qii/Qii/Cache/Redis/Client.php

<?php
namespace Qii\Cache\Redis;
/**
 * Credis_Client (a fork of Redisent)
 *
 * Most commands are compatible with phpredis library:
 *   - use "pipeline()" to start a pipeline of commands instead of multi(Redis::PIPELINE)
 *   - any arrays passed as arguments will be flattened automatically
 *   - setOption and getOption are not supported in standalone mode
 *   - order of arguments follows redis-cli instead of phpredis where they differ (lrem)
 *
 * - Uses phpredis library if extension is installed for better performance.
 * - Establishes connection lazily.
 * - Supports tcp and unix sockets.
 * - Reconnects automatically unless a watch or transaction is in progress.
 * - Can set automatic retry connection attempts for iffy Redis connections.
 *
 * @author Colin Mollenhour <colin@mollenhour.com>
 * @copyright 2011 Colin Mollenhour <colin@mollenhour.com>
 * @license http://www.opensource.org/licenses/mit-license.php The MIT License
 * @package Credis_Client
 */

if (!defined('CRLF')) define('CRLF', sprintf('%s%s', chr(13), chr(10)));

/**
 * Credis-specific errors, wraps native Redis errors
 */
class CredisException extends \Exception
{

	const CODE_TIMED_OUT = 1;
	const CODE_DISCONNECTED = 2;

	public function __construct($message, $code = 0, $exception = NULL)
	{
		if ($exception && get_class($exception) == 'RedisException' && $message == 'read error on connection') {
			$code = CredisException::CODE_DISCONNECTED;
		}
		parent::__construct($message, $code, $exception);
	}

