includes/objectcache/MemcachedClient.php

   1 <?php
   2 // @codingStandardsIgnoreFile It's an external lib and it isn't. Let's not bother.
   3 /**
   4  * Memcached client for PHP.
   5  *
   6  * +---------------------------------------------------------------------------+
   7  * | memcached client, PHP                                                     |
   8  * +---------------------------------------------------------------------------+
   9  * | Copyright (c) 2003 Ryan T. Dean <rtdean@cytherianage.net>                 |
  10  * | All rights reserved.                                                      |
  11  * |                                                                           |
  12  * | Redistribution and use in source and binary forms, with or without        |
  13  * | modification, are permitted provided that the following conditions        |
  14  * | are met:                                                                  |
  15  * |                                                                           |
  16  * | 1. Redistributions of source code must retain the above copyright         |
  17  * |    notice, this list of conditions and the following disclaimer.          |
  18  * | 2. Redistributions in binary form must reproduce the above copyright      |
  19  * |    notice, this list of conditions and the following disclaimer in the    |
  20  * |    documentation and/or other materials provided with the distribution.   |
  21  * |                                                                           |
  22  * | THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR      |
  23  * | IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
  24  * | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.   |
  25  * | IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,          |
  26  * | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT  |
  27  * | NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
  28  * | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY     |
  29  * | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT       |
  30  * | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF  |
  31  * | THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.         |
  32  * +---------------------------------------------------------------------------+
  33  * | Author: Ryan T. Dean <rtdean@cytherianage.net>                            |
  34  * | Heavily influenced by the Perl memcached client by Brad Fitzpatrick.      |
  35  * |   Permission granted by Brad Fitzpatrick for relicense of ported Perl     |
  36  * |   client logic under 2-clause BSD license.                                |
  37  * +---------------------------------------------------------------------------+
  38  *
  39  * @file
  40  * $TCAnet$
  41  */
  42
  43 /**
  44  * This is the PHP client for memcached - a distributed memory cache daemon.
  45  * More information is available at http://www.danga.com/memcached/
  46  *
  47  * Usage example:
  48  *
  49  * require_once 'memcached.php';
  50  *
  51  * $mc = new MWMemcached(array(
  52  *              'servers' => array('127.0.0.1:10000',
  53  *                                 array('192.0.0.1:10010', 2),
  54  *                                 '127.0.0.1:10020'),
  55  *              'debug'   => false,
  56  *              'compress_threshold' => 10240,
  57  *              'persistent' => true));
  58  *
  59  * $mc->add( 'key', array( 'some', 'array' ) );
  60  * $mc->replace( 'key', 'some random string' );
  61  * $val = $mc->get( 'key' );
  62  *
  63  * @author  Ryan T. Dean <rtdean@cytherianage.net>
  64  * @version 0.1.2
  65  */
  66
  67 // {{{ requirements
  68 // }}}
  69
  70 // {{{ class MWMemcached
  71 /**
  72  * memcached client class implemented using (p)fsockopen()
  73  *
  74  * @author  Ryan T. Dean <rtdean@cytherianage.net>
  75  * @ingroup Cache
  76  */
  77 class MWMemcached {
  78         // {{{ properties
  79         // {{{ public
  80
  81         // {{{ constants
  82         // {{{ flags
  83
  84         /**
  85          * Flag: indicates data is serialized
  86          */
  87         const SERIALIZED = 1;
  88
  89         /**
  90          * Flag: indicates data is compressed
  91          */
  92         const COMPRESSED = 2;
  93
  94         // }}}
  95
  96         /**
  97          * Minimum savings to store data compressed
  98          */
  99         const COMPRESSION_SAVINGS = 0.20;
 100
 101         // }}}
 102
 103         /**
 104          * Command statistics
 105          *
 106          * @var array
 107          * @access public
 108          */
 109         var $stats;
 110
 111         // }}}
 112         // {{{ private
 113
 114         /**
 115          * Cached Sockets that are connected
 116          *
 117          * @var array
 118          * @access private
 119          */
 120         var $_cache_sock;
 121
 122         /**
 123          * Current debug status; 0 - none to 9 - profiling
 124          *
 125          * @var bool
 126          * @access private
 127          */
 128         var $_debug;
 129
 130         /**
 131          * Dead hosts, assoc array, 'host'=>'unixtime when ok to check again'
 132          *
 133          * @var array
 134          * @access private
 135          */
 136         var $_host_dead;
 137
 138         /**
 139          * Is compression available?
 140          *
 141          * @var bool
 142          * @access private
 143          */
 144         var $_have_zlib;
 145
 146         /**
 147          * Do we want to use compression?
 148          *
 149          * @var bool
 150          * @access private
 151          */
 152         var $_compress_enable;
 153
 154         /**
 155          * At how many bytes should we compress?
 156          *
 157          * @var int
 158          * @access private
 159          */
 160         var $_compress_threshold;
 161
 162         /**
 163          * Are we using persistent links?
