includes/memcached-client.php

   1 <?php
   2 /**
   3  * +---------------------------------------------------------------------------+
   4  * | memcached client, PHP                                                     |
   5  * +---------------------------------------------------------------------------+
   6  * | Copyright (c) 2003 Ryan T. Dean <rtdean@cytherianage.net>                 |
   7  * | All rights reserved.                                                      |
   8  * |                                                                           |
   9  * | Redistribution and use in source and binary forms, with or without        |
  10  * | modification, are permitted provided that the following conditions        |
  11  * | are met:                                                                  |
  12  * |                                                                           |
  13  * | 1. Redistributions of source code must retain the above copyright         |
  14  * |    notice, this list of conditions and the following disclaimer.          |
  15  * | 2. Redistributions in binary form must reproduce the above copyright      |
  16  * |    notice, this list of conditions and the following disclaimer in the    |
  17  * |    documentation and/or other materials provided with the distribution.   |
  18  * |                                                                           |
  19  * | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR      |
  20  * | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
  21  * | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.   |
  22  * | IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,          |
  23  * | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT  |
  24  * | NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
  25  * | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY     |
  26  * | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT       |
  27  * | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF  |
  28  * | THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.         |
  29  * +---------------------------------------------------------------------------+
  30  * | Author: Ryan T. Dean <rtdean@cytherianage.net>                            |
  31  * | Heavily influenced by the Perl memcached client by Brad Fitzpatrick.      |
  32  * |   Permission granted by Brad Fitzpatrick for relicense of ported Perl     |
  33  * |   client logic under 2-clause BSD license.                                |
  34  * +---------------------------------------------------------------------------+
  35  *
  36  * @file
  37  * $TCAnet$
  38  */
  39
  40 /**
  41  * This is the PHP client for memcached - a distributed memory cache daemon.
  42  * More information is available at http://www.danga.com/memcached/
  43  *
  44  * Usage example:
  45  *
  46  * require_once 'memcached.php';
  47  *
  48  * $mc = new MWMemcached(array(
  49  *              'servers' => array('127.0.0.1:10000',
  50  *                                 array('192.0.0.1:10010', 2),
  51  *                                 '127.0.0.1:10020'),
  52  *              'debug'   => false,
  53  *              'compress_threshold' => 10240,
  54  *              'persistant' => true));
  55  *
  56  * $mc->add('key', array('some', 'array'));
  57  * $mc->replace('key', 'some random string');
  58  * $val = $mc->get('key');
  59  *
  60  * @author  Ryan T. Dean <rtdean@cytherianage.net>
  61  * @version 0.1.2
  62  */
  63
  64 // {{{ requirements
  65 // }}}
  66
  67 // {{{ class MWMemcached
  68 /**
  69  * memcached client class implemented using (p)fsockopen()
  70  *
  71  * @author  Ryan T. Dean <rtdean@cytherianage.net>
  72  * @ingroup Cache
  73  */
  74 class MWMemcached {
  75         // {{{ properties
  76         // {{{ public
  77
  78         // {{{ constants
  79         // {{{ flags
  80
  81         /**
  82          * Flag: indicates data is serialized
  83          */
  84         const SERIALIZED = 1;
  85
  86         /**
  87          * Flag: indicates data is compressed
  88          */
  89         const COMPRESSED = 2;
  90
  91         // }}}
  92
  93         /**
  94          * Minimum savings to store data compressed
  95          */
  96         const COMPRESSION_SAVINGS = 0.20;
  97
  98         // }}}
  99
 100
 101         /**
 102          * Command statistics
 103          *
 104          * @var     array
 105          * @access  public
 106          */
 107         var $stats;
 108
 109         // }}}
 110         // {{{ private
 111
 112         /**
 113          * Cached Sockets that are connected
 114          *
 115          * @var     array
 116          * @access  private
 117          */
 118         var $_cache_sock;
 119
 120         /**
 121          * Current debug status; 0 - none to 9 - profiling
 122          *
 123          * @var     boolean
 124          * @access  private
 125          */
 126         var $_debug;
 127
 128         /**
 129          * Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
 130          *
 131          * @var     array
 132          * @access  private
 133          */
 134         var $_host_dead;
 135
 136         /**
 137          * Is compression available?
