LiteMemcache.class.php

<?php
/**
 * LiteMemcache - tiny, simple and pure-PHP alternative to Memcache and Memcached clients
 * 
 * Protocol specification @link https://github.com/memcached/memcached/blob/master/doc/protocol.txt
 * GitHub repository @link https://github.com/ptrofimov/litememcache
 * Contacts @author Petr Trofimov <petrofimov@yandex.ru>
 */
class LiteMemcache
{
	private $_socket, $_replies, $_lastReply;
	
	public function __construct( $server )
	{
		$this->_socket = stream_socket_client( $server, $errno, $errstr );
		if ( !$this->_socket )
		{
			throw new Exception( "$errstr ($errno)" );
		}
		$this->_replies = array( 
			'STORED' => true, 
			'NOT_STORED' => false, 
			'EXISTS' => false, 
			'OK' => true, 
			'ERROR' => false, 
			'DELETED' => true, 
			'NOT_FOUND' => false, 
			'ERROR' => null, 
			'CLIENT_ERROR' => null, 
			'SERVER_ERROR' => null );
	}
	
	public function add( $key, $value, $exptime = 0, $flags = 0 )
	{
		return $this->query( array( "add $key $flags $exptime " . strlen( $value ), $value ) );
	}
	
	public function append( $key, $value )
	{
		return $this->query( array( "append $key 0 0 " . strlen( $value ), $value ) );
	}
	
	public function cas( $key, $value, $cas, $exptime = 0, $flags = 0 )
	{
		return $this->query( array( "cas $key $flags $exptime " . strlen( $value ) . " $cas", $value ) );
	}
	
	public function decr( $key, $value = 1 )
	{
		return $this->query( "decr $key $value" );
	}
	
	public function del( $key )
	{
		return $this->query( "delete $key" );
	}
	
	public function flushAll( $exptime = 0 )
	{
		return $this->query( "flush_all $exptime" );
	}
	
	public function get( $key, $ext = false )
	{
		$keys = array_fill_keys( ( array ) $key, 
			$ext ? array( 'value' => null, 'flags' => null, 'cas' => null ) : null );
		$words = $this->query( ( $ext ? 'gets' : 'get' ) . ' ' . implode( ' ', array_keys( $keys ) ) );
		while ( $words[ 0 ] == 'VALUE' )
		{
			$value = fread( $this->_socket, $words[ 3 ] + 2 );
			$keys[ $words[ 1 ] ] = $ext ? array( 
				'value' => substr( $value, 0, strlen( $value ) - 2 ), 
				'flags' => $words[ 2 ], 
				'cas' => $words[ 4 ] ) : substr( $value, 0, strlen( $value ) - 2 );
			$words = $this->_readLine();
		}
		return is_array( $key ) ? $keys : reset( $keys );
	}
	
	public function getLastReply()
	{
		return $this->_lastReply;
	}
	
	public function incr( $key, $value = 1 )
	{
		return $this->query( "incr $key $value" );
	}
	
	public function prepend( $key, $value )
	{
		return $this->query( array( "prepend $key 0 0 " . strlen( $value ), $value ) );
	}
	
	public function query( $query )
	{
		$query = is_array( $query ) ? implode( "\r\n", $query ) : $query;
		fwrite( $this->_socket, $query . "\r\n" );
		return $this->_readLine();
	}
	
	public function replace( $key, $value, $exptime = 0, $flags = 0 )
	{
		return $this->query( array( "replace $key $flags $exptime " . strlen( $value ), $value ) );
	}
	
	public function set( $key, $value, $exptime = 0, $flags = 0 )
	{
		return $this->query( array( "set $key $flags $exptime " . strlen( $value ), $value ) );
	}
	
	private function _readLine()
	{
		$line = fgets( $this->_socket );
		$this->_lastReply = substr( $line, 0, strlen( $line ) - 2 );
		$words = explode( ' ', $this->_lastReply );
		$result = isset( $this->_replies[ $words[ 0 ] ] ) ? $this->_replies[ $words[ 0 ] ] : $words;
		if ( is_null( $result ) )
		{
			throw new Exception( $this->_lastReply );
		}
		return ( is_array( $result ) && count( $result ) == 1 ) ? reset( $result ) : $result;
	}
}