includes/BagOStuff.php

   1 <?php
   2 #
   3 # Copyright (C) 2003-2004 Brion Vibber <brion@pobox.com>
   4 # http://www.mediawiki.org/
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License along
  17 # with this program; if not, write to the Free Software Foundation, Inc.,
  18 # 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 # http://www.gnu.org/copyleft/gpl.html
  20 /**
  21  *
  22  * @package MediaWiki
  23  */
  24
  25 /**
  26  * Simple generic object store
  27  *
  28  * interface is intended to be more or less compatible with
  29  * the PHP memcached client.
  30  *
  31  * backends for local hash array and SQL table included:
  32  * $bag = new HashBagOStuff();
  33  * $bag = new MysqlBagOStuff($tablename); # connect to db first
  34  *
  35  * @package MediaWiki
  36  * @abstract
  37  */
  38 class BagOStuff {
  39         var $debugmode;
  40
  41         function BagOStuff() {
  42                 $this->set_debug( false );
  43         }
  44
  45         function set_debug($bool) {
  46                 $this->debugmode = $bool;
  47         }
  48
  49         /* *** THE GUTS OF THE OPERATION *** */
  50         /* Override these with functional things in subclasses */
  51
  52         function get($key) {
  53                 /* stub */
  54                 return false;
  55         }
  56
  57         function set($key, $value, $exptime=0) {
  58                 /* stub */
  59                 return false;
  60         }
  61
  62         function delete($key, $time=0) {
  63                 /* stub */
  64                 return false;
  65         }
  66
  67         function lock($key, $timeout = 0) {
  68                 /* stub */
  69                 return true;
  70         }
  71
  72         function unlock($key) {
  73                 /* stub */
  74                 return true;
  75         }
  76
  77         /* *** Emulated functions *** */
  78         /* Better performance can likely be got with custom written versions */
  79         function get_multi($keys) {
  80                 $out = array();
  81                 foreach($keys as $key)
  82                         $out[$key] = $this->get($key);
  83                 return $out;
  84         }
  85
  86         function set_multi($hash, $exptime=0) {
  87                 foreach($hash as $key => $value)
  88                         $this->set($key, $value, $exptime);
  89         }
  90
  91         function add($key, $value, $exptime=0) {
  92                 if( $this->get($key) == false ) {
  93                         $this->set($key, $value, $exptime);
  94                         return true;
  95                 }
  96         }
  97
  98         function add_multi($hash, $exptime=0) {
  99                 foreach($hash as $key => $value)
 100                         $this->add($key, $value, $exptime);
 101         }
 102
 103         function delete_multi($keys, $time=0) {
 104                 foreach($keys as $key)
 105                         $this->delete($key, $time);
 106         }
 107
 108         function replace($key, $value, $exptime=0) {
 109                 if( $this->get($key) !== false )
 110                         $this->set($key, $value, $exptime);
 111         }
 112
 113         function incr($key, $value=1) {
 114                 if ( !$this->lock($key) ) {
 115                         return false;
 116                 }
 117                 $value = intval($value);
 118                 if($value < 0) $value = 0;
 119
 120                 $n = false;
 121                 if( ($n = $this->get($key)) !== false ) {
 122                         $n += $value;
 123                         $this->set($key, $n); // exptime?
 124                 }
 125                 $this->unlock($key);
 126                 return $n;
 127         }
 128
 129         function decr($key, $value=1) {
 130                 if ( !$this->lock($key) ) {
 131                         return false;
 132                 }
 133                 $value = intval($value);
 134                 if($value < 0) $value = 0;
 135
 136                 $m = false;
 137                 if( ($n = $this->get($key)) !== false ) {
 138                         $m = $n - $value;
 139                         if($m < 0) $m = 0;
 140                         $this->set($key, $m); // exptime?
 141                 }
 142                 $this->unlock($key);
 143                 return $m;
 144         }
 145
 146         function _debug($text) {
 147                 if($this->debugmode)
 148                         wfDebug("BagOStuff debug: $text\n");
 149         }
 150 }
 151
 152
 153 /**
 154  * Functional versions!
