query string
packet_length Query string length, including terminator character.
*/
void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
{
ulong stmt_id= uint4korr(packet);
ulong flags= (ulong) ((uchar) packet[4]);
/*
Query text for binary log, or empty string if the query is not put into
binary log.
*/
String expanded_query;
#ifndef EMBEDDED_LIBRARY
uchar *packet_end= (uchar *) packet + packet_length - 1;
#endif
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_execute");
packet+= 9; /* stmt_id + 5 bytes of flags */
if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_execute",
SEND_ERROR)))
DBUG_VOID_RETURN;
DBUG_PRINT("exec_query:", ("%s", stmt->query));
/* Check if we got an error when sending long data */
if (stmt->get_longdata_error)
{
send_error(thd, stmt->last_errno, stmt->last_error);
DBUG_VOID_RETURN;
}
if (flags & (ulong) CURSOR_TYPE_READ_ONLY)
{
if (stmt->lex->result)
{
/*
If lex->result is set in the parser, this is not a SELECT
statement: we can't open a cursor for it.
*/
flags= 0;
}
else
{
if (!stmt->cursor &&
!(stmt->cursor= new (&stmt->mem_root) Cursor()))
{
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_VOID_RETURN;
}
/* If lex->result is set, mysql_execute_command will use it */
stmt->lex->result= &stmt->cursor->result;
}
}
#ifndef EMBEDDED_LIBRARY
if (stmt->param_count)
{
uchar *null_array= (uchar *) packet;
if (setup_conversion_functions(stmt, (uchar **) &packet, packet_end) ||
stmt->set_params(stmt, null_array, (uchar *) packet, packet_end,
&expanded_query))
goto set_params_data_err;
}
#else
/*
In embedded library we re-install conversion routines each time
we set params, and also we don't need to parse packet.
So we do it in one function.
*/
if (stmt->param_count && stmt->set_params_data(stmt, &expanded_query))
goto set_params_data_err;
#endif
thd->stmt_backup.set_statement(thd);
thd->set_statement(stmt);
thd->current_arena= stmt;
reset_stmt_for_execute(thd, stmt->lex);
/* From now cursors assume that thd->mem_root is clean */
if (expanded_query.length() &&
alloc_query(thd, (char *)expanded_query.ptr(),
expanded_query.length()+1))
{
my_error(ER_OUTOFMEMORY, 0, expanded_query.length());
goto err;
}
thd->protocol= &thd->protocol_prep; // Switch to binary protocol
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),QUERY_PRIOR);
mysql_execute_command(thd);
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(), WAIT_PRIOR);
thd->protocol= &thd->protocol_simple; // Use normal protocol
if (flags & (ulong) CURSOR_TYPE_READ_ONLY)
{
if (stmt->cursor->is_open())
stmt->cursor->init_from_thd(thd);
thd->set_item_arena(&thd->stmt_backup);
}
else
{
thd->lex->unit.cleanup();
cleanup_items(stmt->free_list);
reset_stmt_params(stmt);
close_thread_tables(thd); /* to close derived tables */
/*
Free items that were created during this execution of the PS by
query optimizer.
*/
free_items(thd->free_list);
thd->free_list= 0;
}
thd->set_statement(&thd->stmt_backup);
thd->current_arena= 0;
DBUG_VOID_RETURN;
set_params_data_err:
reset_stmt_params(stmt);
my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_stmt_execute");
err:
send_error(thd);
DBUG_VOID_RETURN;
}
/*
Execute prepared statement using parameter values from
lex->prepared_stmt_params and send result to the client using text protocol.
*/
void mysql_sql_stmt_execute(THD *thd, LEX_STRING *stmt_name)
{
Prepared_statement *stmt;
/*
Query text for binary log, or empty string if the query is not put into
binary log.