 138          *
 139          * @var     boolean
 140          * @access  private
 141          */
 142         var $_have_zlib;
 143
 144         /**
 145          * Do we want to use compression?
 146          *
 147          * @var     boolean
 148          * @access  private
 149          */
 150         var $_compress_enable;
 151
 152         /**
 153          * At how many bytes should we compress?
 154          *
 155          * @var     integer
 156          * @access  private
 157          */
 158         var $_compress_threshold;
 159
 160         /**
 161          * Are we using persistant links?
 162          *
 163          * @var     boolean
 164          * @access  private
 165          */
 166         var $_persistant;
 167
 168         /**
 169          * If only using one server; contains ip:port to connect to
 170          *
 171          * @var     string
 172          * @access  private
 173          */
 174         var $_single_sock;
 175
 176         /**
 177          * Array containing ip:port or array(ip:port, weight)
 178          *
 179          * @var     array
 180          * @access  private
 181          */
 182         var $_servers;
 183
 184         /**
 185          * Our bit buckets
 186          *
 187          * @var     array
 188          * @access  private
 189          */
 190         var $_buckets;
 191
 192         /**
 193          * Total # of bit buckets we have
 194          *
 195          * @var     integer
 196          * @access  private
 197          */
 198         var $_bucketcount;
 199
 200         /**
 201          * # of total servers we have
 202          *
 203          * @var     integer
 204          * @access  private
 205          */
 206         var $_active;
 207
 208         /**
 209          * Stream timeout in seconds. Applies for example to fread()
 210          *
 211          * @var     integer
 212          * @access  private
 213          */
 214         var $_timeout_seconds;
 215
 216         /**
 217          * Stream timeout in microseconds
 218          *
 219          * @var     integer
 220          * @access  private
 221          */
 222         var $_timeout_microseconds;
 223
 224         /**
 225          * Connect timeout in seconds
 226          */
 227         var $_connect_timeout;
 228
 229         /**
 230          * Number of connection attempts for each server
 231          */
 232         var $_connect_attempts;
 233
 234         // }}}
 235         // }}}
 236         // {{{ methods
 237         // {{{ public functions
 238         // {{{ memcached()
 239
 240         /**
 241          * Memcache initializer
 242          *
 243          * @param $args Associative array of settings
 244          *
 245          * @return  mixed
 246          */
 247         public function __construct( $args ) {
 248                 global $wgMemCachedTimeout;
 249                 $this->set_servers( isset( $args['servers'] ) ? $args['servers'] : array() );
 250                 $this->_debug = isset( $args['debug'] ) ? $args['debug'] : false;
 251                 $this->stats = array();
 252                 $this->_compress_threshold = isset( $args['compress_threshold'] ) ? $args['compress_threshold'] : 0;
 253                 $this->_persistant = isset( $args['persistant'] ) ? $args['persistant'] : false;
 254                 $this->_compress_enable = true;
 255                 $this->_have_zlib = function_exists( 'gzcompress' );
 256
 257                 $this->_cache_sock = array();
 258                 $this->_host_dead = array();
 259
 260                 $this->_timeout_seconds = 0;
 261                 $this->_timeout_microseconds = $wgMemCachedTimeout;
 262
 263                 $this->_connect_timeout = 0.01;
 264                 $this->_connect_attempts = 2;
 265         }
 266
 267         // }}}
 268         // {{{ add()
 269
 270         /**
 271          * Adds a key/value to the memcache server if one isn't already set with
 272          * that key
 273          *
 274          * @param $key String: key to set with data
 275          * @param $val Mixed: value to store
 276          * @param $exp Integer: (optional) time to expire data at
 277          *
 278          * @return Boolean
 279          */
 280         public function add( $key, $val, $exp = 0 ) {
 281                 return $this->_set( 'add', $key, $val, $exp );
 282         }
 283
 284         // }}}
 285         // {{{ decr()
 286
 287         /**
 288          * Decriment a value stored on the memcache server
 289          *
 290          * @param $key String: key to decriment
 291          * @param $amt Integer: (optional) amount to decriment
 292          *
 293          * @return Mixed: FALSE on failure, value on success
 294          */
 295         public function decr( $key, $amt = 1 ) {
 296                 return $this->_incrdecr( 'decr', $key, $amt );
 297         }
 298
 299         // }}}
 300         // {{{ delete()
 301
 302         /**
