/**
* Discover and return available cache adapter of false if nothing is available
*
* @return SugarCache_Abstract|false
*/
function discover()
{
// If the cache is manually disabled, turn it off.
if (!empty($GLOBALS['sugar_config']['external_cache_disabled']) && true == $GLOBALS['sugar_config']['external_cache_disabled']) {
if (EXTERNAL_CACHE_DEBUG) {
SugarCache::log("SugarCache::discover() -- caching explicitly disabled", 'fail');
}
$GLOBALS['external_cache_enabled'] = false;
return SugarCache::factory('Base');
}
// check for Zend caching
if (function_exists("output_cache_get") && empty($GLOBALS['sugar_config']['external_cache_disabled_zend'])) {
$GLOBALS['external_cache_enabled'] = true;
$GLOBALS['external_cache_type'] = "zend";
$cache = SugarCache::factory('Zend');
if (EXTERNAL_CACHE_DEBUG) {
SugarCache::log('Found Zend - attempting to use', 'pass');
}
} elseif (extension_loaded('memcache') && empty($GLOBALS['sugar_config']['external_cache_disabled_memcache'])) {
$GLOBALS['external_cache_enabled'] = true;
$GLOBALS['external_cache_type'] = 'memcache';
$cache = SugarCache::factory('Memcache');
if (EXTERNAL_CACHE_DEBUG) {
SugarCache::log('Found memcache - attempting to use', 'pass');
}
} elseif (function_exists("apc_store") && empty($GLOBALS['sugar_config']['external_cache_disabled_apc'])) {
$GLOBALS['external_cache_enabled'] = true;
$GLOBALS['external_cache_type'] = "apc";
$cache = SugarCache::factory('APC');
if (EXTERNAL_CACHE_DEBUG) {
SugarCache::log('Found APC - attempting to use', 'pass');
}
} elseif (function_exists("zget") && empty($GLOBALS['sugar_config']['external_cache_disabled_smash'])) {
$GLOBALS['external_cache_enabled'] = true;
$GLOBALS['external_cache_type'] = "smash";
$cache = SugarCache::factory('sMash');
if (EXTERNAL_CACHE_DEBUG) {
SugarCache::log('Found sMash - attempting to use', 'pass');
}
} else {
// no cache available....return
$GLOBALS['external_cache_enabled'] = true;
$GLOBALS['external_cache_type'] = 'base-in-memory';
$cache = SugarCache::factory('Base');
if (EXTERNAL_CACHE_DEBUG) {
SugarCache::log('Found no caching solution - using base');
}
}
// Check the cache.
if (!$cache->initialized) {
// Validation failed. Turn off the external cache and return SugarCache_Base
$GLOBALS['external_cache_enabled'] = false;
if (EXTERNAL_CACHE_DEBUG) {
SugarCache::log("external cache validation check failed...tried cache {$GLOBALS['external_cache_type']}", 'fail');
SugarCache::log('returning Base');
}
return SugarCache::factory('Base');
}
// If the cache is being reset, turn it off for this round trip
$value = '';
if (isset($GLOBALS['sugar_config']) && isset($GLOBALS['sugar_config']['unique_key'])) {
$value = $cache->get($GLOBALS['sugar_config']['unique_key'] . 'EXTERNAL_CACHE_RESET');
}
if (!empty($value)) {
// We are in a cache reset, do not use the cache.
$GLOBALS['external_cache_enabled'] = false;
} else {
// Add one to the external cache hits. This will keep the end user statistics simple.
// All real checks suceeding will result in 100%. Otherwise people will be looking for
// the one check that did not pass.
$GLOBALS['external_cache_request_external_hits']++;
}
return $cache;
}
