mariadb-columnstore-engine/dbcon/mysql/ha_mcs.h

/* Copyright (C) 2014 InfiniDB, Inc.
   Copyright (C) 2016 MariaDB Corporation
   Copyright (C) 2019 MariaDB Corporation

   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., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */
#ifndef HA_MCS_H__
#define HA_MCS_H__

#include <my_config.h>
#include "idb_mysql.h"
#include "ha_mcs_sysvars.h"
#include "ha_maria.h"

extern handlerton* mcs_hton;

/** @brief
  COLUMNSTORE_SHARE is a structure that will be shared among all open handlers.
  This example implements the minimum of what you will probably need.
*/
typedef struct st_mcs_share
{
    char* table_name;
    uint32_t table_name_length, use_count;
    pthread_mutex_t mutex;
    THR_LOCK lock;
} COLUMNSTORE_SHARE;

/** @brief
  Class definition for the storage engine
*/
class ha_mcs: public handler
{
    THR_LOCK_DATA lock;      ///< MySQL lock
    COLUMNSTORE_SHARE* share;    ///< Shared lock info
    ulonglong int_table_flags;
    // We are using a vector here to mimick the stack functionality
    // using push_back() and pop_back()
    // as apparently there is a linker error on the std::stack<COND*>::pop()
    // call on Ubuntu18.
    std::vector<COND*> condStack;

public:
    ha_mcs(handlerton* hton, TABLE_SHARE* table_arg);
    virtual ~ha_mcs()
    {
    }

    /** @brief
      The name that will be used for display purposes.
     */
    const char* table_type() const
    {
        return "ColumnStore";
    }

    /** @brief
      The name of the index type that will be used for display.
      Don't implement this method unless you really have indexes.
     */
    //const char *index_type(uint32_t inx) { return "HASH"; }

    /** @brief
      The file extensions.
     */
    const char** bas_ext() const;

    /** @brief
      This is a list of flags that indicate what functionality the storage engine
      implements. The current table flags are documented in handler.h
    */
    ulonglong table_flags() const
    {
        return int_table_flags;
    }

    /** @brief
      This is a bitmap of flags that indicates how the storage engine
      implements indexes. The current index flags are documented in
      handler.h. If you do not implement indexes, just return zero here.

        @details
      part is the key part to check. First key part is 0.
      If all_parts is set, MySQL wants to know the flags for the combined
      index, up to and including 'part'.
    */
    ulong index_flags(uint32_t inx, uint32_t part, bool all_parts) const
    {
        return 0;
    }


    /** @brief
      unireg.cc will call max_supported_record_length(), max_supported_keys(),
      max_supported_key_parts(), uint32_t max_supported_key_length()
      to make sure that the storage engine can handle the data it is about to
      send. Return *real* limits of your storage engine here; MySQL will do
      min(your_limits, MySQL_limits) automatically.
     */
    uint32_t max_supported_record_length() const
    {
        return HA_MAX_REC_LENGTH;
    }

    /** @brief
      Called in test_quick_select to determine if indexes should be used.
    */
    virtual double scan_time()
    {
        return (double) (stats.records + stats.deleted) / 20.0 + 10;
    }

    /*
      Everything below are methods that we implement in ha_example.cc.

      Most of these methods are not obligatory, skip them and
      MySQL will treat them as not implemented
    */

    /** @brief
      We implement this in ha_example.cc; it's a required method.
    */
    int open(const char* name, int mode, uint32_t test_if_locked);    // required

    /** @brief
      We implement this in ha_example.cc; it's a required method.
    */
    int close(void);                                              // required

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int write_row(const uchar* buf);

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    void start_bulk_insert(ha_rows rows, uint flags = 0) ;
    void start_bulk_insert_from_cache(ha_rows rows, uint flags = 0) ;

    /**@bug 2461 - Overloaded end_bulk_insert.  MariaDB uses the abort bool, mysql does not. */
    int end_bulk_insert() ;

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int update_row(const uchar* old_data, uchar* new_data);
    int direct_update_rows_init(List<Item> *update_fields);
    int direct_update_rows(ha_rows *update_rows);
    int direct_update_rows(ha_rows *update_rows, ha_rows *found_rows);