 303          * Deletes a key from the server, optionally after $time
 304          *
 305          * @param $key String: key to delete
 306          * @param $time Integer: (optional) how long to wait before deleting
 307          *
 308          * @return Boolean: TRUE on success, FALSE on failure
 309          */
 310         public function delete( $key, $time = 0 ) {
 311                 if ( !$this->_active ) {
 312                         return false;
 313                 }
 314
 315                 $sock = $this->get_sock( $key );
 316                 if ( !is_resource( $sock ) ) {
 317                         return false;
 318                 }
 319
 320                 $key = is_array( $key ) ? $key[1] : $key;
 321
 322                 if ( isset( $this->stats['delete'] ) ) {
 323                         $this->stats['delete']++;
 324                 } else {
 325                         $this->stats['delete'] = 1;
 326                 }
 327                 $cmd = "delete $key $time\r\n";
 328                 if( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 329                         $this->_dead_sock( $sock );
 330                         return false;
 331                 }
 332                 $res = trim( fgets( $sock ) );
 333
 334                 if ( $this->_debug ) {
 335                         $this->_debugprint( sprintf( "MemCache: delete %s (%s)\n", $key, $res ) );
 336                 }
 337
 338                 if ( $res == "DELETED" ) {
 339                         return true;
 340                 }
 341                 return false;
 342         }
 343
 344         // }}}
 345         // {{{ disconnect_all()
 346
 347         /**
 348          * Disconnects all connected sockets
 349          */
 350         public function disconnect_all() {
 351                 foreach ( $this->_cache_sock as $sock ) {
 352                         fclose( $sock );
 353                 }
 354
 355                 $this->_cache_sock = array();
 356         }
 357
 358         // }}}
 359         // {{{ enable_compress()
 360
 361         /**
 362          * Enable / Disable compression
 363          *
 364          * @param $enable Boolean: TRUE to enable, FALSE to disable
 365          */
 366         public function enable_compress( $enable ) {
 367                 $this->_compress_enable = $enable;
 368         }
 369
 370         // }}}
 371         // {{{ forget_dead_hosts()
 372
 373         /**
 374          * Forget about all of the dead hosts
 375          */
 376         public function forget_dead_hosts() {
 377                 $this->_host_dead = array();
 378         }
 379
 380         // }}}
 381         // {{{ get()
 382
 383         /**
 384          * Retrieves the value associated with the key from the memcache server
 385          *
 386          * @param $key Mixed: key to retrieve
 387          *
 388          * @return Mixed
 389          */
 390         public function get( $key ) {
 391                 wfProfileIn( __METHOD__ );
 392
 393                 if ( $this->_debug ) {
 394                         $this->_debugprint( "get($key)\n" );
 395                 }
 396
 397                 if ( !$this->_active ) {
 398                         wfProfileOut( __METHOD__ );
 399                         return false;
 400                 }
 401
 402                 $sock = $this->get_sock( $key );
 403
 404                 if ( !is_resource( $sock ) ) {
 405                         wfProfileOut( __METHOD__ );
 406                         return false;
 407                 }
 408
 409                 if ( isset( $this->stats['get'] ) ) {
 410                         $this->stats['get']++;
 411                 } else {
 412                         $this->stats['get'] = 1;
 413                 }
 414
 415                 $cmd = "get $key\r\n";
 416                 if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 417                         $this->_dead_sock( $sock );
 418                         wfProfileOut( __METHOD__ );
 419                         return false;
 420                 }
 421
 422                 $val = array();
 423                 $this->_load_items( $sock, $val );
 424
 425                 if ( $this->_debug ) {
 426                         foreach ( $val as $k => $v ) {
 427                                 $this->_debugprint( sprintf( "MemCache: sock %s got %s\n", serialize( $sock ), $k ) );
 428                         }
 429                 }
 430
 431                 wfProfileOut( __METHOD__ );
 432                 return @$val[$key];
 433         }
 434
 435         // }}}
 436         // {{{ get_multi()
 437
 438         /**
 439          * Get multiple keys from the server(s)
 440          *
 441          * @param $keys Array: keys to retrieve
 442          *
 443          * @return Array
 444          */
 445         public function get_multi( $keys ) {
 446                 if ( !$this->_active ) {
 447                         return false;
 448                 }
 449
