includes/objectcache/MemcachedClient.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  *              'persistent' => 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 persistent links?
 162          *
 163          * @var     boolean
 164          * @access  private
 165          */
 166         var $_persistent;
 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 Array Associative array of settings
 244          *
 245          * @return  mixed
 246          */
 247         public function __construct( $args ) {
 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->_persistent = isset( $args['persistent'] ) ? $args['persistent'] : 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 = isset( $args['timeout'] ) ? $args['timeout'] : 100000;
 261
 262                 $this->_connect_timeout = isset( $args['connect_timeout'] ) ? $args['connect_timeout'] : 0.1;
 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) Expiration time. This can be a number of seconds
 276          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 277          * longer must be the timestamp of the time at which the mapping should expire. It
 278          * is safe to use timestamps in all cases, regardless of exipration
 279          * eg: strtotime("+3 hour")
 280          *
 281          * @return Boolean
 282          */
 283         public function add( $key, $val, $exp = 0 ) {
 284                 return $this->_set( 'add', $key, $val, $exp );
 285         }
 286
 287         // }}}
 288         // {{{ decr()
 289
 290         /**
 291          * Decrease a value stored on the memcache server
 292          *
 293          * @param $key String: key to decrease
 294          * @param $amt Integer: (optional) amount to decrease
 295          *
 296          * @return Mixed: FALSE on failure, value on success
 297          */
 298         public function decr( $key, $amt = 1 ) {
 299                 return $this->_incrdecr( 'decr', $key, $amt );
 300         }
 301
 302         // }}}
 303         // {{{ delete()
 304
 305         /**
 306          * Deletes a key from the server, optionally after $time
 307          *
 308          * @param $key String: key to delete
 309          * @param $time Integer: (optional) how long to wait before deleting
 310          *
 311          * @return Boolean: TRUE on success, FALSE on failure
 312          */
 313         public function delete( $key, $time = 0 ) {
 314                 if ( !$this->_active ) {
 315                         return false;
 316                 }
 317
 318                 $sock = $this->get_sock( $key );
 319                 if ( !is_resource( $sock ) ) {
 320                         return false;
 321                 }
 322
 323                 $key = is_array( $key ) ? $key[1] : $key;
 324
 325                 if ( isset( $this->stats['delete'] ) ) {
 326                         $this->stats['delete']++;
 327                 } else {
 328                         $this->stats['delete'] = 1;
 329                 }
 330                 $cmd = "delete $key $time\r\n";
 331                 if( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 332                         $this->_dead_sock( $sock );
 333                         return false;
 334                 }
 335                 $res = trim( fgets( $sock ) );
 336
 337                 if ( $this->_debug ) {
 338                         $this->_debugprint( sprintf( "MemCache: delete %s (%s)\n", $key, $res ) );
 339                 }
 340
 341                 if ( $res == "DELETED" ) {
 342                         return true;
 343                 }
 344                 return false;
 345         }
 346
 347         // }}}
 348         // {{{ disconnect_all()
 349
 350         /**
 351          * Disconnects all connected sockets
 352          */
 353         public function disconnect_all() {
 354                 foreach ( $this->_cache_sock as $sock ) {
 355                         fclose( $sock );
 356                 }
 357
 358                 $this->_cache_sock = array();
 359         }
 360
 361         // }}}
 362         // {{{ enable_compress()
 363
 364         /**
 365          * Enable / Disable compression
 366          *
 367          * @param $enable Boolean: TRUE to enable, FALSE to disable
 368          */
 369         public function enable_compress( $enable ) {
 370                 $this->_compress_enable = $enable;
 371         }
 372
 373         // }}}
 374         // {{{ forget_dead_hosts()
 375
 376         /**
 377          * Forget about all of the dead hosts
 378          */
 379         public function forget_dead_hosts() {
 380                 $this->_host_dead = array();
 381         }
 382
 383         // }}}
 384         // {{{ get()
 385
 386         /**
 387          * Retrieves the value associated with the key from the memcache server
 388          *
 389          * @param $key Mixed: key to retrieve
