Your IP : 172.71.120.3
<?php
//
// +---------------------------------------------------------------------------+
// | memcached client, PHP |
// +---------------------------------------------------------------------------+
// | Copyright (c) 2003 Ryan T. Dean <rtdean@cytherianage.net> |
// | All rights reserved. |
// | |
// | Redistribution and use in source and binary forms, with or without |
// | modification, are permitted provided that the following conditions |
// | are met: |
// | |
// | 1. Redistributions of source code must retain the above copyright |
// | notice, this list of conditions and the following disclaimer. |
// | 2. Redistributions in binary form must reproduce the above copyright |
// | notice, this list of conditions and the following disclaimer in the |
// | documentation and/or other materials provided with the distribution. |
// | |
// | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
// | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
// | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
// | IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
// | NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
// | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
// | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
// | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
// | THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
// +---------------------------------------------------------------------------+
// | Author: Ryan T. Dean <rtdean@cytherianage.net> |
// | Heavily influenced by the Perl memcached client by Brad Fitzpatrick. |
// | Permission granted by Brad Fitzpatrick for relicense of ported Perl |
// | client logic under 2-clause BSD license. |
// +---------------------------------------------------------------------------+
//
// $TCAnet$
//
/**
* This is the PHP client for memcached - a distributed memory cache daemon.
* More information is available at http://www.danga.com/memcached/
*
* Usage example:
*
* require_once 'memcached.php';
*
* $mc = new MWMemcached(array(
* 'servers' => array('127.0.0.1:10000',
* array('192.0.0.1:10010', 2),
* '127.0.0.1:10020'),
* 'debug' => false,
* 'compress_threshold' => 10240,
* 'persistant' => true));
*
* $mc->add('key', array('some', 'array'));
* $mc->replace('key', 'some random string');
* $val = $mc->get('key');
*
* @author Ryan T. Dean <rtdean@cytherianage.net>
* @version 0.1.2
*/
// {{{ requirements
// }}}
// {{{ class MWMemcached
/**
* memcached client class implemented using (p)fsockopen()
*
* @author Ryan T. Dean <rtdean@cytherianage.net>
* @ingroup Cache
*/
class MWMemcached {
// {{{ properties
// {{{ public
// {{{ constants
// {{{ flags
/**
* Flag: indicates data is serialized
*/
const SERIALIZED = 1;
/**
* Flag: indicates data is compressed
*/
const COMPRESSED = 2;
// }}}
/**
* Minimum savings to store data compressed
*/
const COMPRESSION_SAVINGS = 0.20;
// }}}
/**
* Command statistics
*
* @var array
* @access public
*/
var $stats;
// }}}
// {{{ private
/**
* Cached Sockets that are connected
*
* @var array
* @access private
*/
var $_cache_sock;
/**
* Current debug status; 0 - none to 9 - profiling
*
* @var boolean
* @access private
*/
var $_debug;
/**
* Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
*
* @var array
* @access private
*/
var $_host_dead;
/**
* Is compression available?
*
* @var boolean
* @access private
*/
var $_have_zlib;
/**
* Do we want to use compression?
*
* @var boolean
* @access private
*/
var $_compress_enable;
/**
* At how many bytes should we compress?
*
* @var integer
* @access private
*/
var $_compress_threshold;
/**
* Are we using persistant links?
