includes/BagOStuff.php

   1 <?php
   2 /**
   3  * Classes to cache objects in PHP accelerators, SQL database or DBA files
   4  *
   5  * Copyright © 2003-2004 Brion Vibber <brion@pobox.com>
   6  * http://www.mediawiki.org/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  * http://www.gnu.org/copyleft/gpl.html
  22  *
  23  * @file
  24  * @ingroup Cache
  25  */
  26
  27 /**
  28  * @defgroup Cache Cache
  29  */
  30
  31 /**
  32  * interface is intended to be more or less compatible with
  33  * the PHP memcached client.
  34  *
  35  * backends for local hash array and SQL table included:
  36  * <code>
  37  *   $bag = new HashBagOStuff();
  38  *   $bag = new SqlBagOStuff(); # connect to db first
  39  * </code>
  40  *
  41  * @ingroup Cache
  42  */
  43 abstract class BagOStuff {
  44         var $debugMode = false;
  45
  46         public function set_debug( $bool ) {
  47                 $this->debugMode = $bool;
  48         }
  49
  50         /* *** THE GUTS OF THE OPERATION *** */
  51         /* Override these with functional things in subclasses */
  52
  53         /**
  54          * Get an item with the given key. Returns false if it does not exist.
  55          * @param $key string
  56          */
  57         abstract public function get( $key );
  58
  59         /**
  60          * Set an item.
  61          * @param $key string
  62          * @param $value mixed
  63          * @param $exptime int Either an interval in seconds or a unix timestamp for expiry
  64          */
  65         abstract public function set( $key, $value, $exptime = 0 );
  66
  67         /*
  68          * Delete an item.
  69          * @param $key string
  70          * @param $time int Amount of time to delay the operation (mostly memcached-specific)
  71          */
  72         abstract public function delete( $key, $time = 0 );
  73
  74         public function lock( $key, $timeout = 0 ) {
  75                 /* stub */
  76                 return true;
  77         }
  78
  79         public function unlock( $key ) {
  80                 /* stub */
  81                 return true;
  82         }
  83
  84         public function keys() {
  85                 /* stub */
  86                 return array();
  87         }
  88
  89         /* *** Emulated functions *** */
  90         /* Better performance can likely be got with custom written versions */
  91         public function get_multi( $keys ) {
  92                 $out = array();
  93
  94                 foreach ( $keys as $key ) {
  95                         $out[$key] = $this->get( $key );
  96                 }
  97
  98                 return $out;
  99         }
 100
 101         public function set_multi( $hash, $exptime = 0 ) {
 102                 foreach ( $hash as $key => $value ) {
 103                         $this->set( $key, $value, $exptime );
 104                 }
 105         }
 106
 107         public function add( $key, $value, $exptime = 0 ) {
 108                 if ( !$this->get( $key ) ) {
 109                         $this->set( $key, $value, $exptime );
 110
 111                         return true;
 112                 }
 113         }
 114
 115         public function add_multi( $hash, $exptime = 0 ) {
 116                 foreach ( $hash as $key => $value ) {
 117                         $this->add( $key, $value, $exptime );
 118                 }
 119         }
 120
 121         public function delete_multi( $keys, $time = 0 ) {
 122                 foreach ( $keys as $key ) {
 123                         $this->delete( $key, $time );
 124                 }
 125         }
 126
 127         public function replace( $key, $value, $exptime = 0 ) {
 128                 if ( $this->get( $key ) !== false ) {
 129                         $this->set( $key, $value, $exptime );
 130                 }
 131         }
 132
 133         public function incr( $key, $value = 1 ) {
 134                 if ( !$this->lock( $key ) ) {
 135                         return false;
 136                 }
 137
 138                 $value = intval( $value );
 139
 140                 $n = false;
 141                 if ( ( $n = $this->get( $key ) ) !== false ) {
 142                         $n += $value;
 143                         $this->set( $key, $n ); // exptime?
 144                 }
 145                 $this->unlock( $key );
 146
 147                 return $n;
 148         }
 149
 150         public function decr( $key, $value = 1 ) {
 151                 return $this->incr( $key, - $value );
 152         }
 153
 154         public function debug( $text ) {
 155                 if ( $this->debugMode ) {
 156                         wfDebug( "BagOStuff debug: $text\n" );
 157                 }
 158         }
 159
 160         /**
 161          * Convert an optionally relative time to an absolute time
 162          */
 163         protected function convertExpiry( $exptime ) {
 164                 if ( ( $exptime != 0 ) && ( $exptime < 86400 * 3650 /* 10 years */ ) ) {
 165                         return time() + $exptime;
 166                 } else {
 167                         return $exptime;
 168                 }
 169         }
 170 }
 171
 172 /**
 173  * Functional versions!