 390          *
 391          * @return Mixed
 392          */
 393         public function get( $key ) {
 394                 wfProfileIn( __METHOD__ );
 395
 396                 if ( $this->_debug ) {
 397                         $this->_debugprint( "get($key)\n" );
 398                 }
 399
 400                 if ( !$this->_active ) {
 401                         wfProfileOut( __METHOD__ );
 402                         return false;
 403                 }
 404
 405                 $sock = $this->get_sock( $key );
 406
 407                 if ( !is_resource( $sock ) ) {
 408                         wfProfileOut( __METHOD__ );
 409                         return false;
 410                 }
 411
 412                 if ( isset( $this->stats['get'] ) ) {
 413                         $this->stats['get']++;
 414                 } else {
 415                         $this->stats['get'] = 1;
 416                 }
 417
 418                 $cmd = "get $key\r\n";
 419                 if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 420                         $this->_dead_sock( $sock );
 421                         wfProfileOut( __METHOD__ );
 422                         return false;
 423                 }
 424
 425                 $val = array();
 426                 $this->_load_items( $sock, $val );
 427
 428                 if ( $this->_debug ) {
 429                         foreach ( $val as $k => $v ) {
 430                                 $this->_debugprint( sprintf( "MemCache: sock %s got %s\n", serialize( $sock ), $k ) );
 431                         }
 432                 }
 433
 434                 $value = false;
 435                 if ( isset( $val[$key] ) ) {
 436                         $value = $val[$key];
 437                 }
 438                 wfProfileOut( __METHOD__ );
 439                 return $value;
 440         }
 441
 442         // }}}
 443         // {{{ get_multi()
 444
 445         /**
 446          * Get multiple keys from the server(s)
 447          *
 448          * @param $keys Array: keys to retrieve
 449          *
 450          * @return Array
 451          */
 452         public function get_multi( $keys ) {
 453                 if ( !$this->_active ) {
 454                         return false;
 455                 }
 456
 457                 if ( isset( $this->stats['get_multi'] ) ) {
 458                         $this->stats['get_multi']++;
 459                 } else {
 460                         $this->stats['get_multi'] = 1;
 461                 }
 462                 $sock_keys = array();
 463
 464                 foreach ( $keys as $key ) {
 465                         $sock = $this->get_sock( $key );
 466                         if ( !is_resource( $sock ) ) {
 467                                 continue;
 468                         }
 469                         $key = is_array( $key ) ? $key[1] : $key;
 470                         if ( !isset( $sock_keys[$sock] ) ) {
 471                                 $sock_keys[$sock] = array();
 472                                 $socks[] = $sock;
 473                         }
 474                         $sock_keys[$sock][] = $key;
 475                 }
 476
 477                 // Send out the requests
 478                 foreach ( $socks as $sock ) {
 479                         $cmd = 'get';
 480                         foreach ( $sock_keys[$sock] as $key ) {
 481                                 $cmd .= ' ' . $key;
 482                         }
 483                         $cmd .= "\r\n";
 484
 485                         if ( $this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 486                                 $gather[] = $sock;
 487                         } else {
 488                                 $this->_dead_sock( $sock );
 489                         }
 490                 }
 491
 492                 // Parse responses
 493                 $val = array();
 494                 foreach ( $gather as $sock ) {
 495                         $this->_load_items( $sock, $val );
 496                 }
 497
 498                 if ( $this->_debug ) {
 499                         foreach ( $val as $k => $v ) {
 500                                 $this->_debugprint( sprintf( "MemCache: got %s\n", $k ) );
 501                         }
 502                 }
 503
 504                 return $val;
 505         }
 506
 507         // }}}
 508         // {{{ incr()
 509
 510         /**
 511          * Increments $key (optionally) by $amt
 512          *
 513          * @param $key String: key to increment
 514          * @param $amt Integer: (optional) amount to increment
 515          *
 516          * @return Integer: null if the key does not exist yet (this does NOT
 517          * create new mappings if the key does not exist). If the key does
 518          * exist, this returns the new value for that key.
