\ticky\cache\driverfile

<?php

namespace ticky\cache\driver;

use ticky\cache\contract;

class file extends contract {

    public function __construct($config) {
        $this->config = $config;
    }

    /**
     * 判断指定键是否存在
     * @param $key
     * @return mixed
     */
    public function exists($key) {
        $file = $this->_file($key);
        if (!is_file($file)) {
            return false;
        }
        return true;
    }

    /**
     * 获取指定键的值
     * @param $key
     * @param null $default
     * @return mixed
     */
    public function get($key) {
        //缓存文件不存在
        if (!$this->exists($key)) {
            return false;
        }
        $file = $this->_file($key);
        $data = $this->_filegetcontents($file);
        if ($data['expire'] == 0 || SYS_TIME < $data['expire']) {
            return $data['contents'];
        }
        return false;
    }

    /**
     * 设置指定键的值
     * @param $key
     * @param $value
     * @param int $expire
     * @return mixed
     */
    public function set($key, $value, $expire = 0) {
        if (empty($value)) {
            return false;
        }
        $cache = array();
        $cache['key'] = $key;
        $cache['contents'] = $value;
        $cache['expire'] = $expire === 0 ? 0 : NOW_TIME + $expire;
        $cache['mtime'] = NOW_TIME;
        if (!is_dir($this->config['save_path'])) {
            @mkdir($this->config['save_path'], 0777, true);
        }
        $file = $this->_file($key);
        return $this->_fileputcontents($file, $cache);
    }

    /**
     * 删除指定键
     * @param $key
     * @return mixed
     */
    public function delete($key) {
        if (!$this->exists($key)) {
            return false;
        }
        $file = $this->_file($key);
        //删除该缓存
        return unlink($file);
    }

    /**
     * 删除所有缓存
     * @return mixed
     */
    public function clean() {
        $glob = glob($this->config['save_path'] . '*' . $this->config['suffix']);

        if (empty($glob)) {
            return false;
        }

        foreach ($glob as $v) {
            $id = $this->_filenametoid(basename($v));
            $this->delete($id);
        }
        return true;
    }

    /**
     * 通过缓存id得到缓存信息路径
     * @param string $id
     * @return string 缓存文件路径
     */
    protected function _file($id) {
        $filenmae = $this->_idtofilename($id);
        return $this->config['save_path'] . DS . $filenmae;
    }

    /**
     * 通过id得到缓存信息存储文件名
     * @param  $id
     * @return string 缓存文件名
     */
    protected function _idtofilename($id) {
        return $id . $this->config['suffix'];
    }

    /**
     * 通过filename得到缓存id
     *
     * @param  $filename
     * @return string 缓存id
     */
    protected function _filenametoid($filename) {
        return str_replace($this->config['suffix'], '', $filename);
    }

    /**
     * 把数据写入文件
     *
     * @param string $file 文件名称
     * @param array  $contents 数据内容
     * @return int | false
     */
    protected function _fileputcontents($file, $contents) {
        if ($this->config['mode'] == 1) {
            $contents = serialize($contents);
        } else {
            $contents = "<?php\nreturn " . var_export($contents, true) . ";\n?>";
        }
        $filesize = file_put_contents($file, $contents, LOCK_EX);
        return $filesize ? $filesize : false;
    }

    /**
     * 从文件得到数据
     * @param  sring $file
     * @return boolean|array
     */
    protected function _filegetcontents($file) {
        if (!file_exists($file)) {
            return false;
        }
        if ($this->config['mode'] == 1) {
            return unserialize(file_get_contents($file));
        } else {
            return @require $file;
        }
    }

}