*
* @var boolean
* @access private
*/
var $_persistant;
/**
* If only using one server; contains ip:port to connect to
*
* @var string
* @access private
*/
var $_single_sock;
/**
* Array containing ip:port or array(ip:port, weight)
*
* @var array
* @access private
*/
var $_servers;
/**
* Our bit buckets
*
* @var array
* @access private
*/
var $_buckets;
/**
* Total # of bit buckets we have
*
* @var integer
* @access private
*/
var $_bucketcount;
/**
* # of total servers we have
*
* @var integer
* @access private
*/
var $_active;
/**
* Stream timeout in seconds. Applies for example to fread()
*
* @var integer
* @access private
*/
var $_timeout_seconds;
/**
* Stream timeout in microseconds
*
* @var integer
* @access private
*/
var $_timeout_microseconds;
/**
* Connect timeout in seconds
*/
var $_connect_timeout;
/**
* Number of connection attempts for each server
*/
var $_connect_attempts;
// }}}
// }}}
// {{{ methods
// {{{ public functions
// {{{ memcached()
/**
* Memcache initializer
*
* @param array $args Associative array of settings
*
* @return mixed
*/
public function __construct( $args ) {
global $wgMemCachedTimeout;
$this->set_servers( @$args['servers'] );
$this->_debug = @$args['debug'];
$this->stats = array();
$this->_compress_threshold = @$args['compress_threshold'];
$this->_persistant = array_key_exists( 'persistant', $args ) ? ( @$args['persistant'] ) : false;
$this->_compress_enable = true;
$this->_have_zlib = function_exists( 'gzcompress' );
$this->_cache_sock = array();
$this->_host_dead = array();
$this->_timeout_seconds = 0;
$this->_timeout_microseconds = $wgMemCachedTimeout;
$this->_connect_timeout = 0.01;
$this->_connect_attempts = 2;
}
// }}}
// {{{ add()
/**
* Adds a key/value to the memcache server if one isn't already set with
* that key
*
* @param string $key Key to set with data
* @param mixed $val Value to store
* @param integer $exp (optional) Time to expire data at
*
* @return boolean
*/
public function add( $key, $val, $exp = 0 ) {
return $this->_set( 'add', $key, $val, $exp );
}
// }}}
// {{{ decr()
/**
* Decriment a value stored on the memcache server
*
* @param string $key Key to decriment
* @param integer $amt (optional) Amount to decriment
*
* @return mixed FALSE on failure, value on success
*/
public function decr( $key, $amt = 1 ) {
return $this->_incrdecr( 'decr', $key, $amt );
}
// }}}
// {{{ delete()
/**
* Deletes a key from the server, optionally after $time
*
* @param string $key Key to delete
* @param integer $time (optional) How long to wait before deleting
*
* @return boolean TRUE on success, FALSE on failure
*/
public function delete( $key, $time = 0 ) {
if ( !$this->_active ) {
return false;
}
$sock = $this->get_sock( $key );
if ( !is_resource( $sock ) ) {
return false;
}
$key = is_array( $key ) ? $key[1] : $key;
@$this->stats['delete']++;
$cmd = "delete $key $time\r\n";
if( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
$this->_dead_sock( $sock );
return false;
}
$res = trim( fgets( $sock ) );
if ( $this->_debug ) {
$this->_debugprint( sprintf( "MemCache: delete %s (%s)\n", $key, $res ) );
}
if ( $res == "DELETED" ) {
return true;
}
return false;
}
// }}}
// {{{ disconnect_all()
/**
* Disconnects all connected sockets
*/
public function disconnect_all() {
foreach ( $this->_cache_sock as $sock ) {
fclose( $sock );
}
$this->_cache_sock = array();
}
// }}}
// {{{ enable_compress()
/**
* Enable / Disable compression
*
* @param boolean $enable TRUE to enable, FALSE to disable
*/
public function enable_compress( $enable ) {
$this->_compress_enable = $enable;
}
// }}}
// {{{ forget_dead_hosts()
/**
* Forget about all of the dead hosts
*/