 519          */
 520         public function incr( $key, $amt = 1 ) {
 521                 return $this->_incrdecr( 'incr', $key, $amt );
 522         }
 523
 524         // }}}
 525         // {{{ replace()
 526
 527         /**
 528          * Overwrites an existing value for key; only works if key is already set
 529          *
 530          * @param $key String: key to set value as
 531          * @param $value Mixed: value to store
 532          * @param $exp Integer: (optional) Expiration time. This can be a number of seconds
 533          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 534          * longer must be the timestamp of the time at which the mapping should expire. It
 535          * is safe to use timestamps in all cases, regardless of exipration
 536          * eg: strtotime("+3 hour")
 537          *
 538          * @return Boolean
 539          */
 540         public function replace( $key, $value, $exp = 0 ) {
 541                 return $this->_set( 'replace', $key, $value, $exp );
 542         }
 543
 544         // }}}
 545         // {{{ run_command()
 546
 547         /**
 548          * Passes through $cmd to the memcache server connected by $sock; returns
 549          * output as an array (null array if no output)
 550          *
 551          * NOTE: due to a possible bug in how PHP reads while using fgets(), each
 552          *       line may not be terminated by a \r\n.  More specifically, my testing
 553          *       has shown that, on FreeBSD at least, each line is terminated only
 554          *       with a \n.  This is with the PHP flag auto_detect_line_endings set
 555          *       to falase (the default).
 556          *
 557          * @param $sock Ressource: socket to send command on
 558          * @param $cmd String: command to run
 559          *
 560          * @return Array: output array
 561          */
 562         public function run_command( $sock, $cmd ) {
 563                 if ( !is_resource( $sock ) ) {
 564                         return array();
 565                 }
 566
 567                 if ( !$this->_safe_fwrite( $sock, $cmd, strlen( $cmd ) ) ) {
 568                         return array();
 569                 }
 570
 571                 while ( true ) {
 572                         $res = fgets( $sock );
 573                         $ret[] = $res;
 574                         if ( preg_match( '/^END/', $res ) ) {
 575                                 break;
 576                         }
 577                         if ( strlen( $res ) == 0 ) {
 578                                 break;
 579                         }
 580                 }
 581                 return $ret;
 582         }
 583
 584         // }}}
 585         // {{{ set()
 586
 587         /**
 588          * Unconditionally sets a key to a given value in the memcache.  Returns true
 589          * if set successfully.
 590          *
 591          * @param $key String: key to set value as
 592          * @param $value Mixed: value to set
 593          * @param $exp Integer: (optional) Expiration time. This can be a number of seconds
 594          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 595          * longer must be the timestamp of the time at which the mapping should expire. It
 596          * is safe to use timestamps in all cases, regardless of exipration
 597          * eg: strtotime("+3 hour")
 598          *
 599          * @return Boolean: TRUE on success
 600          */
 601         public function set( $key, $value, $exp = 0 ) {
 602                 return $this->_set( 'set', $key, $value, $exp );
 603         }
 604
 605         // }}}
 606         // {{{ set_compress_threshold()
 607
 608         /**
 609          * Sets the compression threshold
 610          *
 611          * @param $thresh Integer: threshold to compress if larger than
 612          */
 613         public function set_compress_threshold( $thresh ) {
 614                 $this->_compress_threshold = $thresh;
 615         }
 616
 617         // }}}
 618         // {{{ set_debug()
 619
 620         /**
 621          * Sets the debug flag
 622          *
 623          * @param $dbg Boolean: TRUE for debugging, FALSE otherwise
 624          *
 625          * @see     MWMemcached::__construct
 626          */
 627         public function set_debug( $dbg ) {
 628                 $this->_debug = $dbg;
 629         }
 630
 631         // }}}
 632         // {{{ set_servers()
 633
 634         /**
 635          * Sets the server list to distribute key gets and puts between
 636          *
 637          * @param $list Array of servers to connect to
 638          *
 639          * @see     MWMemcached::__construct()
 640          */
 641         public function set_servers( $list ) {
 642                 $this->_servers = $list;
 643                 $this->_active = count( $list );
 644                 $this->_buckets = null;
 645                 $this->_bucketcount = 0;
