ha_isam.cpp
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:12k
- /* Copyright (C) 2000 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"
- #ifdef HAVE_ISAM
- #include <m_ctype.h>
- #include <myisampack.h>
- #include "ha_isam.h"
- #ifndef MASTER
- #include "../srclib/isam/isamdef.h"
- #else
- #include "../isam/isamdef.h"
- #endif
- /*****************************************************************************
- ** isam tables
- *****************************************************************************/
- const char **ha_isam::bas_ext() const
- { static const char *ext[]= { ".ISM",".ISD", NullS }; return ext; }
- int ha_isam::open(const char *name, int mode, uint test_if_locked)
- {
- char name_buff[FN_REFLEN];
- if (!(file=nisam_open(fn_format(name_buff,name,"","",2 | 4), mode,
- test_if_locked)))
- return (my_errno ? my_errno : -1);
- if (!(test_if_locked == HA_OPEN_WAIT_IF_LOCKED ||
- test_if_locked == HA_OPEN_ABORT_IF_LOCKED))
- (void) nisam_extra(file,HA_EXTRA_NO_WAIT_LOCK);
- info(HA_STATUS_NO_LOCK | HA_STATUS_VARIABLE | HA_STATUS_CONST);
- if (!(test_if_locked & HA_OPEN_WAIT_IF_LOCKED))
- (void) nisam_extra(file,HA_EXTRA_WAIT_LOCK);
- if (!table->db_record_offset)
- int_table_flags|=HA_REC_NOT_IN_SEQ;
- return (0);
- }
- int ha_isam::close(void)
- {
- return !nisam_close(file) ? 0 : my_errno ? my_errno : -1;
- }
- uint ha_isam::min_record_length(uint options) const
- {
- return (options & HA_OPTION_PACK_RECORD) ? 1 : 5;
- }
- int ha_isam::write_row(byte * buf)
- {
- statistic_increment(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();
- return !nisam_write(file,buf) ? 0 : my_errno ? my_errno : -1;
- }
- int ha_isam::update_row(const byte * old_data, byte * new_data)
- {
- statistic_increment(ha_update_count,&LOCK_status);
- if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
- table->timestamp_field->set_time();
- return !nisam_update(file,old_data,new_data) ? 0 : my_errno ? my_errno : -1;
- }
- int ha_isam::delete_row(const byte * buf)
- {
- statistic_increment(ha_delete_count,&LOCK_status);
- return !nisam_delete(file,buf) ? 0 : my_errno ? my_errno : -1;
- }
- int ha_isam::index_read(byte * buf, const byte * key,
- uint key_len, enum ha_rkey_function find_flag)
- {
- statistic_increment(ha_read_key_count,&LOCK_status);
- int error=nisam_rkey(file, buf, active_index, key, key_len, find_flag);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : -1;
- }
- int ha_isam::index_read_idx(byte * buf, uint index, const byte * key,
- uint key_len, enum ha_rkey_function find_flag)
- {
- statistic_increment(ha_read_key_count,&LOCK_status);
- int error=nisam_rkey(file, buf, index, key, key_len, find_flag);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : -1;
- }
- int ha_isam::index_read_last(byte * buf, const byte * key, uint key_len)
- {
- statistic_increment(ha_read_key_count,&LOCK_status);
- int error=nisam_rkey(file, buf, active_index, key, key_len,
- HA_READ_PREFIX_LAST);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : -1;
- }
- int ha_isam::index_next(byte * buf)
- {
- statistic_increment(ha_read_next_count,&LOCK_status);
- int error=nisam_rnext(file,buf,active_index);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : HA_ERR_END_OF_FILE;
- }
- int ha_isam::index_prev(byte * buf)
- {
- statistic_increment(ha_read_prev_count,&LOCK_status);
- int error=nisam_rprev(file,buf, active_index);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : HA_ERR_END_OF_FILE;
- }
- int ha_isam::index_first(byte * buf)
- {
- statistic_increment(ha_read_first_count,&LOCK_status);
- int error=nisam_rfirst(file, buf, active_index);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : HA_ERR_END_OF_FILE;