 155  * @todo document
 156  * @package MediaWiki
 157  */
 158 class HashBagOStuff extends BagOStuff {
 159         /*
 160            This is a test of the interface, mainly. It stores
 161            things in an associative array, which is not going to
 162            persist between program runs.
 163         */
 164         var $bag;
 165
 166         function HashBagOStuff() {
 167                 $this->bag = array();
 168         }
 169
 170         function _expire($key) {
 171                 $et = $this->bag[$key][1];
 172                 if(($et == 0) || ($et > time()))
 173                         return false;
 174                 $this->delete($key);
 175                 return true;
 176         }
 177
 178         function get($key) {
 179                 if(!$this->bag[$key])
 180                         return false;
 181                 if($this->_expire($key))
 182                         return false;
 183                 return $this->bag[$key][0];
 184         }
 185
 186         function set($key,$value,$exptime=0) {
 187                 if(($exptime != 0) && ($exptime < 3600*24*30))
 188                         $exptime = time() + $exptime;
 189                 $this->bag[$key] = array( $value, $exptime );
 190         }
 191
 192         function delete($key,$time=0) {
 193                 if(!$this->bag[$key])
 194                         return false;
 195                 unset($this->bag[$key]);
 196                 return true;
 197         }
 198 }
 199
 200 /*
 201 CREATE TABLE objectcache (
 202   keyname char(255) binary not null default '',
 203   value mediumblob,
 204   exptime datetime,
 205   unique key (keyname),
 206   key (exptime)
 207 );
 208 */
 209
 210 /**
 211  * @todo document
 212  * @abstract
 213  * @package MediaWiki
 214  */
 215 class SqlBagOStuff extends BagOStuff {
 216         var $table;
 217         var $lastexpireall = 0;
 218
 219         function SqlBagOStuff($tablename = 'objectcache') {
 220                 $this->table = $tablename;
 221         }
 222
 223         function get($key) {
 224                 /* expire old entries if any */
 225                 $this->garbageCollect();
 226
 227                 $res = $this->_query(
 228                         "SELECT value,exptime FROM $0 WHERE keyname='$1'", $key);
 229                 if(!$res) {
 230                         $this->_debug("get: ** error: " . $this->_dberror($res) . " **");
 231                         return false;
 232                 }
 233                 if($row=$this->_fetchobject($res)) {
 234                         $this->_debug("get: retrieved data; exp time is " . $row->exptime);
 235                         return $this->_unserialize($row->value);
 236                 } else {
 237                         $this->_debug('get: no matching rows');
 238                 }
 239                 return false;
 240         }
 241
 242         function set($key,$value,$exptime=0) {
 243                 $exptime = intval($exptime);
 244                 if($exptime < 0) $exptime = 0;
 245                 if($exptime == 0) {
 246                         $exp = $this->_maxdatetime();
 247                 } else {
 248                         if($exptime < 3600*24*30)
 249                                 $exptime += time();
 250                         $exp = $this->_fromunixtime($exptime);
 251                 }
 252                 $this->delete( $key );
 253                 $this->_doinsert($this->getTableName(), array(
 254                                         'keyname' => $key,
 255                                         'value' => $this->_blobencode($this->_serialize($value)),
 256                                         'exptime' => $exp
 257                                 ));
 258                 return true; /* ? */
 259         }
 260
 261         function delete($key,$time=0) {
 262                 $this->_query(
 263                         "DELETE FROM $0 WHERE keyname='$1'", $key );
 264                 return true; /* ? */
 265         }
 266
 267         function getTableName() {
 268                 return $this->table;
 269         }
 270
 271         function _query($sql) {
 272                 $reps = func_get_args();
 273                 $reps[0] = $this->getTableName();
 274                 // ewwww
 275                 for($i=0;$i<count($reps);$i++) {
 276                         $sql = str_replace(
 277                                 '$' . $i,
 278                                 $i > 0 ? $this->_strencode($reps[$i]) : $reps[$i],