 646
 647                 $this->_single_sock = null;
 648                 if ( $this->_active == 1 ) {
 649                         $this->_single_sock = $this->_servers[0];
 650                 }
 651         }
 652
 653         /**
 654          * Sets the timeout for new connections
 655          *
 656          * @param $seconds Integer: number of seconds
 657          * @param $microseconds Integer: number of microseconds
 658          */
 659         public function set_timeout( $seconds, $microseconds ) {
 660                 $this->_timeout_seconds = $seconds;
 661                 $this->_timeout_microseconds = $microseconds;
 662         }
 663
 664         // }}}
 665         // }}}
 666         // {{{ private methods
 667         // {{{ _close_sock()
 668
 669         /**
 670          * Close the specified socket
 671          *
 672          * @param $sock String: socket to close
 673          *
 674          * @access  private
 675          */
 676         function _close_sock( $sock ) {
 677                 $host = array_search( $sock, $this->_cache_sock );
 678                 fclose( $this->_cache_sock[$host] );
 679                 unset( $this->_cache_sock[$host] );
 680         }
 681
 682         // }}}
 683         // {{{ _connect_sock()
 684
 685         /**
 686          * Connects $sock to $host, timing out after $timeout
 687          *
 688          * @param $sock Integer: socket to connect
 689          * @param $host String: Host:IP to connect to
 690          *
 691          * @return  boolean
 692          * @access  private
 693          */
 694         function _connect_sock( &$sock, $host ) {
 695                 list( $ip, $port ) = explode( ':', $host );
 696                 $sock = false;
 697                 $timeout = $this->_connect_timeout;
 698                 $errno = $errstr = null;
 699                 for( $i = 0; !$sock && $i < $this->_connect_attempts; $i++ ) {
 700                         wfSuppressWarnings();
 701                         if ( $this->_persistent == 1 ) {
 702                                 $sock = pfsockopen( $ip, $port, $errno, $errstr, $timeout );
 703                         } else {
 704                                 $sock = fsockopen( $ip, $port, $errno, $errstr, $timeout );
 705                         }
 706                         wfRestoreWarnings();
 707                 }
 708                 if ( !$sock ) {
 709                         if ( $this->_debug ) {
 710                                 $this->_debugprint( "Error connecting to $host: $errstr\n" );
 711                         }
 712                         return false;
 713                 }
 714
 715                 // Initialise timeout
 716                 stream_set_timeout( $sock, $this->_timeout_seconds, $this->_timeout_microseconds );
 717
 718                 return true;
 719         }
 720
 721         // }}}
 722         // {{{ _dead_sock()
 723
 724         /**
 725          * Marks a host as dead until 30-40 seconds in the future
 726          *
 727          * @param $sock String: socket to mark as dead
 728          *
 729          * @access  private
 730          */
 731         function _dead_sock( $sock ) {
 732                 $host = array_search( $sock, $this->_cache_sock );
 733                 $this->_dead_host( $host );
 734         }
 735
 736         function _dead_host( $host ) {
 737                 $parts = explode( ':', $host );
 738                 $ip = $parts[0];
 739                 $this->_host_dead[$ip] = time() + 30 + intval( rand( 0, 10 ) );
 740                 $this->_host_dead[$host] = $this->_host_dead[$ip];
 741                 unset( $this->_cache_sock[$host] );
 742         }
 743
 744         // }}}
 745         // {{{ get_sock()
 746
 747         /**
 748          * get_sock
 749          *
 750          * @param $key String: key to retrieve value for;
 751          *
 752          * @return Mixed: resource on success, false on failure
 753          * @access private
 754          */
 755         function get_sock( $key ) {
 756                 if ( !$this->_active ) {
 757                         return false;
 758                 }
 759
 760                 if ( $this->_single_sock !== null ) {
 761                         $this->_flush_read_buffer( $this->_single_sock );
 762                         return $this->sock_to_host( $this->_single_sock );
 763                 }
 764
 765                 $hv = is_array( $key ) ? intval( $key[0] ) : $this->_hashfunc( $key );
 766
 767                 if ( $this->_buckets === null ) {
 768                         foreach ( $this->_servers as $v ) {
 769                                 if ( is_array( $v ) ) {
 770                                         for( $i = 0; $i < $v[1]; $i++ ) {
 771                                                 $bu[] = $v[0];
 772                                         }
 773                                 } else {