 174  * This is a test of the interface, mainly. It stores things in an associative
 175  * array, which is not going to persist between program runs.
 176  *
 177  * @ingroup Cache
 178  */
 179 class HashBagOStuff extends BagOStuff {
 180         var $bag;
 181
 182         function __construct() {
 183                 $this->bag = array();
 184         }
 185
 186         protected function expire( $key ) {
 187                 $et = $this->bag[$key][1];
 188
 189                 if ( ( $et == 0 ) || ( $et > time() ) ) {
 190                         return false;
 191                 }
 192
 193                 $this->delete( $key );
 194
 195                 return true;
 196         }
 197
 198         function get( $key ) {
 199                 if ( !isset( $this->bag[$key] ) ) {
 200                         return false;
 201                 }
 202
 203                 if ( $this->expire( $key ) ) {
 204                         return false;
 205                 }
 206
 207                 return $this->bag[$key][0];
 208         }
 209
 210         function set( $key, $value, $exptime = 0 ) {
 211                 $this->bag[$key] = array( $value, $this->convertExpiry( $exptime ) );
 212         }
 213
 214         function delete( $key, $time = 0 ) {
 215                 if ( !isset( $this->bag[$key] ) ) {
 216                         return false;
 217                 }
 218
 219                 unset( $this->bag[$key] );
 220
 221                 return true;
 222         }
 223
 224         function keys() {
 225                 return array_keys( $this->bag );
 226         }
 227 }
 228
 229 /**
 230  * Class to store objects in the database
 231  *
 232  * @ingroup Cache
 233  */
 234 class SqlBagOStuff extends BagOStuff {
 235         var $lb, $db;
 236         var $lastExpireAll = 0;
 237
 238         protected function getDB() {
 239                 global $wgDBtype;
 240
 241                 if ( !isset( $this->db ) ) {
 242                         /* We must keep a separate connection to MySQL in order to avoid deadlocks
 243                          * However, SQLite has an opposite behaviour.
 244                          * @todo Investigate behaviour for other databases
 245                          */
 246                         if ( $wgDBtype == 'sqlite' ) {
 247                                 $this->db = wfGetDB( DB_MASTER );
 248                         } else {
 249                                 $this->lb = wfGetLBFactory()->newMainLB();
 250                                 $this->db = $this->lb->getConnection( DB_MASTER );
 251                                 $this->db->clearFlag( DBO_TRX );
 252                         }
 253                 }
 254
 255                 return $this->db;
 256         }
 257
 258         public function get( $key ) {
 259                 # expire old entries if any
 260                 $this->garbageCollect();
 261                 $db = $this->getDB();
 262                 $row = $db->selectRow( 'objectcache', array( 'value', 'exptime' ),
 263                         array( 'keyname' => $key ), __METHOD__ );
 264
 265                 if ( !$row ) {
 266                         $this->debug( 'get: no matching rows' );
 267                         return false;
 268                 }
 269
 270                 $this->debug( "get: retrieved data; expiry time is " . $row->exptime );
 271
 272                 if ( $this->isExpired( $row->exptime ) ) {
 273                         $this->debug( "get: key has expired, deleting" );
 274                         try {
 275                                 $db->begin();
 276                                 # Put the expiry time in the WHERE condition to avoid deleting a
 277                                 # newly-inserted value
 278                                 $db->delete( 'objectcache',
 279                                         array(
 280                                                 'keyname' => $key,
 281                                                 'exptime' => $row->exptime
 282                                         ), __METHOD__ );
 283                                 $db->commit();
 284                         } catch ( DBQueryError $e ) {
 285                                 $this->handleWriteError( $e );
 286                         }
 287
 288                         return false;
 289                 }
 290
 291                 return $this->unserialize( $db->decodeBlob( $row->value ) );
 292         }
 293
 294         public function set( $key, $value, $exptime = 0 ) {
 295                 $db = $this->getDB();
 296                 $exptime = intval( $exptime );
 297
 298                 if ( $exptime < 0 ) {
 299                         $exptime = 0;
 300                 }
 301
 302                 if ( $exptime == 0 ) {
 303                         $encExpiry = $this->getMaxDateTime();
 304                 } else {
 305                         if ( $exptime < 3.16e8 ) { # ~10 years
 306                                 $exptime += time();
 307                         }
 308
 309                         $encExpiry = $db->timestamp( $exptime );
 310                 }
 311                 try {
 312                         $db->begin();
 313                         // (bug 24425) use a replace if the db supports it instead of
 314                         // delete/insert to avoid clashes with conflicting keynames
 315                         $db->replace( 'objectcache', array( 'keyname' ),
 316                                 array(
