1<?php 2/** 3 * Generic class to handle caching 4 * 5 * @license GPL 2 (http://www.gnu.org/licenses/gpl.html) 6 * @author Chris Smith <chris@jalakai.co.uk> 7 */ 8 9if(!defined('DOKU_INC')) define('DOKU_INC',realpath(dirname(__FILE__).'/../').'/'); 10 11require_once(DOKU_INC.'inc/io.php'); 12require_once(DOKU_INC.'inc/pageutils.php'); 13require_once(DOKU_INC.'inc/parserutils.php'); 14 15class cache { 16 var $key = ''; // primary identifier for this item 17 var $ext = ''; // file ext for cache data, secondary identifier for this item 18 var $cache = ''; // cache file name 19 var $depends = array(); // array containing cache dependency information, 20 // used by _useCache to determine cache validity 21 22 var $_event = ''; // event to be triggered during useCache 23 24 function cache($key,$ext) { 25 $this->key = $key; 26 $this->ext = $ext; 27 $this->cache = getCacheName($key,$ext); 28 } 29 30 /** 31 * public method to determine whether the cache can be used 32 * 33 * to assist in cetralisation of event triggering and calculation of cache statistics, 34 * don't override this function override _useCache() 35 * 36 * @param array $depends array of cache dependencies, support dependecies: 37 * 'age' => max age of the cache in seconds 38 * 'files' => cache must be younger than mtime of each file 39 * (nb. dependency passes if file doesn't exist) 40 * 41 * @return bool true if cache can be used, false otherwise 42 */ 43 function useCache($depends=array()) { 44 $this->depends = $depends; 45 $this->_addDependencies(); 46 47 if ($this->_event) { 48 return $this->_stats(trigger_event($this->_event,$this,array($this,'_useCache'))); 49 } else { 50 return $this->_stats($this->_useCache()); 51 } 52 } 53 54 /** 55 * private method containing cache use decision logic 56 * 57 * this function processes the following keys in the depends array 58 * purge - force a purge on any non empty value 59 * age - expire cache if older than age (seconds) 60 * files - expire cache if any file in this array was updated more recently than the cache 61 * 62 * can be overridden 63 * 64 * @return bool see useCache() 65 */ 66 function _useCache() { 67 68 if (!empty($this->depends['purge'])) return false; // purge requested? 69 if (!($this->_time = @filemtime($this->cache))) return false; // cache exists? 70 71 // cache too old? 72 if (!empty($this->depends['age']) && ((time() - $this->_time) > $this->depends['age'])) return false; 73 74 if (!empty($this->depends['files'])) { 75 foreach ($this->depends['files'] as $file) { 76 if ($this->_time < @filemtime($file)) return false; // cache older than files it depends on? 77 } 78 } 79 80 return true; 81 } 82 83 /** 84 * add dependencies to the depends array 85 * 86 * this method should only add dependencies, 87 * it should not remove any existing dependencies and 88 * it should only overwrite a dependency when the new value is more stringent than the old 89 */ 90 function _addDependencies() { 91 if (isset($_REQUEST['purge'])) $this->depends['purge'] = true; // purge requested 92 } 93 94 /** 95 * retrieve the cached data 96 * 97 * @param bool $clean true to clean line endings, false to leave line endings alone 98 * @return string cache contents 99 */ 100 function retrieveCache($clean=true) { 101 return io_readFile($this->cache, $clean); 102 } 103 104 /** 105 * cache $data 106 * 107 * @param string $data the data to be cached 108 * @return none 109 */ 110 function storeCache($data) { 111 io_savefile($this->cache, $data); 112 } 113 114 /** 115 * remove any cached data associated with this cache instance 116 */ 117 function removeCache() { 118 @unlink($this->cache); 119 } 120 121 /** 122 * Record cache hits statistics. 123 * (Only when debugging allowed, to reduce overhead.) 124 * 125 * @param bool $success result of this cache use attempt 126 * @return bool pass-thru $success value 127 */ 128 function _stats($success) { 129 global $conf; 130 static $stats = NULL; 131 static $file; 132 133 if (!$conf['allowdebug']) { return $success; } 134 135 if (is_null($stats)) { 136 $file = $conf['cachedir'].'