A PHP background processing class to execure an process in background.

BackgroundProcess.php

<?php

/**
 * -------------------------------------------------------------------------------------
 * Written on - 13-June-2018 14:30:00
 * Wtirren By - Mukesh Patel (http://patelworld.in) | (http://facebook.com/patelnwd)
 * =====================================================================================
 *
 * This Class is written for Process Background Process.
 * Most of cases we saw we need to execute some process without user interaction,
 * why not do it in background.
 * -----------------------------------------------------------------------------------------
 * USES:
 * $backProcessObj = new BackgroundProcess($arg1, $arg2, $arg3, $arg4);
 * $request_json['request'] = [
 * 	[
 *		'type'  => 'GET',
 * 		'url'   => BASE_URL . 'reports/triggerBackgroundMail',
 * 		'function_data' => []
 * 	]
 * ];
 * $backProcessObj->request(json_encode($request_json))->run();
 * -------------------------------------------------------------------------------------
 */

class BackgroundProcess{

	private $pid;
	private $pid_file;
	private $ext;
	private $req_path;
	private $php_exe_path;
	private $port;
	protected $time_out;
	protected $request;

	/**
	 * Constructor need to atleast first two parameter
	 * @param [type] $php_exe_path [path where your server php.exe exist]
	 * @param [type] $request_path [path where your background process file is going to prepare, same file will be read from background process handler]
	 * @param [type] $port         [pass server port ignore it, if it is 80]
	 * @param string $ext          [background Process file extension]
	 */
	public function __construct($php_exe_path = null, $request_path = null, $port = null, $ext = '.pid.json'){
		$this->ext = (false === preg_match('/(\.[a-z]+)$/i', $ext)) ? '.pid' : $ext;
		$this->req_path = $this->validateReqPath($request_path);
		$this->php_exe_path = $php_exe_path;
		$this->port = (null === $port && !is_numeric($port)) ? $this->getPort() : $port;
		$this->time_out = 30;
		$this->request = [];
	}

	private function validateReqPath($request_path = null){
		if($request_path !== null)
			return $request_path;
	}

	private function log_error($exception_obj){
    	// TODO: write exteption message in a common file
	}

	/**
	 * Get created process id
	 * @return [type] [description]
	 */
	public function getPid(){
		return $this->pid;
	}

	/**
	 * Get Process file with full path
	 * @return [type] [description]
	 */
	public function getPidFile(){
		return $this->pid_file;
	}

	/**
	 * logic to create pid
	 * @return [type] [description]
	 */
	private function createPid(){
		$this->pid =  str_replace(["."," "],'_', microtime(true));
		// $this->pid =  str_replace(["."," "],'_', date('d_m_y'));
		return $this->pid;
	}

	/**
	 * set server Port no
	 */
	public function setPort(){
		return $_SERVER['SERVER_PORT'];
	}

	/**
	 * get port number
	 * @return [type] [description]
	 */
	public function getPort(){
		return $this->setPort();
	}

	/**
	 * get process file extention name
	 * @return [type] [description]
	 */
	public function getExt(){
		return $this->ext;
	}

	/**
	 * Get Requested process Json
	 * @return [type] [description]
	 */
	public function getRequestJson(){
		return file_get_contents($this->pid_file);
	}

	/**
	 * Get requested Process JSON as array
	 * @return [type] [description]
	 */
	public function getRequest(){
		return json_decode($this->getRequestJson(), true);
	}

	/**
	 * Delete Background Process
	 * @return [type] [description]
	 */
	private function deleteRequest(){
		if(file_exists($this->pid_file)){
			unlink($this->pid_file);
		}
		return $this;
	}

	/**
	 * Create/Write Main request file
	 * @param  [type] $request_json [description]
	 * @return [type]               [description]
	 */
	public function request($request_json = null){
		try{
			$this->pid_file = $this->req_path.$this->createPid().$this->ext;
			if(file_exists($this->pid_file)){
				unlink($this->pid_file);
			}

			if(!is_dir($this->req_path)){
				mkdir($this->req_path, 0777, true);
			}
			file_put_contents($this->pid_file, $request_json, FILE_APPEND | LOCK_EX);
			return $this;
		}
		catch(Exception $e){
			return null;
		}
	}

	/**
	 * Background Process Execution
	 * @param  [type] $type   [description]
	 * @param  [type] $url    [description]
	 * @param  [type] $params [description]
	 * @return [type]         [description]
	 */
	private function exec($type = null, $url = null, $params = null){
		$errno = null;
		$errstr = null;
		$parts=parse_url($url);
		// GET
		if($type === 'GET'){
			$parts['path'] .= isset($parts['query']) ? '?'. $parts['query'] : '';
			$request =  "GET ".$parts['path']." HTTP/1.1\r\n";
			$request .= "Host: ". $parts['host'] ."\r\n";
			$request .= "Connection: Close\r\n\r\n";

		}
		// POST
		if($type === 'POST'){
			foreach ($params as $key => &$val) {
				if (is_array($val)) $val = implode(',', $val);
				$post_params[] = $key.'='.urlencode($val);
			}
			$post_string = implode('&', $post_params);
			$request = "POST ".$parts['path']." HTTP/1.1\r\n";
			$request.= "Host: ".$parts['host']."\r\n";
			$request.= "Content-Type: application/x-www-form-urlencoded\r\n";
			$request.= "Content-Length: ".strlen($post_string)."\r\n";
		}
		$request.= "Connection: Close\r\n\r\n";
		$fp = @fsockopen($parts['host'], isset($parts['port']) ? $parts['port'] : $this->port, $errno, $errstr, $this->time_out);
		if (!$fp) {
			return null;
		}
		fputs($fp,$request);
		fclose($fp);
		return true;
	}

	/**
	 * Get background process as array and process it one by one on behalf of GET/POST
	 * @return [type] [description]
	 */
	public function run(){
		if(isset($this->pid_file)){
			if(file_exists($this->pid_file)){
				$request_json = $this->getRequest();
				foreach($request_json['request'] as $req){
					if($req['type'] === 'POST' || $req['type'] === 'GET'){
						$req_params = (!isset($req['params'])) ? null : $req['params'];
						$req['status'] = $this->exec($req['type'], $req['url'].'?f='.$this->pid_file, $req_params);
					}
					else{
						$req['status'] = 'unknown request type';
					}
					$this->request[] = $req;
				}
				// $this->deleteRequest();
			}
		}
		return $this;
	}
}