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