includes/libs/objectcache/utils/MemcachedClient.php
<?php
// phpcs:ignoreFile -- It's an external lib and it isn't. Let's not bother.
/**
* Memcached client for 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. |
* +---------------------------------------------------------------------------+
*
* @file
* $TCAnet$
*/
/**
* This is a PHP client for memcached - a distributed memory cache daemon.
*
* More information is available at http://www.danga.com/memcached/
*
* Usage example:
*
* $mc = new MemcachedClient(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,
* 'persistent' => 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
*/
use Psr\Log\LoggerInterface;
use Psr\Log\NullLogger;
use Wikimedia\AtEase\AtEase;
use Wikimedia\IPUtils;
use Wikimedia\LightweightObjectStore\StorageAwareness;
// {{{ class MemcachedClient
/**
* memcached client class implemented using (p)fsockopen()
*
* @author Ryan T. Dean <rtdean@cytherianage.net>
* @ingroup Cache
*/
class MemcachedClient implements StorageAwareness {
// {{{ properties
// {{{ public
// {{{ constants
// {{{ flags
/**
* Flag: indicates data is serialized
*/
const SERIALIZED = 1;
/**
* Flag: indicates data is compressed
*/
const COMPRESSED = 2;
/**
* Flag: indicates data is an integer
*/
const INTVAL = 4;
// }}}
/**
* Minimum savings to store data compressed
*/
const COMPRESSION_SAVINGS = 0.20;
// }}}
/**
* Command statistics
*
* @var array
* @access public
*/
public $stats;
// }}}
// {{{ private
/**
* Cached Sockets that are connected
*
* @var array
* @access private
*/
public $_cache_sock;
/**
* Current debug status; 0 - none to 9 - profiling
*
* @var bool
* @access private
*/
public $_debug;
/**
* Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
*
* @var array
* @access private
*/
public $_host_dead;
/**
* Is compression available?
*
* @var bool
* @access private
*/
public $_have_zlib;
/**
* Do we want to use compression?
*
* @var bool
* @access private
*/
public $_compress_enable;
/**
* At how many bytes should we compress?
*
* @var int
* @access private
*/
public $_compress_threshold;
/**
* Are we using persistent links?
*
* @var bool
* @access private
*/
public $_persistent;
/**
* If only using one server; contains ip:port to connect to
*
* @var string
* @access private
*/
public $_single_sock;
/**
* Array containing ip:port or array(ip:port, weight)
*
* @var array
* @access private
*/
public $_servers;
/**
* Our bit buckets
*
* @var array
* @access private
*/
public $_buckets;
/**
* Total # of bit buckets we have
*
* @var int
* @access private
*/
public $_bucketcount;
/**
* # of total servers we have
*
* @var int
* @access private
*/
public $_active;
/**
* Stream timeout in seconds. Applies for example to fread()
*
* @var int
* @access private
*/
public $_timeout_seconds;
/**
* Stream timeout in microseconds
*
* @var int
* @access private
*/
public $_timeout_microseconds;
/**
* Connect timeout in seconds
*/
public $_connect_timeout;
/**
* Number of connection attempts for each server
*/
public $_connect_attempts;
/** @var int StorageAwareness:ERR_* constant of the last cache command */
public $_last_cmd_status = self::ERR_NONE;
/**
* @var LoggerInterface
*/
private $_logger;
// }}}
// }}}
// {{{ methods
// {{{ public functions
// {{{ memcached()
/**
* Memcache initializer
*
* @param array $args Associative array of settings
*/
public function __construct( $args ) {
$this->set_servers( $args['servers'] ?? array() );
$this->_debug = $args['debug'] ?? false;
$this->stats = array();
$this->_compress_threshold = $args['compress_threshold'] ?? 0;
$this->_persistent = $args['persistent'] ?? 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 = $args['timeout'] ?? 500_000;
$this->_connect_timeout = $args['connect_timeout'] ?? 0.1;