 450                 if ( isset( $this->stats['get_multi'] ) ) {
 451                         $this->stats['get_multi']++;
 452                 } else {
 453                         $this->stats['get_multi'] = 1;
 454                 }
 455                 $sock_keys = array();
 456
 457                 foreach ( $keys as $key ) {
 458                         $sock = $this->get_sock( $key );
 459                         if ( !is_resource( $sock ) ) {
 460                                 continue;
 461                         }
 462                         $key = is_array( $key ) ? $key[1] : $key;
 463                         if ( !isset( $sock_keys[$sock] ) ) {
 464                                 $sock_keys[$sock] = array();
 465                                 $socks[] = $sock;
 466                         }
 467                         $sock_keys[$sock][] = $key;
 468                 }
 469
 470                 // Send out the requests
 471                 foreach ( $socks as $sock ) {
 472                         $cmd = 'get';
 473                         foreach ( $sock_keys[$sock] as $key ) {
 474                                 $cmd .= ' ' . $key;
 475                         }
 476                         $cmd .= "\r\n";
 477
 478                         if ( $this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 479                                 $gather[] = $sock;
 480                         } else {
 481                                 $this->_dead_sock( $sock );
 482                         }
 483                 }
 484
 485                 // Parse responses
 486                 $val = array();
 487                 foreach ( $gather as $sock ) {
 488                         $this->_load_items( $sock, $val );
 489                 }
 490
 491                 if ( $this->_debug ) {
 492                         foreach ( $val as $k => $v ) {
 493                                 $this->_debugprint( sprintf( "MemCache: got %s\n", $k ) );
 494                         }
 495                 }
 496
 497                 return $val;
 498         }
 499
 500         // }}}
 501         // {{{ incr()
 502
 503         /**
 504          * Increments $key (optionally) by $amt
 505          *
 506          * @param $key String: key to increment
 507          * @param $amt Integer: (optional) amount to increment
 508          *
 509          * @return Integer: new key value?
 510          */
 511         public function incr( $key, $amt = 1 ) {
 512                 return $this->_incrdecr( 'incr', $key, $amt );
 513         }
 514
 515         // }}}
 516         // {{{ replace()
 517
 518         /**
 519          * Overwrites an existing value for key; only works if key is already set
 520          *
 521          * @param $key String: key to set value as
 522          * @param $value Mixed: value to store
 523          * @param $exp Integer: (optional) experiation time
 524          *
 525          * @return Boolean
 526          */
 527         public function replace( $key, $value, $exp = 0 ) {
 528                 return $this->_set( 'replace', $key, $value, $exp );
 529         }
 530
 531         // }}}
 532         // {{{ run_command()
 533
 534         /**
 535          * Passes through $cmd to the memcache server connected by $sock; returns
 536          * output as an array (null array if no output)
 537          *
 538          * NOTE: due to a possible bug in how PHP reads while using fgets(), each
 539          *       line may not be terminated by a \r\n.  More specifically, my testing
 540          *       has shown that, on FreeBSD at least, each line is terminated only
 541          *       with a \n.  This is with the PHP flag auto_detect_line_endings set
 542          *       to falase (the default).
 543          *
 544          * @param $sock Ressource: socket to send command on
 545          * @param $cmd String: command to run
 546          *
 547          * @return Array: output array
 548          */
 549         public function run_command( $sock, $cmd ) {
 550                 if ( !is_resource( $sock ) ) {
 551                         return array();
 552                 }
 553
 554                 if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 555                         return array();
 556                 }
 557
 558                 while ( true ) {
 559                         $res = fgets( $sock );
 560                         $ret[] = $res;
 561                         if ( preg_match( '/^END/', $res ) ) {
 562                                 break;
 563                         }
 564                         if ( strlen( $res ) == 0 ) {
 565                                 break;
 566                         }
 567                 }
 568                 return $ret;
 569         }
 570
 571         // }}}
 572         // {{{ set()
 573
 574         /**
 575          * Unconditionally sets a key to a given value in the memcache.  Returns true
 576          * if set successfully.
