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')) die('meh.'); 10 11/** 12 * Generic handling of caching 13 */ 14class cache { 15 public $key = ''; // primary identifier for this item 16 public $ext = ''; // file ext for cache data, secondary identifier for this item 17 public $cache = ''; // cache file name 18 public $depends = array(); // array containing cache dependency information, 19 // used by _useCache to determine cache validity 20 21 var $_event = ''; // event to be triggered during useCache 22 var $_time; 23 24 /** 25 * @param string $key primary identifier 26 * @param string $ext file extension 27 */ 28 public function cache($key,$ext) { 29 $this->key = $key; 30 $this->ext = $ext; 31 $this->cache = getCacheName($key,$ext); 32 } 33 34 /** 35 * public method to determine whether the cache can be used 36 * 37 * to assist in cetralisation of event triggering and calculation of cache statistics, 38 * don't override this function override _useCache() 39 * 40 * @param array $depends array of cache dependencies, support dependecies: 41 * 'age' => max age of the cache in seconds 42 * 'files' => cache must be younger than mtime of each file 43 * (nb. dependency passes if file doesn't exist) 44 * 45 * @return bool true if cache can be used, false otherwise 46 */ 47 public function useCache($depends=array()) { 48 $this->depends = $depends; 49 $this->_addDependencies(); 50 51 if ($this->_event) { 52 return $this->_stats(trigger_event($this->_event,$this,array($this,'_useCache'))); 53 } else { 54 return $this->_stats($this->_useCache()); 55 } 56 } 57 58 /** 59 * private method containing cache use decision logic 60 * 61 * this function processes the following keys in the depends array 62 * purge - force a purge on any non empty value 63 * age - expire cache if older than age (seconds) 64 * files - expire cache if any file in this array was updated more recently than the cache 65 * 66 * Note that this function needs to be public as it is used as callback for the event handler 67 * 68 * can be overridden 69 * 70 * @return bool see useCache() 71 */ 72 public function _useCache() { 73 74 if (!empty($this->depends['purge'])) return false; // purge requested? 75 if (!($this->_time = @filemtime($this->cache))) return false; // cache exists? 76 77 // cache too old? 78 if (!empty($this->depends['age']) && ((time() - $this->_time) > $this->depends['age'])) return false; 79 80 if (!empty($this->depends['files'])) { 81 foreach ($this->depends['files'] as $file) { 82 if ($this->_time <= @filemtime($file)) return false; // cache older than files it depends on? 83 } 84 } 85 86 return true; 87 } 88 89 /** 90 * add dependencies to the depends array 91 * 92 * this method should only add dependencies, 93 * it should not remove any existing dependencies and 94 * it should only overwrite a dependency when the new value is more stringent than the old 95 */ 96 protected function _addDependencies() { 97 global $INPUT; 98 if ($INPUT->has('purge')) $this->depends['purge'] = true; // purge requested 99 } 100 101 /** 102 * retrieve the cached data 103 * 104 * @param bool $clean true to clean line endings, false to leave line endings alone 105 * @return string cache contents 106 */ 107 public function retrieveCache($clean=true) { 108 return io_readFile($this->cache, $clean); 109 } 110 111 /** 112 * cache $data 113 * 114 * @param string $data the data to be cached 115 * @return bool true on success, false otherwise 116 */ 117 public function storeCache($data) { 118 return io_savefile($this->cache, $data); 119 } 120 121 /** 122 * remove any cached data associated with this cache instance 123 */ 124 public function removeCache() { 125 @unlink($this->cache); 126 } 127 128 /** 129 * Record cache hits statistics. 130 * (Only when debugging allowed, to reduce overhead.) 131 * 132 * @param bool $success result of this cache use attempt 133 * @return bool pass-thru $success value 134 */ 135 protected function _stats($success) { 136 global $conf; 137 static $stats = null; 138 static $file; 139 140 if (!$conf['allowdebug']) { return $success; } 141 142 if (is_null($stats)) { 143 $file = $conf['cachedir'].'