 164          *
 165          * @var bool
 166          * @access private
 167          */
 168         var $_persistent;
 169
 170         /**
 171          * If only using one server; contains ip:port to connect to
 172          *
 173          * @var string
 174          * @access private
 175          */
 176         var $_single_sock;
 177
 178         /**
 179          * Array containing ip:port or array(ip:port, weight)
 180          *
 181          * @var array
 182          * @access private
 183          */
 184         var $_servers;
 185
 186         /**
 187          * Our bit buckets
 188          *
 189          * @var array
 190          * @access private
 191          */
 192         var $_buckets;
 193
 194         /**
 195          * Total # of bit buckets we have
 196          *
 197          * @var int
 198          * @access private
 199          */
 200         var $_bucketcount;
 201
 202         /**
 203          * # of total servers we have
 204          *
 205          * @var int
 206          * @access private
 207          */
 208         var $_active;
 209
 210         /**
 211          * Stream timeout in seconds. Applies for example to fread()
 212          *
 213          * @var int
 214          * @access private
 215          */
 216         var $_timeout_seconds;
 217
 218         /**
 219          * Stream timeout in microseconds
 220          *
 221          * @var int
 222          * @access private
 223          */
 224         var $_timeout_microseconds;
 225
 226         /**
 227          * Connect timeout in seconds
 228          */
 229         var $_connect_timeout;
 230
 231         /**
 232          * Number of connection attempts for each server
 233          */
 234         var $_connect_attempts;
 235
 236         // }}}
 237         // }}}
 238         // {{{ methods
 239         // {{{ public functions
 240         // {{{ memcached()
 241
 242         /**
 243          * Memcache initializer
 244          *
 245          * @param array $args Associative array of settings
 246          *
 247          * @return mixed
 248          */
 249         public function __construct( $args ) {
 250                 $this->set_servers( isset( $args['servers'] ) ? $args['servers'] : array() );
 251                 $this->_debug = isset( $args['debug'] ) ? $args['debug'] : false;
 252                 $this->stats = array();
 253                 $this->_compress_threshold = isset( $args['compress_threshold'] ) ? $args['compress_threshold'] : 0;
 254                 $this->_persistent = isset( $args['persistent'] ) ? $args['persistent'] : false;
 255                 $this->_compress_enable = true;
 256                 $this->_have_zlib = function_exists( 'gzcompress' );
 257
 258                 $this->_cache_sock = array();
 259                 $this->_host_dead = array();
 260
 261                 $this->_timeout_seconds = 0;
 262                 $this->_timeout_microseconds = isset( $args['timeout'] ) ? $args['timeout'] : 500000;
 263
 264                 $this->_connect_timeout = isset( $args['connect_timeout'] ) ? $args['connect_timeout'] : 0.1;
 265                 $this->_connect_attempts = 2;
 266         }
 267
 268         // }}}
 269         // {{{ add()
 270
 271         /**
 272          * Adds a key/value to the memcache server if one isn't already set with
 273          * that key
 274          *
 275          * @param string $key Key to set with data
 276          * @param mixed $val Value to store
 277          * @param int $exp (optional) Expiration time. This can be a number of seconds
 278          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 279          * longer must be the timestamp of the time at which the mapping should expire. It
 280          * is safe to use timestamps in all cases, regardless of expiration
 281          * eg: strtotime("+3 hour")
 282          *
 283          * @return bool
 284          */
 285         public function add( $key, $val, $exp = 0 ) {
 286                 return $this->_set( 'add', $key, $val, $exp );
 287         }
 288
 289         // }}}
 290         // {{{ decr()
 291
 292         /**
 293          * Decrease a value stored on the memcache server
 294          *
 295          * @param string $key Key to decrease
 296          * @param int $amt (optional) amount to decrease
 297          *
 298          * @return mixed False on failure, value on success
 299          */
 300         public function decr( $key, $amt = 1 ) {
 301                 return $this->_incrdecr( 'decr', $key, $amt );
 302         }
 303
 304         // }}}
 305         // {{{ delete()
 306
 307         /**
 308          * Deletes a key from the server, optionally after $time
 309          *
 310          * @param string $key Key to delete
 311          * @param int $time (optional) how long to wait before deleting
 312          *
 313          * @return bool True on success, false on failure
 314          */
 315         public function delete( $key, $time = 0 ) {
 316                 if ( !$this->_active ) {
 317                         return false;
 318                 }
 319
 320                 $sock = $this->get_sock( $key );
 321                 if ( !is_resource( $sock ) ) {
 322                         return false;
 323                 }
 324
 325                 $key = is_array( $key ) ? $key[1] : $key;
 326
 327                 if ( isset( $this->stats['delete'] ) ) {
 328                         $this->stats['delete']++;
 329                 } else {
 330                         $this->stats['delete'] = 1;
 331                 }
 332                 $cmd = "delete $key $time\r\n";
 333                 if ( !$this->_fwrite( $sock, $cmd ) ) {
 334                         return false;
 335                 }
 336                 $res = $this->_fgets( $sock );
 337
 338                 if ( $this->_debug ) {
 339                         $this->_debugprint( sprintf( "MemCache: delete %s (%s)\n", $key, $res ) );
 340                 }
 341
 342                 if ( $res == "DELETED" || $res == "NOT_FOUND" ) {
 343                         return true;
 344                 }
 345
 346                 return false;
 347         }
 348
 349         /**
 350          * @param string $key
 351          * @param int $timeout
 352          * @return bool
 353          */
 354         public function lock( $key, $timeout = 0 ) {
 355                 /* stub */
 356                 return true;
 357         }
 358
 359         /**
 360          * @param string $key
 361          * @return bool
 362          */
 363         public function unlock( $key ) {