 279                                 $sql);
 280                 }
 281                 $res = $this->_doquery($sql);
 282                 if($res == false) {
 283                         $this->_debug('query failed: ' . $this->_dberror($res));
 284                 }
 285                 return $res;
 286         }
 287
 288         function _strencode($str) {
 289                 /* Protect strings in SQL */
 290                 return str_replace( "'", "''", $str );
 291         }
 292         function _blobencode($str) {
 293                 return $str;
 294         }
 295         function _doinsert($table, $vals) {
 296                 die( 'abstract function SqlBagOStuff::_doinsert() must be defined' );
 297         }
 298         function _doquery($sql) {
 299                 die( 'abstract function SqlBagOStuff::_doquery() must be defined' );
 300         }
 301
 302         function _fetchrow($res) {
 303                 die( 'abstract function SqlBagOStuff::_fetchrow() must be defined' );
 304         }
 305
 306         function _freeresult($result) {
 307                 /* stub */
 308                 return false;
 309         }
 310
 311         function _dberror($result) {
 312                 /* stub */
 313                 return 'unknown error';
 314         }
 315
 316         function _maxdatetime() {
 317                 die( 'abstract function SqlBagOStuff::_maxdatetime() must be defined' );
 318         }
 319
 320         function _fromunixtime() {
 321                 die( 'abstract function SqlBagOStuff::_fromunixtime() must be defined' );
 322         }
 323
 324         function garbageCollect() {
 325                 /* Ignore 99% of requests */
 326                 if ( !mt_rand( 0, 100 ) ) {
 327                         $nowtime = time();
 328                         /* Avoid repeating the delete within a few seconds */
 329                         if ( $nowtime > ($this->lastexpireall + 1) ) {
 330                                 $this->lastexpireall = $nowtime;
 331                                 $this->expireall();
 332                         }
 333                 }
 334         }
 335
 336         function expireall() {
 337                 /* Remove any items that have expired */
 338                 $now = $this->_fromunixtime( time() );
 339                 $this->_query( "DELETE FROM $0 WHERE exptime < '$now'" );
 340         }
 341
 342         function deleteall() {
 343                 /* Clear *all* items from cache table */
 344                 $this->_query( "DELETE FROM $0" );
 345         }
 346
 347         /**
 348          * Serialize an object and, if possible, compress the representation.
 349          * On typical message and page data, this can provide a 3X decrease
 350          * in storage requirements.
 351          *
 352          * @param mixed $data
 353          * @return string
 354          */
 355         function _serialize( &$data ) {
 356                 $serial = serialize( $data );
 357                 if( function_exists( 'gzdeflate' ) ) {
 358                         return gzdeflate( $serial );
 359                 } else {
 360                         return $serial;
 361                 }
 362         }
 363
 364         /**
 365          * Unserialize and, if necessary, decompress an object.
 366          * @param string $serial
 367          * @return mixed
 368          */
 369         function _unserialize( $serial ) {
 370                 if( function_exists( 'gzinflate' ) ) {
 371                         $decomp = @gzinflate( $serial );
 372                         if( false !== $decomp ) {
 373                                 $serial = $decomp;
 374                         }
 375                 }
 376                 $ret = unserialize( $serial );
 377                 return $ret;
 378         }
 379 }
 380
 381 /**
 382  * @todo document
 383  * @package MediaWiki
 384  */
 385 class MediaWikiBagOStuff extends SqlBagOStuff {
 386         var $tableInitialised = false;
 387
 388         function _doquery($sql) {
 389                 $dbw =& wfGetDB( DB_MASTER );
 390                 return $dbw->query($sql, 'MediaWikiBagOStuff::_doquery');
 391         }
 392         function _doinsert($t, $v) {
 393                 $dbw =& wfGetDB( DB_MASTER );
 394                 return $dbw->insert($t, $v, 'MediaWikiBagOStuff::_doinsert');
 395         }
 396         function _fetchobject($result) {
 397                 $dbw =& wfGetDB( DB_MASTER );