/cache_stats.txt'; 137 $lines = explode("\n",io_readFile($file)); 138 139 foreach ($lines as $line) { 140 $i = strpos($line,','); 141 $stats[substr($line,0,$i)] = $line; 142 } 143 } 144 145 if (isset($stats[$this->ext])) { 146 list($ext,$count,$hits) = explode(',',$stats[$this->ext]); 147 } else { 148 $ext = $this->ext; 149 $count = 0; 150 $hits = 0; 151 } 152 153 $count++; 154 if ($success) $hits++; 155 $stats[$this->ext] = "$ext,$count,$hits"; 156 157 io_saveFile($file,join("\n",$stats)); 158 159 return $success; 160 } 161} 162 163class cache_parser extends cache { 164 165 var $file = ''; // source file for cache 166 var $mode = ''; // input mode (represents the processing the input file will undergo) 167 168 var $_event = 'PARSER_CACHE_USE'; 169 170 function cache_parser($id, $file, $mode) { 171 if ($id) $this->page = $id; 172 $this->file = $file; 173 $this->mode = $mode; 174 175 parent::cache($file.$_SERVER['HTTP_HOST'].$_SERVER['SERVER_PORT'],'.'.$mode); 176 } 177 178 function _useCache() { 179 180 if (!@file_exists($this->file)) return false; // source exists? 181 return parent::_useCache(); 182 } 183 184 function _addDependencies() { 185 global $conf; 186 187 $this->depends['age'] = isset($this->depends['age']) ? 188 min($this->depends['age'],$conf['cachetime']) : $conf['cachetime']; 189 190 // parser cache file dependencies ... 191 $files = array($this->file, // ... source 192 DOKU_CONF.'dokuwiki.php', // ... config 193 DOKU_CONF.'local.php', // ... local config 194 DOKU_INC.'inc/parser/parser.php', // ... parser 195 DOKU_INC.'inc/parser/handler.php', // ... handler 196 ); 197 198 $this->depends['files'] = !empty($this->depends['files']) ? array_merge($files, $this->depends['files']) : $files; 199 parent::_addDependencies(); 200 } 201 202} 203 204class cache_renderer extends cache_parser { 205 206 function useCache($depends=array()) { 207 $use = parent::useCache($depends); 208 209 // meta data needs to be kept in step with the cache 210 if (!$use && isset($this->page)) { 211 p_set_metadata($this->page,array(),true); 212 } 213 214 return $use; 215 } 216 217 function _useCache() { 218 global $conf; 219 220 if (!parent::_useCache()) return false; 221 222 // for wiki pages, check metadata dependencies 223 if (isset($this->page)) { 224 $metadata = p_get_metadata($this->page); 225 226 // check currnent link existence is consistent with cache version 227 // first check the purgefile 228 // - if the cache is more recent that the purgefile we know no links can have been updated 229 if ($this->_time < @filemtime($conf['cachedir'].'/purgefile')) { 230 231# $links = p_get_metadata($this->page,"relation references"); 232 $links = $metadata['relation']['references']; 233 234 if (!empty($links)) { 235 foreach ($links as $id => $exists) { 236 if ($exists != @file_exists(wikiFN($id,'',false))) return false; 237 } 238 } 239 } 240 } 241 242 return true; 243 } 244 245 function _addDependencies() { 246 247 // renderer cache file dependencies ... 248 $files = array( 249 DOKU_INC.'inc/parser/'.$this->mode.'.php', // ... the renderer 250 ); 251 252 // page implies metadata and possibly some other dependencies 253 if (isset($this->page)) { 254 255 $metafile = metaFN($this->page,'.meta'); 256 if (@file_exists($metafile)) { 257 $files[] = $metafile; // ... the page's own metadata 258 $files[] = DOKU_INC.'inc/parser/metadata.php'; // ... the metadata renderer 259 260 $valid = p_get_metadata($this->page, 'date valid'); 261 if (!empty($valid['age'])) { 262 $this->depends['age'] = isset($this->depends['age']) ? 263 min($this->depends['age'],$valid['age']) : $valid['age']; 264 } 265 266 } else { 267 $this->depends['purge'] = true; // ... purging cache will generate metadata 268 return; 269 } 270 } 271 272 $this->depends['files'] = !empty($this->depends['files']) ? array_merge($files, $this->depends['files']) : $files; 273 parent::_addDependencies(); 274 } 275} 276 277class cache_instructions extends cache_parser { 278 279 function cache_instructions($id, $file) { 280 parent::cache_parser($id, $file, 'i'); 281 } 282 283 function retrieveCache() { 284 $contents = io_readFile($this->cache, false); 285 return !empty($contents) ? unserialize($contents) : array(); 286 } 287 288 function storeCache($instructions) { 289 io_savefile($this->cache,serialize($instructions)); 290 } 291} 292