}

/**
 * Credis_Client, a lightweight Redis PHP standalone client and phpredis wrapper
 *
 * Server/Connection:
 * @method Credis_Client pipeline()
 * @method Credis_Client multi()
 * @method array         exec()
 * @method string        flushAll()
 * @method string        flushDb()
 * @method array         info()
 * @method bool|array    config(string $setGet, string $key, string $value = null)
 *
 * Keys:
 * @method int           del(string $key)
 * @method int           exists(string $key)
 * @method int           expire(string $key, int $seconds)
 * @method int           expireAt(string $key, int $timestamp)
 * @method array         keys(string $key)
 * @method int           persist(string $key)
 * @method bool          rename(string $key, string $newKey)
 * @method bool          renameNx(string $key, string $newKey)
 * @method array         sort(string $key, string $arg1, string $valueN = null)
 * @method int           ttl(string $key)
 * @method string        type(string $key)
 *
 * Scalars:
 * @method int           append(string $key, string $value)
 * @method int           decr(string $key)
 * @method int           decrBy(string $key, int $decrement)
 * @method bool|string   get(string $key)
 * @method int           getBit(string $key, int $offset)
 * @method string        getRange(string $key, int $start, int $end)
 * @method string        getSet(string $key, string $value)
 * @method int           incr(string $key)
 * @method int           incrBy(string $key, int $decrement)
 * @method array         mGet(array $keys)
 * @method bool          mSet(array $keysValues)
 * @method int           mSetNx(array $keysValues)
 * @method bool          set(string $key, string $value)
 * @method int           setBit(string $key, int $offset, int $value)
 * @method bool          setEx(string $key, int $seconds, string $value)
 * @method int           setNx(string $key, string $value)
 * @method int           setRange(string $key, int $offset, int $value)
 * @method int           strLen(string $key)
 *
 * Sets:
 * @method int           sAdd(string $key, mixed $value, string $valueN = null)
 * @method int           sRem(string $key, mixed $value, string $valueN = null)
 * @method array         sMembers(string $key)
 * @method array         sUnion(mixed $keyOrArray, string $valueN = null)
 * @method array         sInter(mixed $keyOrArray, string $valueN = null)
 * @method array         sDiff(mixed $keyOrArray, string $valueN = null)
 * @method string        sPop(string $key)
 * @method int           sCard(string $key)
 * @method int           sIsMember(string $key, string $member)
 * @method int           sMove(string $source, string $dest, string $member)
 * @method string|array  sRandMember(string $key, int $count = null)
 * @method int           sUnionStore(string $dest, string $key1, string $key2 = null)
 * @method int           sInterStore(string $dest, string $key1, string $key2 = null)
 * @method int           sDiffStore(string $dest, string $key1, string $key2 = null)
 *
 * Hashes:
 * @method bool|int      hSet(string $key, string $field, string $value)
 * @method bool          hSetNx(string $key, string $field, string $value)
 * @method bool|string   hGet(string $key, string $field)
 * @method bool|int      hLen(string $key)
 * @method bool          hDel(string $key, string $field)
 * @method array         hKeys(string $key, string $field)
 * @method array         hVals(string $key, string $field)
 * @method array         hGetAll(string $key)
 * @method bool          hExists(string $key, string $field)
 * @method int           hIncrBy(string $key, string $field, int $value)
 * @method bool          hMSet(string $key, array $keysValues)
 * @method array         hMGet(string $key, array $fields)
 *
 * Lists:
 * @method array|null    blPop(string $keyN, int $timeout)
 * @method array|null    brPop(string $keyN, int $timeout)
 * @method array|null    brPoplPush(string $source, string $destination, int $timeout)
 * @method string|null   lIndex(string $key, int $index)
 * @method int           lInsert(string $key, string $beforeAfter, string $pivot, string $value)
 * @method int           lLen(string $key)
 * @method string|null   lPop(string $key)
 * @method int           lPush(string $key, mixed $value, mixed $valueN = null)
 * @method int           lPushX(string $key, mixed $value)
 * @method array         lRange(string $key, int $start, int $stop)
 * @method int           lRem(string $key, int $count, mixed $value)
 * @method bool          lSet(string $key, int $index, mixed $value)
 * @method bool          lTrim(string $key, int $start, int $stop)
 * @method string|null   rPop(string $key)
 * @method string|null   rPoplPush(string $source, string $destination)
 * @method int           rPush(string $key, mixed $value, mixed $valueN = null)
 * @method int           rPushX(string $key, mixed $value)
 *
 * Sorted Sets:
 * TODO
 *
 * Pub/Sub
 * @method array         pUnsubscribe(mixed $pattern, string $patternN = NULL))
 * @method array         unsubscribe(mixed $channel, string $channelN = NULL))
 * @method int           publish(string $channel, string $message)
 * @method int|array     pubsub(string $subCommand, $arg = NULL)
 *
 * Scripting:
 * @method string|int    script(string $command, string $arg1 = null)
 * @method string|int|array|bool eval(string $script, array $keys = NULL, array $args = NULL)
 * @method string|int|array|bool evalSha(string $script, array $keys = NULL, array $args = NULL)
 */
class Client
{

	const TYPE_STRING = 'string';
	const TYPE_LIST = 'list';
	const TYPE_SET = 'set';
	const TYPE_ZSET = 'zset';
	const TYPE_HASH = 'hash';
	const TYPE_NONE = 'none';
	const FREAD_BLOCK_SIZE = 8192;

	/**
	 * Socket connection to the Redis server or Redis library instance
	 * @var resource|Redis
	 */
	protected $redis;
	protected $redisMulti;

	/**
	 * Host of the Redis server
	 * @var string
	 */
	protected $host;

	/**
	 * Port on which the Redis server is running
	 * @var integer
	 */
	protected $port;

	/**
	 * Timeout for connecting to Redis server
	 * @var float
	 */
	protected $timeout;

	/**
	 * Timeout for reading response from Redis server
	 * @var float
	 */
	protected $readTimeout;

	/**
	 * Unique identifier for persistent connections
	 * @var string
	 */
	protected $persistent;

