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99 lines
2.9 KiB
C++
99 lines
2.9 KiB
C++
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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#include "mysql_priv.h"
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#include <m_ctype.h>
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#include <my_dir.h>
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#include <hash.h>
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#define SQL_CACHE_LENGTH 30 // 300 crashes apple gcc.
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HASH sql_cache;
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static LEX lex_array_static[SQL_CACHE_LENGTH];
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LEX * lex_array = lex_array_static;
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int last_lex_array_item = SQL_CACHE_LENGTH - 1;
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/* Function to return a text string from a LEX struct */
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static byte *cache_key(const byte *record, uint *length, my_bool not_used)
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{
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#ifdef QQ
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LEX *lex=(LEX*) record;
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*length = lex->sql_query_length;
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// *length = strlen(lex->ptr);
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return (byte*) lex->sql_query_text;
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// return (byte*) lex->ptr;
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#endif
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return 0;
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}
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/* At the moment we do not really want to do anything upon delete */
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static void free_cache_entry(void *entry)
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{
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}
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/* Initialization of the SQL cache hash -- should be called during
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the bootstrap stage */
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bool sql_cache_init(void)
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{
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if (query_buff_size)
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{
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VOID(hash_init(&sql_cache, 4096, 0, 0,
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cache_key,
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(void (*)(void*)) free_cache_entry,
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0));
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}
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return 0;
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}
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/* Clearing the SQL cache hash -- during shutdown */
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void sql_cache_free(void)
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{
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hash_free(&sql_cache);
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}
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/* Finds whether the SQL command is already in the cache, at any case
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establishes correct LEX structure in the THD (either from
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cache or a new one) */
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int sql_cache_hit(THD *thd, char *sql, uint length)
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{
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#ifdef QQ
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LEX *ptr;
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ptr = (LEX *)hash_search(&sql_cache, sql, length);
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if (ptr) {
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fprintf(stderr, "Query `%s' -- hit in the cache (%p)\n", ptr->sql_query_text, ptr);
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thd->lex_ptr = ptr;
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ptr->thd = thd;
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} else {
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thd->lex_ptr = ptr = lex_array + last_lex_array_item--;
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lex_start(thd, (uchar *)sql, length);
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if (hash_insert(&sql_cache, (const byte *)ptr)) {
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fprintf(stderr, "Out of memory during hash_insert?\n");
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}
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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);
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if (!hash_search(&sql_cache, sql, length)) {
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fprintf(stderr, "I just enterred a hash key but it's not where -- what's that?\n");
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} else {
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fprintf(stderr, "Inserted to cache\n");
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}
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return 0;
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}
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#endif
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return 1;
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}
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