PHP 大文件分块上传 底层实现

<?php
class clsSliceUpload
{
    private $_blockFile;       // 分块文件
    private $_blockIdx;       //  第几个文件块
    private $_blockTotal;     //  文件块总数
    private $_config ;
    private $_destination_path = '';//目的路径
    private $_tmp_upload_path = '';//临时路径

    /**
     *
     * @param $blockFile 分块文件
     * @param array $config 基础配置
     */
    public function __construct($blockFile,array $config = [])
    {

        $this->_blockFile = $blockFile;
        $this->_config    = $config;
        $this->init($this->_config);
        $this->moveFile();
    
    }

    /**
     * 基础初始化
     * @param $configs
     */
    private function init($configs){
        $this->_blockIdx   = $configs['blockIdx']; 
        $this->_blockTotal = $configs['blockTotal']; 
        $this->_tmp_upload_path = $configs['tmp_upload_path'];
        $this->_destination_path = $configs['destination_path']; //目的路径
    }
    //  移动文件
    private function moveFile()
    {
         move_uploaded_file($this->_blockFile, $this->_tmp_upload_path);
        // 保持存活状态
        $_SESSION['sess_time'] = time();
        //开始合并文件
        $this->mergeFile();
    }

    /**
     *
     */
    private function mergeFile(){

        $filepath = $this->_destination_path;
        $fp = fopen($filepath, 'ab');
        $blob = file_get_contents($this->_tmp_upload_path);
        fwrite($fp,$blob);
        fclose($fp);
        unlink($this->_tmp_upload_path);

    }
    
    public function api()
    {
        $data = [];
        if ($this->_blockIdx == $this->_blockTotal) {
            if (file_exists($this->_destination_path)) {
                $data['file_path'] = $this->_destination_path;
            }
        } else {
            $data = [
                'percent' =>number_format($this->_blockIdx*100/$this->_blockTotal,2),
            ];
        }
        echo clsFunction::json($data);
    }
}
?>