 774                                         $bu[] = $v;
 775                                 }
 776                         }
 777                         $this->_buckets = $bu;
 778                         $this->_bucketcount = count( $bu );
 779                 }
 780
 781                 $realkey = is_array( $key ) ? $key[1] : $key;
 782                 for( $tries = 0; $tries < 20; $tries++ ) {
 783                         $host = $this->_buckets[$hv % $this->_bucketcount];
 784                         $sock = $this->sock_to_host( $host );
 785                         if ( is_resource( $sock ) ) {
 786                                 $this->_flush_read_buffer( $sock );
 787                                 return $sock;
 788                         }
 789                         $hv = $this->_hashfunc( $hv . $realkey );
 790                 }
 791
 792                 return false;
 793         }
 794
 795         // }}}
 796         // {{{ _hashfunc()
 797
 798         /**
 799          * Creates a hash integer based on the $key
 800          *
 801          * @param $key String: key to hash
 802          *
 803          * @return Integer: hash value
 804          * @access private
 805          */
 806         function _hashfunc( $key ) {
 807                 # Hash function must on [0,0x7ffffff]
 808                 # We take the first 31 bits of the MD5 hash, which unlike the hash
 809                 # function used in a previous version of this client, works
 810                 return hexdec( substr( md5( $key ), 0, 8 ) ) & 0x7fffffff;
 811         }
 812
 813         // }}}
 814         // {{{ _incrdecr()
 815
 816         /**
 817          * Perform increment/decriment on $key
 818          *
 819          * @param $cmd String: command to perform
 820          * @param $key String: key to perform it on
 821          * @param $amt Integer: amount to adjust
 822          *
 823          * @return Integer: new value of $key
 824          * @access private
 825          */
 826         function _incrdecr( $cmd, $key, $amt = 1 ) {
 827                 if ( !$this->_active ) {
 828                         return null;
 829                 }
 830
 831                 $sock = $this->get_sock( $key );
 832                 if ( !is_resource( $sock ) ) {
 833                         return null;
 834                 }
 835
 836                 $key = is_array( $key ) ? $key[1] : $key;
 837                 if ( isset( $this->stats[$cmd] ) ) {
 838                         $this->stats[$cmd]++;
 839                 } else {
 840                         $this->stats[$cmd] = 1;
 841                 }
 842                 if ( !$this->_safe_fwrite( $sock, "$cmd $key $amt\r\n" ) ) {
 843                         return $this->_dead_sock( $sock );
 844                 }
 845
 846                 $line = fgets( $sock );
 847                 $match = array();
 848                 if ( !preg_match( '/^(\d+)/', $line, $match ) ) {
 849                         return null;
 850                 }
 851                 return $match[1];
 852         }
 853
 854         // }}}
 855         // {{{ _load_items()
 856
 857         /**
 858          * Load items into $ret from $sock
 859          *
 860          * @param $sock Ressource: socket to read from
 861          * @param $ret Array: returned values
 862          *
 863          * @access private
 864          */
 865         function _load_items( $sock, &$ret ) {
 866                 while ( 1 ) {
 867                         $decl = fgets( $sock );
 868                         if ( $decl == "END\r\n" ) {
 869                                 return true;
 870                         } elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+)\r\n$/', $decl, $match ) ) {
 871                                 list( $rkey, $flags, $len ) = array( $match[1], $match[2], $match[3] );
 872                                 $bneed = $len + 2;
 873                                 $offset = 0;
 874
 875                                 while ( $bneed > 0 ) {
 876                                         $data = fread( $sock, $bneed );
 877                                         $n = strlen( $data );
 878                                         if ( $n == 0 ) {
 879                                                 break;
 880                                         }
 881                                         $offset += $n;
 882                                         $bneed -= $n;
 883                                         if ( isset( $ret[$rkey] ) ) {
 884                                                 $ret[$rkey] .= $data;
 885                                         } else {
 886                                                 $ret[$rkey] = $data;
 887                                         }
 888                                 }
 889
 890                                 if ( $offset != $len + 2 ) {
 891                                         // Something is borked!