	/**
	 * @var bool
	 */
	protected $closeOnDestruct = TRUE;

	/**
	 * @var bool
	 */
	protected $connected = FALSE;

	/**
	 * @var bool
	 */
	protected $standalone;

	/**
	 * @var int
	 */
	protected $maxConnectRetries = 0;

	/**
	 * @var int
	 */
	protected $connectFailures = 0;

	/**
	 * @var bool
	 */
	protected $usePipeline = FALSE;

	/**
	 * @var array
	 */
	protected $commandNames;

	/**
	 * @var string
	 */
	protected $commands;

	/**
	 * @var bool
	 */
	protected $isMulti = FALSE;

	/**
	 * @var bool
	 */
	protected $isWatching = FALSE;

	/**
	 * @var string
	 */
	protected $authPassword;

	/**
	 * @var int
	 */
	protected $selectedDb = 0;

	/**
	 * Aliases for backwards compatibility with phpredis
	 * @var array
	 */
	protected $wrapperMethods = array('delete' => 'del', 'getkeys' => 'keys', 'sremove' => 'srem');

	/**
	 * @var array
	 */
	protected $renamedCommands;

	/**
	 * Creates a Redisent connection to the Redis server on host {@link $host} and port {@link $port}.
	 * $host may also be a path to a unix socket or a string in the form of tcp://[hostname]:[port] or unix://[path]
	 *
	 * @param string $host The hostname of the Redis server
	 * @param integer $port The port number of the Redis server
	 * @param float $timeout Timeout period in seconds
	 * @param string $persistent Flag to establish persistent connection
	 */
	public function __construct($host = '127.0.0.1', $port = 6379, $timeout = null, $persistent = '')
	{
		$this->host = (string)$host;
		$this->port = (int)$port;
		$this->timeout = $timeout;
		$this->persistent = (string)$persistent;
		$this->standalone = !extension_loaded('redis');
	}

	public function __destruct()
	{
		if ($this->closeOnDestruct) {
			$this->close();
		}
	}

	/**
	 * @throws CredisException
	 * @return Credis_Client
	 */
	public function forceStandalone()
	{
		if ($this->connected) {
			throw new CredisException('Cannot force Credis_Client to use standalone PHP driver after a connection has already been established.');
		}
		$this->standalone = TRUE;
		return $this;
	}

	/**
	 * @param int $retries
	 * @return Credis_Client
	 */
	public function setMaxConnectRetries($retries)
	{
		$this->maxConnectRetries = $retries;
		return $this;
	}

	/**
	 * @param bool $flag
	 * @return Credis_Client
	 */
	public function setCloseOnDestruct($flag)
	{
		$this->closeOnDestruct = $flag;
		return $this;
	}

	/**
	 * @throws CredisException
	 * @return Credis_Client
	 */
	public function connect()
	{
		if ($this->connected) {
			return $this;
		}
		if (preg_match('#^(tcp|unix)://(.*)$#', $this->host, $matches)) {
			if ($matches[1] == 'tcp') {
				if (!preg_match('#^(.*)(?::(\d+))?(?:/(.*))?$#', $matches[2], $matches)) {
					throw new CredisException('Invalid host format; expected tcp://host[:port][/persistent]');
				}
				$this->host = $matches[1];
				$this->port = (int)(isset($matches[2]) ? $matches[2] : 6379);
				$this->persistent = isset($matches[3]) ? $matches[3] : '';
			} else {
				$this->host = $matches[2];
				$this->port = NULL;
				if (substr($this->host, 0, 1) != '/') {
					throw new CredisException('Invalid unix socket format; expected unix:///path/to/redis.sock');
				}
			}
		}
		if ($this->port !== NULL && substr($this->host, 0, 1) == '/') {
			$this->port = NULL;
		}
		if ($this->standalone) {
			$flags = STREAM_CLIENT_CONNECT;
			$remote_socket = $this->port === NULL
				? 'unix://' . $this->host
				: 'tcp://' . $this->host . ':' . $this->port;
			if ($this->persistent) {
				if ($this->port === NULL) { // Unix socket
					throw new CredisException('Persistent connections to UNIX sockets are not supported in standalone mode.');
				}
				$remote_socket .= '/' . $this->persistent;
				$flags = $flags | STREAM_CLIENT_PERSISTENT;
			}
			$result = $this->redis = @stream_socket_client($remote_socket, $errno, $errstr, $this->timeout !== null ? $this->timeout : 2.5, $flags);
		} else {
			if (!$this->redis) {
				$this->redis = new \Redis;
			}
			$result = $this->persistent
				? $this->redis->pconnect($this->host, $this->port, $this->timeout, $this->persistent)
				: $this->redis->connect($this->host, $this->port, $this->timeout);
		}

