diff options
Diffstat (limited to 'isam/_page.c')
| -rw-r--r-- | isam/_page.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/isam/_page.c b/isam/_page.c new file mode 100644 index 00000000000..6f6d632e85d --- /dev/null +++ b/isam/_page.c @@ -0,0 +1,137 @@ +/* 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 */ + +/* L{ser och skriver nyckelblock */ + +#include "isamdef.h" +#ifdef __WIN__ +#include <errno.h> +#endif + + /* Fetch a key-page in memory */ + +uchar *_nisam_fetch_keypage(register N_INFO *info, N_KEYDEF *keyinfo, + my_off_t page, uchar *buff, int return_buffer) +{ + uchar *tmp; + tmp=(uchar*) key_cache_read(info->s->kfile,page,(byte*) buff, + (uint) keyinfo->base.block_length, + (uint) keyinfo->base.block_length, + return_buffer); + if (tmp == info->buff) + { + info->update|=HA_STATE_BUFF_SAVED; + info->int_pos=(ulong) page; + info->buff_used=1; + } + else + { + info->update&= ~HA_STATE_BUFF_SAVED; + if (tmp) + info->int_pos=(ulong) page; + else + { + info->int_pos=NI_POS_ERROR; + DBUG_PRINT("error",("Got errno: %d from key_cache_read",my_errno)); + my_errno=HA_ERR_CRASHED; + } + } + return tmp; +} /* _nisam_fetch_keypage */ + + + /* Write a key-page on disk */ + +int _nisam_write_keypage(register N_INFO *info, register N_KEYDEF *keyinfo, + my_off_t page, uchar *buff) +{ + reg3 uint length; +#ifndef QQ /* Safety check */ + if (page < info->s->base.keystart || + page+keyinfo->base.block_length > info->s->state.key_file_length || + page & (nisam_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,getint(buff)); +#endif + + if ((length=keyinfo->base.block_length) > IO_SIZE*2 && + info->s->state.key_file_length != page+length) + length= ((getint(buff)+IO_SIZE-1) & (uint) ~(IO_SIZE-1)); +#ifdef HAVE_purify + { + length=getint(buff); + bzero((byte*) buff+length,keyinfo->base.block_length-length); + length=keyinfo->base.block_length; + } +#endif + return (key_cache_write(info->s->kfile,page,(byte*) buff,length, + (uint) keyinfo->base.block_length, + (int) (info->lock_type != F_UNLCK))); +} /* nisam_write_keypage */ + + + /* Remove page from disk */ + +int _nisam_dispose(register N_INFO *info, N_KEYDEF *keyinfo, my_off_t pos) +{ + uint keynr= (uint) (keyinfo - info->s->keyinfo); + ulong old_link; /* ulong is ok here */ + DBUG_ENTER("_nisam_dispose"); + + old_link=info->s->state.key_del[keynr]; + info->s->state.key_del[keynr]=(ulong) pos; + DBUG_RETURN(key_cache_write(info->s->kfile,pos,(byte*) &old_link, + sizeof(long), + (uint) keyinfo->base.block_length, + (int) (info->lock_type != F_UNLCK))); +} /* _nisam_dispose */ + + + /* Make new page on disk */ + +ulong _nisam_new(register N_INFO *info, N_KEYDEF *keyinfo) +{ + uint keynr= (uint) (keyinfo - info->s->keyinfo); + ulong pos; + DBUG_ENTER("_nisam_new"); + + if ((pos=info->s->state.key_del[keynr]) == NI_POS_ERROR) + { + if (info->s->state.key_file_length >= info->s->base.max_key_file_length) + { + my_errno=HA_ERR_INDEX_FILE_FULL; + DBUG_RETURN(NI_POS_ERROR); + } + pos=info->s->state.key_file_length; + info->s->state.key_file_length+= keyinfo->base.block_length; + } + else + { + if (!key_cache_read(info->s->kfile,pos, + (byte*) &info->s->state.key_del[keynr], + (uint) sizeof(long), + (uint) keyinfo->base.block_length,0)) + pos= NI_POS_ERROR; + } + DBUG_PRINT("exit",("Pos: %d",pos)); + DBUG_RETURN(pos); +} /* _nisam_new */ |