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 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 abstract 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 abstract 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 $str;
 294         }
 295
 296         abstract function _doinsert($table, $vals);
 297         abstract function _doquery($sql);
 298
 299         function _freeresult($result) {
 300                 /* stub */
 301                 return false;
 302         }
 303
 304         function _dberror($result) {
 305                 /* stub */
 306                 return 'unknown error';
 307         }
 308
 309         abstract function _maxdatetime();
 310         abstract function _fromunixtime($ts);
 311
 312         function garbageCollect() {
 313                 /* Ignore 99% of requests */
 314                 if ( !mt_rand( 0, 100 ) ) {
 315                         $nowtime = time();
 316                         /* Avoid repeating the delete within a few seconds */
 317                         if ( $nowtime > ($this->lastexpireall + 1) ) {
 318                                 $this->lastexpireall = $nowtime;
 319                                 $this->expireall();
 320                         }
 321                 }
 322         }
 323
 324         function expireall() {
 325                 /* Remove any items that have expired */
 326                 $now = $this->_fromunixtime( time() );
 327                 $this->_query( "DELETE FROM $0 WHERE exptime < '$now'" );
 328         }
 329
 330         function deleteall() {
 331                 /* Clear *all* items from cache table */
 332                 $this->_query( "DELETE FROM $0" );
 333         }
 334
 335         /**
 336          * Serialize an object and, if possible, compress the representation.
 337          * On typical message and page data, this can provide a 3X decrease
 338          * in storage requirements.
 339          *
 340          * @param mixed $data
 341          * @return string
 342          */
 343         function _serialize( &$data ) {
 344                 $serial = serialize( $data );
 345                 if( function_exists( 'gzdeflate' ) ) {
 346                         return gzdeflate( $serial );
 347                 } else {
 348                         return $serial;
 349                 }
 350         }
 351
 352         /**
 353          * Unserialize and, if necessary, decompress an object.
 354          * @param string $serial
 355          * @return mixed
 356          */
 357         function _unserialize( $serial ) {
 358                 if( function_exists( 'gzinflate' ) ) {
 359                         $decomp = @gzinflate( $serial );
 360                         if( false !== $decomp ) {
 361                                 $serial = $decomp;
 362                         }
 363                 }
 364                 $ret = unserialize( $serial );
 365                 return $ret;
 366         }
 367 }
 368
 369 /**
 370  * @todo document
 371  * @package MediaWiki
 372  */
 373 class MediaWikiBagOStuff extends SqlBagOStuff {
 374         var $tableInitialised = false;
 375
 376         function _doquery($sql) {
 377                 $dbw =& wfGetDB( DB_MASTER );
 378                 return $dbw->query($sql, 'MediaWikiBagOStuff::_doquery');
 379         }
 380         function _doinsert($t, $v) {
 381                 $dbw =& wfGetDB( DB_MASTER );
 382                 return $dbw->insert($t, $v, 'MediaWikiBagOStuff::_doinsert');
 383         }
 384         function _fetchobject($result) {
 385                 $dbw =& wfGetDB( DB_MASTER );
 386                 return $dbw->fetchObject($result);
 387         }
 388         function _freeresult($result) {
 389                 $dbw =& wfGetDB( DB_MASTER );
 390                 return $dbw->freeResult($result);
 391         }
 392         function _dberror($result) {
 393                 $dbw =& wfGetDB( DB_MASTER );
 394                 return $dbw->lastError();
 395         }
 396         function _maxdatetime() {
 397                 $dbw =& wfGetDB(DB_MASTER);
 398                 return $dbw->timestamp('9999-12-31 12:59:59');
 399         }
 400         function _fromunixtime($ts) {
 401                 $dbw =& wfGetDB(DB_MASTER);
 402                 return $dbw->timestamp($ts);
 403         }
 404         function _strencode($s) {
 405                 $dbw =& wfGetDB( DB_MASTER );
 406                 return $dbw->strencode($s);
 407         }
 408         function _blobencode($s) {
 409                 $dbw =& wfGetDB( DB_MASTER );
 410                 return $dbw->encodeBlob($s);
 411         }
 412         function getTableName() {
 413                 if ( !$this->tableInitialised ) {
 414                         $dbw =& wfGetDB( DB_MASTER );
 415                         /* This is actually a hack, we should be able
 416                            to use Language classes here... or not */
 417                         if (!$dbw)
 418                                 throw new MWException("Could not connect to database");
 419                         $this->table = $dbw->tableName( $this->table );
 420                         $this->tableInitialised = true;
 421                 }
 422                 return $this->table;
 423         }
 424 }
 425
 426 /**
 427  * This is a wrapper for Turck MMCache's shared memory functions.