 577          *
 578          * @param $key String: key to set value as
 579          * @param $value Mixed: value to set
 580          * @param $exp Integer: (optional) Experiation time
 581          *
 582          * @return Boolean: TRUE on success
 583          */
 584         public function set( $key, $value, $exp = 0 ) {
 585                 return $this->_set( 'set', $key, $value, $exp );
 586         }
 587
 588         // }}}
 589         // {{{ set_compress_threshold()
 590
 591         /**
 592          * Sets the compression threshold
 593          *
 594          * @param $thresh Integer: threshold to compress if larger than
 595          */
 596         public function set_compress_threshold( $thresh ) {
 597                 $this->_compress_threshold = $thresh;
 598         }
 599
 600         // }}}
 601         // {{{ set_debug()
 602
 603         /**
 604          * Sets the debug flag
 605          *
 606          * @param $dbg Boolean: TRUE for debugging, FALSE otherwise
 607          *
 608          * @see     MWMemcached::__construct
 609          */
 610         public function set_debug( $dbg ) {
 611                 $this->_debug = $dbg;
 612         }
 613
 614         // }}}
 615         // {{{ set_servers()
 616
 617         /**
 618          * Sets the server list to distribute key gets and puts between
 619          *
 620          * @param $list Array of servers to connect to
 621          *
 622          * @see     MWMemcached::__construct()
 623          */
 624         public function set_servers( $list ) {
 625                 $this->_servers = $list;
 626                 $this->_active = count( $list );
 627                 $this->_buckets = null;
 628                 $this->_bucketcount = 0;
 629
 630                 $this->_single_sock = null;
 631                 if ( $this->_active == 1 ) {
 632                         $this->_single_sock = $this->_servers[0];
 633                 }
 634         }
 635
 636         /**
 637          * Sets the timeout for new connections
 638          *
 639          * @param $seconds Integer: number of seconds
 640          * @param $microseconds Integer: number of microseconds
 641          */
 642         public function set_timeout( $seconds, $microseconds ) {
 643                 $this->_timeout_seconds = $seconds;
 644                 $this->_timeout_microseconds = $microseconds;
 645         }
 646
 647         // }}}
 648         // }}}
 649         // {{{ private methods
 650         // {{{ _close_sock()
 651
 652         /**
 653          * Close the specified socket
 654          *
 655          * @param $sock String: socket to close
 656          *
 657          * @access  private
 658          */
 659         function _close_sock( $sock ) {
 660                 $host = array_search( $sock, $this->_cache_sock );
 661                 fclose( $this->_cache_sock[$host] );
 662                 unset( $this->_cache_sock[$host] );
 663         }
 664
 665         // }}}
 666         // {{{ _connect_sock()
 667
 668         /**
 669          * Connects $sock to $host, timing out after $timeout
 670          *
 671          * @param $sock Integer: socket to connect
 672          * @param $host String: Host:IP to connect to
 673          *
 674          * @return  boolean
 675          * @access  private
 676          */
 677         function _connect_sock( &$sock, $host ) {
 678                 list( $ip, $port ) = explode( ':', $host );
 679                 $sock = false;
 680                 $timeout = $this->_connect_timeout;
 681                 $errno = $errstr = null;
 682                 for( $i = 0; !$sock && $i < $this->_connect_attempts; $i++ ) {
 683                         wfSuppressWarnings();
 684                         if ( $this->_persistant == 1 ) {
 685                                 $sock = pfsockopen( $ip, $port, $errno, $errstr, $timeout );
 686                         } else {
 687                                 $sock = fsockopen( $ip, $port, $errno, $errstr, $timeout );
 688                         }
 689                         wfRestoreWarnings();
 690                 }
 691                 if ( !$sock ) {
 692                         if ( $this->_debug ) {
 693                                 $this->_debugprint( "Error connecting to $host: $errstr\n" );
 694                         }
 695                         return false;
 696                 }
 697
 698                 // Initialise timeout
 699                 stream_set_timeout( $sock, $this->_timeout_seconds, $this->_timeout_microseconds );
 700
 701                 return true;
 702         }
 703
 704         // }}}
 705         // {{{ _dead_sock()
 706
 707         /**
 708          * Marks a host as dead until 30-40 seconds in the future
 709          *
 710          * @param $sock String: socket to mark as dead
 711          *
 712          * @access  private
 713          */
 714         function _dead_sock( $sock ) {