		// Use recursion for connection retries
		if (!$result) {
			$this->connectFailures++;
			if ($this->connectFailures <= $this->maxConnectRetries) {
				return $this->connect();
			}
			$failures = $this->connectFailures;
			$this->connectFailures = 0;
			throw new CredisException("Connection to Redis failed after $failures failures." . (isset($errno) && isset($errstr) ? "Last Error : ({$errno}) {$errstr}" : ""));
		}

		$this->connectFailures = 0;
		$this->connected = TRUE;

		// Set read timeout
		if ($this->readTimeout) {
			$this->setReadTimeout($this->readTimeout);
		}

		return $this;
	}

	/**
	 * Set the read timeout for the connection. Use 0 to disable timeouts entirely (or use a very long timeout
	 * if not supported).
	 *
	 * @param int $timeout 0 (or -1) for no timeout, otherwise number of seconds
	 * @throws CredisException
	 * @return Credis_Client
	 */
	public function setReadTimeout($timeout)
	{
		if ($timeout < -1) {
			throw new CredisException('Timeout values less than -1 are not accepted.');
		}
		$this->readTimeout = $timeout;
		if ($this->connected) {
			if ($this->standalone) {
				$timeout = $timeout <= 0 ? 315360000 : $timeout; // Ten-year timeout
				stream_set_blocking($this->redis, TRUE);
				stream_set_timeout($this->redis, (int)floor($timeout), ($timeout - floor($timeout)) * 1000000);
			} else if (defined('Redis::OPT_READ_TIMEOUT')) {
				// supported in phpredis 2.2.3
				// a timeout value of -1 means reads will not timeout
				$timeout = $timeout == 0 ? -1 : $timeout;
				$this->redis->setOption(Redis::OPT_READ_TIMEOUT, $timeout);
			}
		}
		return $this;
	}

	/**
	 * @return bool
	 */
	public function close()
	{
		$result = TRUE;
		if ($this->connected && !$this->persistent) {
			try {
				$result = $this->standalone ? fclose($this->redis) : $this->redis->close();
				$this->connected = FALSE;
			} catch (\Exception $e) {
				; // Ignore exceptions on close
			}
		}
		return $result;
	}

	/**
	 * Enabled command renaming and provide mapping method. Supported methods are:
	 *
	 * 1. renameCommand('foo') // Salted md5 hash for all commands -> md5('foo'.$command)
	 * 2. renameCommand(function($command){ return 'my'.$command; }); // Callable
	 * 3. renameCommand('get', 'foo') // Single command -> alias
	 * 4. renameCommand(['get' => 'foo', 'set' => 'bar']) // Full map of [command -> alias]
	 *
	 * @param string|callable|array $command
	 * @param string|null $alias
	 * @return $this
	 */
	public function renameCommand($command, $alias = NULL)
	{
		if (!$this->standalone) {
			$this->forceStandalone();
		}
		if ($alias === NULL) {
			$this->renamedCommands = $command;
		} else {
			if (!$this->renamedCommands) {
				$this->renamedCommands = array();
			}
			$this->renamedCommands[$command] = $alias;
		}
		return $this;
	}

