/* Copyright (C) 2000,2004 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 */ #ifdef USE_PRAGMA_IMPLEMENTATION #pragma implementation // gcc: Class implementation #endif #include "mysql_priv.h" #include <myisampack.h> #include "ha_heap.h" static handler *heap_create_handler(TABLE_SHARE *table); static const char heap_hton_name[]= "MEMORY"; static const char heap_hton_comment[]= "Hash based, stored in memory, useful for temporary tables"; handlerton heap_hton= { MYSQL_HANDLERTON_INTERFACE_VERSION, heap_hton_name, SHOW_OPTION_YES, heap_hton_comment, DB_TYPE_HEAP, NULL, 0, /* slot */ 0, /* savepoint size. */ NULL, /* close_connection */ NULL, /* savepoint */ NULL, /* rollback to savepoint */ NULL, /* release savepoint */ NULL, /* commit */ NULL, /* rollback */ NULL, /* prepare */ NULL, /* recover */ NULL, /* commit_by_xid */ NULL, /* rollback_by_xid */ NULL, /* create_cursor_read_view */ NULL, /* set_cursor_read_view */ NULL, /* close_cursor_read_view */ heap_create_handler, /* Create a new handler */ NULL, /* Drop a database */ heap_panic, /* Panic call */ NULL, /* Start Consistent Snapshot */ NULL, /* Flush logs */ NULL, /* Show status */ NULL, /* Partition flags */ NULL, /* Alter table flags */ NULL, /* Alter Tablespace */ NULL, /* Fill Files Table */ HTON_CAN_RECREATE, NULL, /* binlog_func */ NULL, /* binlog_log_query */ NULL /* release_temporary_latches */ }; static handler *heap_create_handler(TABLE_SHARE *table) { return new ha_heap(table); } /***************************************************************************** ** HEAP tables *****************************************************************************/ ha_heap::ha_heap(TABLE_SHARE *table_arg) :handler(&heap_hton, table_arg), file(0), records_changed(0), key_stat_version(0) {} static const char *ha_heap_exts[] = { NullS }; const char **ha_heap::bas_ext() const { return ha_heap_exts; } /* 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, uint test_if_locked) { if (!(file= heap_open(name, mode)) && my_errno == ENOENT) { HA_CREATE_INFO create_info; bzero(&create_info, sizeof(create_info)); if (!create(name, table, &create_info)) { file= heap_open(name, mode); 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 heap_close(file); } /* 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.clear_all(); for (uint i= 0 ; i < table->s->keys ; i++) { if (table->key_info[i].algorithm == HA_KEY_ALG_BTREE) btree_keys.set_bit(i); } } void ha_heap::update_key_stats() { for (uint 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; uint no_records= hash_buckets ? 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(byte * buf) { int res; statistic_increment(table->in_use->status_var.ha_write_count,&LOCK_status); if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT) table->timestamp_field->set_time(); if (table->next_number_field && buf == table->record[0]) update_auto_increment(); 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 byte * old_data, byte * new_data) { int res; statistic_increment(table->in_use->status_var.ha_update_count,&LOCK_status); 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 byte * buf) { int res; statistic_increment(table->in_use->status_var.ha_delete_count,&LOCK_status); 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(byte * buf, const byte * key, uint key_len, enum ha_rkey_function find_flag) { DBUG_ASSERT(inited==INDEX); statistic_increment(table->in_use->status_var.ha_read_key_count, &LOCK_status); int error = heap_rkey(file,buf,active_index, key, key_len, find_flag); table->status = error ? STATUS_NOT_FOUND : 0; return error; } int ha_heap::index_read_last(byte *buf, const byte *key, uint