public function forget_dead_hosts() {
$this->_host_dead = array();
}
// }}}
// {{{ get()
/**
* Retrieves the value associated with the key from the memcache server
*
* @param string $key Key to retrieve
*
* @return mixed
*/
public function get( $key ) {
wfProfileIn( __METHOD__ );
if ( $this->_debug ) {
$this->_debugprint( "get($key)\n" );
}
if ( !$this->_active ) {
wfProfileOut( __METHOD__ );
return false;
}
$sock = $this->get_sock( $key );
if ( !is_resource( $sock ) ) {
wfProfileOut( __METHOD__ );
return false;
}
@$this->stats['get']++;
$cmd = "get $key\r\n";
if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
$this->_dead_sock( $sock );
wfProfileOut( __METHOD__ );
return false;
}
$val = array();
$this->_load_items( $sock, $val );
if ( $this->_debug ) {
foreach ( $val as $k => $v ) {
$this->_debugprint( sprintf( "MemCache: sock %s got %s\n", serialize( $sock ), $k ) );
}
}
wfProfileOut( __METHOD__ );
return @$val[$key];
}
// }}}
// {{{ get_multi()
/**
* Get multiple keys from the server(s)
*
* @param array $keys Keys to retrieve
*
* @return array
*/
public function get_multi( $keys ) {
if ( !$this->_active ) {
return false;
}
@$this->stats['get_multi']++;
$sock_keys = array();
foreach ( $keys as $key ) {
$sock = $this->get_sock( $key );
if ( !is_resource( $sock ) ) {
continue;
}
$key = is_array( $key ) ? $key[1] : $key;
if ( !isset( $sock_keys[$sock] ) ) {
$sock_keys[$sock] = array();
$socks[] = $sock;
}
$sock_keys[$sock][] = $key;
}
// Send out the requests
foreach ( $socks as $sock ) {
$cmd = 'get';
foreach ( $sock_keys[$sock] as $key ) {
$cmd .= ' ' . $key;
}
$cmd .= "\r\n";
if ( $this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
$gather[] = $sock;
} else {
$this->_dead_sock( $sock );
}
}
// Parse responses
$val = array();
foreach ( $gather as $sock ) {
$this->_load_items( $sock, $val );
}
if ( $this->_debug ) {
foreach ( $val as $k => $v ) {
$this->_debugprint( sprintf( "MemCache: got %s\n", $k ) );
}
}
return $val;
}
// }}}
// {{{ incr()
/**
* Increments $key (optionally) by $amt
*
* @param string $key Key to increment
* @param integer $amt (optional) amount to increment
*
* @return integer New key value?
*/
public function incr( $key, $amt = 1 ) {
return $this->_incrdecr( 'incr', $key, $amt );
}
// }}}
// {{{ replace()
/**
* Overwrites an existing value for key; only works if key is already set
*
* @param string $key Key to set value as
* @param mixed $value Value to store
* @param integer $exp (optional) Experiation time
*
* @return boolean
*/
public function replace( $key, $value, $exp = 0 ) {
return $this->_set( 'replace', $key, $value, $exp );
}
// }}}
// {{{ run_command()
/**
* Passes through $cmd to the memcache server connected by $sock; returns
* output as an array (null array if no output)
*
* NOTE: due to a possible bug in how PHP reads while using fgets(), each
* line may not be terminated by a \r\n. More specifically, my testing
* has shown that, on FreeBSD at least, each line is terminated only
* with a \n. This is with the PHP flag auto_detect_line_endings set
* to falase (the default).
*
* @param resource $sock Socket to send command on
* @param string $cmd Command to run
*
* @return array Output array
* @access public
*/
function run_command( $sock, $cmd ) {
if ( !is_resource( $sock ) ) {
return array();
}
if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
return array();
}
while ( true ) {
$res = fgets( $sock );
$ret[] = $res;
if ( preg_match( '/^END/', $res ) ) {
break;
}
if ( strlen( $res ) == 0 ) {
break;
}
}
return $ret;
}
// }}}
// {{{ set()
/**
* Unconditionally sets a key to a given value in the memcache. Returns true
* if set successfully.
