Detailed explanation of the case of php curl batch processing to achieve controllable concurrent asynchronous operations

<?php
/**
 * cURL批量处理 工具类
 * 
 * @since Version 1.0
 * @author Justmepzy <justmepzy@gmail.com>
 * @link http://t.qq.com/JustPzy
 */
/**
 *单一的请求对象
 */
class Curl_request {
 public $url   = &#39;&#39;;
 public $method   = &#39;GET&#39;;
 public $post_data  = null;
 public $headers  = null;
 public $options  = null;
 /**
  * 
  * @param string $url
  * @param string $method
  * @param string $post_data
  * @param string $headers
  * @param array $options
  * @return void
  */
 public function construct($url, $method = &#39;GET&#39;, $post_data = null, $headers = null, $options = null) {
  $this->url = $url;
  $this->method = strtoupper( $method );
  $this->post_data = $post_data;
  $this->headers = $headers;
  $this->options = $options;
 }
 /**
  * @return void
  */
 public function destruct() {
  unset ( $this->url, $this->method, $this->post_data, $this->headers, $this->options );
 }
}
/**
 * 包含请求列队处理
 */
class Curl {
 /**
  * 请求url个数
  * @var int
  */
 private $size    = 5;
 /**
  * 等待所有cURL批处理中的活动连接等待响应时间
  * @var int
  */
 private $timeout   = 5;
 /**
  * 完成请求回调函数
  * @var string
  */
 private $callback   = null;
 /**
  * cRUL配置
  * @var array
  */
 private $options   = array (CURLOPT_SSL_VERIFYPEER => 0,CURLOPT_RETURNTRANSFER => 1,CURLOPT_CONNECTTIMEOUT => 30 );
 /**
  * 请求头
  * @var array
  */
 private $headers   = array ();
 /**
  * 请求列队
  * @var array
  */
 private $requests   = array ();
 /**
  * 请求列队索引
  * @var array
  */
 private $request_map  = array ();
 /**
  * 错误
  * @var array
  */
 private $errors   = array ();
 /**
  * @access public
  * @param string $callback 回调函数
  * 该函数有4个参数($response,$info,$error,$request)
  * $response url返回的body
  * $info  cURL连接资源句柄的信息
  * $error  错误
  * $request  请求对象
  */
 public function construct($callback = null) {
  $this->callback = $callback;
 }
 /**
  * 添加一个请求对象到列队
  * @access public
  * @param object $request
  * @return boolean
  */
 public function add($request) {
  $this->requests [] = $request;
  return TRUE;
 }
 /**
  * 创建一个请求对象并添加到列队
  * @access public
  * @param string $url
  * @param string $method
  * @param string $post_data
  * @param string $headers
  * @param array $options
  * @return boolean
  */
 public function request($url, $method = &#39;GET&#39;, $post_data = null, $headers = null, $options = null) {
  $this->requests [] = new Curl_request ( $url, $method, $post_data, $headers, $options );
  return TRUE;
 }
 /**
  * 创建GET请求对象
  * @access public
  * @param string $url
  * @param string $headers
  * @param array $options
  * @return boolean
  */
 public function get($url, $headers = null, $options = null) {
  return $this->request ( $url, "GET", null, $headers, $options );
 }
 /**
  * 创建一个POST请求对象
  * @access public
  * @param string $url
  * @param string $post_data
  * @param string $headers
  * @param array $options
  * @return boolean
  */
 public function post($url, $post_data = null, $headers = null, $options = null) {
  return $this->request ( $url, "POST", $post_data, $headers, $options );
 }
 /**
  * 执行cURL
  * @access public
  * @param int $size 最大连接数
  * @return Ambigous <boolean, mixed>|boolean
  */
 public function execute($size = null) {
  if (sizeof ( $this->requests ) == 1) {
   return $this->single_curl ();
  } else {
   return $this->rolling_curl ( $size );
  }
 }
 /**
  * 单个url请求
  * @access private
  * @return mixed|boolean
  */
 private function single_curl() {
  $ch = curl_init ();
  $request = array_shift ( $this->requests );
  $options = $this->get_options ( $request );
  curl_setopt_array ( $ch, $options );
  $output = curl_exec ( $ch );
  $info = curl_getinfo ( $ch );
  // it&#39;s not neccesary to set a callback for one-off requests
  if ($this->callback) {
   $callback = $this->callback;
   if (is_callable ( $this->callback )) {
