<?php
/*
        ---------- RollingCurlX 3.0.2 -----------
        an easy to use curl_multi wrapper for php

            Copyright (c) 2015-2017 Marcus Leath
                    License: MIT
        https://github.com/marcushat/RollingCurlX
*/

Class RollingCurlX {
		private $_curl_version;

		private $_maxConcurrent = 0; //max. number of simultaneous connections allowed
		private $_options = []; //shared cURL options
		private $_headers = []; //shared cURL request headers
		private $_callback = NULL; //default callback
		private $_timeout = 5000; //all requests must be completed by this time
		public $requests = []; //request_queue


		function __construct($max_concurrent = 10) {
				$this->setMaxConcurrent($max_concurrent);

				$this->_curl_version = curl_version()['version'];
		}

		public function setMaxConcurrent($max_requests) {
				if($max_requests > 0) {
						$this->_maxConcurrent = $max_requests;
				}
		}

		public function setOptions(array $options) {
				$this->_options = $options;
		}

		public function setHeaders(array $headers) {
				if(is_array($headers) && count($headers)) {
						$this->_headers = $headers;
				}
		}

		public function setCallback(callable $callback) {
				$this->_callback = $callback;
		}

		public function setTimeout($timeout) { //in milliseconds
				if($timeout > 0) {
						$this->_timeout = $timeout;
				}
		}

		//Add a request to the request queue
		public function addRequest(
				$url,
				$post_data = NULL,
				callable $callback = NULL, //individual callback
				$user_data = NULL,
				array $options = NULL, //individual cURL options
				array $headers = NULL //individual cURL request headers
		) { //Add to request queue
				$this->requests[] = [
						'url' => $url,
						'post_data' => ($post_data) ? $post_data : NULL,
						'callback' => ($callback) ? $callback : $this->_callback,
						'user_data' => ($user_data) ? $user_data : NULL,
						'options' => ($options) ? $options : NULL,
						'headers' => ($headers) ? $headers : NULL
				];
				return count($this->requests) - 1; //return request number/index
		}

		//Reset request queue
		public function reset() {
				$this->requests = [];
		}

		private function normalize_headers(array $headers) {
				$normalized = [];
				foreach($headers as $key => $header) {
						if(is_string($key)) {
								$normal = "$key: $header";
						} else {
								$header;
						}
						$normalized = [];
				}
		}

		//Execute the request queue
		public function execute() {
				//the request map that maps the request queue to request curl handles
				$requests_map = [];
				$multi_handle = curl_multi_init();
				$num_outstanding = 0;

				//start processing the initial request queue
				$num_initial_requests = min($this->_maxConcurrent, count($this->requests));
				for($i = 0; $i < $num_initial_requests; $i++) {
						$this->init_request($i, $multi_handle, $requests_map);
						$num_outstanding++;
				}

				do{
						do{
								$mh_status = curl_multi_exec($multi_handle, $active);
						} while($mh_status == CURLM_CALL_MULTI_PERFORM);
						if($mh_status != CURLM_OK) {
								break;
						}

						//a request is just completed, find out which one
						while($completed = curl_multi_info_read($multi_handle)) {
								$this->process_request($completed, $multi_handle, $requests_map);
								$num_outstanding--;

								//try to add/start a new requests to the request queue
								while(
										$num_outstanding < $this->_maxConcurrent && //under the limit
										$i < count($this->requests) && isset($this->requests[$i]) // requests left
								) {
										$this->init_request($i, $multi_handle, $requests_map);
										$num_outstanding++;
										$i++;
								}
						}

						usleep(15); //save CPU cycles, prevent continuous checking
				} while ($active || count($requests_map)); //End do-while

				$this->reset();
				curl_multi_close($multi_handle);
		}



		//Build individual cURL options for a request
		private function buildOptions(array $request) {
				$url = $request['url'];
				$post_data = $request['post_data'];
				$individual_opts = $request['options'];
				$individual_headers = $request['headers'];

				$options = ($individual_opts) ? $individual_opts + $this->_options : $this->_options; //merge shared and individual request options
				$headers = ($individual_headers) ? $individual_headers + $this->_headers : $this->_headers; //merge shared and individual request headers

				//the below will overide the corresponding default or individual options
				$options[CURLOPT_RETURNTRANSFER] = true;