 364                 /* stub */
 365                 return true;
 366         }
 367
 368         // }}}
 369         // {{{ disconnect_all()
 370
 371         /**
 372          * Disconnects all connected sockets
 373          */
 374         public function disconnect_all() {
 375                 foreach ( $this->_cache_sock as $sock ) {
 376                         fclose( $sock );
 377                 }
 378
 379                 $this->_cache_sock = array();
 380         }
 381
 382         // }}}
 383         // {{{ enable_compress()
 384
 385         /**
 386          * Enable / Disable compression
 387          *
 388          * @param bool $enable True to enable, false to disable
 389          */
 390         public function enable_compress( $enable ) {
 391                 $this->_compress_enable = $enable;
 392         }
 393
 394         // }}}
 395         // {{{ forget_dead_hosts()
 396
 397         /**
 398          * Forget about all of the dead hosts
 399          */
 400         public function forget_dead_hosts() {
 401                 $this->_host_dead = array();
 402         }
 403
 404         // }}}
 405         // {{{ get()
 406
 407         /**
 408          * Retrieves the value associated with the key from the memcache server
 409          *
 410          * @param array|string $key key to retrieve
 411          * @param float $casToken [optional]
 412          *
 413          * @return mixed
 414          */
 415         public function get( $key, &$casToken = null ) {
 416                 wfProfileIn( __METHOD__ );
 417
 418                 if ( $this->_debug ) {
 419                         $this->_debugprint( "get($key)\n" );
 420                 }
 421
 422                 if ( !is_array( $key ) && strval( $key ) === '' ) {
 423                         $this->_debugprint( "Skipping key which equals to an empty string" );
 424                         wfProfileOut( __METHOD__ );
 425                         return false;
 426                 }
 427
 428                 if ( !$this->_active ) {
 429                         wfProfileOut( __METHOD__ );
 430                         return false;
 431                 }
 432
 433                 $sock = $this->get_sock( $key );
 434
 435                 if ( !is_resource( $sock ) ) {
 436                         wfProfileOut( __METHOD__ );
 437                         return false;
 438                 }
 439
 440                 $key = is_array( $key ) ? $key[1] : $key;
 441                 if ( isset( $this->stats['get'] ) ) {
 442                         $this->stats['get']++;
 443                 } else {
 444                         $this->stats['get'] = 1;
 445                 }
 446
 447                 $cmd = "gets $key\r\n";
 448                 if ( !$this->_fwrite( $sock, $cmd ) ) {
 449                         wfProfileOut( __METHOD__ );
 450                         return false;
 451                 }
 452
 453                 $val = array();
 454                 $this->_load_items( $sock, $val, $casToken );
 455
 456                 if ( $this->_debug ) {
 457                         foreach ( $val as $k => $v ) {
 458                                 $this->_debugprint( sprintf( "MemCache: sock %s got %s\n", serialize( $sock ), $k ) );
 459                         }
 460                 }
 461
 462                 $value = false;
 463                 if ( isset( $val[$key] ) ) {
 464                         $value = $val[$key];
 465                 }
 466                 wfProfileOut( __METHOD__ );
 467                 return $value;
 468         }
 469
 470         // }}}
 471         // {{{ get_multi()
 472
 473         /**
 474          * Get multiple keys from the server(s)
 475          *
 476          * @param array $keys Keys to retrieve
 477          *
 478          * @return array
 479          */
 480         public function get_multi( $keys ) {
 481                 if ( !$this->_active ) {
 482                         return false;
 483                 }
 484
 485                 if ( isset( $this->stats['get_multi'] ) ) {
 486                         $this->stats['get_multi']++;
 487                 } else {
 488                         $this->stats['get_multi'] = 1;
 489                 }
 490                 $sock_keys = array();
 491                 $socks = array();
 492                 foreach ( $keys as $key ) {
 493                         $sock = $this->get_sock( $key );
 494                         if ( !is_resource( $sock ) ) {
 495                                 continue;
 496                         }
 497                         $key = is_array( $key ) ? $key[1] : $key;
 498                         if ( !isset( $sock_keys[$sock] ) ) {
 499                                 $sock_keys[intval( $sock )] = array();
 500                                 $socks[] = $sock;
 501                         }
 502                         $sock_keys[intval( $sock )][] = $key;
 503                 }
 504
 505                 $gather = array();
 506                 // Send out the requests
 507                 foreach ( $socks as $sock ) {
 508                         $cmd = 'gets';
 509                         foreach ( $sock_keys[intval( $sock )] as $key ) {
 510                                 $cmd .= ' ' . $key;
 511                         }
 512                         $cmd .= "\r\n";
 513
 514                         if ( $this->_fwrite( $sock, $cmd ) ) {
 515                                 $gather[] = $sock;
 516                         }
 517                 }
 518
 519                 // Parse responses
 520                 $val = array();
 521                 foreach ( $gather as $sock ) {
 522                         $this->_load_items( $sock, $val, $casToken );
 523                 }
 524
 525                 if ( $this->_debug ) {
 526                         foreach ( $val as $k => $v ) {
 527                                 $this->_debugprint( sprintf( "MemCache: got %s\n", $k ) );
 528                         }
 529                 }
 530
 531                 return $val;
 532         }
 533
 534         // }}}
 535         // {{{ incr()
 536
 537         /**
 538          * Increments $key (optionally) by $amt
 539          *
 540          * @param string $key Key to increment
 541          * @param int $amt (optional) amount to increment
 542          *
 543          * @return int|null Null if the key does not exist yet (this does NOT
 544          * create new mappings if the key does not exist). If the key does
 545          * exist, this returns the new value for that key.