    call_user_func ( $callback, $output, $info, $request );
   }
  } else
   return $output;
  return true;
 }
 /**
  * 多个url请求
  * @access private
  * @param int $size 最大连接数
  * @return boolean
  */
 private function rolling_curl($size = null) {
  if ($size)
   $this->size = $size;
  else 
   $this->size = count($this->requests);
  if (sizeof ( $this->requests ) < $this->size)
   $this->size = sizeof ( $this->requests );
  if ($this->size < 2)
   $this->set_error ( &#39;size must be greater than 1&#39; );
  $master = curl_multi_init ();
  //添加cURL连接资源句柄到map索引
  for($i = 0; $i < $this->size; $i ++) {
   $ch = curl_init ();
   $options = $this->get_options ( $this->requests [$i] );
   curl_setopt_array ( $ch, $options );
   curl_multi_add_handle ( $master, $ch );
   $key = ( string ) $ch;
   $this->request_map [$key] = $i;
  }
  $active = $done = null;
  do {
   while ( ($execrun = curl_multi_exec ( $master, $active )) == CURLM_CALL_MULTI_PERFORM )
    ;
   if ($execrun != CURLM_OK)
    break;
   //有一个请求完成则回调
   while ( $done = curl_multi_info_read ( $master ) ) {
    //$done 完成的请求句柄
    $info = curl_getinfo ( $done [&#39;handle&#39;] );//
    $output = curl_multi_getcontent ( $done [&#39;handle&#39;] );//
    $error = curl_error ( $done [&#39;handle&#39;] );//
    $this->set_error ( $error );
    //调用回调函数,如果存在的话
    $callback = $this->callback;
    if (is_callable ( $callback )) {
     $key = ( string ) $done [&#39;handle&#39;];
     $request = $this->requests [$this->request_map [$key]];
     unset ( $this->request_map [$key] );
     call_user_func ( $callback, $output, $info, $error, $request );
    }
    curl_close ( $done [&#39;handle&#39;] );
    //从列队中移除已经完成的request
    curl_multi_remove_handle ( $master, $done [&#39;handle&#39;] );
   }
   //等待所有cURL批处理中的活动连接
   if ($active)
    curl_multi_select ( $master, $this->timeout );
  } while ( $active );
  //完成关闭
  curl_multi_close ( $master );
  return true;
 }
 /**
  * 获取没得请求对象的cURL配置
  * @access private
  * @param object $request
  * @return array
  */
 private function get_options($request) {
  $options = $this->get ( &#39;options&#39; );
  if (ini_get ( &#39;safe_mode&#39; ) == &#39;Off&#39; || ! ini_get ( &#39;safe_mode&#39; )) {
   $options [CURLOPT_FOLLOWLOCATION] = 1;
   $options [CURLOPT_MAXREDIRS] = 5;
  }
  $headers = $this->get ( &#39;headers&#39; );
  if ($request->options) {
   $options = $request->options + $options;
  }
  $options [CURLOPT_URL] = $request->url;
  if ($request->post_data && strtolower($request->method) == &#39;post&#39; ) {
   $options [CURLOPT_POST] = 1;
   $options [CURLOPT_POSTFIELDS] = $request->post_data;
  }
  if ($headers) {
   $options [CURLOPT_HEADER] = 0;
   $options [CURLOPT_HTTPHEADER] = $headers;
  }
  return $options;
 }
 /**
  * 设置错误信息
  * @access public
  * @param string $msg
  */
 public function set_error($msg) {
  if (! empty ( $msg ))
   $this->errors [] = $msg;
 }
 /**
  * 获取错误信息
  * @access public
  * @param string $open
  * @param string $close
  * @return string
  */
 public function display_errors($open = &#39;<p>&#39;, $close = &#39;</p>&#39;) {
  $str = &#39;&#39;;
  foreach ( $this->errors as $val ) {
   $str .= $open . $val . $close;
  }
  return $str;
 }
 /**
  * @access public
  * @param string $name
  * @param string $value
  * @return boolean
  */
 public function set($name, $value) {
  if ($name == &#39;options&#39; || $name == &#39;headers&#39;) {
   $this->{$name} = $value + $this->{$name};
  } else {
   $this->{$name} = $value;
  }
  return TRUE;
 }
 /**
  * 
  * @param string $name
  * @return mixed
  * @access public
  */
 public function get($name) {
  return (isset ( $this->{$name} )) ? $this->{$name} : null;
 }
 /**
  * @return void
  * @access public
  */
 public function destruct() {
  unset ( $this->size, $this->timeout, $this->callback, $this->options, $this->headers, $this->requests, $this->request_map, $this->errors );
 }
}
// END Curl Class
/* End of file curl.class.php */