 715                 $host = array_search( $sock, $this->_cache_sock );
 716                 $this->_dead_host( $host );
 717         }
 718
 719         function _dead_host( $host ) {
 720                 $parts = explode( ':', $host );
 721                 $ip = $parts[0];
 722                 $this->_host_dead[$ip] = time() + 30 + intval( rand( 0, 10 ) );
 723                 $this->_host_dead[$host] = $this->_host_dead[$ip];
 724                 unset( $this->_cache_sock[$host] );
 725         }
 726
 727         // }}}
 728         // {{{ get_sock()
 729
 730         /**
 731          * get_sock
 732          *
 733          * @param $key String: key to retrieve value for;
 734          *
 735          * @return Mixed: resource on success, false on failure
 736          * @access private
 737          */
 738         function get_sock( $key ) {
 739                 if ( !$this->_active ) {
 740                         return false;
 741                 }
 742
 743                 if ( $this->_single_sock !== null ) {
 744                         $this->_flush_read_buffer( $this->_single_sock );
 745                         return $this->sock_to_host( $this->_single_sock );
 746                 }
 747
 748                 $hv = is_array( $key ) ? intval( $key[0] ) : $this->_hashfunc( $key );
 749
 750                 if ( $this->_buckets === null ) {
 751                         foreach ( $this->_servers as $v ) {
 752                                 if ( is_array( $v ) ) {
 753                                         for( $i = 0; $i < $v[1]; $i++ ) {
 754                                                 $bu[] = $v[0];
 755                                         }
 756                                 } else {
 757                                         $bu[] = $v;
 758                                 }
 759                         }
 760                         $this->_buckets = $bu;
 761                         $this->_bucketcount = count( $bu );
 762                 }
 763
 764                 $realkey = is_array( $key ) ? $key[1] : $key;
 765                 for( $tries = 0; $tries < 20; $tries++ ) {
 766                         $host = $this->_buckets[$hv % $this->_bucketcount];
 767                         $sock = $this->sock_to_host( $host );
 768                         if ( is_resource( $sock ) ) {
 769                                 $this->_flush_read_buffer( $sock );
 770                                 return $sock;
 771                         }
 772                         $hv = $this->_hashfunc( $hv . $realkey );
 773                 }
 774
 775                 return false;
 776         }
 777
 778         // }}}
 779         // {{{ _hashfunc()
 780
 781         /**
 782          * Creates a hash integer based on the $key
 783          *
 784          * @param $key String: key to hash
 785          *
 786          * @return Integer: hash value
 787          * @access private
 788          */
 789         function _hashfunc( $key ) {
 790                 # Hash function must on [0,0x7ffffff]
 791                 # We take the first 31 bits of the MD5 hash, which unlike the hash
 792                 # function used in a previous version of this client, works
 793                 return hexdec( substr( md5( $key ), 0, 8 ) ) & 0x7fffffff;
 794         }
 795
 796         // }}}
 797         // {{{ _incrdecr()
 798
 799         /**
 800          * Perform increment/decriment on $key
 801          *
 802          * @param $cmd String: command to perform
 803          * @param $key String: key to perform it on
 804          * @param $amt Integer: amount to adjust
 805          *
 806          * @return Integer: new value of $key
 807          * @access private
 808          */
 809         function _incrdecr( $cmd, $key, $amt = 1 ) {
 810                 if ( !$this->_active ) {
 811                         return null;
 812                 }
 813
 814                 $sock = $this->get_sock( $key );
 815                 if ( !is_resource( $sock ) ) {
 816                         return null;
 817                 }
 818
 819                 $key = is_array( $key ) ? $key[1] : $key;
 820                 if ( isset( $this->stats[$cmd] ) ) {
 821                         $this->stats[$cmd]++;
 822                 } else {
 823                         $this->stats[$cmd] = 1;
 824                 }
 825                 if ( !$this->_safe_fwrite( $sock, "$cmd $key $amt\r\n" ) ) {
 826                         return $this->_dead_sock( $sock );
 827                 }
 828
 829                 $line = fgets( $sock );
 830                 $match = array();
 831                 if ( !preg_match( '/^(\d+)/', $line, $match ) ) {
 832                         return null;
 833                 }
 834                 return $match[1];
 835         }
 836
 837         // }}}
 838         // {{{ _load_items()
 839
 840         /**