 546          */
 547         public function incr( $key, $amt = 1 ) {
 548                 return $this->_incrdecr( 'incr', $key, $amt );
 549         }
 550
 551         // }}}
 552         // {{{ replace()
 553
 554         /**
 555          * Overwrites an existing value for key; only works if key is already set
 556          *
 557          * @param string $key Key to set value as
 558          * @param mixed $value Value to store
 559          * @param int $exp (optional) Expiration time. This can be a number of seconds
 560          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 561          * longer must be the timestamp of the time at which the mapping should expire. It
 562          * is safe to use timestamps in all cases, regardless of exipration
 563          * eg: strtotime("+3 hour")
 564          *
 565          * @return bool
 566          */
 567         public function replace( $key, $value, $exp = 0 ) {
 568                 return $this->_set( 'replace', $key, $value, $exp );
 569         }
 570
 571         // }}}
 572         // {{{ run_command()
 573
 574         /**
 575          * Passes through $cmd to the memcache server connected by $sock; returns
 576          * output as an array (null array if no output)
 577          *
 578          * @param Resource $sock Socket to send command on
 579          * @param string $cmd Command to run
 580          *
 581          * @return array Output array
 582          */
 583         public function run_command( $sock, $cmd ) {
 584                 if ( !is_resource( $sock ) ) {
 585                         return array();
 586                 }
 587
 588                 if ( !$this->_fwrite( $sock, $cmd ) ) {
 589                         return array();
 590                 }
 591
 592                 $ret = array();
 593                 while ( true ) {
 594                         $res = $this->_fgets( $sock );
 595                         $ret[] = $res;
 596                         if ( preg_match( '/^END/', $res ) ) {
 597                                 break;
 598                         }
 599                         if ( strlen( $res ) == 0 ) {
 600                                 break;
 601                         }
 602                 }
 603                 return $ret;
 604         }
 605
 606         // }}}
 607         // {{{ set()
 608
 609         /**
 610          * Unconditionally sets a key to a given value in the memcache.  Returns true
 611          * if set successfully.
 612          *
 613          * @param string $key Key to set value as
 614          * @param mixed $value Value to set
 615          * @param int $exp (optional) Expiration time. This can be a number of seconds
 616          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 617          * longer must be the timestamp of the time at which the mapping should expire. It
 618          * is safe to use timestamps in all cases, regardless of exipration
 619          * eg: strtotime("+3 hour")
 620          *
 621          * @return bool True on success
 622          */
 623         public function set( $key, $value, $exp = 0 ) {
 624                 return $this->_set( 'set', $key, $value, $exp );
 625         }
 626
 627         // }}}
 628         // {{{ cas()
 629
 630         /**
 631          * Sets a key to a given value in the memcache if the current value still corresponds
 632          * to a known, given value.  Returns true if set successfully.