	/**
	 * @param $command
	 */
	public function getRenamedCommand($command)
	{
		static $map;

		// Command renaming not enabled
		if ($this->renamedCommands === NULL) {
			return $command;
		}

		// Initialize command map
		if ($map === NULL) {
			if (is_array($this->renamedCommands)) {
				$map = $this->renamedCommands;
			} else {
				$map = array();
			}
		}

		// Generate and return cached result
		if (!isset($map[$command])) {
			// String means all commands are hashed with salted md5
			if (is_string($this->renamedCommands)) {
				$map[$command] = md5($this->renamedCommands . $command);
			} // Would already be set in $map if it was intended to be renamed
			else if (is_array($this->renamedCommands)) {
				return $command;
			} // User-supplied function
			else if (is_callable($this->renamedCommands)) {
				$map[$command] = call_user_func($this->renamedCommands, $command);
			}
		}
		return $map[$command];
	}

	/**
	 * @param string $password
	 * @return bool
	 */
	public function auth($password)
	{
		$this->authPassword = $password;
		$response = $this->__call('auth', array($this->authPassword));
		return $response;
	}

	/**
	 * @param int $index
	 * @return bool
	 */
	public function select($index)
	{
		$this->selectedDb = (int)$index;
		$response = $this->__call('select', array($this->selectedDb));
		return $response;
	}

	/**
	 * @param string|array $patterns
	 * @param $callback
	 * @return $this|array|bool|Credis_Client|mixed|null|string
	 * @throws CredisException
	 */
	public function pSubscribe($patterns, $callback)
	{
		if (!$this->standalone) {
			return $this->__call('pSubscribe', array((array)$patterns, $callback));
		}

		// Standalone mode: use infinite loop to subscribe until timeout
		$patternCount = is_array($patterns) ? count($patterns) : 1;
		while ($patternCount--) {
			if (isset($status)) {
				list($command, $pattern, $status) = $this->read_reply();
			} else {
				list($command, $pattern, $status) = $this->__call('psubscribe', array($patterns));
			}
			if (!$status) {
				throw new CredisException('Invalid pSubscribe response.');
			}
		}
		try {
			while (1) {
				list($type, $pattern, $channel, $message) = $this->read_reply();
				if ($type != 'pmessage') {
					throw new CredisException('Received non-pmessage reply.');
				}
				$callback($this, $pattern, $channel, $message);
			}
		} catch (CredisException $e) {
			if ($e->getCode() == CredisException::CODE_TIMED_OUT) {
				try {
					list($command, $pattern, $status) = $this->pUnsubscribe($patterns);
					while ($status !== 0) {
						list($command, $pattern, $status) = $this->read_reply();
					}
				} catch (CredisException $e2) {
					throw $e2;
				}
			}
			throw $e;
		}
	}

	/**
	 * @param string|array $channels
	 * @param $callback
	 * @throws CredisException
	 * @return $this|array|bool|Credis_Client|mixed|null|string
	 */
	public function subscribe($channels, $callback)
	{
		if (!$this->standalone) {
			return $this->__call('subscribe', array((array)$channels, $callback));
		}

		// Standalone mode: use infinite loop to subscribe until timeout
		$channelCount = is_array($channels) ? count($channels) : 1;
		while ($channelCount--) {
			if (isset($status)) {
				list($command, $channel, $status) = $this->read_reply();
			} else {
				list($command, $channel, $status) = $this->__call('subscribe', array($channels));
			}
			if (!$status) {
				throw new CredisException('Invalid subscribe response.');
			}
		}
		try {
			while (1) {
				list($type, $channel, $message) = $this->read_reply();
				if ($type != 'message') {
					throw new CredisException('Received non-message reply.');
				}
				$callback($this, $channel, $message);
			}
		} catch (CredisException $e) {
			if ($e->getCode() == CredisException::CODE_TIMED_OUT) {
				try {
					list($command, $channel, $status) = $this->unsubscribe($channels);
					while ($status !== 0) {
						list($command, $channel, $status) = $this->read_reply();
					}
				} catch (CredisException $e2) {
					throw $e2;
				}
			}
			throw $e;
		}
	}

	public function __call($name, $args)
	{
		// Lazy connection
		$this->connect();

