~drizzle-trunk/drizzle/development

/* 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 */

#include <drizzled/server_includes.h>

#include <drizzled/error.h>

#include <drizzled/table.h>

#include <drizzled/session.h>

#include <drizzled/current_session.h>

#include <drizzled/field/timestamp.h>

#include <drizzled/field/varstring.h>

#include "heap.h"

#include "ha_heap.h"

#include "heapdef.h"

#include <string>

using namespace std;

static const string engine_name("MEMORY");

pthread_mutex_t THR_LOCK_heap= PTHREAD_MUTEX_INITIALIZER;

static const char *ha_heap_exts[] = {

  NULL

};

class HeapEngine : public StorageEngine

{

public:

  HeapEngine(string name_arg) : StorageEngine(name_arg, HTON_CAN_RECREATE)

  {

    addAlias("HEAP");

  }

  virtual handler *create(TableShare *table,

                          MEM_ROOT *mem_root)

  {

    return new (mem_root) ha_heap(this, table);

  }

  const char **bas_ext() const {

    return ha_heap_exts;

  }

  int createTableImpl(Session *session, const char *table_name,

                      Table *table_arg, HA_CREATE_INFO *create_info);

  /* For whatever reason, internal tables can be created by handler::open()

     for HEAP.

     Instead of diving down a rat hole, let's just cry ourselves to sleep

     at night with this odd hackish workaround.

   */

  int heap_create_table(Session *session, const char *table_name,

                        Table *table_arg, HA_CREATE_INFO *create_info,

                        bool internal_table,

                        HP_SHARE **internal_share);

  int renameTableImpl(Session*, const char * from, const char * to);

  int deleteTableImpl(Session *, const string table_path);

};

/*

  We have to ignore ENOENT entries as the HEAP table is created on open and

  not when doing a CREATE on the table.

*/

int HeapEngine::deleteTableImpl(Session*, const string table_path)

{

  return heap_delete_table(table_path.c_str());

}

static HeapEngine *heap_storage_engine= NULL;

int heap_init(PluginRegistry &registry)

{

  heap_storage_engine= new HeapEngine(engine_name);

  registry.add(heap_storage_engine);

  pthread_mutex_init(&THR_LOCK_heap, MY_MUTEX_INIT_FAST);

  return 0;

}

int heap_deinit(PluginRegistry &registry)

{

  registry.remove(heap_storage_engine);

  delete heap_storage_engine;

  pthread_mutex_destroy(&THR_LOCK_heap);

  return hp_panic(HA_PANIC_CLOSE);

}

/*****************************************************************************

** HEAP tables

*****************************************************************************/

ha_heap::ha_heap(StorageEngine *engine_arg, TableShare *table_arg)

  :handler(engine_arg, table_arg), file(0), records_changed(0), key_stat_version(0),

  internal_table(0)

{}

/*

  Hash index statistics is updated (copied from HP_KEYDEF::hash_buckets to

  rec_per_key) after 1/HEAP_STATS_UPDATE_THRESHOLD fraction of table records

  have been inserted/updated/deleted. delete_all_rows() and table flush cause

  immediate update.

  NOTE

   hash index statistics must be updated when number of table records changes

   from 0 to non-zero value and vice versa. Otherwise records_in_range may

   erroneously return 0 and 'range' may miss records.

*/

#define HEAP_STATS_UPDATE_THRESHOLD 10

int ha_heap::open(const char *name, int mode, uint32_t test_if_locked)

{

  if ((test_if_locked & HA_OPEN_INTERNAL_TABLE) || (!(file= heap_open(name, mode)) && my_errno == ENOENT))

  {

    HA_CREATE_INFO create_info;

    internal_table= test(test_if_locked & HA_OPEN_INTERNAL_TABLE);

    memset(&create_info, 0, sizeof(create_info));

    file= 0;

    HP_SHARE *internal_share= NULL;

    if (!heap_storage_engine->heap_create_table(ha_session(), name, table,

                                                &create_info,

                                                internal_table,&internal_share))

    {

        file= internal_table ?

          heap_open_from_share(internal_share, mode) :

          heap_open_from_share_and_register(internal_share, mode);

      if (!file)

      {

         /* Couldn't open table; Remove the newly created table */

        pthread_mutex_lock(&THR_LOCK_heap);

        hp_free(internal_share);

        pthread_mutex_unlock(&THR_LOCK_heap);

      }

      implicit_emptied= 1;

    }

  }

  ref_length= sizeof(HEAP_PTR);

  if (file)

  {

    /* Initialize variables for the opened table */

    set_keys_for_scanning();

    /*

      We cannot run update_key_stats() here because we do not have a

      lock on the table. The 'records' count might just be changed

      temporarily at this moment and we might get wrong statistics (Bug

      #10178). Instead we request for update. This will be done in

      ha_heap::info(), which is always called before key statistics are

      used.