 317                                         'keyname' => $key,
 318                                         'value' => $db->encodeBlob( $this->serialize( $value ) ),
 319                                         'exptime' => $encExpiry
 320                                 ), __METHOD__ );
 321                         $db->commit();
 322                 } catch ( DBQueryError $e ) {
 323                         $this->handleWriteError( $e );
 324
 325                         return false;
 326                 }
 327
 328                 return true;
 329         }
 330
 331         public function delete( $key, $time = 0 ) {
 332                 $db = $this->getDB();
 333
 334                 try {
 335                         $db->begin();
 336                         $db->delete( 'objectcache', array( 'keyname' => $key ), __METHOD__ );
 337                         $db->commit();
 338                 } catch ( DBQueryError $e ) {
 339                         $this->handleWriteError( $e );
 340
 341                         return false;
 342                 }
 343
 344                 return true;
 345         }
 346
 347         public function incr( $key, $step = 1 ) {
 348                 $db = $this->getDB();
 349                 $step = intval( $step );
 350
 351                 try {
 352                         $db->begin();
 353                         $row = $db->selectRow( 'objectcache', array( 'value', 'exptime' ),
 354                                 array( 'keyname' => $key ), __METHOD__, array( 'FOR UPDATE' ) );
 355                         if ( $row === false ) {
 356                                 // Missing
 357                                 $db->commit();
 358
 359                                 return false;
 360                         }
 361                         $db->delete( 'objectcache', array( 'keyname' => $key ), __METHOD__ );
 362                         if ( $this->isExpired( $row->exptime ) ) {
 363                                 // Expired, do not reinsert
 364                                 $db->commit();
 365
 366                                 return false;
 367                         }
 368
 369                         $oldValue = intval( $this->unserialize( $db->decodeBlob( $row->value ) ) );
 370                         $newValue = $oldValue + $step;
 371                         $db->insert( 'objectcache',
 372                                 array(
 373                                         'keyname' => $key,
 374                                         'value' => $db->encodeBlob( $this->serialize( $newValue ) ),
 375                                         'exptime' => $row->exptime
 376                                 ), __METHOD__ );
 377                         $db->commit();
 378                 } catch ( DBQueryError $e ) {
 379                         $this->handleWriteError( $e );
 380
 381                         return false;
 382                 }
 383
 384                 return $newValue;
 385         }
 386
 387         public function keys() {
 388                 $db = $this->getDB();
 389                 $res = $db->select( 'objectcache', array( 'keyname' ), false, __METHOD__ );
 390                 $result = array();
 391
 392                 foreach ( $res as $row ) {
 393                         $result[] = $row->keyname;
 394                 }
 395
 396                 return $result;
 397         }
 398
 399         protected function isExpired( $exptime ) {
 400                 return $exptime != $this->getMaxDateTime() && wfTimestamp( TS_UNIX, $exptime ) < time();
 401         }
 402
 403         protected function getMaxDateTime() {
 404                 if ( time() > 0x7fffffff ) {
 405                         return $this->getDB()->timestamp( 1 << 62 );
 406                 } else {
 407                         return $this->getDB()->timestamp( 0x7fffffff );
 408                 }
 409         }
 410
 411         protected function garbageCollect() {
 412                 /* Ignore 99% of requests */
 413                 if ( !mt_rand( 0, 100 ) ) {
 414                         $now = time();
 415                         /* Avoid repeating the delete within a few seconds */
 416                         if ( $now > ( $this->lastExpireAll + 1 ) ) {
 417                                 $this->lastExpireAll = $now;
 418                                 $this->expireAll();
 419                         }
 420                 }
 421         }
 422
 423         public function expireAll() {
 424                 $db = $this->getDB();
 425                 $now = $db->timestamp();
 426
 427                 try {
 428                         $db->begin();
 429                         $db->delete( 'objectcache', array( 'exptime < ' . $db->addQuotes( $now ) ), __METHOD__ );
 430                         $db->commit();
 431                 } catch ( DBQueryError $e ) {
 432                         $this->handleWriteError( $e );
 433                 }
 434         }
 435
 436         public function deleteAll() {
 437                 $db = $this->getDB();
 438
 439                 try {
 440                         $db->begin();
 441                         $db->delete( 'objectcache', '*', __METHOD__ );
 442                         $db->commit();
 443                 } catch ( DBQueryError $e ) {
 444                         $this->handleWriteError( $e );
 445                 }
 446         }
 447
 448         /**
 449          * Serialize an object and, if possible, compress the representation.