				$options[CURLOPT_NOSIGNAL] = 1;

				if(version_compare($this->_curl_version, '7.16.2') >= 0) {
						$options[CURLOPT_CONNECTTIMEOUT_MS] = $this->_timeout;
						$options[CURLOPT_TIMEOUT_MS] = $this->_timeout;
						unset($options[CURLOPT_CONNECTTIMEOUT]);
						unset($options[CURLOPT_TIMEOUT]);
				} else {
						$options[CURLOPT_CONNECTTIMEOUT] = round($this->_timeout / 1000);
						$options[CURLOPT_TIMEOUT] = round($this->_timeout / 1000);
						unset($options[CURLOPT_CONNECTTIMEOUT_MS]);
						unset($options[CURLOPT_TIMEOUT_MS]);
				}

				if($url) {
						$options[CURLOPT_URL] = $url;
				}

				if($headers) {
						$options[CURLOPT_HTTPHEADER] = $headers;
				}

				// enable POST method and set POST parameters
				if($post_data !== null) {
						$options[CURLOPT_POST] = 1;
						$options[CURLOPT_POSTFIELDS] = is_array($post_data)? http_build_query($post_data) : $post_data;
				}
				return $options;
		}


		private function init_request($request_num, $multi_handle, &$requests_map) {
				$request =& $this->requests[$request_num];
				$this->addTimer($request);

				$ch = curl_init();
				$options = $this->buildOptions($request);
				$request['options_set'] = $options; //merged options
				$opts_set = curl_setopt_array($ch, $options);
				if(!$opts_set) {
						echo 'options not set';
						exit;
				}
				curl_multi_add_handle($multi_handle, $ch);

				//add curl handle of a new request to the request map
				$ch_hash = (string) $ch;
				$requests_map[$ch_hash] = $request_num;
		}


		private function process_request($completed, $multi_handle, array &$requests_map) {
				$ch = $completed['handle'];
				$ch_hash = (string) $ch;
				$request =& $this->requests[$requests_map[$ch_hash]]; //map handler to request index to get request info

				$request_info = curl_getinfo($ch);
				$request_info['curle'] = $completed['result'];
				$request_info['curle_msg'] = isset($this->curle_msgs[$completed['result']]) ? $this->curle_msgs[$completed['result']] : curl_strerror($completed['result']);
				$request_info['handle'] = $ch;
				$request_info['time'] = $time = $this->stopTimer($request); //record request time
				$request_info['url_raw'] = $url = $request['url'];
				$request_info['user_data'] = $user_data = $request['user_data'];

				if(curl_errno($ch) !== 0 || intval($request_info['http_code']) !== 200) { //if server responded with http error
						$response = false;
				} else { //sucessful response
						$response = curl_multi_getcontent($ch);
				}

				//get request info
				$callback = $request['callback'];
				$options = $request['options_set'];

				if($response && !empty($options[CURLOPT_HEADER])) {
						$k = intval($request_info['header_size']);
						$request_info['response_header'] = substr($response, 0, $k);
						$response = substr($response, $k);
				}

				//remove completed request and its curl handle
				unset($requests_map[$ch_hash]);
				curl_multi_remove_handle($multi_handle, $ch);

				//call the callback function and pass request info and user data to it
				if($callback) {
						call_user_func($callback, $response, $url, $request_info, $user_data, $time);
				}
				$request = NULL; //free up memory now just incase response was large
		}


		private function check_for_timeouts($mh) { //DO NOT USE!!! Not implemented yet.
				$now = microtime(true);
				$requests = $this->_requests;
				foreach($requests as $request) {
						$timeout = $request->timeout;
						$start_time = $request->start_time;
						$ch = $request->handle;
						if($now >=  $start_time + $timeout) {
								curl_multi_remove_handle($mh, $ch);
						}
				}
		}


		private function addTimer(array &$request) { //adds timer object to request
				$request['timer'] = microtime(true); //start time
				$request['time'] = false; //default if not overridden by time later
		}

		private function stopTimer(array &$request) {
				$elapsed = microtime(true) - $request['timer'];
				$request['time'] = $elapsed;
				unset($request['timer']);
				return $elapsed;
		}

