| * | 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 | * | 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 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, * 'persistent' => true)); * * $mc->add( 'key', array( 'some', 'array' ) ); * $mc->replace( 'key', 'some random string' ); * $val = $mc->get( 'key' ); * * @author Ryan T. Dean * @version 0.1.2 */ // {{{ requirements // }}} // {{{ class MWMemcached /** * memcached client class implemented using (p)fsockopen() * * @author Ryan T. Dean * @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 */ 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; // }}} // }}} // {{{ methods // {{{ public functions // {{{ memcached() /** * Memcache initializer * * @param array $args Associative array of settings * * @return mixed */ public function __construct( $args ) { $this->set_servers( isset( $args['servers'] ) ? $args['servers'] : array() ); $this->_debug = isset( $args['debug'] ) ? $args['debug'] : false; $this->stats = array(); $this->_compress_threshold = isset( $args['compress_threshold'] ) ? $args['compress_threshold'] : 0; $this->_persistent = isset( $args['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 = isset( $args['timeout'] ) ? $args['timeout'] : 500000; $this->_connect_timeout = isset( $args['connect_timeout'] ) ? $args['connect_timeout'] : 0.1; $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 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 ) { 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 ) { 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, $time = 0 ) { if ( !$this->_active ) { return false; } $sock = $this->get_sock( $key ); if ( !is_resource( $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)\n", $key, $res ) ); } if ( $res == "DELETED" || $res == "NOT_FOUND" ) { return true; } return false; } /** * @param string $key * @param int $timeout * @return bool */ public function lock( $key, $timeout = 0 ) { /* stub */ return true; } /** * @param string $key * @return bool */ public function unlock( $key ) { /* stub */ return true; } // }}} // {{{ 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 ) { wfProfileIn( __METHOD__ ); if ( $this->_debug ) { $this->_debugprint( "get($key)\n" ); } if ( !is_array( $key ) && strval( $key ) === '' ) { $this->_debugprint( "Skipping key which equals to an empty string" ); wfProfileOut( __METHOD__ ); return false; } if ( !$this->_active ) { wfProfileOut( __METHOD__ ); return false; } $sock = $this->get_sock( $key ); if ( !is_resource( $sock ) ) { wfProfileOut( __METHOD__ ); return false; } $key = is_array( $key ) ? $key[1] : $key; if ( isset( $this->stats['get'] ) ) { $this->stats['get']++; } else { $this->stats['get'] = 1; } $cmd = "gets $key\r\n"; if ( !$this->_fwrite( $sock, $cmd ) ) { wfProfileOut( __METHOD__ ); return false; } $val = array(); $this->_load_items( $sock, $val, $casToken ); if ( $this->_debug ) { foreach ( $val as $k => $v ) { $this->_debugprint( sprintf( "MemCache: sock %s got %s\n", serialize( $sock ), $k ) ); } } $value = false; if ( isset( $val[$key] ) ) { $value = $val[$key]; } wfProfileOut( __METHOD__ ); return $value; } // }}} // {{{ 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; } 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 ( !is_resource( $sock ) ) { continue; } $key = is_array( $key ) ? $key[1] : $key; if ( !isset( $sock_keys[$sock] ) ) { $sock_keys[intval( $sock )] = array(); $socks[] = $sock; } $sock_keys[intval( $sock )][] = $key; } $gather = array(); // Send out the requests foreach ( $socks as $sock ) { $cmd = 'gets'; foreach ( $sock_keys[intval( $sock )] as $key ) { $cmd .= ' ' . $key; } $cmd .= "\r\n"; if ( $this->_fwrite( $sock, $cmd ) ) { $gather[] = $sock; } } // Parse responses $val = array(); foreach ( $gather as $sock ) { $this->_load_items( $sock, $val, $casToken ); } 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 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 exipration * 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 ( !is_resource( $sock ) ) { return array(); } if ( !$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 exipration * 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 exipration * 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() /** * Sets the compression threshold * * @param int $thresh Threshold to compress if larger than */ public function set_compress_threshold( $thresh ) { $this->_compress_threshold = $thresh; } // }}} // {{{ set_debug() /** * Sets the debug flag * * @param bool $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 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 ) { list( $ip, $port ) = preg_split( '/:(?=\d)/', $host ); $sock = false; $timeout = $this->_connect_timeout; $errno = $errstr = null; for ( $i = 0; !$sock && $i < $this->_connect_attempts; $i++ ) { wfSuppressWarnings(); if ( $this->_persistent == 1 ) { $sock = pfsockopen( $ip, $port, $errno, $errstr, $timeout ); } else { $sock = fsockopen( $ip, $port, $errno, $errstr, $timeout ); } wfRestoreWarnings(); } if ( !$sock ) { $this->_error_log( "Error connecting to $host: $errstr\n" ); $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 ) { $parts = explode( ':', $host ); $ip = $parts[0]; $this->_host_dead[$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 ( is_resource( $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/decriment 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, $amt = 1 ) { if ( !$this->_active ) { return null; } $sock = $this->get_sock( $key ); if ( !is_resource( $sock ) ) { 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" ) ) { return null; } $line = $this->_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 * @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], // casToken $this->_fread( $sock, $match[3] + 2 ), // data ); } elseif ( $decl == "END" ) { if ( count( $results ) == 0 ) { return false; } /** * All data has been read, time to process the data and build * meaningful return values. */ foreach ( $results as $vars ) { list( $rkey, $flags, $len, $casToken, $data ) = $vars; 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] = unserialize( $ret[$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 exipration * eg: strtotime("+3 hour") * @param float $casToken [optional] * * @return bool * @access private */ function _set( $cmd, $key, $val, $exp, $casToken = null ) { if ( !$this->_active ) { return false; } $sock = $this->get_sock( $key ); if ( !is_resource( $sock ) ) { return false; } if ( isset( $this->stats[$cmd] ) ) { $this->stats[$cmd]++; } else { $this->stats[$cmd] = 1; } $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; } } $command = "$cmd $key $flags $exp $len"; if ( $casToken ) { $command .= " $casToken"; } if ( !$this->_fwrite( $sock, "$command\r\n$val\r\n" ) ) { return false; } $line = $this->_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 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(); 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 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 ) { wfDebugLog( 'memcached', $text ); } /** * @param string $text */ function _error_log( $text ) { wfDebugLog( 'memcached-serious', "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\n" ); $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 ( !is_resource( $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 ); } } // }}} // }}} // }}} } // }}} class MemCachedClientforWiki extends MWMemcached { }