 633          *
 634          * @param float $casToken Current known value
 635          * @param string $key Key to set value as
 636          * @param mixed $value Value to set
 637          * @param int $exp (optional) Expiration time. This can be a number of seconds
 638          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
 639          * longer must be the timestamp of the time at which the mapping should expire. It
 640          * is safe to use timestamps in all cases, regardless of exipration
 641          * eg: strtotime("+3 hour")
 642          *
 643          * @return bool True on success
 644          */
 645         public function cas( $casToken, $key, $value, $exp = 0 ) {
 646                 return $this->_set( 'cas', $key, $value, $exp, $casToken );
 647         }
 648
 649         // }}}
 650         // {{{ set_compress_threshold()
 651
 652         /**
 653          * Sets the compression threshold
 654          *
 655          * @param int $thresh Threshold to compress if larger than
 656          */
 657         public function set_compress_threshold( $thresh ) {
 658                 $this->_compress_threshold = $thresh;
 659         }
 660
 661         // }}}
 662         // {{{ set_debug()
 663
 664         /**
 665          * Sets the debug flag
 666          *
 667          * @param bool $dbg True for debugging, false otherwise
 668          *
 669          * @see MWMemcached::__construct
 670          */
 671         public function set_debug( $dbg ) {
 672                 $this->_debug = $dbg;
 673         }
 674
 675         // }}}
 676         // {{{ set_servers()
 677
 678         /**
 679          * Sets the server list to distribute key gets and puts between
 680          *
 681          * @param array $list Array of servers to connect to
 682          *
 683          * @see MWMemcached::__construct()
 684          */
 685         public function set_servers( $list ) {
 686                 $this->_servers = $list;
 687                 $this->_active = count( $list );
 688                 $this->_buckets = null;
 689                 $this->_bucketcount = 0;
 690
 691                 $this->_single_sock = null;
 692                 if ( $this->_active == 1 ) {
 693                         $this->_single_sock = $this->_servers[0];
 694                 }
 695         }
 696
 697         /**
 698          * Sets the timeout for new connections
 699          *
 700          * @param int $seconds Number of seconds
 701          * @param int $microseconds Number of microseconds
 702          */
 703         public function set_timeout( $seconds, $microseconds ) {
 704                 $this->_timeout_seconds = $seconds;
 705                 $this->_timeout_microseconds = $microseconds;
 706         }
 707
 708         // }}}
 709         // }}}
 710         // {{{ private methods
 711         // {{{ _close_sock()
 712
 713         /**
 714          * Close the specified socket
 715          *
 716          * @param string $sock Socket to close
 717          *
 718          * @access private
 719          */
 720         function _close_sock( $sock ) {
 721                 $host = array_search( $sock, $this->_cache_sock );
 722                 fclose( $this->_cache_sock[$host] );
 723                 unset( $this->_cache_sock[$host] );
 724         }
 725
 726         // }}}
 727         // {{{ _connect_sock()
 728
 729         /**
 730          * Connects $sock to $host, timing out after $timeout
 731          *
 732          * @param int $sock Socket to connect
 733          * @param string $host Host:IP to connect to
 734          *
 735          * @return bool
 736          * @access private
 737          */
 738         function _connect_sock( &$sock, $host ) {
 739                 list( $ip, $port ) = preg_split( '/:(?=\d)/', $host );
 740                 $sock = false;
 741                 $timeout = $this->_connect_timeout;
 742                 $errno = $errstr = null;
 743                 for ( $i = 0; !$sock && $i < $this->_connect_attempts; $i++ ) {
 744                         wfSuppressWarnings();
 745                         if ( $this->_persistent == 1 ) {
 746                                 $sock = pfsockopen( $ip, $port, $errno, $errstr, $timeout );
 747                         } else {
 748                                 $sock = fsockopen( $ip, $port, $errno, $errstr, $timeout );
 749                         }
 750                         wfRestoreWarnings();
 751                 }
 752                 if ( !$sock ) {
 753                         $this->_error_log( "Error connecting to $host: $errstr\n" );
 754                         $this->_dead_host( $host );
 755                         return false;
 756                 }
 757
 758                 // Initialise timeout
 759                 stream_set_timeout( $sock, $this->_timeout_seconds, $this->_timeout_microseconds );
 760
 761                 // If the connection was persistent, flush the read buffer in case there
 762                 // was a previous incomplete request on this connection
 763                 if ( $this->_persistent ) {
 764                         $this->_flush_read_buffer( $sock );
 765                 }
 766                 return true;
 767         }
 768
 769         // }}}
 770         // {{{ _dead_sock()
 771
 772         /**
 773          * Marks a host as dead until 30-40 seconds in the future
 774          *
 775          * @param string $sock Socket to mark as dead
 776          *
 777          * @access private
 778          */
 779         function _dead_sock( $sock ) {
 780                 $host = array_search( $sock, $this->_cache_sock );
 781                 $this->_dead_host( $host );
 782         }
 783
 784         /**
 785          * @param string $host
 786          */
 787         function _dead_host( $host ) {
 788                 $parts = explode( ':', $host );
 789                 $ip = $parts[0];
 790                 $this->_host_dead[$ip] = time() + 30 + intval( rand( 0, 10 ) );
 791                 $this->_host_dead[$host] = $this->_host_dead[$ip];
 792                 unset( $this->_cache_sock[$host] );
 793         }
 794
 795         // }}}
 796         // {{{ get_sock()
 797
 798         /**
 799          * get_sock
 800          *
 801          * @param string $key Key to retrieve value for;
 802          *
 803          * @return Resource|bool Resource on success, false on failure
 804          * @access private
 805          */
 806         function get_sock( $key ) {
 807                 if ( !$this->_active ) {
 808                         return false;
 809                 }
 810
 811                 if ( $this->_single_sock !== null ) {
 812                         return $this->sock_to_host( $this->_single_sock );
 813                 }
 814
 815                 $hv = is_array( $key ) ? intval( $key[0] ) : $this->_hashfunc( $key );
 816                 if ( $this->_buckets === null ) {
 817                         $bu = array();
 818                         foreach ( $this->_servers as $v ) {
 819                                 if ( is_array( $v ) ) {
 820                                         for ( $i = 0; $i < $v[1]; $i++ ) {
 821                                                 $bu[] = $v[0];
 822                                         }
 823                                 } else {
