From f7aed0240511510dfe51083bd7ff12482d8716bc Mon Sep 17 00:00:00 2001
From: unknown <igor@rurik.mysql.com>
Date: Thu, 12 Jun 2003 04:29:02 -0700
Subject: Many files:   New feature: preload indexes into key cache.
 mi_preload.c:   new file Many files:   Added preload statement.

sql/ha_myisam.h:
  Added preload statement.
sql/handler.cc:
  Added preload statement.
sql/lex.h:
  Added preload statement.
sql/mysql_priv.h:
  Added preload statement.
sql/sql_lex.h:
  Added preload statement.
sql/sql_base.cc:
  Added preload statement.
sql/sql_table.cc:
  New feature: preload indexes into key cache.
sql/sql_parse.cc:
  New feature: preload indexes into key cache.
sql/mysqld.cc:
  New feature: preload indexes into key cache.
sql/set_var.cc:
  New feature: preload indexes into key cache.
sql/sql_yacc.yy:
  New feature: preload indexes into key cache.
sql/ha_myisam.cc:
  New feature: preload indexes into key cache.
sql/table.h:
  New feature: preload indexes into key cache.
mysys/mf_keycache.c:
  New feature: preload indexes into key cache.
myisam/myisamdef.h:
  New feature: preload indexes into key cache.
myisam/mi_extra.c:
  New feature: preload indexes into key cache.
myisam/Makefile.am:
  New feature: preload indexes into key cache.
include/my_base.h:
  New feature: preload indexes into key cache.
include/my_sys.h:
  New feature: preload indexes into key cache.
include/myisam.h:
  New feature: preload indexes into key cache.
---
 myisam/mi_preload.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 myisam/mi_preload.c

(limited to 'myisam/mi_preload.c')

diff --git a/myisam/mi_preload.c b/myisam/mi_preload.c
new file mode 100644
index 00000000000..be45be66ecf
--- /dev/null
+++ b/myisam/mi_preload.c
@@ -0,0 +1,118 @@
+/* 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 */
+
+/*
+  Preload indexes into key cache
+*/
+
+#include "myisamdef.h"
+
+
+/*
+  Preload pages of the index file for a table into the key cache
+
+  SYNOPSIS
+    mi_preload()
+      info          open table
+      map           map of indexes to preload into key cache 
+      ignore_leaves only non-leaves pages are to be preloaded
+
+  RETURN VALUE
+    0 if a success. error code - otherwise.
+
+  NOTES.
+    At present pages for all indexes are preloaded.
+    In future only pages for indexes specified in the key_map parameter
+    of the table will be preloaded.
+*/
+
+int mi_preload(MI_INFO *info, ulonglong key_map, my_bool ignore_leaves)
+{
+  uint i;
+  uint length;
+  uint block_length= 0;
+  uchar *buff= NULL;
+  MYISAM_SHARE* share= info->s;
+  uint keys= share->state.header.keys;
+  MI_KEYDEF *keyinfo= share->keyinfo;
+  my_off_t key_file_length= share->state.state.key_file_length;
+  my_off_t pos= share->base.keystart;
+
+  if (!keys || !key_map || key_file_length == pos)
+    return 0;
+
+  block_length= keyinfo[0].block_length;
+
+  if (!key_map)
+    return 0;
+
+  /* Check whether all indexes use the same block size */
+  for (i= 1 ; i < keys ; i++)
+  {
+    if (keyinfo[i].block_length != block_length)
+      return (my_errno= HA_ERR_NON_UNIQUE_BLOCK_SIZE); 
+  }
+
+  length= info->preload_buff_size/block_length * block_length;
+  set_if_bigger(length, block_length);
+
+  if (!(buff= (uchar *) my_malloc(length, MYF(MY_WME))))
+    return (my_errno= HA_ERR_OUT_OF_MEM);
+
+  if (flush_key_blocks(share->kfile, FLUSH_RELEASE))
+    goto err;
+ 
+  do
+  {
+    /* Read the next block of index file into the preload buffer */
+    set_if_smaller(length, key_file_length-pos);
+    if (my_pread(share->kfile, (byte*) buff, length, pos, MYF(MY_FAE)))
+      goto err;
+          
+    if (ignore_leaves)
+    {
+      uchar *end= buff+length;
+      do
+      {
+        if (mi_test_if_nod(buff))
+        {
+          if (key_cache_insert(share->kfile, pos, (byte*) buff, block_length))
+	    goto err;
+	}
+        pos+= block_length;
+      }
+      while ((buff+= block_length) != end);
+      buff= end-length;
+    }
+    else
+    {
+      if (key_cache_insert(share->kfile, pos, (byte*) buff, length))
+	goto err;
+      pos+= length;
+    }
+
+  }
+  while (pos != key_file_length);
+
+  my_free(buff, MYF(0));
+
+  return 0;
+
+err:
+  my_free(buff, MYF(MY_ALLOW_ZERO_PTR));
+  return (my_errno= errno);
+}
+
-- 
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