includes/ObjectCache.php

   1 <?php
   2 # $Id$
   3 #
   4 # Copyright (C) 2003-2004 Brion Vibber <brion@pobox.com>
   5 # http://www.mediawiki.org/
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 2 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License along
  18 # with this program; if not, write to the Free Software Foundation, Inc.,
  19 # 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20 # http://www.gnu.org/copyleft/gpl.html
  21
  22 # Simple generic object store
  23 # interface is intended to be more or less compatible with
  24 # the PHP memcached client.
  25 #
  26 # backends for local hash array and SQL table included:
  27 #  $bag = new HashBagOStuff();
  28 #  $bag = new MysqlBagOStuff($tablename); # connect to db first
  29
  30 class /* abstract */ BagOStuff {
  31         var $debugmode;
  32
  33         function BagOStuff() {
  34                 $this->set_debug( false );
  35         }
  36
  37         function set_debug($bool) {
  38                 $this->debugmode = $bool;
  39         }
  40
  41         /* *** THE GUTS OF THE OPERATION *** */
  42         /* Override these with functional things in subclasses */
  43
  44         function get($key) {
  45                 /* stub */
  46                 return false;
  47         }
  48
  49         function set($key, $value, $exptime=0) {
  50                 /* stub */
  51                 return false;
  52         }
  53
  54         function delete($key, $time=0) {
  55                 /* stub */
  56                 return false;
  57         }
  58
  59         function lock($key, $timeout = 0) {
  60                 /* stub */
  61                 return true;
  62         }
  63
  64         function unlock($key) {
  65                 /* stub */
  66                 return true;
  67         }
  68
  69         /* *** Emulated functions *** */
  70         /* Better performance can likely be got with custom written versions */
  71         function get_multi($keys) {
  72                 $out = array();
  73                 foreach($keys as $key)
  74                         $out[$key] = $this->get($key);
  75                 return $out;
  76         }
  77
  78         function set_multi($hash, $exptime=0) {
  79                 foreach($hash as $key => $value)
  80                         $this->set($key, $value, $exptime);
  81         }
  82
  83         function add($key, $value, $exptime=0) {
  84                 if( $this->get($key) == false ) {
  85                         $this->set($key, $value, $exptime);
  86                         return true;
  87                 }
  88         }
  89
  90         function add_multi($hash, $exptime=0) {
  91                 foreach($hash as $key => $value)
  92                         $this->add($key, $value, $exptime);
  93         }
  94
  95         function delete_multi($keys, $time=0) {
  96                 foreach($keys as $key)
  97                         $this->delete($key, $time);
  98         }
  99
 100         function replace($key, $value, $exptime=0) {
 101                 if( $this->get($key) !== false )
 102                         $this->set($key, $value, $exptime);
 103         }
 104
 105         function incr($key, $value=1) {
 106                 if ( !$this->lock($key) ) {
 107                         return false;
 108                 }
 109                 $value = intval($value);
 110                 if($value < 0) $value = 0;
 111
 112                 $n = false;
 113                 if( ($n = $this->get($key)) !== false ) {
 114                         $n += $value;
 115                         $this->set($key, $n); // exptime?
 116                 }
 117                 $this->unlock($key);
 118                 return $n;
 119         }
 120
 121         function decr($key, $value=1) {
 122                 if ( !$this->lock($key) ) {
 123                         return false;
 124                 }
 125                 $value = intval($value);
 126                 if($value < 0) $value = 0;
 127
 128                 $m = false;
 129                 if( ($n = $this->get($key)) !== false ) {
 130                         $m = $n - $value;
 131                         if($m < 0) $m = 0;
 132                         $this->set($key, $m); // exptime?
 133                 }
 134                 $this->unlock($key);
 135                 return $m;
 136         }
 137
 138         function _debug($text) {
 139                 if($this->debugmode)
 140                         wfDebug("BagOStuff debug: $text\n");
 141         }
 142 }
 143
 144
 145 /* Functional versions! */
 146 class HashBagOStuff extends BagOStuff {
 147         /*
 148            This is a test of the interface, mainly. It stores
 149            things in an associative array, which is not going to
 150            persist between program runs.