 398                 return $dbw->fetchObject($result);
 399         }
 400         function _freeresult($result) {
 401                 $dbw =& wfGetDB( DB_MASTER );
 402                 return $dbw->freeResult($result);
 403         }
 404         function _dberror($result) {
 405                 $dbw =& wfGetDB( DB_MASTER );
 406                 return $dbw->lastError();
 407         }
 408         function _maxdatetime() {
 409                 $dbw =& wfGetDB(DB_MASTER);
 410                 return $dbw->timestamp('9999-12-31 12:59:59');
 411         }
 412         function _fromunixtime($ts) {
 413                 $dbw =& wfGetDB(DB_MASTER);
 414                 return $dbw->timestamp($ts);
 415         }
 416         function _strencode($s) {
 417                 $dbw =& wfGetDB( DB_MASTER );
 418                 return $dbw->strencode($s);
 419         }
 420         function _blobencode($s) {
 421                 $dbw =& wfGetDB( DB_MASTER );
 422                 return $dbw->encodeBlob($s);
 423         }
 424         function getTableName() {
 425                 if ( !$this->tableInitialised ) {
 426                         $dbw =& wfGetDB( DB_MASTER );
 427                         /* This is actually a hack, we should be able
 428                            to use Language classes here... or not */
 429                         if (!$dbw)
 430                                 die("Could not connect to database");
 431                         $this->table = $dbw->tableName( $this->table );
 432                         $this->tableInitialised = true;
 433                 }
 434                 return $this->table;
 435         }
 436 }
 437
 438 /**
 439  * This is a wrapper for Turck MMCache's shared memory functions.
 440  *
 441  * You can store objects with mmcache_put() and mmcache_get(), but Turck seems
 442  * to use a weird custom serializer that randomly segfaults. So we wrap calls
 443  * with serialize()/unserialize().
 444  *
 445  * The thing I noticed about the Turck serialized data was that unlike ordinary
 446  * serialize(), it contained the names of methods, and judging by the amount of
 447  * binary data, perhaps even the bytecode of the methods themselves. It may be
 448  * that Turck's serializer is faster, so a possible future extension would be
 449  * to use it for arrays but not for objects.
 450  *
 451  * @package MediaWiki
 452  */
 453 class TurckBagOStuff extends BagOStuff {
 454         function get($key) {
 455                 $val = mmcache_get( $key );
 456                 if ( is_string( $val ) ) {
 457                         $val = unserialize( $val );
 458                 }
 459                 return $val;
 460         }
 461
 462         function set($key, $value, $exptime=0) {
 463                 mmcache_put( $key, serialize( $value ), $exptime );
 464                 return true;
 465         }
 466
 467         function delete($key, $time=0) {
 468                 mmcache_rm( $key );
 469                 return true;
 470         }
 471
 472         function lock($key, $waitTimeout = 0 ) {
 473                 mmcache_lock( $key );
 474                 return true;
 475         }
 476
 477         function unlock($key) {
 478                 mmcache_unlock( $key );
 479                 return true;
 480         }
 481 }
 482
 483 /**
 484  * This is a wrapper for eAccelerator's shared memory functions.
 485  *
 486  * This is basically identical to the Turck MMCache version,
 487  * mostly because eAccelerator is based on Turck MMCache.
 488  *
 489  * @package MediaWiki
 490  */
 491 class eAccelBagOStuff extends BagOStuff {
 492         function get($key) {
 493                 $val = eaccelerator_get( $key );
 494                 if ( is_string( $val ) ) {
 495                         $val = unserialize( $val );
 496                 }
 497                 return $val;
 498         }
 499
 500         function set($key, $value, $exptime=0) {
 501                 eaccelerator_put( $key, serialize( $value ), $exptime );
 502                 return true;
 503         }
 504
 505         function delete($key, $time=0) {
 506                 eaccelerator_rm( $key );
 507                 return true;
 508         }
 509
 510         function lock($key, $waitTimeout = 0 ) {
 511                 eaccelerator_lock( $key );
 512                 return true;
 513         }
 514
 515         function unlock($key) {
 516                 eaccelerator_unlock( $key );
 517                 return true;
 518         }
 519 }
 520 ?>