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int delete_row(const uchar* buf);
    int direct_delete_rows_init();
    int direct_delete_rows(ha_rows *deleted_rows);

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int index_read_map(uchar* buf, const uchar* key,
                       key_part_map keypart_map, enum ha_rkey_function find_flag);

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int index_next(uchar* buf);

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int index_prev(uchar* buf);

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int index_first(uchar* buf);

    /** @brief
      We implement this in ha_example.cc. It's not an obligatory method;
      skip it and and MySQL will treat it as not implemented.
    */
    int index_last(uchar* buf);

    /** @brief
      Unlike index_init(), rnd_init() can be called two consecutive times
      without rnd_end() in between (it only makes sense if scan=1). In this
      case, the second call should prepare for the new table scan (e.g if
      rnd_init() allocates the cursor, the second call should position the
      cursor to the start of the table; no need to deallocate and allocate
      it again. This is a required method.
    */
    int rnd_init(bool scan);                                      //required
    int rnd_end();
    int rnd_next(uchar* buf);                                     ///< required
    int rnd_pos(uchar* buf, uchar* pos);                          ///< required
    int reset() override;
    void position(const uchar* record);                           ///< required
    int info(uint32_t);                                               ///< required
    int extra(enum ha_extra_function operation);
    int external_lock(THD* thd, int lock_type);                   ///< required
    int delete_all_rows(void);
    ha_rows records_in_range(uint32_t inx, key_range* min_key,
                             key_range* max_key);
    int delete_table(const char* from);
    int rename_table(const char* from, const char* to);
    int create(const char* name, TABLE* form,
               HA_CREATE_INFO* create_info);                      ///< required

    THR_LOCK_DATA** store_lock(THD* thd, THR_LOCK_DATA** to,
                               enum thr_lock_type lock_type);     ///< required
    const COND* cond_push(const COND* cond);
    void cond_pop() override;
    uint8 table_cache_type()
    {
        return HA_CACHE_TBL_NOCACHE;
    }

    int repair(THD* thd, HA_CHECK_OPT* check_opt);
    bool is_crashed() const;
};


class ha_mcs_cache_share
{
  ha_mcs_cache_share *next;                         /* Next open share */
  const char *name;
  uint open_count;
public:
  ulonglong cached_rows;
  THR_LOCK org_lock;
  friend ha_mcs_cache_share *find_cache_share(const char *name,
                                              ulonglong cached_rows);
  void close();
};



class ha_mcs_cache :public ha_mcs
{
  typedef ha_mcs parent;
  int original_lock_type;
  bool insert_command, cache_locked;

public:
  uint lock_counter;
  ha_maria *cache_handler;
  ha_mcs_cache_share *share;

  ha_mcs_cache(handlerton *hton, TABLE_SHARE *table_arg, MEM_ROOT *mem_root);
  ~ha_mcs_cache();

  /*
    The following functions duplicates calls to derived handler and
    cache handler
  */

  int create(const char *name, TABLE *table_arg,
             HA_CREATE_INFO *ha_create_info);
  int open(const char *name, int mode, uint open_flags);
  int delete_table(const char *name);
  int rename_table(const char *from, const char *to);
  int delete_all_rows(void);
  int close(void);

  uint lock_count(void) const;
  THR_LOCK_DATA **store_lock(THD *thd,
                             THR_LOCK_DATA **to,
                             enum thr_lock_type lock_type);
  int external_lock(THD *thd, int lock_type);
  int repair(THD *thd, HA_CHECK_OPT *check_opt);
  bool is_crashed() const;

  /*
    Write row uses cache_handler, for normal inserts, otherwise derived
    handler
  */
  int write_row(const uchar *buf);
  void start_bulk_insert(ha_rows rows, uint flags);
  int end_bulk_insert();

  /* Cache functions */
  void free_locks();
  ha_rows num_rows_cached();
  int flush_insert_cache();
  friend my_bool get_status_and_flush_cache(void *param,
                                            my_bool concurrent_insert);
  friend my_bool cache_start_trans(void *param);
};

#endif //HA_MCS_H__