$this->_connect_attempts = 2;
$this->_logger = $args['logger'] ?? new NullLogger();
}
// }}}
/**
* @param mixed $value
* @return string|integer
*/
public function serialize( $value ) {
return serialize( $value );
}
/**
* @param string $value
* @return mixed
*/
public function unserialize( $value ) {
return unserialize( $value );
}
// {{{ 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 int $exp (optional) Expiration time. This can be a number of seconds
* to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
* longer must be the timestamp of the time at which the mapping should expire. It
* is safe to use timestamps in all cases, regardless of expiration
* eg: strtotime("+3 hour")
*
* @return bool
*/
public function add( $key, $val, $exp = 0 ) {
$this->_last_cmd_status = self::ERR_NONE;
return $this->_set( 'add', $key, $val, $exp );
}
// }}}
// {{{ decr()
/**
* Decrease a value stored on the memcache server
*
* @param string $key Key to decrease
* @param int $amt (optional) amount to decrease
*
* @return mixed False on failure, value on success
*/
public function decr( $key, $amt = 1 ) {
$this->_last_cmd_status = self::ERR_NONE;
return $this->_incrdecr( 'decr', $key, $amt );
}
// }}}
// {{{ delete()
/**
* Deletes a key from the server, optionally after $time
*
* @param string $key Key to delete
* @param int $time (optional) how long to wait before deleting
*
* @return bool True on success, false on failure
*/
public function delete( $key, $time = 0 ) {
$this->_last_cmd_status = self::ERR_NONE;
if ( !$this->_active ) {
return false;
}
$sock = $this->get_sock( $key );
if ( !$sock ) {
return false;
}
$key = is_array( $key ) ? $key[1] : $key;
if ( isset( $this->stats['delete'] ) ) {
$this->stats['delete']++;
} else {
$this->stats['delete'] = 1;
}
$cmd = "delete $key $time\r\n";
if ( !$this->_fwrite( $sock, $cmd ) ) {
return false;
}
$res = $this->_fgets( $sock );
if ( $this->_debug ) {
$this->_debugprint( sprintf( "MemCache: delete %s (%s)", $key, $res ) );
}
if ( $res == "DELETED" || $res == "NOT_FOUND" ) {
return true;
}
$this->_last_cmd_status = self::ERR_UNEXPECTED;
return false;
}
/**
* Changes the TTL on a key from the server to $time
*
* @param string $key
* @param int $time TTL in seconds
*
* @return bool True on success, false on failure
*/
public function touch( $key, $time = 0 ) {
$this->_last_cmd_status = self::ERR_NONE;
if ( !$this->_active ) {
return false;
}
$sock = $this->get_sock( $key );
if ( !$sock ) {
return false;
}
$key = is_array( $key ) ? $key[1] : $key;
if ( isset( $this->stats['touch'] ) ) {
$this->stats['touch']++;
} else {
$this->stats['touch'] = 1;
}
$cmd = "touch $key $time\r\n";
if ( !$this->_fwrite( $sock, $cmd ) ) {
return false;
}
$res = $this->_fgets( $sock );
if ( $this->_debug ) {
$this->_debugprint( sprintf( "MemCache: touch %s (%s)", $key, $res ) );
}
if ( $res == "TOUCHED" ) {
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 bool $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 array|string $key key to retrieve
* @param float $casToken [optional]
*
* @return mixed
*/
public function get( $key, &$casToken = null ) {
$getToken = ( func_num_args() >= 2 );
$this->_last_cmd_status = self::ERR_NONE;
if ( $this->_debug ) {
$this->_debugprint( "get($key)" );
}
if ( !is_array( $key ) && strval( $key ) === '' ) {
$this->_last_cmd_status = self::ERR_UNEXPECTED;
$this->_debugprint( "Skipping key which equals to an empty string" );
return false;
}
if ( !$this->_active ) {
$this->_last_cmd_status = self::ERR_UNEXPECTED;
return false;
}
$sock = $this->get_sock( $key );
if ( !$sock ) {
$this->_last_cmd_status = self::ERR_UNREACHABLE;
return false;
}
$key = is_array( $key ) ? $key[1] : $key;
if ( isset( $this->stats['get'] ) ) {