 450          * On typical message and page data, this can provide a 3X decrease
 451          * in storage requirements.
 452          *
 453          * @param $data mixed
 454          * @return string
 455          */
 456         protected function serialize( &$data ) {
 457                 $serial = serialize( $data );
 458
 459                 if ( function_exists( 'gzdeflate' ) ) {
 460                         return gzdeflate( $serial );
 461                 } else {
 462                         return $serial;
 463                 }
 464         }
 465
 466         /**
 467          * Unserialize and, if necessary, decompress an object.
 468          * @param $serial string
 469          * @return mixed
 470          */
 471         protected function unserialize( $serial ) {
 472                 if ( function_exists( 'gzinflate' ) ) {
 473                         $decomp = @gzinflate( $serial );
 474
 475                         if ( false !== $decomp ) {
 476                                 $serial = $decomp;
 477                         }
 478                 }
 479
 480                 $ret = unserialize( $serial );
 481
 482                 return $ret;
 483         }
 484
 485         /**
 486          * Handle a DBQueryError which occurred during a write operation.
 487          * Ignore errors which are due to a read-only database, rethrow others.
 488          */
 489         protected function handleWriteError( $exception ) {
 490                 $db = $this->getDB();
 491
 492                 if ( !$db->wasReadOnlyError() ) {
 493                         throw $exception;
 494                 }
 495
 496                 try {
 497                         $db->rollback();
 498                 } catch ( DBQueryError $e ) {
 499                 }
 500
 501                 wfDebug( __METHOD__ . ": ignoring query error\n" );
 502                 $db->ignoreErrors( false );
 503         }
 504 }
 505
 506 /**
 507  * Backwards compatibility alias
 508  */
 509 class MediaWikiBagOStuff extends SqlBagOStuff { }
 510
 511 /**
 512  * This is a wrapper for APC's shared memory functions
 513  *
 514  * @ingroup Cache
 515  */
 516 class APCBagOStuff extends BagOStuff {
 517         public function get( $key ) {
 518                 $val = apc_fetch( $key );
 519
 520                 if ( is_string( $val ) ) {
 521                         $val = unserialize( $val );
 522                 }
 523
 524                 return $val;
 525         }
 526
 527         public function set( $key, $value, $exptime = 0 ) {
 528                 apc_store( $key, serialize( $value ), $exptime );
 529
 530                 return true;
 531         }
 532
 533         public function delete( $key, $time = 0 ) {
 534                 apc_delete( $key );
 535
 536                 return true;
 537         }
 538
 539         public function keys() {
 540                 $info = apc_cache_info( 'user' );
 541                 $list = $info['cache_list'];
 542                 $keys = array();
 543
 544                 foreach ( $list as $entry ) {
 545                         $keys[] = $entry['info'];
 546                 }
 547
 548                 return $keys;
 549         }
 550 }
 551
 552 /**
 553  * This is a wrapper for eAccelerator's shared memory functions.
 554  *
 555  * This is basically identical to the deceased Turck MMCache version,
 556  * mostly because eAccelerator is based on Turck MMCache.