*
* @param string $key Key to set value as
* @param mixed $value Value to set
* @param integer $exp (optional) Experiation time
*
* @return boolean TRUE on success
*/
public function set( $key, $value, $exp = 0 ) {
return $this->_set( 'set', $key, $value, $exp );
}
// }}}
// {{{ set_compress_threshold()
/**
* Sets the compression threshold
*
* @param integer $thresh Threshold to compress if larger than
*/
public function set_compress_threshold( $thresh ) {
$this->_compress_threshold = $thresh;
}
// }}}
// {{{ set_debug()
/**
* Sets the debug flag
*
* @param boolean $dbg TRUE for debugging, FALSE otherwise
*
* @see MWMemcached::__construct
*/
public function set_debug( $dbg ) {
$this->_debug = $dbg;
}
// }}}
// {{{ set_servers()
/**
* Sets the server list to distribute key gets and puts between
*
* @param array $list Array of servers to connect to
*
* @see MWMemcached::__construct()
*/
public function set_servers( $list ) {
$this->_servers = $list;
$this->_active = count( $list );
$this->_buckets = null;
$this->_bucketcount = 0;
$this->_single_sock = null;
if ( $this->_active == 1 ) {
$this->_single_sock = $this->_servers[0];
}
}
/**
* Sets the timeout for new connections
*
* @param integer $seconds Number of seconds
* @param integer $microseconds Number of microseconds
*/
public function set_timeout( $seconds, $microseconds ) {
$this->_timeout_seconds = $seconds;
$this->_timeout_microseconds = $microseconds;
}
// }}}
// }}}
// {{{ private methods
// {{{ _close_sock()
/**
* Close the specified socket
*
* @param string $sock Socket to close
*
* @access private
*/
function _close_sock( $sock ) {
$host = array_search( $sock, $this->_cache_sock );
fclose( $this->_cache_sock[$host] );
unset( $this->_cache_sock[$host] );
}
// }}}
// {{{ _connect_sock()
/**
* Connects $sock to $host, timing out after $timeout
*
* @param integer $sock Socket to connect
* @param string $host Host:IP to connect to
*
* @return boolean
* @access private
*/
function _connect_sock( &$sock, $host ) {
list( $ip, $port ) = explode( ':', $host );
$sock = false;
$timeout = $this->_connect_timeout;
$errno = $errstr = null;
for( $i = 0; !$sock && $i < $this->_connect_attempts; $i++ ) {
if ( $this->_persistant == 1 ) {
$sock = @pfsockopen( $ip, $port, $errno, $errstr, $timeout );
} else {
$sock = @fsockopen( $ip, $port, $errno, $errstr, $timeout );
}
}
if ( !$sock ) {
if ( $this->_debug ) {
$this->_debugprint( "Error connecting to $host: $errstr\n" );
}
return false;
}
// Initialise timeout
stream_set_timeout( $sock, $this->_timeout_seconds, $this->_timeout_microseconds );
return true;
}
// }}}
// {{{ _dead_sock()
/**
* Marks a host as dead until 30-40 seconds in the future
*
* @param string $sock Socket to mark as dead
*
* @access private
*/
function _dead_sock( $sock ) {
$host = array_search( $sock, $this->_cache_sock );
$this->_dead_host( $host );
}
function _dead_host( $host ) {
@list( $ip, /* $port */) = explode( ':', $host );
