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.
---
 mysys/mf_keycache.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

(limited to 'mysys')

diff --git a/mysys/mf_keycache.c b/mysys/mf_keycache.c
index 264037e9a70..3276044fc2f 100644
--- a/mysys/mf_keycache.c
+++ b/mysys/mf_keycache.c
@@ -1258,6 +1258,86 @@ byte *key_cache_read(File file, my_off_t filepos, byte *buff, uint length,
 }
 
 
+/*
+  Insert a block of file data from a buffer into key cache
+
+  SYNOPSIS
+    key_cache_insert()
+      file      file descriptor
+      filepos   file offset of the data from the buffer 
+      buff      buffer with data to insert into key cache
+      length    length of the data in the buffer
+
+  RETURN VALUE
+    0 if a success, 1 -otherwise.
+*/
+
+int key_cache_insert(File file, my_off_t filepos, byte *buff, uint length)
+{
+  DBUG_ENTER("key_cache_insert");
+  DBUG_PRINT("enter", ("file %u, filepos %lu, length %u",
+               (uint) file,(ulong) filepos, length));
+
+  if (my_disk_blocks > 0)
+  {
+    /* Key cache is used */
+    reg1 BLOCK_LINK *block;
+    uint offset= (uint) (filepos & (key_cache_block_size-1));
+    uint read_length;
+    int page_st;
+
+    /* Read data into key cache from buff in key_cache_block_size increments */
+    filepos-= offset;
+    do
+    {
+      read_length= length > key_cache_block_size ?
+                   key_cache_block_size : length;
+      KEYCACHE_DBUG_ASSERT(read_length > 0);
+      keycache_pthread_mutex_lock(&THR_LOCK_keycache);
+      my_cache_r_requests++;
+      block=find_key_block(file, filepos, 0, &page_st);
+      if (block->status != BLOCK_ERROR && page_st != PAGE_READ)
+      {
+        /* The requested page is to be read into the block buffer */
+#if !defined(SERIALIZED_READ_FROM_CACHE)
+        keycache_pthread_mutex_unlock(&THR_LOCK_keycache);
+#endif
+
+        /* Copy data from buff */
+        if (!(read_length & 511))
+          bmove512(block->buffer+offset, buff, read_length);
+        else
+          memcpy(block->buffer+offset, buff, (size_t) read_length);
+
+#if !defined(SERIALIZED_READ_FROM_CACHE)
+        keycache_pthread_mutex_lock(&THR_LOCK_keycache);
+#endif
+        block->status= BLOCK_READ;
+        block->length= read_length+offset;
+      }
+
+      remove_reader(block);
+      /*
+         Link the block into the LRU chain
+         if it's the last submitted request for the block
+      */
+      unreg_request(block,1);
+
+      keycache_pthread_mutex_unlock(&THR_LOCK_keycache);
+
+      if (block->status & BLOCK_ERROR)
+        DBUG_RETURN(1);
+
+      buff+=read_length;
+      filepos+=read_length;
+      offset=0;
+
+    } while ((length-= read_length));
+  }
+  DBUG_RETURN(0);
+}
+
+
 /*
   Write a buffer into disk;
   filepos must be a multiple of 'block_length', but it doesn't
-- 
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