$this->stats['get']++;
} else {
$this->stats['get'] = 1;
}
$cmd = $getToken ? "gets" : "get";
$cmd .= " $key\r\n";
if ( !$this->_fwrite( $sock, $cmd ) ) {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
return false;
}
$val = array();
if ( !$this->_load_items( $sock, $val, $casToken ) ) {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
}
if ( $this->_debug ) {
foreach ( $val as $k => $v ) {
$this->_debugprint(
sprintf( "MemCache: sock %s got %s", $this->serialize( $sock ), $k ) );
}
}
$value = false;
if ( isset( $val[$key] ) ) {
$value = $val[$key];
}
return $value;
}
// }}}
// {{{ get_multi()
/**
* Get multiple keys from the server(s)
*
* @param array $keys Keys to retrieve
*
* @return array
*/
public function get_multi( $keys ) {
$this->_last_cmd_status = self::ERR_NONE;
if ( !$this->_active ) {
$this->_last_cmd_status = self::ERR_UNEXPECTED;
return array();
}
if ( isset( $this->stats['get_multi'] ) ) {
$this->stats['get_multi']++;
} else {
$this->stats['get_multi'] = 1;
}
$sock_keys = array();
$socks = array();
foreach ( $keys as $key ) {
$sock = $this->get_sock( $key );
if ( !$sock ) {
$this->_last_cmd_status = self::ERR_UNREACHABLE;
continue;
}
$key = is_array( $key ) ? $key[1] : $key;
$sockValue = intval( $sock );
if ( !isset( $sock_keys[$sockValue] ) ) {
$sock_keys[$sockValue] = array();
$socks[] = $sock;
}
$sock_keys[$sockValue][] = $key;
}
$gather = array();
// Send out the requests
foreach ( $socks as $sock ) {
$cmd = 'get';
foreach ( $sock_keys[intval( $sock )] as $key ) {
$cmd .= ' ' . $key;
}
$cmd .= "\r\n";
if ( $this->_fwrite( $sock, $cmd ) ) {
$gather[] = $sock;
} else {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
}
}
// Parse responses
$val = array();
foreach ( $gather as $sock ) {
if ( !$this->_load_items( $sock, $val ) ) {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
}
}
if ( $this->_debug ) {
foreach ( $val as $k => $v ) {
$this->_debugprint( sprintf( "MemCache: got %s", $k ) );
}
}
return $val;
}
// }}}
// {{{ incr()
/**
* Increments $key (optionally) by $amt
*
* @param string $key Key to increment
* @param int $amt (optional) amount to increment
*
* @return int|null Null if the key does not exist yet (this does NOT
* create new mappings if the key does not exist). If the key does
* exist, this returns the new value for that key.
*/
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 int $exp (optional) Expiration time. This can be a number of seconds
* to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
* longer must be the timestamp of the time at which the mapping should expire. It
* is safe to use timestamps in all cases, regardless of expiration
* eg: strtotime("+3 hour")
*
* @return bool
*/
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)
*
* @param Resource $sock Socket to send command on
* @param string $cmd Command to run
*
* @return array Output array
*/
public function run_command( $sock, $cmd ) {
if ( !$sock ) {
return array();
}
if ( !$this->_fwrite( $sock, $cmd ) ) {
return array();
}
$ret = array();
while ( true ) {
$res = $this->_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 int $exp (optional) Expiration time. This can be a number of seconds
* to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
* longer must be the timestamp of the time at which the mapping should expire. It
* is safe to use timestamps in all cases, regardless of expiration
* eg: strtotime("+3 hour")
*
* @return bool True on success
*/
public function set( $key, $value, $exp = 0 ) {
return $this->_set( 'set', $key, $value, $exp );
}
// }}}
// {{{ cas()
/**
* Sets a key to a given value in the memcache if the current value still corresponds
* to a known, given value. Returns true if set successfully.