$this->_host_dead[$ip] = time() + 30 + intval( rand( 0, 10 ) );
$this->_host_dead[$host] = $this->_host_dead[$ip];
unset( $this->_cache_sock[$host] );
}
// }}}
// {{{ get_sock()
/**
* get_sock
*
* @param string $key Key to retrieve value for;
*
* @return mixed resource on success, false on failure
* @access private
*/
function get_sock( $key ) {
if ( !$this->_active ) {
return false;
}
if ( $this->_single_sock !== null ) {
$this->_flush_read_buffer( $this->_single_sock );
return $this->sock_to_host( $this->_single_sock );
}
$hv = is_array( $key ) ? intval( $key[0] ) : $this->_hashfunc( $key );
if ( $this->_buckets === null ) {
foreach ( $this->_servers as $v ) {
if ( is_array( $v ) ) {
for( $i = 0; $i < $v[1]; $i++ ) {
$bu[] = $v[0];
}
} else {
$bu[] = $v;
}
}
$this->_buckets = $bu;
$this->_bucketcount = count( $bu );
}
$realkey = is_array( $key ) ? $key[1] : $key;
for( $tries = 0; $tries < 20; $tries++ ) {
$host = $this->_buckets[$hv % $this->_bucketcount];
$sock = $this->sock_to_host( $host );
if ( is_resource( $sock ) ) {
$this->_flush_read_buffer( $sock );
return $sock;
}
$hv = $this->_hashfunc( $hv . $realkey );
}
return false;
}
// }}}
// {{{ _hashfunc()
/**
* Creates a hash integer based on the $key
*
* @param string $key Key to hash
*
* @return integer Hash value
* @access private
*/
function _hashfunc( $key ) {
# Hash function must on [0,0x7ffffff]
# We take the first 31 bits of the MD5 hash, which unlike the hash
# function used in a previous version of this client, works
return hexdec( substr( md5( $key ), 0, 8 ) ) & 0x7fffffff;
}
// }}}
// {{{ _incrdecr()
/**
* Perform increment/decriment on $key
*
* @param string $cmd Command to perform
* @param string $key Key to perform it on
* @param integer $amt Amount to adjust
*
* @return integer New value of $key
* @access private
*/
function _incrdecr( $cmd, $key, $amt = 1 ) {
if ( !$this->_active ) {
return null;
}
$sock = $this->get_sock( $key );
if ( !is_resource( $sock ) ) {
return null;
}
$key = is_array( $key ) ? $key[1] : $key;
@$this->stats[$cmd]++;
if ( !$this->_safe_fwrite( $sock, "$cmd $key $amt\r\n" ) ) {
return $this->_dead_sock( $sock );
}
$line = fgets( $sock );
$match = array();
if ( !preg_match( '/^(\d+)/', $line, $match ) ) {
return null;
}
return $match[1];
}
// }}}
// {{{ _load_items()
/**
* Load items into $ret from $sock
*
* @param resource $sock Socket to read from
* @param array $ret Returned values
*
* @access private
*/
function _load_items( $sock, &$ret ) {
while ( 1 ) {
$decl = fgets( $sock );
if ( $decl == "END\r\n" ) {
return true;
} elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+)\r\n$/', $decl, $match ) ) {
list( $rkey, $flags, $len ) = array( $match[1], $match[2], $match[3] );
$bneed = $len + 2;
$offset = 0;
while ( $bneed > 0 ) {
$data = fread( $sock, $bneed );
$n = strlen( $data );
if ( $n == 0 ) {
break;
}
$offset += $n;
$bneed -= $n;
@$ret[$rkey] .= $data;
}
if ( $offset != $len + 2 ) {
// Something is borked!