    */

    key_stat_version= file->s->key_stat_version-1;

  }

  return (file ? 0 : 1);

}

int ha_heap::close(void)

{

  return internal_table ? hp_close(file) : heap_close(file);

}

/*

  Create a copy of this table

  DESCRIPTION

    Do same as default implementation but use file->s->name instead of

    table->s->path. This is needed by Windows where the clone() call sees

    '/'-delimited path in table->s->path, while ha_peap::open() was called

    with '\'-delimited path.

*/

handler *ha_heap::clone(MEM_ROOT *mem_root)

{

  handler *new_handler= get_new_handler(table->s, mem_root, table->s->db_type());

  if (new_handler && !new_handler->ha_open(table, file->s->name, table->db_stat,

                                           HA_OPEN_IGNORE_IF_LOCKED))

    return new_handler;

  return NULL;  /* purecov: inspected */

}

const char *ha_heap::index_type(uint32_t inx)

{

  return ((table_share->key_info[inx].algorithm == HA_KEY_ALG_BTREE) ?

          "BTREE" : "HASH");

}

uint32_t ha_heap::index_flags(uint32_t inx, uint32_t, bool) const

{

  return ((table_share->key_info[inx].algorithm == HA_KEY_ALG_BTREE) ?

          HA_READ_NEXT | HA_READ_PREV | HA_READ_ORDER | HA_READ_RANGE :

          HA_ONLY_WHOLE_INDEX | HA_KEY_SCAN_NOT_ROR);

}

/*

  Compute which keys to use for scanning

  SYNOPSIS

    set_keys_for_scanning()

    no parameter

  DESCRIPTION

    Set the bitmap btree_keys, which is used when the upper layers ask

    which keys to use for scanning. For each btree index the

    corresponding bit is set.

  RETURN

    void

*/

void ha_heap::set_keys_for_scanning(void)

{

  btree_keys.reset();

  for (uint32_t i= 0 ; i < table->s->keys ; i++)

  {

    if (table->key_info[i].algorithm == HA_KEY_ALG_BTREE)

      btree_keys.set(i);

  }

}

void ha_heap::update_key_stats()

{

  for (uint32_t i= 0; i < table->s->keys; i++)

  {

    KEY *key=table->key_info+i;

    if (!key->rec_per_key)

      continue;

    if (key->algorithm != HA_KEY_ALG_BTREE)

    {

      if (key->flags & HA_NOSAME)

        key->rec_per_key[key->key_parts-1]= 1;

      else

      {

        ha_rows hash_buckets= file->s->keydef[i].hash_buckets;

        uint32_t no_records= hash_buckets ? (uint) (file->s->records/hash_buckets) : 2;

        if (no_records < 2)

          no_records= 2;

        key->rec_per_key[key->key_parts-1]= no_records;

      }

    }

  }

  records_changed= 0;

  /* At the end of update_key_stats() we can proudly claim they are OK. */

  key_stat_version= file->s->key_stat_version;

}

int ha_heap::write_row(unsigned char * buf)

{

  int res;

  ha_statistic_increment(&SSV::ha_write_count);

  if (table->next_number_field && buf == table->record[0])

  {

    if ((res= update_auto_increment()))

      return res;

  }

  res= heap_write(file,buf);

  if (!res && (++records_changed*HEAP_STATS_UPDATE_THRESHOLD >

               file->s->records))

  {

    /*

       We can perform this safely since only one writer at the time is

       allowed on the table.

    */

    file->s->key_stat_version++;

  }

  return res;

}

int ha_heap::update_row(const unsigned char * old_data, unsigned char * new_data)

{

  int res;

  ha_statistic_increment(&SSV::ha_update_count);

  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)

    table->timestamp_field->set_time();

  res= heap_update(file,old_data,new_data);

  if (!res && ++records_changed*HEAP_STATS_UPDATE_THRESHOLD >

              file->s->records)

  {

    /*

       We can perform this safely since only one writer at the time is

       allowed on the table.

