/**
* Loads the cached version of a specified view into the given sandbox.
* If the specified view is not found in the cache folder, the view is
* rendered to PHP and then written into a new cache file, which is then
* loaded for this request and future requests. This function requires
* that Config::setCachePath has been called (probably already done in the
* autoconfig file).
*
* @param string $viewName The view file to load from the cache, or create
* in the cache if it is not found.
* @param ViewSandbox $sandbox The sandbox into which the cached view should
* be loaded.
* @throws NoSuchViewException if the specified view cannot be found.
* @throws ViewCacheException if there is any problem creating/writing to
* cache files.
*/
protected static function loadCachedIntoSandbox($viewName, $sandbox)
{
$path = Config::getCachePath() . '/hydrogen/view/' . $viewName . '.php';
try {
$sandbox->loadPHPFile($path);
} catch (NoSuchViewException $e) {
$php = static::getViewPHP($viewName);
$folder = dirname($path);
// Create the view cache folder if it doesn't exist.
if (!file_exists($folder)) {
$success = @mkdir($folder, 0777, true);
if (!$success) {
throw new ViewCacheException('Could not create the view cache folder: "' . $folder . '". Check your filesystem permissions!');
}
}
// Attempt to open the file for writing
$fp = @fopen($path, 'w');
if (!$fp) {
throw new ViewCacheException('Could not create or open the cached view file for writing: ' . $path);
}
// Get the lock on the file. If we can't get the lock, bypass all
// this and load the raw PHP into the sandbox; another user is
// writing the cache file.
if (@flock($fp, LOCK_EX | LOCAL_NB)) {
$success = @fwrite($fp, $php);
@fclose($fp);
if (!$success) {
throw new ViewCacheException('Could not write to view cache file.');
}
$sandbox->loadPHPFile($path);
} else {
@fclose($fp);
$sandbox->loadRawPHP($php);
}
}
}
