1 files changed, 98 insertions, 0 deletions
diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc
new file mode 100644
index 00000000000..78053d0d3e3
--- /dev/null
+++ b/sql/sql_cache.cc
@@ -0,0 +1,98 @@
+/* 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 */
+
+#include "mysql_priv.h"
+#include <m_ctype.h>
+#include <my_dir.h>
+#include <hash.h>
+
+#define SQL_CACHE_LENGTH 300
+
+HASH sql_cache;
+LEX lex_array_static[SQL_CACHE_LENGTH];
+LEX * lex_array = lex_array_static;
+int last_lex_array_item = SQL_CACHE_LENGTH - 1;
+
+/* Function to return a text string from a LEX struct */
+static byte *cache_key(const byte *record, uint *length, my_bool not_used)
+{
+#ifdef QQ
+	LEX *lex=(LEX*) record;
+	*length = lex->sql_query_length;
+	// *length = strlen(lex->ptr);
+	return (byte*) lex->sql_query_text;
+	// return (byte*) lex->ptr;
+#endif
+  return 0;
+}
+
+/* At the moment we do not really want to do anything upon delete */
+static void free_cache_entry(void *entry)
+{
+}
+
+/* Initialization of the SQL cache hash -- should be called during
+   the bootstrap stage */
+bool sql_cache_init(void)
+{
+  if (query_buff_size)
+  {
+    VOID(hash_init(&sql_cache, 4096, 0, 0,
+		   cache_key,
+		   (void (*)(void*)) free_cache_entry,
+		   0));
+  }
+  return 0;
+}
+
+/* Clearing the SQL cache hash -- during shutdown */
+void sql_cache_free(void)
+{
+  hash_free(&sql_cache);
+}
+
+/* Finds whether the  SQL command is already in the cache, at any case
+	establishes correct LEX structure in the THD (either from
+	cache or a new one) */
+
+int sql_cache_hit(THD *thd, char *sql, uint length)
+{
+#ifdef QQ
+  LEX *ptr;
+  ptr = (LEX *)hash_search(&sql_cache, sql, length);
+  if (ptr) {
+    fprintf(stderr, "Query `%s' -- hit in the cache (%p)\n", ptr->sql_query_text, ptr);
+    thd->lex_ptr = ptr;
+    ptr->thd = thd;
+  } else {
+    thd->lex_ptr = ptr = lex_array + last_lex_array_item--;
+
+    lex_start(thd, (uchar *)sql, length);
+
+    if (hash_insert(&sql_cache, (const byte *)ptr)) {
+      fprintf(stderr, "Out of memory during hash_insert?\n");
+    }
+    fprintf(stderr, "Query `%s' not found in the cache -- insert %p from slot %d\n", thd->lex_ptr->ptr, ptr, last_lex_array_item+1);
+    if (!hash_search(&sql_cache, sql, length)) {
+      fprintf(stderr, "I just enterred a hash key but it's not where -- what's that?\n");
+    } else {
+      fprintf(stderr, "Inserted to cache\n");
+    }
+    return 0;
+  }
+#endif
+  return 1;
+}