    */

    file->s->key_stat_version++;

  }

  return res;

}

int ha_heap::delete_row(const unsigned char * buf)

{

  int res;

  ha_statistic_increment(&SSV::ha_delete_count);

  res= heap_delete(file,buf);

  if (!res && table->s->tmp_table == NO_TMP_TABLE &&

      ++records_changed*HEAP_STATS_UPDATE_THRESHOLD > file->s->records)

  {

    /*

       We can perform this safely since only one writer at the time is

       allowed on the table.

    */

    file->s->key_stat_version++;

  }

  return res;

}

int ha_heap::index_read_map(unsigned char *buf, const unsigned char *key,

                            key_part_map keypart_map,

                            enum ha_rkey_function find_flag)

{

  assert(inited==INDEX);

  ha_statistic_increment(&SSV::ha_read_key_count);

  int error = heap_rkey(file,buf,active_index, key, keypart_map, find_flag);

  table->status = error ? STATUS_NOT_FOUND : 0;

  return error;

}

int ha_heap::index_read_last_map(unsigned char *buf, const unsigned char *key,

                                 key_part_map keypart_map)

{

  assert(inited==INDEX);

  ha_statistic_increment(&SSV::ha_read_key_count);

  int error= heap_rkey(file, buf, active_index, key, keypart_map,

		       HA_READ_PREFIX_LAST);

  table->status= error ? STATUS_NOT_FOUND : 0;

  return error;

}

int ha_heap::index_read_idx_map(unsigned char *buf, uint32_t index, const unsigned char *key,

                                key_part_map keypart_map,

                                enum ha_rkey_function find_flag)

{

  ha_statistic_increment(&SSV::ha_read_key_count);

  int error = heap_rkey(file, buf, index, key, keypart_map, find_flag);

  table->status = error ? STATUS_NOT_FOUND : 0;

  return error;

}

int ha_heap::index_next(unsigned char * buf)

{

  assert(inited==INDEX);

  ha_statistic_increment(&SSV::ha_read_next_count);

  int error=heap_rnext(file,buf);

  table->status=error ? STATUS_NOT_FOUND: 0;

  return error;

}

int ha_heap::index_prev(unsigned char * buf)

{

  assert(inited==INDEX);

  ha_statistic_increment(&SSV::ha_read_prev_count);

  int error=heap_rprev(file,buf);

  table->status=error ? STATUS_NOT_FOUND: 0;

  return error;

}

int ha_heap::index_first(unsigned char * buf)

{

  assert(inited==INDEX);

  ha_statistic_increment(&SSV::ha_read_first_count);

  int error=heap_rfirst(file, buf, active_index);

  table->status=error ? STATUS_NOT_FOUND: 0;

  return error;

}

int ha_heap::index_last(unsigned char * buf)

{

  assert(inited==INDEX);

  ha_statistic_increment(&SSV::ha_read_last_count);

  int error=heap_rlast(file, buf, active_index);

  table->status=error ? STATUS_NOT_FOUND: 0;

  return error;

}

int ha_heap::rnd_init(bool scan)

{

  return scan ? heap_scan_init(file) : 0;

}

int ha_heap::rnd_next(unsigned char *buf)

{

  ha_statistic_increment(&SSV::ha_read_rnd_next_count);

  int error=heap_scan(file, buf);

  table->status=error ? STATUS_NOT_FOUND: 0;

  return error;

}

int ha_heap::rnd_pos(unsigned char * buf, unsigned char *pos)

{

  int error;

  HEAP_PTR heap_position;

  ha_statistic_increment(&SSV::ha_read_rnd_count);

  memcpy(&heap_position, pos, sizeof(HEAP_PTR));

  error=heap_rrnd(file, buf, heap_position);

  table->status=error ? STATUS_NOT_FOUND: 0;

  return error;

}

void ha_heap::position(const unsigned char *)

{

  *(HEAP_PTR*) ref= heap_position(file);	// Ref is aligned

}

int ha_heap::info(uint32_t flag)

{

  HEAPINFO hp_info;

  (void) heap_info(file,&hp_info,flag);

  errkey=                     hp_info.errkey;

  stats.records=              hp_info.records;

  stats.deleted=              hp_info.deleted;

  stats.mean_rec_length=      hp_info.reclength;

  stats.data_file_length=     hp_info.data_length;

  stats.index_file_length=    hp_info.index_length;

  stats.max_data_file_length= hp_info.max_records * hp_info.reclength;

  stats.delete_length=        hp_info.deleted * hp_info.reclength;

  if (flag & HA_STATUS_AUTO)

    stats.auto_increment_value= hp_info.auto_increment;

  /*

    If info() is called for the first time after open(), we will still

    have to update the key statistics. Hoping that a table lock is now

    in place.