 557  *
 558  * @ingroup Cache
 559  */
 560 class eAccelBagOStuff extends BagOStuff {
 561         public function get( $key ) {
 562                 $val = eaccelerator_get( $key );
 563
 564                 if ( is_string( $val ) ) {
 565                         $val = unserialize( $val );
 566                 }
 567
 568                 return $val;
 569         }
 570
 571         public function set( $key, $value, $exptime = 0 ) {
 572                 eaccelerator_put( $key, serialize( $value ), $exptime );
 573
 574                 return true;
 575         }
 576
 577         public function delete( $key, $time = 0 ) {
 578                 eaccelerator_rm( $key );
 579
 580                 return true;
 581         }
 582
 583         public function lock( $key, $waitTimeout = 0 ) {
 584                 eaccelerator_lock( $key );
 585
 586                 return true;
 587         }
 588
 589         public function unlock( $key ) {
 590                 eaccelerator_unlock( $key );
 591
 592                 return true;
 593         }
 594 }
 595
 596 /**
 597  * Wrapper for XCache object caching functions; identical interface
 598  * to the APC wrapper
 599  *
 600  * @ingroup Cache
 601  */
 602 class XCacheBagOStuff extends BagOStuff {
 603         /**
 604          * Get a value from the XCache object cache
 605          *
 606          * @param $key String: cache key
 607          * @return mixed
 608          */
 609         public function get( $key ) {
 610                 $val = xcache_get( $key );
 611
 612                 if ( is_string( $val ) ) {
 613                         $val = unserialize( $val );
 614                 }
 615
 616                 return $val;
 617         }
 618
 619         /**
 620          * Store a value in the XCache object cache
 621          *
 622          * @param $key String: cache key
 623          * @param $value Mixed: object to store
 624          * @param $expire Int: expiration time
 625          * @return bool
 626          */
 627         public function set( $key, $value, $expire = 0 ) {
 628                 xcache_set( $key, serialize( $value ), $expire );
 629
 630                 return true;
 631         }
 632
 633         /**
 634          * Remove a value from the XCache object cache
 635          *
 636          * @param $key String: cache key
 637          * @param $time Int: not used in this implementation
 638          * @return bool
 639          */
 640         public function delete( $key, $time = 0 ) {
 641                 xcache_unset( $key );
 642
 643                 return true;
 644         }
 645 }
 646
 647 /**
 648  * Cache that uses DBA as a backend.
 649  * Slow due to the need to constantly open and close the file to avoid holding
 650  * writer locks. Intended for development use only,  as a memcached workalike
 651  * for systems that don't have it.
 652  *
 653  * @ingroup Cache
 654  */
 655 class DBABagOStuff extends BagOStuff {
 656         var $mHandler, $mFile, $mReader, $mWriter, $mDisabled;
 657
 658         public function __construct( $dir = false ) {
 659                 global $wgDBAhandler;
 660
 661                 if ( $dir === false ) {
 662                         global $wgTmpDirectory;
 663                         $dir = $wgTmpDirectory;
 664                 }
 665
 666                 $this->mFile = "$dir/mw-cache-" . wfWikiID();
 667                 $this->mFile .= '.db';
 668                 wfDebug( __CLASS__ . ": using cache file {$this->mFile}\n" );
 669                 $this->mHandler = $wgDBAhandler;
 670         }
 671
 672         /**
 673          * Encode value and expiry for storage
 674          */
 675         function encode( $value, $expiry ) {
 676                 # Convert to absolute time
 677                 $expiry = $this->convertExpiry( $expiry );
 678
 679                 return sprintf( '%010u', intval( $expiry ) ) . ' ' . serialize( $value );
 680         }
 681
 682         /**
 683          * @return list containing value first and expiry second
 684          */
 685         function decode( $blob ) {
 686                 if ( !is_string( $blob ) ) {
 687                         return array( null, 0 );
 688                 } else {
 689                         return array(
 690                                 unserialize( substr( $blob, 11 ) ),
 691                                 intval( substr( $blob, 0, 10 ) )
 692                         );
 693                 }
 694         }
 695
 696         function getReader() {
 697                 if ( file_exists( $this->mFile ) ) {
 698                         $handle = dba_open( $this->mFile, 'rl', $this->mHandler );
 699                 } else {
 700                         $handle = $this->getWriter();
 701                 }
 702
 703                 if ( !$handle ) {
 704                         wfDebug( "Unable to open DBA cache file {$this->mFile}\n" );
 705                 }
 706
 707                 return $handle;
 708         }
 709
 710         function getWriter() {
 711                 $handle = dba_open( $this->mFile, 'cl', $this->mHandler );
 712
 713                 if ( !$handle ) {
 714                         wfDebug( "Unable to open DBA cache file {$this->mFile}\n" );
 715                 }
 716
 717                 return $handle;
 718         }
 719
 720         function get( $key ) {
 721                 wfProfileIn( __METHOD__ );
 722                 wfDebug( __METHOD__ . "($key)\n" );
 723
 724                 $handle = $this->getReader();
 725                 if ( !$handle ) {
 726                         return null;
 727                 }