		$name = strtolower($name);

		// Send request via native PHP
		if ($this->standalone) {
			switch ($name) {
				case 'eval':
				case 'evalsha':
					$script = array_shift($args);
					$keys = (array)array_shift($args);
					$eArgs = (array)array_shift($args);
					$args = array($script, count($keys), $keys, $eArgs);
					break;
			}
			// Flatten arguments
			$argsFlat = NULL;
			foreach ($args as $index => $arg) {
				if (is_array($arg)) {
					if ($argsFlat === NULL) {
						$argsFlat = array_slice($args, 0, $index);
					}
					if ($name == 'mset' || $name == 'msetnx' || $name == 'hmset') {
						foreach ($arg as $key => $value) {
							$argsFlat[] = $key;
							$argsFlat[] = $value;
						}
					} else {
						$argsFlat = array_merge($argsFlat, $arg);
					}
				} else if ($argsFlat !== NULL) {
					$argsFlat[] = $arg;
				}
			}
			if ($argsFlat !== NULL) {
				$args = $argsFlat;
				$argsFlat = NULL;
			}

			// In pipeline mode
			if ($this->usePipeline) {
				if ($name == 'pipeline') {
					throw new CredisException('A pipeline is already in use and only one pipeline is supported.');
				} else if ($name == 'exec') {
					if ($this->isMulti) {
						$this->commandNames[] = $name;
						$this->commands .= self::_prepare_command(array($this->getRenamedCommand($name)));
					}

					// Write request
					if ($this->commands) {
						$this->write_command($this->commands);
					}
					$this->commands = NULL;

					// Read response
					$response = array();
					foreach ($this->commandNames as $command) {
						$response[] = $this->read_reply($command);
					}
					$this->commandNames = NULL;

					if ($this->isMulti) {
						$response = array_pop($response);
					}
					$this->usePipeline = $this->isMulti = FALSE;
					return $response;
				} else {
					if ($name == 'multi') {
						$this->isMulti = TRUE;
					}
					array_unshift($args, $this->getRenamedCommand($name));
					$this->commandNames[] = $name;
					$this->commands .= self::_prepare_command($args);
					return $this;
				}
			}

			// Start pipeline mode
			if ($name == 'pipeline') {
				$this->usePipeline = TRUE;
				$this->commandNames = array();
				$this->commands = '';
				return $this;
			}

			// If unwatching, allow reconnect with no error thrown
			if ($name == 'unwatch') {
				$this->isWatching = FALSE;
			}

			// Non-pipeline mode
			array_unshift($args, $this->getRenamedCommand($name));
			$command = self::_prepare_command($args);
			$this->write_command($command);
			$response = $this->read_reply($name);

