/* 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); info->s->state.changed|= STATE_NOT_SORTED_PAGES; 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); } info->s->state.changed|= STATE_NOT_SORTED_PAGES; DBUG_PRINT("exit",("Pos: %d",pos)); DBUG_RETURN(pos); } /* _mi_new */