/**
* Return an instance of the Resque_Redis class instantiated for Resque.
*
* @return Resque_Redis Instance of Resque_Redis.
*/
public static function redis()
{
// Detect when the PID of the current process has changed (from a fork, etc)
// and force a reconnect to redis.
$pid = getmypid();
if (self::$pid !== $pid) {
self::$redis = null;
self::$pid = $pid;
}
if (!is_null(self::$redis)) {
return self::$redis;
}
$server = self::$redisServer;
if (empty($server)) {
$server = 'localhost:6379';
}
if (is_array($server)) {
require_once dirname(__FILE__) . '/Resque/RedisCluster.php';
self::$redis = new Resque_RedisCluster($server);
} else {
if (strpos($server, 'unix:') === false) {
list($host, $port) = explode(':', $server);
} else {
$host = $server;
$port = null;
}
require_once dirname(__FILE__) . '/Resque/Redis.php';
$redisInstance = new Resque_Redis($host, $port);
$redisInstance->prefix(self::$namespace);
self::$redis = $redisInstance;
}
self::$redis->select(self::$redisDatabase);
return self::$redis;
}
/**
* Return an instance of the Resque_Redis class instantiated for Resque.
* 获取一个redis的实例
* @return Resque_Redis Instance of Resque_Redis.
*/
public static function redis()
{
// Detect when the PID of the current process has changed (from a fork, etc)
// and force a reconnect to redis.
// getmypid — 获取 PHP 进程的 ID
$pid = getmypid();
// 如果当前PHP进程的ID与类中定义的不同，清空redis实例，将类中定义的ID改为当前PHP进程的ID
if (self::$pid !== $pid) {
self::$redis = null;
self::$pid = $pid;
}
// redis实例存在，直接返回
if (!is_null(self::$redis)) {
return self::$redis;
}
// redis实例不存在，取出redis配置，默认为'localhost:6379'
$server = self::$redisServer;
if (empty($server)) {
$server = 'localhost:6379';
}
// 如果配置是个array，就会生成多个redis实例
// 配置项$server是[['host' => hostname0, 'port' => port0], ['host' => hostname1, 'port' => port1]]
// 也可以是['redis0' => ['host' => hostname0, 'port' => port0], 'redis1' => ['host' => hostname1, 'port' => port1]]
if (is_array($server)) {
require_once dirname(__FILE__) . '/Resque/RedisCluster.php';
self::$redis = new Resque_RedisCluster($server);
} else {
if (strpos($server, 'unix:') === false) {
// $server is '127.0.0.1:6379'
list($host, $port) = explode(':', $server);
} else {
// $server is 'unix:/tmp/redis.sock'
// 注：redis 默认没有开启unix socket，需要在/etc/redis/redis.conf中修改
$host = $server;
$port = null;
}
require_once dirname(__FILE__) . '/Resque/Redis.php';
self::$redis = new Resque_Redis($host, $port);
}
// 选择redis的数据库
self::$redis->select(self::$redisDatabase);
return self::$redis;
}