 428  *
 429  * You can store objects with mmcache_put() and mmcache_get(), but Turck seems
 430  * to use a weird custom serializer that randomly segfaults. So we wrap calls
 431  * with serialize()/unserialize().
 432  *
 433  * The thing I noticed about the Turck serialized data was that unlike ordinary
 434  * serialize(), it contained the names of methods, and judging by the amount of
 435  * binary data, perhaps even the bytecode of the methods themselves. It may be
 436  * that Turck's serializer is faster, so a possible future extension would be
 437  * to use it for arrays but not for objects.
 438  *
 439  * @package MediaWiki
 440  */
 441 class TurckBagOStuff extends BagOStuff {
 442         function get($key) {
 443                 $val = mmcache_get( $key );
 444                 if ( is_string( $val ) ) {
 445                         $val = unserialize( $val );
 446                 }
 447                 return $val;
 448         }
 449
 450         function set($key, $value, $exptime=0) {
 451                 mmcache_put( $key, serialize( $value ), $exptime );
 452                 return true;
 453         }
 454
 455         function delete($key, $time=0) {
 456                 mmcache_rm( $key );
 457                 return true;
 458         }
 459
 460         function lock($key, $waitTimeout = 0 ) {
 461                 mmcache_lock( $key );
 462                 return true;
 463         }
 464
 465         function unlock($key) {
 466                 mmcache_unlock( $key );
 467                 return true;
 468         }
 469 }
 470
 471 /**
 472  * This is a wrapper for APC's shared memory functions
 473  *
 474  * @package MediaWiki
 475  */
 476
 477 class APCBagOStuff extends BagOStuff {
 478         function get($key) {
 479                 $val = apc_fetch($key);
 480                 return $val;
 481         }
 482
 483         function set($key, $value, $exptime=0) {
 484                 apc_store($key, $value, $exptime);
 485                 return true;
 486         }
 487
 488         function delete($key) {
 489                 apc_delete($key);
 490                 return true;
 491         }
 492 }
 493
 494
 495 /**
 496  * This is a wrapper for eAccelerator's shared memory functions.
 497  *
 498  * This is basically identical to the Turck MMCache version,
 499  * mostly because eAccelerator is based on Turck MMCache.
 500  *
 501  * @package MediaWiki
 502  */
 503 class eAccelBagOStuff extends BagOStuff {
 504         function get($key) {
 505                 $val = eaccelerator_get( $key );
 506                 if ( is_string( $val ) ) {
 507                         $val = unserialize( $val );
 508                 }
 509                 return $val;
 510         }
 511
 512         function set($key, $value, $exptime=0) {
 513                 eaccelerator_put( $key, serialize( $value ), $exptime );
 514                 return true;
 515         }
 516
 517         function delete($key, $time=0) {
 518                 eaccelerator_rm( $key );
 519                 return true;
 520         }
 521
 522         function lock($key, $waitTimeout = 0 ) {
 523                 eaccelerator_lock( $key );
 524                 return true;
 525         }
 526
 527         function unlock($key) {
 528                 eaccelerator_unlock( $key );
 529                 return true;
 530         }
 531 }
 532 ?>