  */

  if (key_stat_version != file->s->key_stat_version)

    update_key_stats();

  return 0;

}

enum row_type ha_heap::get_row_type() const

{

  if (file->s->recordspace.is_variable_size)

    return ROW_TYPE_DYNAMIC;

  return ROW_TYPE_FIXED;

}

int ha_heap::extra(enum ha_extra_function operation)

{

  return heap_extra(file,operation);

}

int ha_heap::reset()

{

  return heap_reset(file);

}

int ha_heap::delete_all_rows()

{

  heap_clear(file);

  if (table->s->tmp_table == NO_TMP_TABLE)

  {

    /*

       We can perform this safely since only one writer at the time is

       allowed on the table.

    */

    file->s->key_stat_version++;

  }

  return 0;

}

int ha_heap::external_lock(Session *, int)

{

  return 0;					// No external locking

}

/*

  Disable indexes.

  SYNOPSIS

    disable_indexes()

    mode        mode of operation:

                HA_KEY_SWITCH_NONUNIQ      disable all non-unique keys

                HA_KEY_SWITCH_ALL          disable all keys

                HA_KEY_SWITCH_NONUNIQ_SAVE dis. non-uni. and make persistent

                HA_KEY_SWITCH_ALL_SAVE     dis. all keys and make persistent

  DESCRIPTION

    Disable indexes and clear keys to use for scanning.

  IMPLEMENTATION

    HA_KEY_SWITCH_NONUNIQ       is not implemented.

    HA_KEY_SWITCH_NONUNIQ_SAVE  is not implemented with HEAP.

    HA_KEY_SWITCH_ALL_SAVE      is not implemented with HEAP.

  RETURN

    0  ok

    HA_ERR_WRONG_COMMAND  mode not implemented.

*/

int ha_heap::disable_indexes(uint32_t mode)

{

  int error;

  if (mode == HA_KEY_SWITCH_ALL)

  {

    if (!(error= heap_disable_indexes(file)))

      set_keys_for_scanning();

  }

  else

  {

    /* mode not implemented */

    error= HA_ERR_WRONG_COMMAND;

  }

  return error;

}

/*

  Enable indexes.

  SYNOPSIS

    enable_indexes()

    mode        mode of operation:

                HA_KEY_SWITCH_NONUNIQ      enable all non-unique keys

                HA_KEY_SWITCH_ALL          enable all keys

                HA_KEY_SWITCH_NONUNIQ_SAVE en. non-uni. and make persistent

                HA_KEY_SWITCH_ALL_SAVE     en. all keys and make persistent

  DESCRIPTION

    Enable indexes and set keys to use for scanning.

    The indexes might have been disabled by disable_index() before.

    The function works only if both data and indexes are empty,

    since the heap storage engine cannot repair the indexes.

    To be sure, call handler::delete_all_rows() before.

  IMPLEMENTATION

    HA_KEY_SWITCH_NONUNIQ       is not implemented.

    HA_KEY_SWITCH_NONUNIQ_SAVE  is not implemented with HEAP.

    HA_KEY_SWITCH_ALL_SAVE      is not implemented with HEAP.

  RETURN

    0  ok

    HA_ERR_CRASHED  data or index is non-empty. Delete all rows and retry.

    HA_ERR_WRONG_COMMAND  mode not implemented.

*/

int ha_heap::enable_indexes(uint32_t mode)

{

  int error;

  if (mode == HA_KEY_SWITCH_ALL)

  {

    if (!(error= heap_enable_indexes(file)))

      set_keys_for_scanning();

  }

  else

  {

    /* mode not implemented */

    error= HA_ERR_WRONG_COMMAND;

  }

  return error;

}

/*

  Test if indexes are disabled.

