/**
* Compile a LESS file into CSS.
*
* Keeps track of all used files and adds them to localFileRefs.
*
* @since 1.22
* @throws Exception If less.php encounters a parse error
* @param string $fileName File path of LESS source
* @param Less_Parser $parser Compiler to use, if not default
* @return string CSS source
*/
protected function compileLessFile($fileName, $compiler = null)
{
static $cache;
if (!$cache) {
$cache = ObjectCache::newAccelerator(CACHE_ANYTHING);
}
// Construct a cache key from the LESS file name and a hash digest
// of the LESS variables used for compilation.
$varsHash = hash('md4', serialize(ResourceLoader::getLessVars($this->getConfig())));
$cacheKey = wfGlobalCacheKey('LESS', $fileName, $varsHash);
$cachedCompile = $cache->get($cacheKey);
// If we got a cached value, we have to validate it by getting a
// checksum of all the files that were loaded by the parser and
// ensuring it matches the cached entry's.
if (isset($cachedCompile['hash'])) {
$contentHash = FileContentsHasher::getFileContentsHash($cachedCompile['files']);
if ($contentHash === $cachedCompile['hash']) {
$this->localFileRefs += $cachedCompile['files'];
return $cachedCompile['css'];
}
}
if (!$compiler) {
$compiler = $this->getLessCompiler();
}
$css = $compiler->parseFile($fileName)->getCss();
$files = $compiler->AllParsedFiles();
$this->localFileRefs = array_merge($this->localFileRefs, $files);
$cache->set($cacheKey, array('css' => $css, 'files' => $files, 'hash' => FileContentsHasher::getFileContentsHash($files)), 60 * 60 * 24);
// 86400 seconds, or 24 hours.
return $css;
}