- }
- int ha_isam::index_last(byte * buf)
- {
- statistic_increment(ha_read_last_count,&LOCK_status);
- int error=nisam_rlast(file, buf, active_index);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : HA_ERR_END_OF_FILE;
- }
- int ha_isam::rnd_init(bool scan)
- {
- return nisam_extra(file,HA_EXTRA_RESET) ? 0 : my_errno ? my_errno : -1;;
- }
- int ha_isam::rnd_next(byte *buf)
- {
- statistic_increment(ha_read_rnd_next_count,&LOCK_status);
- int error=nisam_rrnd(file, buf, NI_POS_ERROR);
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : -1;
- }
- int ha_isam::rnd_pos(byte * buf, byte *pos)
- {
- statistic_increment(ha_read_rnd_count,&LOCK_status);
- int error=nisam_rrnd(file, buf, (ulong) ha_get_ptr(pos,ref_length));
- table->status=error ? STATUS_NOT_FOUND: 0;
- return !error ? 0 : my_errno ? my_errno : -1;
- }
- void ha_isam::position(const byte *record)
- {
- my_off_t position=nisam_position(file);
- if (position == (my_off_t) ~ (ulong) 0)
- position=HA_OFFSET_ERROR;
- ha_store_ptr(ref, ref_length, position);
- }
- void ha_isam::info(uint flag)
- {
- N_ISAMINFO info;
- (void) nisam_info(file,&info,flag);
- if (flag & HA_STATUS_VARIABLE)
- {
- records = info.records;
- deleted = info.deleted;
- data_file_length=info.data_file_length;
- index_file_length=info.index_file_length;
- delete_length = info.delete_length;
- check_time = info.isamchk_time;
- mean_rec_length=info.mean_reclength;
- }
- if (flag & HA_STATUS_CONST)
- {
- max_data_file_length=info.max_data_file_length;
- max_index_file_length=info.max_index_file_length;
- create_time = info.create_time;
- sortkey = info.sortkey;
- block_size=nisam_block_size;
- table->keys = min(table->keys,info.keys);
- table->keys_in_use.set_prefix(table->keys);
- table->db_options_in_use= info.options;
- table->db_record_offset=
- (table->db_options_in_use &
- (HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD)) ? 0 :
- table->reclength;
- if (!table->tmp_table)
- {
- ulong *rec_per_key=info.rec_per_key;
- for (uint i=0 ; i < table->keys ; i++)
- {
- table->key_info[i].rec_per_key[table->key_info[i].key_parts-1]=
- *(rec_per_key++);
- }
- }
- ref_length=4;
- }
- if (flag & HA_STATUS_ERRKEY)
- {
- errkey = info.errkey;
- ha_store_ptr(dupp_ref, ref_length, info.dupp_key_pos);
- }
- if (flag & HA_STATUS_TIME)
- update_time = info.update_time;
- }
- int ha_isam::extra(enum ha_extra_function operation)
- {
- if ((specialflag & SPECIAL_SAFE_MODE || test_flags & TEST_NO_EXTRA) &&
- (operation == HA_EXTRA_WRITE_CACHE ||
- operation == HA_EXTRA_KEYREAD))
- return 0;
- return nisam_extra(file,operation);
- }
- int ha_isam::external_lock(THD *thd, int lock_type)
- {
- if (!table->tmp_table)
- return nisam_lock_database(file,lock_type);
- return 0;
- }
- THR_LOCK_DATA **ha_isam::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;
- }
- int ha_isam::create(const char *name, register TABLE *form,
- HA_CREATE_INFO *create_info)
- {
- uint options=form->db_options_in_use;
- int error;
- uint i,j,recpos,minpos,fieldpos,temp_length,length;
- enum ha_base_keytype type;
- char buff[FN_REFLEN];
- KEY *pos;
- N_KEYDEF keydef[MAX_KEY];
- N_RECINFO *recinfo,*recinfo_pos;
- DBUG_ENTER("ha_isam::create");
- type=HA_KEYTYPE_BINARY; // Keep compiler happy
- if (!(recinfo= (N_RECINFO*) my_malloc((form->fields*2+2)*sizeof(N_RECINFO),
- MYF(MY_WME))))
- DBUG_RETURN(HA_ERR_OUT_OF_MEM);
- pos=form->key_info;
- for (i=0; i < form->keys ; i++, pos++)
- {
- keydef[i].base.flag= (pos->flags & HA_NOSAME);
- for (j=0 ; (int7) j < pos->key_parts ; j++)
- {
- keydef[i].seg[j].base.flag=pos->key_part[j].key_part_flag;
