1 files changed, 107 insertions, 0 deletions
diff --git a/mysys/mf_keycaches.c b/mysys/mf_keycaches.c
new file mode 100644
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+++ b/mysys/mf_keycaches.c
@@ -0,0 +1,107 @@
+/* Copyright (c) 2003, 2011, Oracle and/or its affiliates.
+   Copyright (c) 2010, 2011, Monty Program 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 St, 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 "mysys_priv.h"
+#include <keycache.h>
+#include <hash.h>
+#include <m_string.h>
+#include "my_safehash.h"
+
+/*****************************************************************************
+  Functions to handle the key cache objects
+*****************************************************************************/
+
+/* Variable to store all key cache objects */
+static SAFE_HASH key_cache_hash;
+
+
+my_bool multi_keycache_init(void)
+{
+  return safe_hash_init(&key_cache_hash, 16, (uchar*) dflt_key_cache);
+}
+
+
+void multi_keycache_free(void)
+{
+  safe_hash_free(&key_cache_hash);
+}
+
+/*
+  Get a key cache to be used for a specific table.
+
+  SYNOPSIS
+    multi_key_cache_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_keycache_init.
+    This will ensure that it works with old MyISAM clients.
+
+  RETURN
+    key cache to use
+*/
+
+KEY_CACHE *multi_key_cache_search(uchar *key, uint length,
+                                  KEY_CACHE *def)
+{
+  if (!key_cache_hash.hash.records)
+    return def;
+  return (KEY_CACHE*) safe_hash_search(&key_cache_hash, key, length,
+                                       (void*) def);
+}
+
+
+/*
+  Assosiate a key cache with a key
+
+
+  SYONOPSIS
+    multi_key_cache_set()
+    key				key (path to table etc..)
+    length			Length of key
+    key_cache			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_key_cache_set(const uchar *key, uint length,
+			    KEY_CACHE *key_cache)
+{
+  return safe_hash_set(&key_cache_hash, key, length, (uchar*) key_cache);
+}
+
+
+void multi_key_cache_change(KEY_CACHE *old_data,
+			    KEY_CACHE *new_data)
+{
+  safe_hash_change(&key_cache_hash, (uchar*) old_data, (uchar*) new_data);
+}
+
+