framework/caching/FileCache.php
public function init()
    {
        parent::init();
        $this->cachePath = Yii::getAlias($this->cachePath);
        if (!is_dir($this->cachePath)) {
            FileHelper::createDirectory($this->cachePath, $this->dirMode, true);
        }
    }
public function init()
    {
        parent::init();
        $this->cachePath = Yii::getAlias($this->cachePath);
        if (!is_dir($this->cachePath)) {
            FileHelper::createDirectory($this->cachePath, $this->dirMode, true);
        }
    }
Initializes this component by ensuring the existence of the cache path.