*/
String expanded_query;
DBUG_ENTER("mysql_sql_stmt_execute");
if (!(stmt= (Prepared_statement*)thd->stmt_map.find_by_name(stmt_name)))
{
my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), stmt_name->length,
stmt_name->str, "EXECUTE");
send_error(thd);
DBUG_VOID_RETURN;
}
if (stmt->param_count != thd->lex->prepared_stmt_params.elements)
{
my_error(ER_WRONG_ARGUMENTS, MYF(0), "EXECUTE");
send_error(thd);
DBUG_VOID_RETURN;
}
thd->stmt_backup.set_statement(thd);
thd->set_statement(stmt);
if (stmt->set_params_from_vars(stmt,
thd->stmt_backup.lex->prepared_stmt_params,
&expanded_query))
{
my_error(ER_WRONG_ARGUMENTS, MYF(0), "EXECUTE");
send_error(thd);
}
thd->current_arena= stmt;
execute_stmt(thd, stmt, &expanded_query);
thd->current_arena= 0;
DBUG_VOID_RETURN;
}
/*
Execute prepared statement.
SYNOPSIS
execute_stmt()
thd Current thread
stmt Statement to execute
expanded_query If binary log is enabled, query string with parameter
placeholders replaced with actual values. Otherwise empty
string.
NOTES
Caller must set parameter values and thd::protocol.
*/
static void execute_stmt(THD *thd, Prepared_statement *stmt,
String *expanded_query)
{
DBUG_ENTER("execute_stmt");
reset_stmt_for_execute(thd, stmt->lex);
if (expanded_query->length() &&
alloc_query(thd, (char *)expanded_query->ptr(),
expanded_query->length()+1))
{
my_error(ER_OUTOFMEMORY, 0, expanded_query->length());
DBUG_VOID_RETURN;
}
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),QUERY_PRIOR);
mysql_execute_command(thd);
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(), WAIT_PRIOR);
thd->lex->unit.cleanup();
cleanup_items(stmt->free_list);
reset_stmt_params(stmt);
close_thread_tables(thd); // to close derived tables
thd->set_statement(&thd->stmt_backup);
/* Free Items that were created during this execution of the PS. */
free_items(thd->free_list);
/*
In the rest of prepared statements code we assume that free_list
never points to garbage: keep this predicate true.
*/
thd->free_list= 0;
DBUG_VOID_RETURN;
}
/*
COM_FETCH handler: fetches requested amount of rows from cursor
SYNOPSIS
*/
void mysql_stmt_fetch(THD *thd, char *packet, uint packet_length)
{
/* assume there is always place for 8-16 bytes */
ulong stmt_id= uint4korr(packet);
ulong num_rows= uint4korr(packet+=4);
Statement *stmt;
int error;
DBUG_ENTER("mysql_stmt_fetch");
if (!(stmt= thd->stmt_map.find(stmt_id)) ||
!stmt->cursor ||
!stmt->cursor->is_open())
{
my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), stmt_id, "fetch");
send_error(thd);
DBUG_VOID_RETURN;
}
thd->stmt_backup.set_statement(thd);
thd->stmt_backup.set_item_arena(thd);
thd->set_statement(stmt);
stmt->cursor->init_thd(thd);
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(), QUERY_PRIOR);
thd->protocol= &thd->protocol_prep; // Switch to binary protocol
error= stmt->cursor->fetch(num_rows);
thd->protocol= &thd->protocol_simple; // Use normal protocol
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(), WAIT_PRIOR);
/* Restore THD state */
stmt->cursor->reset_thd(thd);
thd->set_statement(&thd->stmt_backup);
thd->set_item_arena(&thd->stmt_backup);
if (error && error != -4)
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_VOID_RETURN;
}
/*
Reset a prepared statement in case there was a recoverable error.
SYNOPSIS
mysql_stmt_reset()
thd Thread handle
packet Packet with stmt id
DESCRIPTION
This function resets statement to the state it was right after prepare.
It can be used to:
- clear an error happened during mysql_stmt_send_long_data
- cancel long data stream for all placeholders without
having to call mysql_stmt_execute.
Sends 'OK' packet in case of success (statement was reset)
or 'ERROR' packet (unrecoverable error/statement not found/etc).