			// Watch mode disables reconnect so error is thrown
			if ($name == 'watch') {
				$this->isWatching = TRUE;
			} // Transaction mode
			else if ($this->isMulti && ($name == 'exec' || $name == 'discard')) {
				$this->isMulti = FALSE;
			} // Started transaction
			else if ($this->isMulti || $name == 'multi') {
				$this->isMulti = TRUE;
				$response = $this;
			}
		} // Send request via phpredis client
		else {
			// Tweak arguments
			switch ($name) {
				case 'get':   // optimize common cases
				case 'set':
				case 'hget':
				case 'hset':
				case 'setex':
				case 'mset':
				case 'msetnx':
				case 'hmset':
				case 'hmget':
				case 'del':
					break;
				case 'mget':
					if (isset($args[0]) && !is_array($args[0])) {
						$args = array($args);
					}
					break;
				case 'lrem':
					$args = array($args[0], $args[2], $args[1]);
					break;
				case 'eval':
				case 'evalsha':
					if (isset($args[1]) && is_array($args[1])) {
						$cKeys = $args[1];
					} elseif (isset($args[1]) && is_string($args[1])) {
						$cKeys = array($args[1]);
					} else {
						$cKeys = array();
					}
					if (isset($args[2]) && is_array($args[2])) {
						$cArgs = $args[2];
					} elseif (isset($args[2]) && is_string($args[2])) {
						$cArgs = array($args[2]);
					} else {
						$cArgs = array();
					}
					$args = array($args[0], array_merge($cKeys, $cArgs), count($cKeys));
					break;
				case 'subscribe':
				case 'psubscribe':
					break;
				default:
					// Flatten arguments
					$argsFlat = NULL;
					foreach ($args as $index => $arg) {
						if (is_array($arg)) {
							if ($argsFlat === NULL) {
								$argsFlat = array_slice($args, 0, $index);
							}
							$argsFlat = array_merge($argsFlat, $arg);
						} else if ($argsFlat !== NULL) {
							$argsFlat[] = $arg;
						}
					}
					if ($argsFlat !== NULL) {
						$args = $argsFlat;
						$argsFlat = NULL;
					}
			}

			try {
				// Proxy pipeline mode to the phpredis library
				if ($name == 'pipeline' || $name == 'multi') {
					if ($this->isMulti) {
						return $this;
					} else {
						$this->isMulti = TRUE;
						$this->redisMulti = call_user_func_array(array($this->redis, $name), $args);
					}
				} else if ($name == 'exec' || $name == 'discard') {
					$this->isMulti = FALSE;
					$response = $this->redisMulti->$name();
					$this->redisMulti = NULL;
					#echo "> $name : ".substr(print_r($response, TRUE),0,100)."\n";
					return $response;
				}

				// Use aliases to be compatible with phpredis wrapper
				if (isset($this->wrapperMethods[$name])) {
					$name = $this->wrapperMethods[$name];
				}

				// Multi and pipeline return self for chaining
				if ($this->isMulti) {
					call_user_func_array(array($this->redisMulti, $name), $args);
					return $this;
				}

				$response = call_user_func_array(array($this->redis, $name), $args);
			} // Wrap exceptions
			catch (RedisException $e) {
				$code = 0;
				if (!($result = $this->redis->IsConnected())) {
					$this->connected = FALSE;
					$code = CredisException::CODE_DISCONNECTED;
				}
				throw new CredisException($e->getMessage(), $code, $e);
			}

			#echo "> $name : ".substr(print_r($response, TRUE),0,100)."\n";

			// change return values where it is too difficult to minim in standalone mode
			switch ($name) {
				case 'hmget':
					$response = array_values($response);
					break;

				case 'type':
					$typeMap = array(
						self::TYPE_NONE,
						self::TYPE_STRING,
						self::TYPE_SET,
						self::TYPE_LIST,
						self::TYPE_ZSET,
						self::TYPE_HASH,
					);
					$response = $typeMap[$response];
					break;

				// Handle scripting errors
				case 'eval':
				case 'evalsha':
				case 'script':
					$error = $this->redis->getLastError();
					$this->redis->clearLastError();
					if ($error && substr($error, 0, 8) == 'NOSCRIPT') {
						$response = NULL;
					} else if ($error) {
						throw new CredisException($error);
					}
					break;
			}
		}

		return $response;
	}

	protected function write_command($command)
	{
		// Reconnect on lost connection (Redis server "timeout" exceeded since last command)
		if (feof($this->redis)) {
			$this->close();
			// If a watch or transaction was in progress and connection was lost, throw error rather than reconnect
			// since transaction/watch state will be lost.
			if (($this->isMulti && !$this->usePipeline) || $this->isWatching) {
				$this->isMulti = $this->isWatching = FALSE;
				throw new CredisException('Lost connection to Redis server during watch or transaction.');
			}
			$this->connected = FALSE;
			$this->connect();
			if ($this->authPassword) {
				$this->auth($this->authPassword);
			}
			if ($this->selectedDb != 0) {
				$this->select($this->selectedDb);
			}
		}

