Files
archived-pecl-caching-memcache/memcache_standard_hash.c
2008-08-16 10:15:54 +00:00

133 lines
3.8 KiB
C

/*
+----------------------------------------------------------------------+
| PHP Version 5 |
+----------------------------------------------------------------------+
| Copyright (c) 1997-2007 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.0 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.php.net/license/3_0.txt. |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Antony Dovgal <tony@daylessday.org> |
| Mikael Johansson <mikael AT synd DOT info> |
+----------------------------------------------------------------------+
*/
/* $Id$ */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "php.h"
#include "php_memcache.h"
ZEND_EXTERN_MODULE_GLOBALS(memcache)
typedef struct mmc_standard_state {
int num_servers;
mmc_t **buckets;
int num_buckets;
mmc_hash_function hash;
} mmc_standard_state_t;
void *mmc_standard_create_state(mmc_hash_function hash) /* {{{ */
{
mmc_standard_state_t *state = emalloc(sizeof(mmc_standard_state_t));
memset(state, 0, sizeof(mmc_standard_state_t));
state->hash = hash;
return state;
}
/* }}} */
void mmc_standard_free_state(void *s) /* {{{ */
{
mmc_standard_state_t *state = s;
if (state != NULL) {
if (state->buckets != NULL) {
efree(state->buckets);
}
efree(state);
}
}
/* }}} */
static unsigned int mmc_hash(mmc_standard_state_t *state, const char *key, int key_len) /* {{{ */
{
unsigned int hash = (state->hash(key, key_len) >> 16) & 0x7fff;
return hash ? hash : 1;
}
/* }}} */
mmc_t *mmc_standard_find_server(void *s, const char *key, int key_len TSRMLS_DC) /* {{{ */
{
mmc_standard_state_t *state = s;
mmc_t *mmc;
if (state->num_servers > 1) {
unsigned int hash = mmc_hash(state, key, key_len), i;
mmc = state->buckets[hash % state->num_buckets];
/* perform failover if needed */
for (i=0; !mmc_open(mmc, 0, NULL, NULL TSRMLS_CC) && MEMCACHE_G(allow_failover) && i<MEMCACHE_G(max_failover_attempts); i++) {
char *next_key = emalloc(key_len + MAX_LENGTH_OF_LONG + 1);
int next_len = sprintf(next_key, "%d%s", i+1, key);
MMC_DEBUG(("mmc_standard_find_server: failed to connect to server '%s:%d' status %d, trying next", mmc->host, mmc->port, mmc->status));
hash += mmc_hash(state, next_key, next_len);
mmc = state->buckets[hash % state->num_buckets];
efree(next_key);
}
}
else {
mmc = state->buckets[0];
mmc_open(mmc, 0, NULL, NULL TSRMLS_CC);
}
return mmc->status != MMC_STATUS_FAILED ? mmc : NULL;
}
/* }}} */
void mmc_standard_add_server(void *s, mmc_t *mmc, unsigned int weight) /* {{{ */
{
mmc_standard_state_t *state = s;
int i;
/* add weight number of buckets for this server */
if (state->num_buckets) {
state->buckets = erealloc(state->buckets, sizeof(mmc_t *) * (state->num_buckets + weight));
}
else {
state->buckets = emalloc(sizeof(mmc_t *) * (weight));
}
for (i=0; i<weight; i++) {
state->buckets[state->num_buckets + i] = mmc;
}
state->num_buckets += weight;
state->num_servers++;
}
/* }}} */
mmc_hash_t mmc_standard_hash = {
mmc_standard_create_state,
mmc_standard_free_state,
mmc_standard_find_server,
mmc_standard_add_server
};
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: noet sw=4 ts=4 fdm=marker
* vim<600: noet sw=4 ts=4
*/