 841          * Load items into $ret from $sock
 842          *
 843          * @param $sock Ressource: socket to read from
 844          * @param $ret Array: returned values
 845          *
 846          * @access private
 847          */
 848         function _load_items( $sock, &$ret ) {
 849                 while ( 1 ) {
 850                         $decl = fgets( $sock );
 851                         if ( $decl == "END\r\n" ) {
 852                                 return true;
 853                         } elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+)\r\n$/', $decl, $match ) ) {
 854                                 list( $rkey, $flags, $len ) = array( $match[1], $match[2], $match[3] );
 855                                 $bneed = $len + 2;
 856                                 $offset = 0;
 857
 858                                 while ( $bneed > 0 ) {
 859                                         $data = fread( $sock, $bneed );
 860                                         $n = strlen( $data );
 861                                         if ( $n == 0 ) {
 862                                                 break;
 863                                         }
 864                                         $offset += $n;
 865                                         $bneed -= $n;
 866                                         if ( isset( $ret[$rkey] ) ) {
 867                                                 $ret[$rkey] .= $data;
 868                                         } else {
 869                                                 $ret[$rkey] = $data;
 870                                         }
 871                                 }
 872
 873                                 if ( $offset != $len + 2 ) {
 874                                         // Something is borked!
 875                                         if ( $this->_debug ) {
 876                                                 $this->_debugprint( sprintf( "Something is borked!  key %s expecting %d got %d length\n", $rkey, $len + 2, $offset ) );
 877                                         }
 878
 879                                         unset( $ret[$rkey] );
 880                                         $this->_close_sock( $sock );
 881                                         return false;
 882                                 }
 883
 884                                 if ( $this->_have_zlib && $flags & self::COMPRESSED ) {
 885                                         $ret[$rkey] = gzuncompress( $ret[$rkey] );
 886                                 }
 887
 888                                 $ret[$rkey] = rtrim( $ret[$rkey] );
 889
 890                                 if ( $flags & self::SERIALIZED ) {
 891                                         $ret[$rkey] = unserialize( $ret[$rkey] );
 892                                 }
 893
 894                         } else {
 895                                 $this->_debugprint( "Error parsing memcached response\n" );
 896                                 return 0;
 897                         }
 898                 }
 899         }
 900
 901         // }}}
 902         // {{{ _set()
 903
 904         /**
 905          * Performs the requested storage operation to the memcache server
 906          *
 907          * @param $cmd String: command to perform
 908          * @param $key String: key to act on
 909          * @param $val Mixed: what we need to store
 910          * @param $exp Integer: when it should expire
 911          *
 912          * @return Boolean
 913          * @access private
 914          */
 915         function _set( $cmd, $key, $val, $exp ) {
 916                 if ( !$this->_active ) {
 917                         return false;
 918                 }
 919
 920                 $sock = $this->get_sock( $key );
 921                 if ( !is_resource( $sock ) ) {
 922                         return false;
 923                 }
 924
 925                 if ( isset( $this->stats[$cmd] ) ) {
 926                         $this->stats[$cmd]++;
 927                 } else {
 928                         $this->stats[$cmd] = 1;
 929                 }
 930
 931                 $flags = 0;
 932
 933                 if ( !is_scalar( $val ) ) {
 934                         $val = serialize( $val );
 935                         $flags |= self::SERIALIZED;
 936                         if ( $this->_debug ) {
 937                                 $this->_debugprint( sprintf( "client: serializing data as it is not scalar\n" ) );
 938                         }
 939                 }
 940
 941                 $len = strlen( $val );
 942
 943                 if ( $this->_have_zlib && $this->_compress_enable &&
 944                          $this->_compress_threshold && $len >= $this->_compress_threshold )
 945                 {
 946                         $c_val = gzcompress( $val, 9 );
 947                         $c_len = strlen( $c_val );
 948