 728
 729                 $val = dba_fetch( $key, $handle );
 730                 list( $val, $expiry ) = $this->decode( $val );
 731
 732                 # Must close ASAP because locks are held
 733                 dba_close( $handle );
 734
 735                 if ( !is_null( $val ) && $expiry && $expiry < time() ) {
 736                         # Key is expired, delete it
 737                         $handle = $this->getWriter();
 738                         dba_delete( $key, $handle );
 739                         dba_close( $handle );
 740                         wfDebug( __METHOD__ . ": $key expired\n" );
 741                         $val = null;
 742                 }
 743
 744                 wfProfileOut( __METHOD__ );
 745                 return $val;
 746         }
 747
 748         function set( $key, $value, $exptime = 0 ) {
 749                 wfProfileIn( __METHOD__ );
 750                 wfDebug( __METHOD__ . "($key)\n" );
 751
 752                 $blob = $this->encode( $value, $exptime );
 753
 754                 $handle = $this->getWriter();
 755                 if ( !$handle ) {
 756                         return false;
 757                 }
 758
 759                 $ret = dba_replace( $key, $blob, $handle );
 760                 dba_close( $handle );
 761
 762                 wfProfileOut( __METHOD__ );
 763                 return $ret;
 764         }
 765
 766         function delete( $key, $time = 0 ) {
 767                 wfProfileIn( __METHOD__ );
 768                 wfDebug( __METHOD__ . "($key)\n" );
 769
 770                 $handle = $this->getWriter();
 771                 if ( !$handle ) {
 772                         return false;
 773                 }
 774
 775                 $ret = dba_delete( $key, $handle );
 776                 dba_close( $handle );
 777
 778                 wfProfileOut( __METHOD__ );
 779                 return $ret;
 780         }
 781
 782         function add( $key, $value, $exptime = 0 ) {
 783                 wfProfileIn( __METHOD__ );
 784
 785                 $blob = $this->encode( $value, $exptime );
 786
 787                 $handle = $this->getWriter();
 788
 789                 if ( !$handle ) {
 790                         return false;
 791                 }
 792
 793                 $ret = dba_insert( $key, $blob, $handle );
 794
 795                 # Insert failed, check to see if it failed due to an expired key
 796                 if ( !$ret ) {
 797                         list( $value, $expiry ) = $this->decode( dba_fetch( $key, $handle ) );
 798
 799                         if ( $expiry < time() ) {
 800                                 # Yes expired, delete and try again
 801                                 dba_delete( $key, $handle );
 802                                 $ret = dba_insert( $key, $blob, $handle );
 803                                 # This time if it failed then it will be handled by the caller like any other race
 804                         }
 805                 }
 806
 807                 dba_close( $handle );
 808
 809                 wfProfileOut( __METHOD__ );
 810                 return $ret;
 811         }
 812
 813         function keys() {
 814                 $reader = $this->getReader();
 815                 $k1 = dba_firstkey( $reader );
 816
 817                 if ( !$k1 ) {
 818                         return array();
 819                 }
 820
 821                 $result[] = $k1;
 822
 823                 while ( $key = dba_nextkey( $reader ) ) {
 824                         $result[] = $key;
 825                 }
 826
 827                 return $result;
 828         }
 829 }
 830
 831 /**
 832  * Wrapper for WinCache object caching functions; identical interface
 833  * to the APC wrapper
 834  *
 835  * @ingroup Cache
 836  */
 837 class WinCacheBagOStuff extends BagOStuff {
 838
 839         /**
 840          * Get a value from the WinCache object cache
 841          *
 842          * @param $key String: cache key
 843          * @return mixed
 844          */
 845         public function get( $key ) {
 846                 $val = wincache_ucache_get( $key );
 847
 848                 if ( is_string( $val ) ) {
 849                         $val = unserialize( $val );
 850                 }
 851
 852                 return $val;
 853         }
 854
 855         /**
 856          * Store a value in the WinCache object cache
 857          *
 858          * @param $key String: cache key
 859          * @param $value Mixed: object to store
 860          * @param $expire Int: expiration time
 861          * @return bool
 862          */
 863         public function set( $key, $value, $expire = 0 ) {
 864                 wincache_ucache_set( $key, serialize( $value ), $expire );
 865
 866                 return true;
 867         }
 868
 869         /**
 870          * Remove a value from the WinCache object cache
 871          *
 872          * @param $key String: cache key
 873          * @param $time Int: not used in this implementation
 874          * @return bool
 875          */
 876         public function delete( $key, $time = 0 ) {
 877                 wincache_ucache_delete( $key );
 878
 879                 return true;
 880         }
 881
 882         public function keys() {
 883                 $info = wincache_ucache_info();
 884                 $list = $info['ucache_entries'];
 885                 $keys = array();
 886
 887                 foreach ( $list as $entry ) {
 888                         $keys[] = $entry['key_name'];
 889                 }
 890
 891                 return $keys;
 892         }
 893 }