*
* @param float $casToken Current known value
* @param string $key Key to set value as
* @param mixed $value Value to set
* @param int $exp (optional) Expiration time. This can be a number of seconds
* to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
* longer must be the timestamp of the time at which the mapping should expire. It
* is safe to use timestamps in all cases, regardless of expiration
* eg: strtotime("+3 hour")
*
* @return bool True on success
*/
public function cas( $casToken, $key, $value, $exp = 0 ) {
return $this->_set( 'cas', $key, $value, $exp, $casToken );
}
// }}}
// {{{ set_compress_threshold()
/**
* Set the compression threshold
*
* @param int $thresh Threshold to compress if larger than
*/
public function set_compress_threshold( $thresh ) {
$this->_compress_threshold = $thresh;
}
// }}}
// {{{ set_debug()
/**
* Set the debug flag
*
* @see __construct()
* @param bool $dbg True for debugging, false otherwise
*/
public function set_debug( $dbg ) {
$this->_debug = $dbg;
}
// }}}
// {{{ set_servers()
/**
* Set the server list to distribute key gets and puts between
*
* @see __construct()
* @param array $list Array of servers to connect to
*/
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 int $seconds Number of seconds
* @param int $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 int $sock Socket to connect
* @param string $host Host:IP to connect to
*
* @return bool
* @access private
*/
function _connect_sock( &$sock, $host ) {
$port = null;
$hostAndPort = IPUtils::splitHostAndPort( $host );
if ( $hostAndPort ) {
$ip = $hostAndPort[0];
if ( $hostAndPort[1] ) {
$port = $hostAndPort[1];
}
} else {
$ip = $host;
}
$sock = false;
$timeout = $this->_connect_timeout;
$errno = $errstr = null;
for ( $i = 0; !$sock && $i < $this->_connect_attempts; $i++ ) {
AtEase::suppressWarnings();
if ( $this->_persistent == 1 ) {
$sock = pfsockopen( $ip, $port, $errno, $errstr, $timeout );
} else {
$sock = fsockopen( $ip, $port, $errno, $errstr, $timeout );
}
AtEase::restoreWarnings();
}
if ( !$sock ) {
$this->_error_log( "Error connecting to $host: $errstr" );
$this->_dead_host( $host );
return false;
}
// Initialise timeout
stream_set_timeout( $sock, $this->_timeout_seconds, $this->_timeout_microseconds );
// If the connection was persistent, flush the read buffer in case there
// was a previous incomplete request on this connection
if ( $this->_persistent ) {
$this->_flush_read_buffer( $sock );
}
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 );
}
/**
* @param string $host
*/
function _dead_host( $host ) {
$hostAndPort = IPUtils::splitHostAndPort( $host );
if ( $hostAndPort ) {
$ip = $hostAndPort[0];
} else {
$ip = $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 Resource|bool Resource on success, false on failure
* @access private
*/
function get_sock( $key ) {
if ( !$this->_active ) {
return false;
}
if ( $this->_single_sock !== null ) {
return $this->sock_to_host( $this->_single_sock );
}
$hv = is_array( $key ) ? intval( $key[0] ) : $this->_hashfunc( $key );
if ( $this->_buckets === null ) {
$bu = array();
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 ( $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 int Hash value
* @access private
*/
function _hashfunc( $key ) {
# Hash function must be in [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/decrement on $key
*
* @param string $cmd Command to perform
* @param string|array $key Key to perform it on
* @param int $amt Amount to adjust
*
* @return int New value of $key
* @access private
*/
function _incrdecr( $cmd, $key, $amt = 1 ) {
$this->_last_cmd_status = self::ERR_NONE;
if ( !$this->_active ) {
$this->_last_cmd_status = self::ERR_UNEXPECTED;
return null;
}
$sock = $this->get_sock( $key );
if ( !$sock ) {
$this->_last_cmd_status = self::ERR_UNREACHABLE;
return null;
}
$key = is_array( $key ) ? $key[1] : $key;
if ( isset( $this->stats[$cmd] ) ) {
$this->stats[$cmd]++;
} else {
$this->stats[$cmd] = 1;
}
if ( !$this->_fwrite( $sock, "$cmd $key $amt\r\n" ) ) {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
return null;
}
$line = $this->_fgets( $sock );
if ( $this->_debug ) {
$this->_debugprint( "$cmd($key): $line" );
}
$match = array();
if ( !preg_match( '/^(\d+)/', $line, $match ) ) {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
return null;
}
return (int)$match[1];
}
// }}}
// {{{ _load_items()
/**
* Load items into $ret from $sock
*
* @param Resource $sock Socket to read from
* @param array $ret returned values
* @param float $casToken [optional]
* @return bool True for success, false for failure
*
* @access private
*/
function _load_items( $sock, &$ret, &$casToken = null ) {
$results = array();
while ( 1 ) {
$decl = $this->_fgets( $sock );
if ( $decl === false ) {
/*
* If nothing can be read, something is wrong because we know exactly when
* to stop reading (right after "END") and we return right after that.
