diff options
Diffstat (limited to 'myisam/mi_page.c')
| -rw-r--r-- | myisam/mi_page.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/myisam/mi_page.c b/myisam/mi_page.c new file mode 100644 index 00000000000..dd7de9ba8b6 --- /dev/null +++ b/myisam/mi_page.c @@ -0,0 +1,144 @@ +/* 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 */ + +/* Read and write key blocks */ + +#include "myisamdef.h" +#ifdef __WIN__ +#include <errno.h> +#endif + + /* Fetch a key-page in memory */ + +uchar *_mi_fetch_keypage(register MI_INFO *info, MI_KEYDEF *keyinfo, + my_off_t page, uchar *buff, int return_buffer) +{ + uchar *tmp; + uint page_size; + tmp=(uchar*) key_cache_read(info->s->kfile,page,(byte*) buff, + (uint) keyinfo->block_length, + (uint) keyinfo->block_length, + return_buffer); + if (tmp == info->buff) + info->buff_used=1; + else if (!tmp) + { + DBUG_PRINT("error",("Got errno: %d from key_cache_read",my_errno)); + info->last_keypage=HA_OFFSET_ERROR; + my_errno=HA_ERR_CRASHED; + return 0; + } + info->last_keypage=page; + page_size=mi_getint(tmp); + if (page_size < 4 || page_size > keyinfo->block_length) + { + DBUG_PRINT("error",("page %lu had wrong page length: %u", + (ulong) page, page_size)); + info->last_keypage = HA_OFFSET_ERROR; + my_errno = HA_ERR_CRASHED; + tmp = 0; + } + return tmp; +} /* _mi_fetch_keypage */ + + + /* Write a key-page on disk */ + +int _mi_write_keypage(register MI_INFO *info, register MI_KEYDEF *keyinfo, + my_off_t page, uchar *buff) +{ + reg3 uint length; +#ifndef FAST /* Safety check */ + if (page < info->s->base.keystart || + page+keyinfo->block_length > info->state->key_file_length || + page & (myisam_block_size-1)) + { + DBUG_PRINT("error",("Trying to write outside key region: %lu", + (long) page)); + my_errno=EINVAL; + return(-1); + } + DBUG_PRINT("page",("write page at: %lu",(long) page,buff)); + DBUG_DUMP("buff",(byte*) buff,mi_getint(buff)); +#endif + + if ((length=keyinfo->block_length) > IO_SIZE*2 && + info->state->key_file_length != page+length) + length= ((mi_getint(buff)+IO_SIZE-1) & (uint) ~(IO_SIZE-1)); +#ifdef HAVE_purify + { + length=mi_getint(buff); + bzero((byte*) buff+length,keyinfo->block_length-length); + length=keyinfo->block_length; + } +#endif + return (key_cache_write(info->s->kfile,page,(byte*) buff,length, + (uint) keyinfo->block_length, + (int) ((info->lock_type != F_UNLCK) || + info->s->delay_key_write))); +} /* mi_write_keypage */ + + + /* Remove page from disk */ + +int _mi_dispose(register MI_INFO *info, MI_KEYDEF *keyinfo, my_off_t pos) +{ + my_off_t old_link; + char buff[8]; + DBUG_ENTER("_mi_dispose"); + + old_link=info->s->state.key_del[keyinfo->block_size]; + info->s->state.key_del[keyinfo->block_size]=pos; + mi_sizestore(buff,old_link); + DBUG_RETURN(key_cache_write(info->s->kfile,pos,buff, + sizeof(buff), + (uint) keyinfo->block_length, + (int) (info->lock_type != F_UNLCK))); +} /* _mi_dispose */ + + + /* Make new page on disk */ + +my_off_t _mi_new(register MI_INFO *info, MI_KEYDEF *keyinfo) +{ + my_off_t pos; + char buff[8]; + DBUG_ENTER("_mi_new"); + + if ((pos=info->s->state.key_del[keyinfo->block_size]) == HA_OFFSET_ERROR) + { + if (info->state->key_file_length >= + info->s->base.max_key_file_length - keyinfo->block_length) + { + my_errno=HA_ERR_INDEX_FILE_FULL; + DBUG_RETURN(HA_OFFSET_ERROR); + } + pos=info->state->key_file_length; + info->state->key_file_length+= keyinfo->block_length; + } + else + { + if (!key_cache_read(info->s->kfile,pos, + buff, + (uint) sizeof(buff), + (uint) keyinfo->block_length,0)) + pos= HA_OFFSET_ERROR; + else + info->s->state.key_del[keyinfo->block_size]=mi_sizekorr(buff); + } + DBUG_PRINT("exit",("Pos: %d",pos)); + DBUG_RETURN(pos); +} /* _mi_new */ |