release/src/router/mysql/storage/myisam/mi_page.c

   1 /*
   2    Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; version 2 of the License.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12
  13    You should have received a copy of the GNU General Public License
  14    along with this program; if not, write to the Free Software
  15    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
  16 */
  17
  18 /* Read and write key blocks */
  19
  20 #include "myisamdef.h"
  21
  22         /* Fetch a key-page in memory */
  23
  24 uchar *_mi_fetch_keypage(register MI_INFO *info, MI_KEYDEF *keyinfo,
  25                          my_off_t page, int level,
  26                          uchar *buff, int return_buffer)
  27 {
  28   uchar *tmp;
  29   uint page_size;
  30   DBUG_ENTER("_mi_fetch_keypage");
  31   DBUG_PRINT("enter",("page: %ld", (long) page));
  32
  33   tmp=(uchar*) key_cache_read(info->s->key_cache,
  34                              info->s->kfile, page, level, (uchar*) buff,
  35                              (uint) keyinfo->block_length,
  36                              (uint) keyinfo->block_length,
  37                              return_buffer);
  38   if (tmp == info->buff)
  39     info->buff_used=1;
  40   else if (!tmp)
  41   {
  42     DBUG_PRINT("error",("Got errno: %d from key_cache_read",my_errno));
  43     info->last_keypage=HA_OFFSET_ERROR;
  44     mi_print_error(info->s, HA_ERR_CRASHED);
  45     my_errno=HA_ERR_CRASHED;
  46     DBUG_RETURN(0);
  47   }
  48   info->last_keypage=page;
  49   page_size=mi_getint(tmp);
  50   if (page_size < 4 || page_size > keyinfo->block_length)
  51   {
  52     DBUG_PRINT("error",("page %lu had wrong page length: %u",
  53                         (ulong) page, page_size));
  54     DBUG_DUMP("page", tmp, keyinfo->block_length);
  55     info->last_keypage = HA_OFFSET_ERROR;
  56     mi_print_error(info->s, HA_ERR_CRASHED);
  57     my_errno = HA_ERR_CRASHED;
  58     tmp = 0;
  59   }
  60   DBUG_RETURN(tmp);
  61 } /* _mi_fetch_keypage */
  62
  63
  64         /* Write a key-page on disk */
  65
  66 int _mi_write_keypage(register MI_INFO *info, register MI_KEYDEF *keyinfo,
  67                       my_off_t page, int level, uchar *buff)
  68 {
  69   reg3 uint length;
  70   DBUG_ENTER("_mi_write_keypage");
  71
  72 #ifndef FAST                                    /* Safety check */
  73   if (page < info->s->base.keystart ||
  74       page+keyinfo->block_length > info->state->key_file_length ||
  75       (page & (MI_MIN_KEY_BLOCK_LENGTH-1)))
  76   {
  77     DBUG_PRINT("error",("Trying to write inside key status region: key_start: %lu  length: %lu  page: %lu",
  78                         (long) info->s->base.keystart,
  79                         (long) info->state->key_file_length,
  80                         (long) page));
  81     my_errno=EINVAL;
  82     DBUG_RETURN((-1));
  83   }
  84   DBUG_PRINT("page",("write page at: %lu",(long) page));
  85   DBUG_DUMP("buff",(uchar*) buff,mi_getint(buff));
  86 #endif
  87
  88   if ((length=keyinfo->block_length) > IO_SIZE*2 &&
  89       info->state->key_file_length != page+length)
  90     length= ((mi_getint(buff)+IO_SIZE-1) & (uint) ~(IO_SIZE-1));
  91   DBUG_RETURN((key_cache_write(info->s->key_cache,
  92                          info->s->kfile,page, level, (uchar*) buff,length,
  93                          (uint) keyinfo->block_length,
  94                          (int) ((info->lock_type != F_UNLCK) ||
  95                                 info->s->delay_key_write))));
  96 } /* mi_write_keypage */
  97
  98
  99         /* Remove page from disk */
 100
 101 int _mi_dispose(register MI_INFO *info, MI_KEYDEF *keyinfo, my_off_t pos,
 102                 int level)
 103 {
 104   my_off_t old_link;
 105   uchar buff[8];
 106   DBUG_ENTER("_mi_dispose");
 107   DBUG_PRINT("enter",("pos: %ld", (long) pos));
 108
 109   old_link= info->s->state.key_del[keyinfo->block_size_index];
 110   info->s->state.key_del[keyinfo->block_size_index]= pos;
 111   mi_sizestore(buff,old_link);
 112   info->s->state.changed|= STATE_NOT_SORTED_PAGES;
 113   DBUG_RETURN(key_cache_write(info->s->key_cache,
 114                               info->s->kfile, pos , level, buff,
 115                               sizeof(buff),
 116                               (uint) keyinfo->block_length,
 117                               (int) (info->lock_type != F_UNLCK)));
 118 } /* _mi_dispose */
 119
 120
 121         /* Make new page on disk */
 122
 123 my_off_t _mi_new(register MI_INFO *info, MI_KEYDEF *keyinfo, int level)
 124 {
 125   my_off_t pos;
 126   uchar buff[8];
 127   DBUG_ENTER("_mi_new");
 128
 129   if ((pos= info->s->state.key_del[keyinfo->block_size_index]) ==
 130       HA_OFFSET_ERROR)
 131   {
 132     if (info->state->key_file_length >=
 133         info->s->base.max_key_file_length - keyinfo->block_length)
 134     {
 135       my_errno=HA_ERR_INDEX_FILE_FULL;
 136       DBUG_RETURN(HA_OFFSET_ERROR);
 137     }
 138     pos=info->state->key_file_length;
 139     info->state->key_file_length+= keyinfo->block_length;
 140   }
 141   else
 142   {
 143     if (!key_cache_read(info->s->key_cache,
 144                         info->s->kfile, pos, level,
 145                         buff,
 146                         (uint) sizeof(buff),
 147                         (uint) keyinfo->block_length,0))
 148       pos= HA_OFFSET_ERROR;
 149     else
 150       info->s->state.key_del[keyinfo->block_size_index]= mi_sizekorr(buff);
 151   }
 152   info->s->state.changed|= STATE_NOT_SORTED_PAGES;
 153   DBUG_PRINT("exit",("Pos: %ld",(long) pos));
 154   DBUG_RETURN(pos);
 155 } /* _mi_new */