*/
return false;
} elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+)(?: (\d+))?$/', $decl, $match ) ) {
/*
* Read all data returned. This can be either one or multiple values.
* Save all that data (in an array) to be processed later: we'll first
* want to continue reading until "END" before doing anything else,
* to make sure that we don't leave our client in a state where it's
* output is not yet fully read.
*/
$results[] = array(
$match[1], // rkey
$match[2], // flags
$match[3], // len
$match[4] ?? null, // casToken (appears with "gets" but not "get")
$this->_fread( $sock, $match[3] + 2 ), // data
);
} elseif ( $decl == "END" ) {
/**
* All data has been read, time to process the data and build
* meaningful return values.
*/
foreach ( $results as [ $rkey, $flags, /* length */, $casToken, $data ] ) {
if ( $data === false || substr( $data, -2 ) !== "\r\n" ) {
$this->_handle_error( $sock,
'line ending missing from data block from $1' );
return false;
}
$data = substr( $data, 0, -2 );
$ret[$rkey] = $data;
if ( $this->_have_zlib && $flags & self::COMPRESSED ) {
$ret[$rkey] = gzuncompress( $ret[$rkey] );
}
/*
* This unserialize is the exact reason that we only want to
* process data after having read until "END" (instead of doing
* this right away): "unserialize" can trigger outside code:
* in the event that $ret[$rkey] is a serialized object,
* unserializing it will trigger __wakeup() if present. If that
* function attempted to read from memcached (while we did not
* yet read "END"), these 2 calls would collide.
*/
if ( $flags & self::SERIALIZED ) {
$ret[$rkey] = $this->unserialize( $ret[$rkey] );
} elseif ( $flags & self::INTVAL ) {
$ret[$rkey] = intval( $ret[$rkey] );
}
}
return true;
} else {
$this->_handle_error( $sock, 'Error parsing response from $1' );
return false;
}
}
}
// }}}
// {{{ _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 int $exp (optional) Expiration time. This can be a number of seconds
* to cache for (up to 30 days inclusive). Any timespans of 30 days + 1 second or
* longer must be the timestamp of the time at which the mapping should expire. It
* is safe to use timestamps in all cases, regardless of expiration
* eg: strtotime("+3 hour")
* @param float $casToken [optional]
*
* @return bool
* @access private
*/
function _set( $cmd, $key, $val, $exp, $casToken = null ) {
$this->_last_cmd_status = self::ERR_NONE;
if ( !$this->_active ) {
$this->_last_cmd_status = self::ERR_UNEXPECTED;
return false;
}
$sock = $this->get_sock( $key );
if ( !$sock ) {
$this->_last_cmd_status = self::ERR_UNREACHABLE;
return false;
}
if ( isset( $this->stats[$cmd] ) ) {
$this->stats[$cmd]++;
} else {
$this->stats[$cmd] = 1;
}
$flags = 0;
if ( is_int( $val ) ) {
$flags |= self::INTVAL;
} elseif ( !is_scalar( $val ) ) {
$val = $this->serialize( $val );
$flags |= self::SERIALIZED;
if ( $this->_debug ) {
$this->_debugprint( "client: serializing data as it is not scalar" );
}
}
$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", $len, $c_len ) );
}
$val = $c_val;
$len = $c_len;
$flags |= self::COMPRESSED;
}
}
$command = "$cmd $key $flags $exp $len";
if ( $casToken ) {
$command .= " $casToken";
}
if ( !$this->_fwrite( $sock, "$command\r\n$val\r\n" ) ) {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
return false;
}
$line = $this->_fgets( $sock );
if ( $this->_debug ) {
$this->_debugprint( sprintf( "%s %s (%s)", $cmd, $key, $line ) );
}
if ( $line === "STORED" ) {
return true;
} elseif ( $line === "NOT_STORED" && $cmd === "set" ) {
// "Not stored" is always used as the mcrouter response with AllAsyncRoute
return true;
}
if ( $line === false ) {
$this->_last_cmd_status = self::ERR_NO_RESPONSE;
}
return false;
}
// }}}
// {{{ sock_to_host()
/**
* Returns the socket for the host
*
* @param string $host Host:IP to get socket for
*
* @return Resource|bool 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();
$hostAndPort = IPUtils::splitHostAndPort( $host );
if ( $hostAndPort ) {
$ip = $hostAndPort[0];
} else {
$ip = $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 null;
}
// Do not buffer writes
stream_set_write_buffer( $sock, 0 );
$this->_cache_sock[$host] = $sock;
return $this->_cache_sock[$host];
}
/**
* @param string $text
*/
function _debugprint( $text ) {
$this->_logger->debug( $text );
}
/**
* @param string $text
*/
function _error_log( $text ) {
$this->_logger->error( "Memcached error: $text" );
}
/**
* Write to a stream. If there is an error, mark the socket dead.
