function load($filename)
{
$file = new \SplFileInfo($filename);
$cacheDir = $this->cacheDir . '/config';
$cachedConfig = $cacheDir . '/' . $file->getFilename() . '.cache';
$hash = md5(file_get_contents($filename));
if (!file_exists($cacheDir)) {
mkdir($cacheDir, 0750, true);
}
if (file_exists($cachedConfig)) {
$config = (require $cachedConfig);
if ($hash === $config['hash']) {
unset($config['hash']);
return $config;
}
}
$config = $this->driver->load($filename);
file_put_contents($cachedConfig, '<?php return ' . var_export($config + array('hash' => $hash), true) . ' ?>');
return $config;
}
private function readConfig()
{
if (!$this->filename) {
throw new \RuntimeException('A valid configuration file must be passed before reading the config.');
}
if (!file_exists($this->filename)) {
throw new \InvalidArgumentException(sprintf("The config file '%s' does not exist.", $this->filename));
}
if ($this->driver->supports($this->filename)) {
return $this->driver->load($this->filename);
}
throw new \InvalidArgumentException(sprintf("The config file '%s' appears to have an invalid format.", $this->filename));
}