- Field *field=pos->key_part[j].field;
- type=field->key_type();
- if ((options & HA_OPTION_PACK_KEYS ||
- (pos->flags & (HA_PACK_KEY | HA_BINARY_PACK_KEY |
- HA_SPACE_PACK_USED))) &&
- pos->key_part[j].length > 8 &&
- (type == HA_KEYTYPE_TEXT ||
- type == HA_KEYTYPE_NUM ||
- (type == HA_KEYTYPE_BINARY && !field->zero_pack())))
- {
- if (j == 0)
- keydef[i].base.flag|=HA_PACK_KEY;
- if (!(field->flags & ZEROFILL_FLAG) &&
- (field->type() == FIELD_TYPE_STRING ||
- field->type() == FIELD_TYPE_VAR_STRING ||
- ((int) (pos->key_part[j].length - field->decimals()))
- >= 4))
- keydef[i].seg[j].base.flag|=HA_SPACE_PACK;
- }
- keydef[i].seg[j].base.type=(int) type;
- keydef[i].seg[j].base.start= pos->key_part[j].offset;
- keydef[i].seg[j].base.length= pos->key_part[j].length;
- }
- keydef[i].seg[j].base.type=(int) HA_KEYTYPE_END; /* End of key-parts */
- }
- recpos=0; recinfo_pos=recinfo;
- while (recpos < (uint) form->reclength)
- {
- Field **field,*found=0;
- minpos=form->reclength; length=0;
- for (field=form->field ; *field ; field++)
- {
- if ((fieldpos=(*field)->offset()) >= recpos &&
- fieldpos <= minpos)
- {
- /* skip null fields */
- if (!(temp_length= (*field)->pack_length()))
- continue; /* Skip null-fields */
- if (! found || fieldpos < minpos ||
- (fieldpos == minpos && temp_length < length))
- {
- minpos=fieldpos; found= *field; length=temp_length;
- }
- }
- }
- DBUG_PRINT("loop",("found: %lx recpos: %d minpos: %d length: %d",
- found,recpos,minpos,length));
- if (recpos != minpos)
- { // Reserved space (Null bits?)
- recinfo_pos->base.type=(int) FIELD_NORMAL;
- recinfo_pos++->base.length= (uint16) (minpos-recpos);
- }
- if (! found)
- break;
- if (found->flags & BLOB_FLAG)
- {
- /* ISAM can only handle blob pointers of sizeof(char(*)) */
- recinfo_pos->base.type= (int) FIELD_BLOB;
- if (options & HA_OPTION_LONG_BLOB_PTR)
- length= length-portable_sizeof_char_ptr+sizeof(char*);
- }
- else if (!(options & HA_OPTION_PACK_RECORD))
- recinfo_pos->base.type= (int) FIELD_NORMAL;
- else if (found->zero_pack())
- recinfo_pos->base.type= (int) FIELD_SKIP_ZERO;
- else
- recinfo_pos->base.type= (int) ((length <= 3 ||
- (found->flags & ZEROFILL_FLAG)) ?
- FIELD_NORMAL :
- found->type() == FIELD_TYPE_STRING ||
- found->type() == FIELD_TYPE_VAR_STRING ?
- FIELD_SKIP_ENDSPACE :
- FIELD_SKIP_PRESPACE);
- recinfo_pos++ ->base.length=(uint16) length;
- recpos=minpos+length;
- DBUG_PRINT("loop",("length: %d type: %d",
- recinfo_pos[-1].base.length,recinfo_pos[-1].base.type));
- if ((found->flags & BLOB_FLAG) && (options & HA_OPTION_LONG_BLOB_PTR) &&
- sizeof(char*) != portable_sizeof_char_ptr)
- { // Not used space
- recinfo_pos->base.type=(int) FIELD_ZERO;
- recinfo_pos++->base.length=
- (uint16) (portable_sizeof_char_ptr-sizeof(char*));
- recpos+= (portable_sizeof_char_ptr-sizeof(char*));
- }
- }
- recinfo_pos->base.type= (int) FIELD_LAST; /* End of fieldinfo */
- error=nisam_create(fn_format(buff,name,"","",2+4+16),form->keys,keydef,
- recinfo,(ulong) form->max_rows, (ulong) form->min_rows,
- 0, 0, 0L);
- my_free((gptr) recinfo,MYF(0));
- DBUG_RETURN(error);
- }
- static key_range no_range= { (byte*) 0, 0, HA_READ_KEY_EXACT };
- ha_rows ha_isam::records_in_range(uint inx, key_range *min_key,
- key_range *max_key)
- {
- /* ISAM checks if 'key' pointer <> 0 to know if there is no range */
- if (!min_key)
- min_key= &no_range;
- if (!max_key)
- max_key= &no_range;
- return (ha_rows) nisam_records_in_range(file,
- (int) inx,
- min_key->key, min_key->length,
- min_key->flag,
- max_key->key, max_key->length,
- max_key->flag);
- }
- #endif /* HAVE_ISAM */