Function flush_key_blocks_int

mysys/mf_keycache.c:3587–4018

*/

static int flush_key_blocks_int(KEY_CACHE *keycache,
				File file, enum flush_type type)
{
  BLOCK_LINK *cache_buff[FLUSH_CACHE],**cache;
  int last_errno= 0;
  int last_errcnt= 0;
  DBUG_ENTER("flush_key_blocks_int");
  DBUG_PRINT("enter",("file: %d  blocks_used: %lu  blocks_changed: %lu",
              file, keycache->blocks_used, keycache->blocks_changed));

#if !defined(DBUG_OFF) && defined(EXTRA_DEBUG)
  DBUG_EXECUTE("check_keycache",
               test_key_cache(keycache, "start of flush_key_blocks", 0););
#endif

  cache= cache_buff;
  if (keycache->disk_blocks > 0 &&
      (!my_disable_flush_key_blocks || type != FLUSH_KEEP))
  {
    /* Key cache exists and flush is not disabled */
    int error= 0;
    uint count= FLUSH_CACHE;
    BLOCK_LINK **pos,**end;
    BLOCK_LINK *first_in_switch= NULL;
    BLOCK_LINK *last_in_flush;
    BLOCK_LINK *last_for_update;
    BLOCK_LINK *block, *next;
#if defined(KEYCACHE_DEBUG)
    uint cnt=0;
#endif

    if (type != FLUSH_IGNORE_CHANGED)
    {
      /*
         Count how many key blocks we have to cache to be able
         to flush all dirty pages with minimum seek moves
      */
      count= 0;
      for (block= keycache->changed_blocks[FILE_HASH(file)] ;
           block ;
           block= block->next_changed)
      {
        if ((block->hash_link->file == file) &&
            !(block->status & BLOCK_IN_FLUSH))
        {
          count++;
          KEYCACHE_DBUG_ASSERT(count<= keycache->blocks_used);
        }
      }
      /*
        Allocate a new buffer only if its bigger than the one we have.
        Assure that we always have some entries for the case that new
        changed blocks appear while we need to wait for something.
      */
      if ((count > FLUSH_CACHE) &&
          !(cache= (BLOCK_LINK**) my_malloc(sizeof(BLOCK_LINK*)*count,
                                            MYF(0))))
        cache= cache_buff;