key_len) { DBUG_ASSERT(inited==INDEX); statistic_increment(table->in_use->status_var.ha_read_key_count, &LOCK_status); int error= heap_rkey(file, buf, active_index, key, key_len, HA_READ_PREFIX_LAST); table->status= error ? STATUS_NOT_FOUND : 0; return error; } int ha_heap::index_read_idx(byte * buf, uint index, const byte * key, uint key_len, enum ha_rkey_function find_flag) { statistic_increment(table->in_use->status_var.ha_read_key_count, &LOCK_status); int error = heap_rkey(file, buf, index, key, key_len, find_flag); table->status = error ? STATUS_NOT_FOUND : 0; return error; } int ha_heap::index_next(byte * buf) { DBUG_ASSERT(inited==INDEX); statistic_increment(table->in_use->status_var.ha_read_next_count, &LOCK_status); int error=heap_rnext(file,buf); table->status=error ? STATUS_NOT_FOUND: 0; return error; } int ha_heap::index_prev(byte * buf) { DBUG_ASSERT(inited==INDEX); statistic_increment(table->in_use->status_var.ha_read_prev_count, &LOCK_status); int error=heap_rprev(file,buf); table->status=error ? STATUS_NOT_FOUND: 0; return error; } int ha_heap::index_first(byte * buf) { DBUG_ASSERT(inited==INDEX); statistic_increment(table->in_use->status_var.ha_read_first_count, &LOCK_status); int error=heap_rfirst(file, buf, active_index); table->status=error ? STATUS_NOT_FOUND: 0; return error; } int ha_heap::index_last(byte * buf) { DBUG_ASSERT(inited==INDEX); statistic_increment(table->in_use->status_var.ha_read_last_count, &LOCK_status); 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(byte *buf) { statistic_increment(table->in_use->status_var.ha_read_rnd_next_count, &LOCK_status); int error=heap_scan(file, buf); table->status=error ? STATUS_NOT_FOUND: 0; return error; } int ha_heap::rnd_pos(byte * buf, byte *pos) { int error; HEAP_PTR position; statistic_increment(table->in_use->status_var.ha_read_rnd_count, &LOCK_status); memcpy_fixed((char*) &position,pos,sizeof(HEAP_PTR)); error=heap_rrnd(file, buf, position); table->status=error ? STATUS_NOT_FOUND: 0; return error; } void ha_heap::position(const byte *record) { *(HEAP_PTR*) ref= heap_position(file); // Ref is aligned } void ha_heap::info(uint flag) { HEAPINFO info; (void) heap_info(file,&info,flag); records = info.records; deleted = info.deleted; errkey = info.errkey; mean_rec_length=info.reclength; data_file_length=info.data_length; index_file_length=info.index_length; max_data_file_length= info.max_records* info.reclength; delete_length= info.deleted * info.reclength; if (flag & HA_STATUS_AUTO) auto_increment_value= 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(); } int ha_heap::extra(enum ha_extra_function operation) { return heap_extra(file,operation); } 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(THD *thd, int lock_type) { 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(uint 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(uint 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(THD *thd, 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; } /* We have to ignore ENOENT entries as the HEAP table is created on open and not when doing a CREATE on the table. */ int ha_heap::delete_table(const char *name) { int error= heap_delete_table(name); return error == ENOENT ? 0 : error; } void ha_heap::drop_table(const char *name) { heap_drop_table(file); close(); } int ha_heap::rename_table(const char * from, const char * to) { return heap_rename(from,to); } ha_rows ha_heap::records_in_range(uint 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 (records <= 1) return records; /* Assert that info() did run. We need current statistics here. */ DBUG_ASSERT(key_stat_version == file->s->key_stat_version); return key->rec_per_key[key->key_parts-1]; } int ha_heap::create(const char *name, TABLE *table_arg, HA_CREATE_INFO *create_info) { uint key, parts, mem_per_row= 0, keys= table_arg->s->keys; uint auto_key= 0, auto_key_type= 0; ha_rows max_rows; HP_KEYDEF *keydef; HA_KEYSEG *seg; int error; TABLE_SHARE *share= table_arg->s; bool found_real_auto_increment= 0; for (key= parts= 0; key < keys; key++) parts+= table_arg->key_info[key].key_parts; if (!