*
* @param Resource $sock The socket
* @param string $buf The string to write
* @return bool True on success, false on failure
*/
function _fwrite( $sock, $buf ) {
$bytesWritten = 0;
$bufSize = strlen( $buf );
while ( $bytesWritten < $bufSize ) {
$result = fwrite( $sock, $buf );
$data = stream_get_meta_data( $sock );
if ( $data['timed_out'] ) {
$this->_handle_error( $sock, 'timeout writing to $1' );
return false;
}
// Contrary to the documentation, fwrite() returns zero on error in PHP 5.3.
if ( $result === false || $result === 0 ) {
$this->_handle_error( $sock, 'error writing to $1' );
return false;
}
$bytesWritten += $result;
}
return true;
}
/**
* Handle an I/O error. Mark the socket dead and log an error.
*
* @param Resource $sock
* @param string $msg
*/
function _handle_error( $sock, $msg ) {
$peer = stream_socket_get_name( $sock, true /** remote **/ );
if ( strval( $peer ) === '' ) {
$peer = array_search( $sock, $this->_cache_sock );
if ( $peer === false ) {
$peer = '[unknown host]';
}
}
$msg = str_replace( '$1', $peer, $msg );
$this->_error_log( "$msg" );
$this->_dead_sock( $sock );
}
/**
* Read the specified number of bytes from a stream. If there is an error,
* mark the socket dead.
*
* @param Resource $sock The socket
* @param int $len The number of bytes to read
* @return string|bool The string on success, false on failure.
*/
function _fread( $sock, $len ) {
$buf = '';
while ( $len > 0 ) {
$result = fread( $sock, $len );
$data = stream_get_meta_data( $sock );
if ( $data['timed_out'] ) {
$this->_handle_error( $sock, 'timeout reading from $1' );
return false;
}
if ( $result === false ) {
$this->_handle_error( $sock, 'error reading buffer from $1' );
return false;
}
if ( $result === '' ) {
// This will happen if the remote end of the socket is shut down
$this->_handle_error( $sock, 'unexpected end of file reading from $1' );
return false;
}
$len -= strlen( $result );
$buf .= $result;
}
return $buf;
}
/**
* Read a line from a stream. If there is an error, mark the socket dead.
* The \r\n line ending is stripped from the response.
*
* @param Resource $sock The socket
* @return string|bool The string on success, false on failure
*/
function _fgets( $sock ) {
$result = fgets( $sock );
// fgets() may return a partial line if there is a select timeout after
// a successful recv(), so we have to check for a timeout even if we
// got a string response.
$data = stream_get_meta_data( $sock );
if ( $data['timed_out'] ) {
$this->_handle_error( $sock, 'timeout reading line from $1' );
return false;
}
if ( $result === false ) {
$this->_handle_error( $sock, 'error reading line from $1' );
return false;
}
if ( substr( $result, -2 ) === "\r\n" ) {
$result = substr( $result, 0, -2 );
} elseif ( substr( $result, -1 ) === "\n" ) {
$result = substr( $result, 0, -1 );
} else {
$this->_handle_error( $sock, 'line ending missing in response from $1' );
return false;
}
return $result;
}
/**
* Flush the read buffer of a stream
* @param Resource $f
*/
function _flush_read_buffer( $f ) {
if ( !$f ) {
return;
}
$r = array( $f );
$w = null;
$e = null;
$n = stream_select( $r, $w, $e, 0, 0 );
while ( $n == 1 && !feof( $f ) ) {
fread( $f, 1024 );
$r = array( $f );
$w = null;
$e = null;
$n = stream_select( $r, $w, $e, 0, 0 );
}
}
// }}}
// }}}
// }}}
}
// }}}