		$commandLen = strlen($command);
		for ($written = 0; $written < $commandLen; $written += $fwrite) {
			$fwrite = fwrite($this->redis, substr($command, $written));
			if ($fwrite === FALSE || $fwrite == 0) {
				$this->connected = FALSE;
				throw new CredisException('Failed to write entire command to stream');
			}
		}
	}

	protected function read_reply($name = '')
	{
		$reply = fgets($this->redis);
		if ($reply === FALSE) {
			$info = stream_get_meta_data($this->redis);
			if ($info['timed_out']) {
				throw new CredisException('Read operation timed out.', CredisException::CODE_TIMED_OUT);
			} else {
				$this->connected = FALSE;
				throw new CredisException('Lost connection to Redis server.', CredisException::CODE_DISCONNECTED);
			}
		}
		$reply = rtrim($reply, CRLF);
		#echo "> $name: $reply\n";
		$replyType = substr($reply, 0, 1);
		switch ($replyType) {
			/* Error reply */
			case '-':
				if ($this->isMulti || $this->usePipeline) {
					$response = FALSE;
				} else if ($name == 'evalsha' && substr($reply, 0, 9) == '-NOSCRIPT') {
					$response = NULL;
				} else {
					throw new CredisException(substr($reply, 0, 4) == '-ERR' ? substr($reply, 5) : substr($reply, 1));
				}
				break;
			/* Inline reply */
			case '+':
				$response = substr($reply, 1);
				if ($response == 'OK' || $response == 'QUEUED') {
					return TRUE;
				}
				break;
			/* Bulk reply */
			case '$':
				if ($reply == '$-1') return FALSE;
				$size = (int)substr($reply, 1);
				$response = stream_get_contents($this->redis, $size + 2);
				if (!$response) {
					$this->connected = FALSE;
					throw new CredisException('Error reading reply.');
				}
				$response = substr($response, 0, $size);
				break;
			/* Multi-bulk reply */
			case '*':
				$count = substr($reply, 1);
				if ($count == '-1') return FALSE;

				$response = array();
				for ($i = 0; $i < $count; $i++) {
					$response[] = $this->read_reply();
				}
				break;
			/* Integer reply */
			case ':':
				$response = intval(substr($reply, 1));
				break;
			default:
				throw new CredisException('Invalid response: ' . print_r($reply, TRUE));
				break;
		}

		// Smooth over differences between phpredis and standalone response
		switch ($name) {
			case '': // Minor optimization for multi-bulk replies
				break;
			case 'config':
			case 'hgetall':
				$keys = $values = array();
				while ($response) {
					$keys[] = array_shift($response);
					$values[] = array_shift($response);
				}
				$response = count($keys) ? array_combine($keys, $values) : array();
				break;
			case 'info':
				$lines = explode(CRLF, trim($response, CRLF));
				$response = array();
				foreach ($lines as $line) {
					if (!$line || substr($line, 0, 1) == '#') {
						continue;
					}
					list($key, $value) = explode(':', $line, 2);
					$response[$key] = $value;
				}
				break;
			case 'ttl':
				if ($response === -1) {
					$response = FALSE;
				}
				break;
		}

		return $response;
	}

	/**
	 * Build the Redis unified protocol command
	 *
	 * @param array $args
	 * @return string
	 */
	private static function _prepare_command($args)
	{
		return sprintf('*%d%s%s%s', count($args), CRLF, implode(array_map(array('self', '_map'), $args), CRLF), CRLF);
	}

	private static function _map($arg)
	{
		return sprintf('$%d%s%s', strlen($arg), CRLF, $arg);
	}

}