 824                                         $bu[] = $v;
 825                                 }
 826                         }
 827                         $this->_buckets = $bu;
 828                         $this->_bucketcount = count( $bu );
 829                 }
 830
 831                 $realkey = is_array( $key ) ? $key[1] : $key;
 832                 for ( $tries = 0; $tries < 20; $tries++ ) {
 833                         $host = $this->_buckets[$hv % $this->_bucketcount];
 834                         $sock = $this->sock_to_host( $host );
 835                         if ( is_resource( $sock ) ) {
 836                                 return $sock;
 837                         }
 838                         $hv = $this->_hashfunc( $hv . $realkey );
 839                 }
 840
 841                 return false;
 842         }
 843
 844         // }}}
 845         // {{{ _hashfunc()
 846
 847         /**
 848          * Creates a hash integer based on the $key
 849          *
 850          * @param string $key Key to hash
 851          *
 852          * @return int Hash value
 853          * @access private
 854          */
 855         function _hashfunc( $key ) {
 856                 # Hash function must be in [0,0x7ffffff]
 857                 # We take the first 31 bits of the MD5 hash, which unlike the hash
 858                 # function used in a previous version of this client, works
 859                 return hexdec( substr( md5( $key ), 0, 8 ) ) & 0x7fffffff;
 860         }
 861
 862         // }}}
 863         // {{{ _incrdecr()
 864
 865         /**
 866          * Perform increment/decriment on $key
 867          *
 868          * @param string $cmd Command to perform
 869          * @param string|array $key Key to perform it on
 870          * @param int $amt Amount to adjust
 871          *
 872          * @return int New value of $key
 873          * @access private
 874          */
 875         function _incrdecr( $cmd, $key, $amt = 1 ) {
 876                 if ( !$this->_active ) {
 877                         return null;
 878                 }
 879
 880                 $sock = $this->get_sock( $key );
 881                 if ( !is_resource( $sock ) ) {
 882                         return null;
 883                 }
 884
 885                 $key = is_array( $key ) ? $key[1] : $key;
 886                 if ( isset( $this->stats[$cmd] ) ) {
 887                         $this->stats[$cmd]++;
 888                 } else {
 889                         $this->stats[$cmd] = 1;
 890                 }
 891                 if ( !$this->_fwrite( $sock, "$cmd $key $amt\r\n" ) ) {
 892                         return null;
 893                 }
 894
 895                 $line = $this->_fgets( $sock );
 896                 $match = array();
 897                 if ( !preg_match( '/^(\d+)/', $line, $match ) ) {
 898                         return null;
 899                 }
 900                 return $match[1];
 901         }
 902
 903         // }}}
 904         // {{{ _load_items()
 905
 906         /**
 907          * Load items into $ret from $sock
 908          *
 909          * @param Resource $sock Socket to read from
 910          * @param array $ret returned values
 911          * @param float $casToken [optional]
 912          * @return bool True for success, false for failure
 913          *
 914          * @access private
 915          */
 916         function _load_items( $sock, &$ret, &$casToken = null ) {
 917                 $results = array();
 918
 919                 while ( 1 ) {
 920                         $decl = $this->_fgets( $sock );
 921
 922                         if ( $decl === false ) {
 923                                 /*
 924                                  * If nothing can be read, something is wrong because we know exactly when
 925                                  * to stop reading (right after "END") and we return right after that.
 926                                  */
 927                                 return false;
 928                         } elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+) (\d+)$/', $decl, $match ) ) {
 929                                 /*
 930                                  * Read all data returned. This can be either one or multiple values.
 931                                  * Save all that data (in an array) to be processed later: we'll first
 932                                  * want to continue reading until "END" before doing anything else,
 933                                  * to make sure that we don't leave our client in a state where it's
 934                                  * output is not yet fully read.
 935                                  */
 936                                 $results[] = array(
 937                                         $match[1], // rkey
 938                                         $match[2], // flags
 939                                         $match[3], // len
 940                                         $match[4], // casToken
 941                                         $this->_fread( $sock, $match[3] + 2 ), // data
 942                                 );
 943                         } elseif ( $decl == "END" ) {
 944                                 if ( count( $results ) == 0 ) {
 945                                         return false;
 946                                 }
 947
 948                                 /**
 949                                  * All data has been read, time to process the data and build
 950                                  * meaningful return values.
 951                                  */
 952                                 foreach ( $results as $vars ) {
 953                                         list( $rkey, $flags, $len, $casToken, $data ) = $vars;
 954
 955                                         if ( $data === false || substr( $data, -2 ) !== "\r\n" ) {
 956                                                 $this->_handle_error( $sock,
 957                                                         'line ending missing from data block from $1' );
 958                                                 return false;
 959                                         }
 960                                         $data = substr( $data, 0, -2 );
 961                                         $ret[$rkey] = $data;
 962
 963                                         if ( $this->_have_zlib && $flags & self::COMPRESSED ) {
 964                                                 $ret[$rkey] = gzuncompress( $ret[$rkey] );
 965                                         }
 966
 967                                         /*
 968                                          * This unserialize is the exact reason that we only want to
 969                                          * process data after having read until "END" (instead of doing
 970                                          * this right away): "unserialize" can trigger outside code:
 971                                          * in the event that $ret[$rkey] is a serialized object,
 972                                          * unserializing it will trigger __wakeup() if present. If that
 973                                          * function attempted to read from memcached (while we did not
 974                                          * yet read "END"), these 2 calls would collide.