(keydef= (HP_KEYDEF*) my_malloc(keys * sizeof(HP_KEYDEF) + parts * sizeof(HA_KEYSEG), MYF(MY_WME)))) return my_errno; seg= my_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+= sizeof(char*) * 2; // = sizeof(HASH_INFO) break; case HA_KEY_ALG_BTREE: keydef[key].algorithm= HA_KEY_ALG_BTREE; mem_per_row+=sizeof(TREE_ELEMENT)+pos->key_length+sizeof(char*); break; default: DBUG_ASSERT(0); // cannot happen } for (; key_part != key_part_end; key_part++, seg++) { Field *field= key_part->field; if (pos->algorithm == HA_KEY_ALG_BTREE) seg->type= field->key_type(); else { if ((seg->type = field->key_type()) != (int) HA_KEYTYPE_TEXT && seg->type != HA_KEYTYPE_VARTEXT1 && seg->type != HA_KEYTYPE_VARTEXT2 && seg->type != HA_KEYTYPE_VARBINARY1 && seg->type != HA_KEYTYPE_VARBINARY2) seg->type= HA_KEYTYPE_BINARY; } seg->start= (uint) key_part->offset; seg->length= (uint) key_part->length; seg->flag= key_part->key_part_flag; seg->charset= field->charset(); if (field->null_ptr) { seg->null_bit= field->null_bit; seg->null_pos= (uint) (field->null_ptr - (uchar*) table_arg->record[0]); } else { seg->null_bit= 0; seg->null_pos= 0; } if (field->flags & AUTO_INCREMENT_FLAG && table_arg->found_next_number_field && key == share->next_number_index) { /* Store key number and type for found auto_increment key We have to store type as seg->type can differ from it */ auto_key= key+ 1; auto_key_type= field->key_type(); } } } mem_per_row+= MY_ALIGN(share->reclength + 1, sizeof(char*)); max_rows = (ha_rows) (table_arg->in_use->variables.max_heap_table_size / mem_per_row); if (table_arg->found_next_number_field) { keydef[share->next_number_index].flag|= HA_AUTO_KEY; found_real_auto_increment= share->next_number_key_offset == 0; } HP_CREATE_INFO hp_create_info; hp_create_info.auto_key= auto_key; hp_create_info.auto_key_type= auto_key_type; hp_create_info.auto_increment= (create_info->auto_increment_value ? create_info->auto_increment_value - 1 : 0); hp_create_info.max_table_size=current_thd->variables.max_heap_table_size; hp_create_info.with_auto_increment= found_real_auto_increment; max_rows = (ha_rows) (hp_create_info.max_table_size / mem_per_row); error= heap_create(name, keys, keydef, share->reclength, (ulong) ((share->max_rows < max_rows && share->max_rows) ? share->max_rows : max_rows), (ulong) share->min_rows, &hp_create_info); my_free((gptr) keydef, MYF(0)); if (file) info(HA_STATUS_NO_LOCK | HA_STATUS_CONST | HA_STATUS_VARIABLE); return (error); } void ha_heap::update_create_info(HA_CREATE_INFO *create_info) { table->file->info(HA_STATUS_AUTO); if (!(create_info->used_fields & HA_CREATE_USED_AUTO)) create_info->auto_increment_value= auto_increment_value; } ulonglong ha_heap::get_auto_increment() { ha_heap::info(HA_STATUS_AUTO); return auto_increment_value; } bool ha_heap::check_if_incompatible_data(HA_CREATE_INFO *info, uint table_changes) { /* Check that auto_increment value was not changed */ if ((table_changes != IS_EQUAL_YES && info->used_fields & HA_CREATE_USED_AUTO) && info->auto_increment_value != 0) return COMPATIBLE_DATA_NO; return COMPATIBLE_DATA_YES; } mysql_declare_plugin(heap) { MYSQL_STORAGE_ENGINE_PLUGIN, &heap_hton, heap_hton_name, "MySQL AB", heap_hton_comment, NULL, NULL, 0x0100, /* 1.0 */ 0 } mysql_declare_plugin_end;