php语言实现redis的客户端

为了更好的了解redis协议，我们用php来实现一个支持大部份命令的客户端类.

redis的协议可参考这个文章http://redis.cn/topics/protocol.html

代码如下：

namespace xtgxiso;
class Redis {
    private $redis_socket = false;
    private $cmd = '';
    public function __construct($host='127.0.0.1',$port=6379,$timeout = 3) {
        $this->redis_socket = stream_socket_client("tcp://".$host.":".$port, $errno, $errstr,  $timeout);
        if ( !$this->redis_socket) {
            throw new Exception("{$errno} - {$errstr}");
        }
    }
    public function __destruct() {
        fclose($this->redis_socket);
    }
    public function __call($name, $args) {
        $crlf = "rn";
        array_unshift($args,$name);
        $command = '*' . count($args) . $crlf;
        foreach ($args as $arg) {
            $command .= '$' . strlen($arg) . $crlf . $arg . $crlf;
        }
        $fwrite = fwrite($this->redis_socket,$command);
        if ($fwrite === FALSE || $fwrite <= 0) {
            throw new Exception('Failed to write entire command to stream');
        }
        return $this->readResponse();
    }
    private function readResponse() {
        $reply = trim(fgets($this->redis_socket, 1024));
        switch (substr($reply, 0, 1)) {
            case '-':
                throw new Exception(trim(substr($reply, 4)));
                break;
            case '+':
                $response = substr(trim($reply), 1);
                if ($response === 'OK') {
                    $response = TRUE;
                }
                break;
            case '$':
                $response = NULL;
                if ($reply == '$-1') {
                    break;
                }
                $read = 0;
                $size = intval(substr($reply, 1));
                if ($size > 0) {
                    do {
                        $block_size = ($size - $read) > 1024 ? 1024 : ($size - $read);
                        $r = fread($this->redis_socket, $block_size);
                        if ($r === FALSE) {
                            throw new Exception('Failed to read response from stream');
                        } else {
                            $read += strlen($r);
                            $response .= $r;
                        }
                    } while ($read < $size);
                }
                fread($this->redis_socket, 2); /* discard crlf */
                break;
            /* Multi-bulk reply */
            case '*':
                $count = intval(substr($reply, 1));
                if ($count == '-1') {
                    return NULL;
                }
                $response = array();
                for ($i = 0; $i < $count; $i++) {
                    $response[] = $this->readResponse();
                }
                break;
            /* Integer reply */
            case ':':
                $response = intval(substr(trim($reply), 1));
                break;
            default:
                throw new RedisException("Unknown response: {$reply}");
                break;
        }
        return $response;
    }
}
/*
$redis = new Client_test();
var_dump($redis->auth("123456"));
var_dump($redis->set("xtgxiso",'abc'));
var_dump($redis->get("xtgxiso"));
*/
通过实现，我们基本了解redis的协议。