 892                                         if ( $this->_debug ) {
 893                                                 $this->_debugprint( sprintf( "Something is borked!  key %s expecting %d got %d length\n", $rkey, $len + 2, $offset ) );
 894                                         }
 895
 896                                         unset( $ret[$rkey] );
 897                                         $this->_close_sock( $sock );
 898                                         return false;
 899                                 }
 900
 901                                 if ( $this->_have_zlib && $flags & self::COMPRESSED ) {
 902                                         $ret[$rkey] = gzuncompress( $ret[$rkey] );
 903                                 }
 904
 905                                 $ret[$rkey] = rtrim( $ret[$rkey] );
 906
 907                                 if ( $flags & self::SERIALIZED ) {
 908                                         $ret[$rkey] = unserialize( $ret[$rkey] );
 909                                 }
 910
 911                         } else {
 912                                 $this->_debugprint( "Error parsing memcached response\n" );
 913                                 return 0;
 914                         }
 915                 }
 916         }
 917
 918         // }}}
 919         // {{{ _set()
 920
 921         /**
 922          * Performs the requested storage operation to the memcache server
 923          *
 924          * @param $cmd String: command to perform
 925          * @param $key String: key to act on
 926          * @param $val Mixed: what we need to store
 927          * @param $exp Integer: (optional) Expiration time. This can be a number of seconds
 928          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 929          * longer must be the timestamp of the time at which the mapping should expire. It
 930          * is safe to use timestamps in all cases, regardless of exipration
 931          * eg: strtotime("+3 hour")
 932          *
 933          * @return Boolean
 934          * @access private
 935          */
 936         function _set( $cmd, $key, $val, $exp ) {
 937                 if ( !$this->_active ) {
 938                         return false;
 939                 }
 940
 941                 $sock = $this->get_sock( $key );
 942                 if ( !is_resource( $sock ) ) {
 943                         return false;
 944                 }
 945
 946                 if ( isset( $this->stats[$cmd] ) ) {
 947                         $this->stats[$cmd]++;
 948                 } else {
 949                         $this->stats[$cmd] = 1;
 950                 }
 951
 952                 $flags = 0;
 953
 954                 if ( !is_scalar( $val ) ) {
 955                         $val = serialize( $val );
 956                         $flags |= self::SERIALIZED;
 957                         if ( $this->_debug ) {
 958                                 $this->_debugprint( sprintf( "client: serializing data as it is not scalar\n" ) );
 959                         }
 960                 }
 961
 962                 $len = strlen( $val );
 963
 964                 if ( $this->_have_zlib && $this->_compress_enable &&
 965                          $this->_compress_threshold && $len >= $this->_compress_threshold )
 966                 {
 967                         $c_val = gzcompress( $val, 9 );
 968                         $c_len = strlen( $c_val );
 969
 970                         if ( $c_len < $len * ( 1 - self::COMPRESSION_SAVINGS ) ) {
 971                                 if ( $this->_debug ) {
 972                                         $this->_debugprint( sprintf( "client: compressing data; was %d bytes is now %d bytes\n", $len, $c_len ) );
 973                                 }
 974                                 $val = $c_val;
 975                                 $len = $c_len;
 976                                 $flags |= self::COMPRESSED;
 977                         }
 978                 }
 979                 if ( !$this->_safe_fwrite( $sock, "$cmd $key $flags $exp $len\r\n$val\r\n" ) ) {
 980                         return $this->_dead_sock( $sock );
 981                 }
 982