 151         */
 152         var $bag;
 153
 154         function HashBagOStuff() {
 155                 $this->bag = array();
 156         }
 157
 158         function _expire($key) {
 159                 $et = $this->bag[$key][1];
 160                 if(($et == 0) || ($et > time()))
 161                         return false;
 162                 $this->delete($key);
 163                 return true;
 164         }
 165
 166         function get($key) {
 167                 if(!$this->bag[$key])
 168                         return false;
 169                 if($this->_expire($key))
 170                         return false;
 171                 return $this->bag[$key][0];
 172         }
 173
 174         function set($key,$value,$exptime=0) {
 175                 if(($exptime != 0) && ($exptime < 3600*24*30))
 176                         $exptime = time() + $exptime;
 177                 $this->bag[$key] = array( $value, $exptime );
 178         }
 179
 180         function delete($key,$time=0) {
 181                 if(!$this->bag[$key])
 182                         return false;
 183                 unset($this->bag[$key]);
 184                 return true;
 185         }
 186 }
 187
 188 /*
 189 CREATE TABLE objectcache (
 190   keyname char(255) binary not null default '',
 191   value mediumblob,
 192   exptime datetime,
 193   unique key (keyname),
 194   key (exptime)
 195 );
 196 */
 197 class /* abstract */ SqlBagOStuff extends BagOStuff {
 198         var $table;
 199         function SqlBagOStuff($tablename = "objectcache") {
 200                 $this->table = $tablename;
 201         }
 202
 203         function get($key) {
 204                 /* expire old entries if any */
 205                 $this->expireall();
 206
 207                 $res = $this->_query(
 208                         "SELECT value,exptime FROM $0 WHERE keyname='$1'", $key);
 209                 if(!$res) {
 210                         $this->_debug("get: ** error: " . $this->_dberror($res) . " **");
 211                         return false;
 212                 }
 213                 if($row=$this->_fetchobject($res)) {
 214                         $this->_debug("get: retrieved data; exp time is " . $row->exptime);
 215                         return unserialize($row->value);
 216                 } else {
 217                         $this->_debug("get: no matching rows");
 218                 }
 219                 return false;
 220         }
 221
 222         function set($key,$value,$exptime=0) {
 223                 $exptime = intval($exptime);
 224                 if($exptime < 0) $exptime = 0;
 225                 if($exptime == 0) {
 226                         $exp = $this->_maxdatetime();
 227                 } else {
 228                         if($exptime < 3600*24*30)
 229                                 $exptime += time();
 230                         $exp = $this->_fromunixtime($exptime);
 231                 }
 232                 $this->delete( $key );
 233                 $this->_query(
 234                         "INSERT INTO $0 (keyname,value,exptime) VALUES('$1','$2','$exp')",
 235                         $key, serialize($value));
 236                 return true; /* ? */
 237         }
 238
 239         function delete($key,$time=0) {
 240                 $this->_query(
 241                         "DELETE FROM $0 WHERE keyname='$1'", $key );
 242                 return true; /* ? */
 243         }
 244
 245         function _query($sql) {
 246                 $reps = func_get_args();
 247                 $reps[0] = $this->table;
 248                 // ewwww
 249                 for($i=0;$i<count($reps);$i++) {
 250                         $sql = str_replace(
 251                                 "$" . $i,
 252                                 $this->_strencode($reps[$i]),
 253                                 $sql);
 254                 }
 255                 $res = $this->_doquery($sql);
 256                 if($res == false) {
 257                         $this->_debug("query failed: " . $this->_dberror($res));
 258                 }
 259                 return $res;
 260         }
 261
 262         function _strencode($str) {
 263                 /* Protect strings in SQL */
 264                 return str_replace( "'", "''", $str );
 265         }
 266
 267         function _doquery($sql) {
 268                 die( "abstract function SqlBagOStuff::_doquery() must be defined" );
 269         }
 270
 271         function _fetchrow($res) {
 272                 die( "abstract function SqlBagOStuff::_fetchrow() must be defined" );
 273         }
 274
 275         function _freeresult($result) {
 276                 /* stub */
 277                 return false;
 278         }
 279
 280         function _dberror($result) {
 281                 /* stub */
 282                 return "unknown error";
 283         }
 284
 285         function _maxdatetime() {
 286                 die( "abstract function SqlBagOStuff::_maxdatetime() must be defined" );
 287         }
 288
 289         function _fromunixtime() {
 290                 die( "abstract function SqlBagOStuff::_fromunixtime() must be defined" );
 291         }
 292
 293         function expireall() {
 294                 /* Remove any items that have expired */
 295                 $now=$this->_fromunixtime(time());
 296                 $this->_query( "DELETE FROM $0 WHERE exptime<'$now'" );
 297         }
 298
 299         function deleteall() {
 300                 /* Clear *all* items from cache table */
 301                 $this->_query( "DELETE FROM $0" );
 302         }
 303 }
 304
 305 class MediaWikiBagOStuff extends SqlBagOStuff {
 306         function _doquery($sql) {
 307                 $dbw =& wfGetDB( DB_MASTER );
 308                 return $dbw->query($sql, "MediaWikiBagOStuff:_doquery");
 309         }
 310         function _fetchobject($result) {
 311                 $dbw =& wfGetDB( DB_MASTER );
 312                 return $dbw->fetchObject($result);
 313         }
 314         function _freeresult($result) {
 315                 $dbw =& wfGetDB( DB_MASTER );
 316                 return $dbw->freeResult($result);
 317         }
 318         function _dberror($result) {
 319                 $dbw =& wfGetDB( DB_MASTER );
 320                 return $dbw->lastError();
 321         }
 322         function _maxdatetime() {
 323                 return "9999-12-31 12:59:59";
 324         }
 325         function _fromunixtime($ts) {
 326                 return gmdate( "Y-m-d H:i:s", $ts );
 327         }
 328         function _strencode($s) {
 329                 $dbw =& wfGetDB( DB_MASTER );
 330                 return $dbw->strencode($s);
 331         }
 332 }
 333
 334 class TurckBagOStuff extends BagOStuff {
 335         function get($key) {
 336                 return mmcache_get( $key );
 337         }
 338
 339         function set($key, $value, $exptime=0) {
 340                 mmcache_put( $key, $value, $exptime );
 341                 return true;
 342         }
 343
 344         function delete($key, $time=0) {
 345                 mmcache_rm( $key );
 346                 return true;
 347         }
 348
 349         function lock($key, $waitTimeout = 0 ) {
 350                 mmcache_lock( $key );
 351                 return true;
 352         }
 353
 354         function unlock($key) {
 355                 mmcache_unlock( $key );
 356                 return true;
 357         }
 358 }
 359 ?>