 949                         if ( $c_len < $len * ( 1 - self::COMPRESSION_SAVINGS ) ) {
 950                                 if ( $this->_debug ) {
 951                                         $this->_debugprint( sprintf( "client: compressing data; was %d bytes is now %d bytes\n", $len, $c_len ) );
 952                                 }
 953                                 $val = $c_val;
 954                                 $len = $c_len;
 955                                 $flags |= self::COMPRESSED;
 956                         }
 957                 }
 958                 if ( !$this->_safe_fwrite( $sock, "$cmd $key $flags $exp $len\r\n$val\r\n" ) ) {
 959                         return $this->_dead_sock( $sock );
 960                 }
 961
 962                 $line = trim( fgets( $sock ) );
 963
 964                 if ( $this->_debug ) {
 965                         $this->_debugprint( sprintf( "%s %s (%s)\n", $cmd, $key, $line ) );
 966                 }
 967                 if ( $line == "STORED" ) {
 968                         return true;
 969                 }
 970                 return false;
 971         }
 972
 973         // }}}
 974         // {{{ sock_to_host()
 975
 976         /**
 977          * Returns the socket for the host
 978          *
 979          * @param $host String: Host:IP to get socket for
 980          *
 981          * @return Mixed: IO Stream or false
 982          * @access private
 983          */
 984         function sock_to_host( $host ) {
 985                 if ( isset( $this->_cache_sock[$host] ) ) {
 986                         return $this->_cache_sock[$host];
 987                 }
 988
 989                 $sock = null;
 990                 $now = time();
 991                 list( $ip, /* $port */) = explode( ':', $host );
 992                 if ( isset( $this->_host_dead[$host] ) && $this->_host_dead[$host] > $now ||
 993                         isset( $this->_host_dead[$ip] ) && $this->_host_dead[$ip] > $now
 994                 ) {
 995                         return null;
 996                 }
 997
 998                 if ( !$this->_connect_sock( $sock, $host ) ) {
 999                         return $this->_dead_host( $host );
1000                 }
1001
1002                 // Do not buffer writes
1003                 stream_set_write_buffer( $sock, 0 );
1004
1005                 $this->_cache_sock[$host] = $sock;
1006
1007                 return $this->_cache_sock[$host];
1008         }
1009
1010         function _debugprint( $str ) {
1011                 print( $str );
1012         }
1013
1014         /**
1015          * Write to a stream, timing out after the correct amount of time
1016          *
1017          * @return Boolean: false on failure, true on success
1018          */
1019         /*
1020         function _safe_fwrite( $f, $buf, $len = false ) {
1021                 stream_set_blocking( $f, 0 );
1022
1023                 if ( $len === false ) {
1024                         wfDebug( "Writing " . strlen( $buf ) . " bytes\n" );
1025                         $bytesWritten = fwrite( $f, $buf );
1026                 } else {
1027                         wfDebug( "Writing $len bytes\n" );
1028                         $bytesWritten = fwrite( $f, $buf, $len );
1029                 }
1030                 $n = stream_select( $r = null, $w = array( $f ), $e = null, 10, 0 );
1031                 #   $this->_timeout_seconds, $this->_timeout_microseconds );
1032
1033                 wfDebug( "stream_select returned $n\n" );
1034                 stream_set_blocking( $f, 1 );
1035                 return $n == 1;
1036                 return $bytesWritten;
1037         }*/
1038
1039         /**
1040          * Original behaviour
1041          */
1042         function _safe_fwrite( $f, $buf, $len = false ) {
1043                 if ( $len === false ) {
1044                         $bytesWritten = fwrite( $f, $buf );
1045                 } else {
1046                         $bytesWritten = fwrite( $f, $buf, $len );
1047                 }
1048                 return $bytesWritten;
1049         }
1050
1051         /**
1052          * Flush the read buffer of a stream
1053          */
1054         function _flush_read_buffer( $f ) {
1055                 if ( !is_resource( $f ) ) {
1056                         return;
1057                 }
1058                 $n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
1059                 while ( $n == 1 && !feof( $f ) ) {
1060                         fread( $f, 1024 );
1061                         $n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
1062                 }
1063         }
1064
1065         // }}}
1066         // }}}
1067         // }}}
1068 }
1069
1070 // vim: sts=3 sw=3 et
1071
1072 // }}}
1073
1074 class MemCachedClientforWiki extends MWMemcached {
1075         function _debugprint( $text ) {
1076                 wfDebug( "memcached: $text" );
1077         }
1078 }