 975                                          */
 976                                         if ( $flags & self::SERIALIZED ) {
 977                                                 $ret[$rkey] = unserialize( $ret[$rkey] );
 978                                         }
 979                                 }
 980
 981                                 return true;
 982                         } else {
 983                                 $this->_handle_error( $sock, 'Error parsing response from $1' );
 984                                 return false;
 985                         }
 986                 }
 987         }
 988
 989         // }}}
 990         // {{{ _set()
 991
 992         /**
 993          * Performs the requested storage operation to the memcache server
 994          *
 995          * @param string $cmd Command to perform
 996          * @param string $key Key to act on
 997          * @param mixed $val What we need to store
 998          * @param int $exp (optional) Expiration time. This can be a number of seconds
 999          * to cache for (up to 30 days inclusive).  Any timespans of 30 days + 1 second or
1000          * longer must be the timestamp of the time at which the mapping should expire. It
1001          * is safe to use timestamps in all cases, regardless of exipration
1002          * eg: strtotime("+3 hour")
1003          * @param float $casToken [optional]
1004          *
1005          * @return bool
1006          * @access private
1007          */
1008         function _set( $cmd, $key, $val, $exp, $casToken = null ) {
1009                 if ( !$this->_active ) {
1010                         return false;
1011                 }
1012
1013                 $sock = $this->get_sock( $key );
1014                 if ( !is_resource( $sock ) ) {
1015                         return false;
1016                 }
1017
1018                 if ( isset( $this->stats[$cmd] ) ) {
1019                         $this->stats[$cmd]++;
1020                 } else {
1021                         $this->stats[$cmd] = 1;
1022                 }
1023
1024                 $flags = 0;
1025
1026                 if ( !is_scalar( $val ) ) {
1027                         $val = serialize( $val );
1028                         $flags |= self::SERIALIZED;
1029                         if ( $this->_debug ) {
1030                                 $this->_debugprint( sprintf( "client: serializing data as it is not scalar\n" ) );
1031                         }
1032                 }
1033
1034                 $len = strlen( $val );
1035
1036                 if ( $this->_have_zlib && $this->_compress_enable
1037                         && $this->_compress_threshold && $len >= $this->_compress_threshold
1038                 ) {
1039                         $c_val = gzcompress( $val, 9 );
1040                         $c_len = strlen( $c_val );
1041
1042                         if ( $c_len < $len * ( 1 - self::COMPRESSION_SAVINGS ) ) {
1043                                 if ( $this->_debug ) {
1044                                         $this->_debugprint( sprintf( "client: compressing data; was %d bytes is now %d bytes\n", $len, $c_len ) );
1045                                 }
1046                                 $val = $c_val;
1047                                 $len = $c_len;
1048                                 $flags |= self::COMPRESSED;
1049                         }
1050                 }
1051
1052                 $command = "$cmd $key $flags $exp $len";
1053                 if ( $casToken ) {
1054                         $command .= " $casToken";
1055                 }
1056
1057                 if ( !$this->_fwrite( $sock, "$command\r\n$val\r\n" ) ) {
1058                         return false;
1059                 }
1060
1061                 $line = $this->_fgets( $sock );
1062
1063                 if ( $this->_debug ) {
1064                         $this->_debugprint( sprintf( "%s %s (%s)\n", $cmd, $key, $line ) );
1065                 }
1066                 if ( $line == "STORED" ) {
1067                         return true;
1068                 }
1069                 return false;
1070         }
1071
1072         // }}}
1073         // {{{ sock_to_host()
1074
1075         /**
1076          * Returns the socket for the host
1077          *
1078          * @param string $host Host:IP to get socket for
1079          *
1080          * @return Resource|bool IO Stream or false
1081          * @access private
1082          */
1083         function sock_to_host( $host ) {
1084                 if ( isset( $this->_cache_sock[$host] ) ) {
1085                         return $this->_cache_sock[$host];
1086                 }
1087
1088                 $sock = null;
1089                 $now = time();
1090                 list( $ip, /* $port */) = explode( ':', $host );
1091                 if ( isset( $this->_host_dead[$host] ) && $this->_host_dead[$host] > $now ||
1092                         isset( $this->_host_dead[$ip] ) && $this->_host_dead[$ip] > $now
1093                 ) {
1094                         return null;
1095                 }
1096
1097                 if ( !$this->_connect_sock( $sock, $host ) ) {
1098                         return null;
1099                 }
1100
1101                 // Do not buffer writes
1102                 stream_set_write_buffer( $sock, 0 );
1103
1104                 $this->_cache_sock[$host] = $sock;
1105
1106                 return $this->_cache_sock[$host];
1107         }
1108
1109         /**
1110          * @param string $text
1111          */
1112         function _debugprint( $text ) {
1113                 wfDebugLog( 'memcached', $text );
1114         }
1115
1116         /**
1117          * @param string $text
1118          */
1119         function _error_log( $text ) {
1120                 wfDebugLog( 'memcached-serious', "Memcached error: $text" );
1121         }
1122
1123         /**
1124          * Write to a stream. If there is an error, mark the socket dead.