if ( $this->_debug ) {
$this->_debugprint( sprintf( "Something is borked! key %s expecting %d got %d length\n", $rkey, $len + 2, $offset ) );
}
unset( $ret[$rkey] );
$this->_close_sock( $sock );
return false;
}
if ( $this->_have_zlib && $flags & self::COMPRESSED ) {
$ret[$rkey] = gzuncompress( $ret[$rkey] );
}
$ret[$rkey] = rtrim( $ret[$rkey] );
if ( $flags & self::SERIALIZED ) {
$ret[$rkey] = unserialize( $ret[$rkey] );
}
} else {
$this->_debugprint( "Error parsing memcached response\n" );
return 0;
}
}
}
// }}}
// {{{ _set()
/**
* Performs the requested storage operation to the memcache server
*
* @param string $cmd Command to perform
* @param string $key Key to act on
* @param mixed $val What we need to store
* @param integer $exp When it should expire
*
* @return boolean
* @access private
*/
function _set( $cmd, $key, $val, $exp ) {
if ( !$this->_active ) {
return false;
}
$sock = $this->get_sock( $key );
if ( !is_resource( $sock ) ) {
return false;
}
@$this->stats[$cmd]++;
$flags = 0;
if ( !is_scalar( $val ) ) {
$val = serialize( $val );
$flags |= self::SERIALIZED;
if ( $this->_debug ) {
$this->_debugprint( sprintf( "client: serializing data as it is not scalar\n" ) );
}
}
$len = strlen( $val );
if ( $this->_have_zlib && $this->_compress_enable &&
$this->_compress_threshold && $len >= $this->_compress_threshold )
{
$c_val = gzcompress( $val, 9 );
$c_len = strlen( $c_val );
if ( $c_len < $len * ( 1 - self::COMPRESSION_SAVINGS ) ) {
if ( $this->_debug ) {
$this->_debugprint( sprintf( "client: compressing data; was %d bytes is now %d bytes\n", $len, $c_len ) );
}
$val = $c_val;
$len = $c_len;
$flags |= self::COMPRESSED;
}
}
if ( !$this->_safe_fwrite( $sock, "$cmd $key $flags $exp $len\r\n$val\r\n" ) ) {
return $this->_dead_sock( $sock );
}
$line = trim( fgets( $sock ) );
if ( $this->_debug ) {
$this->_debugprint( sprintf( "%s %s (%s)\n", $cmd, $key, $line ) );
}
if ( $line == "STORED" ) {
return true;
}
return false;
}
// }}}
// {{{ sock_to_host()
/**
* Returns the socket for the host
*
* @param string $host Host:IP to get socket for
*
* @return mixed IO Stream or false
* @access private
*/
function sock_to_host( $host ) {
if ( isset( $this->_cache_sock[$host] ) ) {
return $this->_cache_sock[$host];
}
$sock = null;
$now = time();
list( $ip, /* $port */) = explode( ':', $host );
if ( isset( $this->_host_dead[$host] ) && $this->_host_dead[$host] > $now ||
isset( $this->_host_dead[$ip] ) && $this->_host_dead[$ip] > $now
) {
return null;
}
if ( !$this->_connect_sock( $sock, $host ) ) {
return $this->_dead_host( $host );
}
// Do not buffer writes
stream_set_write_buffer( $sock, 0 );
$this->_cache_sock[$host] = $sock;
return $this->_cache_sock[$host];
}
function _debugprint( $str ) {
print( $str );
}
/**
* Write to a stream, timing out after the correct amount of time
*
* @return bool false on failure, true on success
*/
/*
function _safe_fwrite( $f, $buf, $len = false ) {
stream_set_blocking( $f, 0 );
if ( $len === false ) {
wfDebug( "Writing " . strlen( $buf ) . " bytes\n" );
$bytesWritten = fwrite( $f, $buf );
} else {
wfDebug( "Writing $len bytes\n" );
$bytesWritten = fwrite( $f, $buf, $len );
}
$n = stream_select( $r = null, $w = array( $f ), $e = null, 10, 0 );
# $this->_timeout_seconds, $this->_timeout_microseconds );
wfDebug( "stream_select returned $n\n" );
stream_set_blocking( $f, 1 );
return $n == 1;
return $bytesWritten;
}*/
/**
* Original behaviour
*/
function _safe_fwrite( $f, $buf, $len = false ) {
if ( $len === false ) {
$bytesWritten = fwrite( $f, $buf );
} else {
$bytesWritten = fwrite( $f, $buf, $len );
}
return $bytesWritten;
}
/**
* Flush the read buffer of a stream
*/
function _flush_read_buffer( $f ) {
if ( !is_resource( $f ) ) {
return;
}
$n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
while ( $n == 1 && !feof( $f ) ) {
fread( $f, 1024 );
$n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
}
}
// }}}
// }}}
// }}}
}
// vim: sts=3 sw=3 et
// }}}
class MemCachedClientforWiki extends MWMemcached {
function _debugprint( $text ) {
wfDebug( "memcached: $text" );
}
}