/cache_stats.txt'; 144 $lines = explode("\n",io_readFile($file)); 145 146 foreach ($lines as $line) { 147 $i = strpos($line,','); 148 $stats[substr($line,0,$i)] = $line; 149 } 150 } 151 152 if (isset($stats[$this->ext])) { 153 list($ext,$count,$hits) = explode(',',$stats[$this->ext]); 154 } else { 155 $ext = $this->ext; 156 $count = 0; 157 $hits = 0; 158 } 159 160 $count++; 161 if ($success) $hits++; 162 $stats[$this->ext] = "$ext,$count,$hits"; 163 164 io_saveFile($file,join("\n",$stats)); 165 166 return $success; 167 } 168} 169 170/** 171 * Parser caching 172 */ 173class cache_parser extends cache { 174 175 public $file = ''; // source file for cache 176 public $mode = ''; // input mode (represents the processing the input file will undergo) 177 178 var $_event = 'PARSER_CACHE_USE'; 179 180 /** 181 * 182 * @param string $id page id 183 * @param string $file source file for cache 184 * @param string $mode input mode 185 */ 186 public function cache_parser($id, $file, $mode) { 187 if ($id) $this->page = $id; 188 $this->file = $file; 189 $this->mode = $mode; 190 191 parent::cache($file.$_SERVER['HTTP_HOST'].$_SERVER['SERVER_PORT'],'.'.$mode); 192 } 193 194 /** 195 * method contains cache use decision logic 196 * 197 * @return bool see useCache() 198 */ 199 public function _useCache() { 200 201 if (!@file_exists($this->file)) return false; // source exists? 202 return parent::_useCache(); 203 } 204 205 protected function _addDependencies() { 206 global $conf; 207 208 $this->depends['age'] = isset($this->depends['age']) ? 209 min($this->depends['age'],$conf['cachetime']) : $conf['cachetime']; 210 211 // parser cache file dependencies ... 212 $files = array($this->file, // ... source 213 DOKU_INC.'inc/parser/parser.php', // ... parser 214 DOKU_INC.'inc/parser/handler.php', // ... handler 215 ); 216 $files = array_merge($files, getConfigFiles('main')); // ... wiki settings 217 218 $this->depends['files'] = !empty($this->depends['files']) ? array_merge($files, $this->depends['files']) : $files; 219 parent::_addDependencies(); 220 } 221 222} 223 224/** 225 * Caching of data of renderer 226 */ 227class cache_renderer extends cache_parser { 228 229 /** 230 * method contains cache use decision logic 231 * 232 * @return bool see useCache() 233 */ 234 public function _useCache() { 235 global $conf; 236 237 if (!parent::_useCache()) return false; 238 239 if (!isset($this->page)) { 240 return true; 241 } 242 243 if ($this->_time < @filemtime(metaFN($this->page,'.meta'))) return false; // meta cache older than file it depends on? 244 245 // check current link existence is consistent with cache version 246 // first check the purgefile 247 // - if the cache is more recent than the purgefile we know no links can have been updated 248 if ($this->_time >= @filemtime($conf['cachedir'].'/purgefile')) { 249 return true; 250 } 251 252 // for wiki pages, check metadata dependencies 253 $metadata = p_get_metadata($this->page); 254 255 if (!isset($metadata['relation']['references']) || 256 empty($metadata['relation']['references'])) { 257 return true; 258 } 259 260 foreach ($metadata['relation']['references'] as $id => $exists) { 261 if ($exists != page_exists($id,'',false)) return false; 262 } 263 264 return true; 265 } 266 267 protected function _addDependencies() { 268 269 // renderer cache file dependencies ... 270 $files = array( 271 DOKU_INC.'inc/parser/'.$this->mode.'.php', // ... the renderer 272 ); 273 274 // page implies metadata and possibly some other dependencies 275 if (isset($this->page)) { 276 277 $valid = p_get_metadata($this->page, 'date valid'); // for xhtml this will render the metadata if needed 278 if (!empty($valid['age'])) { 279 $this->depends['age'] = isset($this->depends['age']) ? 280 min($this->depends['age'],$valid['age']) : $valid['age']; 281 } 282 } 283 284 $this->depends['files'] = !empty($this->depends['files']) ? array_merge($files, $this->depends['files']) : $files; 285 parent::_addDependencies(); 286 } 287} 288 289/** 290 * Caching of parser instructions 291 */ 292class cache_instructions extends cache_parser { 293 294 /** 295 * @param string $id page id 296 * @param string $file source file for cache 297 */ 298 public function cache_instructions($id, $file) { 299 parent::cache_parser($id, $file, 'i'); 300 } 301 302 /** 303 * retrieve the cached data 304 * 305 * @param bool $clean true to clean line endings, false to leave line endings alone 306 * @return string cache contents 307 */ 308 public function retrieveCache($clean=true) { 309 $contents = io_readFile($this->cache, false); 310 return !empty($contents) ? unserialize($contents) : array(); 311 } 312 313 /** 314 * cache $instructions 315 * 316 * @param string $instructions the instruction to be cached 317 * @return bool true on success, false otherwise 318 */ 319 public function storeCache($instructions) { 320 return io_savefile($this->cache,serialize($instructions)); 321 } 322} 323