1125          *
1126          * @param Resource $sock The socket
1127          * @param string $buf The string to write
1128          * @return bool True on success, false on failure
1129          */
1130         function _fwrite( $sock, $buf ) {
1131                 $bytesWritten = 0;
1132                 $bufSize = strlen( $buf );
1133                 while ( $bytesWritten < $bufSize ) {
1134                         $result = fwrite( $sock, $buf );
1135                         $data = stream_get_meta_data( $sock );
1136                         if ( $data['timed_out'] ) {
1137                                 $this->_handle_error( $sock, 'timeout writing to $1' );
1138                                 return false;
1139                         }
1140                         // Contrary to the documentation, fwrite() returns zero on error in PHP 5.3.
1141                         if ( $result === false || $result === 0 ) {
1142                                 $this->_handle_error( $sock, 'error writing to $1' );
1143                                 return false;
1144                         }
1145                         $bytesWritten += $result;
1146                 }
1147
1148                 return true;
1149         }
1150
1151         /**
1152          * Handle an I/O error. Mark the socket dead and log an error.
1153          *
1154          * @param Resource $sock
1155          * @param string $msg
1156          */
1157         function _handle_error( $sock, $msg ) {
1158                 $peer = stream_socket_get_name( $sock, true /** remote **/ );
1159                 if ( strval( $peer ) === '' ) {
1160                         $peer = array_search( $sock, $this->_cache_sock );
1161                         if ( $peer === false ) {
1162                                 $peer = '[unknown host]';
1163                         }
1164                 }
1165                 $msg = str_replace( '$1', $peer, $msg );
1166                 $this->_error_log( "$msg\n" );
1167                 $this->_dead_sock( $sock );
1168         }
1169
1170         /**
1171          * Read the specified number of bytes from a stream. If there is an error,
1172          * mark the socket dead.
1173          *
1174          * @param Resource $sock The socket
1175          * @param int $len The number of bytes to read
1176          * @return string|bool The string on success, false on failure.
1177          */
1178         function _fread( $sock, $len ) {
1179                 $buf = '';
1180                 while ( $len > 0 ) {
1181                         $result = fread( $sock, $len );
1182                         $data = stream_get_meta_data( $sock );
1183                         if ( $data['timed_out'] ) {
1184                                 $this->_handle_error( $sock, 'timeout reading from $1' );
1185                                 return false;
1186                         }
1187                         if ( $result === false ) {
1188                                 $this->_handle_error( $sock, 'error reading buffer from $1' );
1189                                 return false;
1190                         }
1191                         if ( $result === '' ) {
1192                                 // This will happen if the remote end of the socket is shut down
1193                                 $this->_handle_error( $sock, 'unexpected end of file reading from $1' );
1194                                 return false;
1195                         }
1196                         $len -= strlen( $result );
1197                         $buf .= $result;
1198                 }
1199                 return $buf;
1200         }
1201
1202         /**
1203          * Read a line from a stream. If there is an error, mark the socket dead.
1204          * The \r\n line ending is stripped from the response.
1205          *
1206          * @param Resource $sock The socket
1207          * @return string|bool The string on success, false on failure
1208          */
1209         function _fgets( $sock ) {
1210                 $result = fgets( $sock );
1211                 // fgets() may return a partial line if there is a select timeout after
1212                 // a successful recv(), so we have to check for a timeout even if we
1213                 // got a string response.
1214                 $data = stream_get_meta_data( $sock );
1215                 if ( $data['timed_out'] ) {
1216                         $this->_handle_error( $sock, 'timeout reading line from $1' );
1217                         return false;
1218                 }
1219                 if ( $result === false ) {
1220                         $this->_handle_error( $sock, 'error reading line from $1' );
1221                         return false;
1222                 }
1223                 if ( substr( $result, -2 ) === "\r\n" ) {
1224                         $result = substr( $result, 0, -2 );
1225                 } elseif ( substr( $result, -1 ) === "\n" ) {
1226                         $result = substr( $result, 0, -1 );
1227                 } else {
1228                         $this->_handle_error( $sock, 'line ending missing in response from $1' );
1229                         return false;
1230                 }
1231                 return $result;
1232         }
1233
1234         /**
1235          * Flush the read buffer of a stream
1236          * @param Resource $f
1237          */
1238         function _flush_read_buffer( $f ) {
1239                 if ( !is_resource( $f ) ) {
1240                         return;
1241                 }
1242                 $r = array( $f );
1243                 $w = null;
1244                 $e = null;
1245                 $n = stream_select( $r, $w, $e, 0, 0 );
1246                 while ( $n == 1 && !feof( $f ) ) {
1247                         fread( $f, 1024 );
1248                         $r = array( $f );
1249                         $w = null;
1250                         $e = null;
1251                         $n = stream_select( $r, $w, $e, 0, 0 );
1252                 }
1253         }
1254
1255         // }}}
1256         // }}}
1257         // }}}
1258 }
1259
1260 // }}}
1261
1262 class MemCachedClientforWiki extends MWMemcached {
1263 }