		private $curle_msgs = [CURLE_OK => 'OK', CURLE_UNSUPPORTED_PROTOCOL => 'UNSUPPORTED_PROTOCOL', CURLE_FAILED_INIT => 'FAILED_INIT', CURLE_URL_MALFORMAT => 'URL_MALFORMAT', CURLE_URL_MALFORMAT_USER => 'URL_MALFORMAT_USER', CURLE_COULDNT_RESOLVE_PROXY => 'COULDNT_RESOLVE_PROXY', CURLE_COULDNT_RESOLVE_HOST => 'COULDNT_RESOLVE_HOST', CURLE_COULDNT_CONNECT => 'COULDNT_CONNECT', CURLE_FTP_WEIRD_SERVER_REPLY => 'FTP_WEIRD_SERVER_REPLY', CURLE_FTP_ACCESS_DENIED => 'FTP_ACCESS_DENIED', CURLE_FTP_USER_PASSWORD_INCORRECT => 'FTP_USER_PASSWORD_INCORRECT', CURLE_FTP_WEIRD_PASS_REPLY => 'FTP_WEIRD_PASS_REPLY', CURLE_FTP_WEIRD_USER_REPLY => 'FTP_WEIRD_USER_REPLY', CURLE_FTP_WEIRD_PASV_REPLY => 'FTP_WEIRD_PASV_REPLY', CURLE_FTP_WEIRD_227_FORMAT => 'FTP_WEIRD_227_FORMAT', CURLE_FTP_CANT_GET_HOST => 'FTP_CANT_GET_HOST', CURLE_FTP_CANT_RECONNECT => 'FTP_CANT_RECONNECT', CURLE_FTP_COULDNT_SET_BINARY => 'FTP_COULDNT_SET_BINARY', CURLE_PARTIAL_FILE => 'PARTIAL_FILE', CURLE_FTP_COULDNT_RETR_FILE => 'FTP_COULDNT_RETR_FILE', CURLE_FTP_WRITE_ERROR => 'FTP_WRITE_ERROR', CURLE_FTP_QUOTE_ERROR => 'FTP_QUOTE_ERROR', CURLE_HTTP_NOT_FOUND => 'HTTP_NOT_FOUND', CURLE_WRITE_ERROR => 'WRITE_ERROR', CURLE_MALFORMAT_USER => 'MALFORMAT_USER', CURLE_FTP_COULDNT_STOR_FILE => 'FTP_COULDNT_STOR_FILE', CURLE_READ_ERROR => 'READ_ERROR', CURLE_OUT_OF_MEMORY => 'OUT_OF_MEMORY', CURLE_OPERATION_TIMEOUTED => 'OPERATION_TIMEOUTED', CURLE_FTP_COULDNT_SET_ASCII => 'FTP_COULDNT_SET_ASCII', CURLE_FTP_PORT_FAILED => 'FTP_PORT_FAILED', CURLE_FTP_COULDNT_USE_REST => 'FTP_COULDNT_USE_REST', CURLE_FTP_COULDNT_GET_SIZE => 'FTP_COULDNT_GET_SIZE', CURLE_HTTP_RANGE_ERROR => 'HTTP_RANGE_ERROR', CURLE_HTTP_POST_ERROR => 'HTTP_POST_ERROR', CURLE_SSL_CONNECT_ERROR => 'SSL_CONNECT_ERROR', CURLE_FTP_BAD_DOWNLOAD_RESUME => 'FTP_BAD_DOWNLOAD_RESUME', CURLE_FILE_COULDNT_READ_FILE => 'FILE_COULDNT_READ_FILE', CURLE_LDAP_CANNOT_BIND => 'LDAP_CANNOT_BIND', CURLE_LDAP_SEARCH_FAILED => 'LDAP_SEARCH_FAILED', CURLE_LIBRARY_NOT_FOUND => 'LIBRARY_NOT_FOUND', CURLE_FUNCTION_NOT_FOUND => 'FUNCTION_NOT_FOUND', CURLE_ABORTED_BY_CALLBACK => 'ABORTED_BY_CALLBACK', CURLE_BAD_FUNCTION_ARGUMENT => 'BAD_FUNCTION_ARGUMENT', CURLE_BAD_CALLING_ORDER => 'BAD_CALLING_ORDER', CURLE_HTTP_PORT_FAILED => 'HTTP_PORT_FAILED', CURLE_BAD_PASSWORD_ENTERED => 'BAD_PASSWORD_ENTERED', CURLE_TOO_MANY_REDIRECTS => 'TOO_MANY_REDIRECTS', CURLE_UNKNOWN_TELNET_OPTION => 'UNKNOWN_TELNET_OPTION', CURLE_TELNET_OPTION_SYNTAX => 'TELNET_OPTION_SYNTAX', CURLE_OBSOLETE => 'OBSOLETE', CURLE_SSL_PEER_CERTIFICATE => 'SSL_PEER_CERTIFICATE', CURLE_GOT_NOTHING => 'GOT_NOTHING', CURLE_SSL_ENGINE_NOTFOUND => 'SSL_ENGINE_NOTFOUND', CURLE_SSL_ENGINE_SETFAILED => 'SSL_ENGINE_SETFAILED', CURLE_SEND_ERROR => 'SEND_ERROR', CURLE_RECV_ERROR => 'RECV_ERROR', CURLE_SHARE_IN_USE => 'SHARE_IN_USE', CURLE_SSL_CERTPROBLEM => 'SSL_CERTPROBLEM', CURLE_SSL_CIPHER => 'SSL_CIPHER', CURLE_SSL_CACERT => 'SSL_CACERT', CURLE_BAD_CONTENT_ENCODING => 'BAD_CONTENT_ENCODING', CURLE_LDAP_INVALID_URL => 'LDAP_INVALID_URL', CURLE_FILESIZE_EXCEEDED => 'FILESIZE_EXCEEDED', CURLE_FTP_SSL_FAILED => 'FTP_SSL_FAILED', CURLE_SSH => 'SSH'
		];
}
?>