Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 104 insertions, 0 deletions

diff --git a/storage/maria/ma_pagecaches.c b/storage/maria/ma_pagecaches.c
new file mode 100644
index 00000000..fd5cd209
--- /dev/null
+++ b/storage/maria/ma_pagecaches.c
@@ -0,0 +1,104 @@
+/* Copyright (C) 2003-2007 MySQL 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; version 2 of the License.
+
+   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/*
+  Handling of multiple key caches
+
+  The idea is to have a thread safe hash on the table name,
+  with a default key cache value that is returned if the table name is not in
+  the cache.
+*/
+
+#include "maria_def.h"
+#include "ma_pagecache.h"
+#include <hash.h>
+#include <m_string.h>
+#include "../../mysys/my_safehash.h"
+
+/*****************************************************************************
+  Functions to handle the pagecache objects
+*****************************************************************************/
+
+/* Variable to store all key cache objects */
+static SAFE_HASH pagecache_hash;
+
+
+my_bool multi_pagecache_init(void)
+{
+  return safe_hash_init(&pagecache_hash, 16, (uchar*) maria_pagecache);
+}
+
+
+void multi_pagecache_free(void)
+{
+  safe_hash_free(&pagecache_hash);
+}
+
+/*
+  Get a key cache to be used for a specific table.
+
+  SYNOPSIS
+    multi_pagecache_search()
+    key				key to find (usually table path)
+    uint length			Length of key.
+    def				Default value if no key cache
+
+  NOTES
+    This function is coded in such a way that we will return the
+    default key cache even if one never called multi_pagecache_init.
+    This will ensure that it works with old MyISAM clients.
+
+  RETURN
+    key cache to use
+*/
+
+PAGECACHE *multi_pagecache_search(uchar *key, uint length,
+                                  PAGECACHE *def)
+{
+  if (!pagecache_hash.hash.records)
+    return def;
+  return (PAGECACHE*) safe_hash_search(&pagecache_hash, key, length,
+                                       (void*) def);
+}
+
+
+/*
+  Assosiate a key cache with a key
+
+
+  SYONOPSIS
+    multi_pagecache_set()
+    key				key (path to table etc..)
+    length			Length of key
+    pagecache			cache to assococite with the table
+
+  NOTES
+    This can be used both to insert a new entry and change an existing
+    entry
+*/
+
+
+my_bool multi_pagecache_set(const uchar *key, uint length,
+			    PAGECACHE *pagecache)
+{
+  return safe_hash_set(&pagecache_hash, key, length, (uchar*) pagecache);
+}
+
+
+void multi_pagecache_change(PAGECACHE *old_data,
+			    PAGECACHE *new_data)
+{
+  safe_hash_change(&pagecache_hash, (uchar*) old_data, (uchar*) new_data);
+}