 983                 $line = trim( fgets( $sock ) );
 984
 985                 if ( $this->_debug ) {
 986                         $this->_debugprint( sprintf( "%s %s (%s)\n", $cmd, $key, $line ) );
 987                 }
 988                 if ( $line == "STORED" ) {
 989                         return true;
 990                 }
 991                 return false;
 992         }
 993
 994         // }}}
 995         // {{{ sock_to_host()
 996
 997         /**
 998          * Returns the socket for the host
 999          *
1000          * @param $host String: Host:IP to get socket for
1001          *
1002          * @return Mixed: IO Stream or false
1003          * @access private
1004          */
1005         function sock_to_host( $host ) {
1006                 if ( isset( $this->_cache_sock[$host] ) ) {
1007                         return $this->_cache_sock[$host];
1008                 }
1009
1010                 $sock = null;
1011                 $now = time();
1012                 list( $ip, /* $port */) = explode( ':', $host );
1013                 if ( isset( $this->_host_dead[$host] ) && $this->_host_dead[$host] > $now ||
1014                         isset( $this->_host_dead[$ip] ) && $this->_host_dead[$ip] > $now
1015                 ) {
1016                         return null;
1017                 }
1018
1019                 if ( !$this->_connect_sock( $sock, $host ) ) {
1020                         return $this->_dead_host( $host );
1021                 }
1022
1023                 // Do not buffer writes
1024                 stream_set_write_buffer( $sock, 0 );
1025
1026                 $this->_cache_sock[$host] = $sock;
1027
1028                 return $this->_cache_sock[$host];
1029         }
1030
1031         function _debugprint( $str ) {
1032                 print( $str );
1033         }
1034
1035         /**
1036          * Write to a stream, timing out after the correct amount of time
1037          *
1038          * @return Boolean: false on failure, true on success
1039          */
1040         /*
1041         function _safe_fwrite( $f, $buf, $len = false ) {
1042                 stream_set_blocking( $f, 0 );
1043
1044                 if ( $len === false ) {
1045                         wfDebug( "Writing " . strlen( $buf ) . " bytes\n" );
1046                         $bytesWritten = fwrite( $f, $buf );
1047                 } else {
1048                         wfDebug( "Writing $len bytes\n" );
1049                         $bytesWritten = fwrite( $f, $buf, $len );
1050                 }
1051                 $n = stream_select( $r = null, $w = array( $f ), $e = null, 10, 0 );
1052                 #   $this->_timeout_seconds, $this->_timeout_microseconds );
1053
1054                 wfDebug( "stream_select returned $n\n" );
1055                 stream_set_blocking( $f, 1 );
1056                 return $n == 1;
1057                 return $bytesWritten;
1058         }*/
1059
1060         /**
1061          * Original behaviour
1062          */
1063         function _safe_fwrite( $f, $buf, $len = false ) {
1064                 if ( $len === false ) {
1065                         $bytesWritten = fwrite( $f, $buf );
1066                 } else {
1067                         $bytesWritten = fwrite( $f, $buf, $len );
1068                 }
1069                 return $bytesWritten;
1070         }
1071
1072         /**
1073          * Flush the read buffer of a stream
1074          */
1075         function _flush_read_buffer( $f ) {
1076                 if ( !is_resource( $f ) ) {
1077                         return;
1078                 }
1079                 $n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
1080                 while ( $n == 1 && !feof( $f ) ) {
1081                         fread( $f, 1024 );
1082                         $n = stream_select( $r = array( $f ), $w = null, $e = null, 0, 0 );
1083                 }
1084         }
1085
1086         // }}}
1087         // }}}
1088         // }}}
1089 }
1090
1091 // vim: sts=3 sw=3 et
1092
1093 // }}}
1094
1095 class MemCachedClientforWiki extends MWMemcached {
1096         function _debugprint( $text ) {
1097                 wfDebug( "memcached: $text" );
1098         }
1099 }