*/
void mysql_stmt_reset(THD *thd, char *packet)
{
/* There is always space for 4 bytes in buffer */
ulong stmt_id= uint4korr(packet);
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_reset");
if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_reset",
SEND_ERROR)))
DBUG_VOID_RETURN;
stmt->get_longdata_error= 0;
/*
Clear parameters from data which could be set by
mysql_stmt_send_long_data() call.
*/
reset_stmt_params(stmt);
send_ok(thd);
DBUG_VOID_RETURN;
}
/*
Delete a prepared statement from memory.
Note: we don't send any reply to that command.
*/
void mysql_stmt_free(THD *thd, char *packet)
{
/* There is always space for 4 bytes in packet buffer */
ulong stmt_id= uint4korr(packet);
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_free");
if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_close",
DONT_SEND_ERROR)))
DBUG_VOID_RETURN;
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
DBUG_VOID_RETURN;
}
/*
Long data in pieces from client
SYNOPSIS
mysql_stmt_get_longdata()
thd Thread handle
pos String to append
packet_length Length of string
DESCRIPTION
Get a part of a long data.
To make the protocol efficient, we are not sending any return packages
here.
If something goes wrong, then we will send the error on 'execute'
We assume that the client takes care of checking that all parts are sent
to the server. (No checking that we get a 'end of column' in the server)
*/
void mysql_stmt_get_longdata(THD *thd, char *packet, ulong packet_length)
{
ulong stmt_id;
uint param_number;
Prepared_statement *stmt;
Item_param *param;
char *packet_end= packet + packet_length - 1;
DBUG_ENTER("mysql_stmt_get_longdata");
#ifndef EMBEDDED_LIBRARY
/* Minimal size of long data packet is 6 bytes */
if ((ulong) (packet_end - packet) < MYSQL_LONG_DATA_HEADER)
{
my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_stmt_send_long_data");
DBUG_VOID_RETURN;
}
#endif
stmt_id= uint4korr(packet);
packet+= 4;
if (!(stmt=find_prepared_statement(thd, stmt_id, "mysql_stmt_send_long_data",
DONT_SEND_ERROR)))
DBUG_VOID_RETURN;
param_number= uint2korr(packet);
packet+= 2;
#ifndef EMBEDDED_LIBRARY
if (param_number >= stmt->param_count)
{
/* Error will be sent in execute call */
stmt->get_longdata_error= 1;
stmt->last_errno= ER_WRONG_ARGUMENTS;
sprintf(stmt->last_error, ER(ER_WRONG_ARGUMENTS),
"mysql_stmt_send_long_data");
DBUG_VOID_RETURN;
}
#endif
param= stmt->param_array[param_number];
#ifndef EMBEDDED_LIBRARY
param->set_longdata(packet, (ulong) (packet_end - packet));
#else
param->set_longdata(thd->extra_data, thd->extra_length);
#endif
DBUG_VOID_RETURN;
}
Prepared_statement::Prepared_statement(THD *thd_arg)
:Statement(thd_arg),
thd(thd_arg),
param_array(0),
param_count(0),
last_errno(0),
get_longdata_error(0)
{
*last_error= '\0';
}
void Prepared_statement::setup_set_params()
{
/* Setup binary logging */
if (mysql_bin_log.is_open() && is_update_query(lex->sql_command))
{
set_params_from_vars= insert_params_from_vars_with_log;
#ifndef EMBEDDED_LIBRARY
set_params= insert_params_withlog;
#else
set_params_data= emb_insert_params_withlog;
#endif
}
else
{
set_params_from_vars= insert_params_from_vars;
#ifndef EMBEDDED_LIBRARY
set_params= insert_params;
#else
set_params_data= emb_insert_params;
#endif
}
}
Prepared_statement::~Prepared_statement()
{
if (cursor)
cursor->Cursor::~Cursor();
free_items(free_list);
}
Statement::Type Prepared_statement::type() const
{
return PREPARED_STATEMENT;
}
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