  SYNOPSIS

    indexes_are_disabled()

    no parameters

  RETURN

    0  indexes are not disabled

    1  all indexes are disabled

   [2  non-unique indexes are disabled - NOT YET IMPLEMENTED]

*/

int ha_heap::indexes_are_disabled(void)

{

  return heap_indexes_are_disabled(file);

}

THR_LOCK_DATA **ha_heap::store_lock(Session *,

                                    THR_LOCK_DATA **to,

                                    enum thr_lock_type lock_type)

{

  if (lock_type != TL_IGNORE && file->lock.type == TL_UNLOCK)

    file->lock.type=lock_type;

  *to++= &file->lock;

  return to;

}

void ha_heap::drop_table(const char *)

{

  file->s->delete_on_close= 1;

  close();

}

int HeapEngine::renameTableImpl(Session*, const char *from, const char *to)

{

  return heap_rename(from,to);

}

ha_rows ha_heap::records_in_range(uint32_t inx, key_range *min_key,

                                  key_range *max_key)

{

  KEY *key=table->key_info+inx;

  if (key->algorithm == HA_KEY_ALG_BTREE)

    return hp_rb_records_in_range(file, inx, min_key, max_key);

  if (!min_key || !max_key ||

      min_key->length != max_key->length ||

      min_key->length != key->key_length ||

      min_key->flag != HA_READ_KEY_EXACT ||

      max_key->flag != HA_READ_AFTER_KEY)

    return HA_POS_ERROR;			// Can only use exact keys

  if (stats.records <= 1)

    return stats.records;

  /* Assert that info() did run. We need current statistics here. */

  assert(key_stat_version == file->s->key_stat_version);

  return key->rec_per_key[key->key_parts-1];

}

int HeapEngine::createTableImpl(Session *session, const char *table_name,

                                Table *table_arg,

                                HA_CREATE_INFO *create_info)

{

  HP_SHARE *internal_share;

  return heap_create_table(session, table_name, table_arg, create_info,

                           false, &internal_share);

}

int HeapEngine::heap_create_table(Session *session, const char *table_name,

                             Table *table_arg, HA_CREATE_INFO *create_info,

                             bool internal_table, HP_SHARE **internal_share)

{

  uint32_t key, parts, mem_per_row_keys= 0, keys= table_arg->s->keys;

  uint32_t auto_key= 0, auto_key_type= 0;

  uint32_t max_key_fieldnr = 0, key_part_size = 0, next_field_pos = 0;

  uint32_t column_idx, column_count= table_arg->s->fields;

  HP_COLUMNDEF *columndef;

  HP_KEYDEF *keydef;

  HA_KEYSEG *seg;

  char buff[FN_REFLEN];

  int error;

  TableShare *share= table_arg->s;

  bool found_real_auto_increment= 0;

  if (!(columndef= (HP_COLUMNDEF*) malloc(column_count * sizeof(HP_COLUMNDEF))))

    return my_errno;

  for (column_idx= 0; column_idx < column_count; column_idx++)

  {

    Field* field= *(table_arg->field + column_idx);

    HP_COLUMNDEF* column= columndef + column_idx;

    column->type= (uint16_t)field->type();

    column->length= field->pack_length();

    column->offset= field->offset(field->table->record[0]);

    if (field->null_bit)

    {

      column->null_bit= field->null_bit;

      column->null_pos= (uint) (field->null_ptr - (unsigned char*) table_arg->record[0]);

    }

    else

    {

      column->null_bit= 0;

      column->null_pos= 0;

    }

    if (field->type() == DRIZZLE_TYPE_VARCHAR)

    {

      column->length_bytes= (uint8_t)(((Field_varstring*)field)->length_bytes);

    }

    else

    {

      column->length_bytes= 0;

    }

  }

  for (key= parts= 0; key < keys; key++)

    parts+= table_arg->key_info[key].key_parts;

  if (!(keydef= (HP_KEYDEF*) malloc(keys * sizeof(HP_KEYDEF) +

				    parts * sizeof(HA_KEYSEG))))

  {

    free((void *) columndef);

    return my_errno;

  }

  seg= reinterpret_cast<HA_KEYSEG*> (keydef + keys);

  for (key= 0; key < keys; key++)

  {

    KEY *pos= table_arg->key_info+key;

    KEY_PART_INFO *key_part=     pos->key_part;

    KEY_PART_INFO *key_part_end= key_part + pos->key_parts;

    keydef[key].keysegs=   (uint) pos->key_parts;

    keydef[key].flag=      (pos->flags & (HA_NOSAME | HA_NULL_ARE_EQUAL));

    keydef[key].seg=       seg;

    switch (pos->algorithm) {

    case HA_KEY_ALG_UNDEF:

    case HA_KEY_ALG_HASH:

      keydef[key].algorithm= HA_KEY_ALG_HASH;

      mem_per_row_keys+= sizeof(char*) * 2; // = sizeof(HASH_INFO)