Merge pull request php-curl-class#468 from zachborboa/master

Implement Curl::setRetry()

Author: zachborboa

README.md

@@ -194,6 +194,7 @@ More examples are available under [/examples](https://github.com/php-curl-class/
 Curl::__construct($base_url = null)
 Curl::__destruct()
 Curl::__get($name)
+Curl::attemptRetry()
 Curl::beforeSend($callback)
 Curl::buildPostData($data)
 Curl::call()
@@ -203,6 +204,7 @@ Curl::delete($url, $query_parameters = array(), $data = array())
 Curl::download($url, $mixed_filename)
 Curl::error($callback)
 Curl::exec($ch = null)
+Curl::execDone()
 Curl::get($url, $data = array())
 Curl::getCookie($key)
 Curl::getInfo($opt = null)
@@ -238,6 +240,7 @@ Curl::setOpts($options)
 Curl::setPort($port)
 Curl::setReferer($referer)
 Curl::setReferrer($referrer)
+Curl::setRetry($mixed)
 Curl::setTimeout($seconds)
 Curl::setUrl($url, $mixed_data = '')
 Curl::setUserAgent($user_agent)
@@ -280,6 +283,7 @@ MultiCurl::setOpts($options)
 MultiCurl::setPort($port)
 MultiCurl::setReferer($referer)
 MultiCurl::setReferrer($referrer)
+MultiCurl::setRetry($mixed)
 MultiCurl::setTimeout($seconds)
 MultiCurl::setUrl($url)
 MultiCurl::setUserAgent($user_agent)

examples/get_with_callable_retry.php

@@ -0,0 +1,19 @@
+<?php
+require __DIR__ . '/../vendor/autoload.php';
+
+use \Curl\Curl;
+
+$curl = new Curl();
+$curl->setRetry(function ($instance) {
+    return $instance->retries < 3;
+});
+$curl->get('https://httpbin.org/status/503');
+
+if ($curl->error) {
+    echo 'Error: ' . $curl->errorCode . ': ' . $curl->errorMessage . "\n";
+    echo 'attempts: ' . $curl->attempts . "\n";
+    echo 'retries: ' . $curl->retries . "\n";
+} else {
+    echo 'Response:' . "\n";
+    var_dump($curl->response);
+}

examples/get_with_retry.php

@@ -0,0 +1,19 @@
+<?php
+require __DIR__ . '/../vendor/autoload.php';
+
+use \Curl\Curl;
+
+$max_retries = 3;
+
+$curl = new Curl();
+$curl->setRetry($max_retries);
+$curl->get('https://httpbin.org/status/503');
+
+if ($curl->error) {
+    echo 'Error: ' . $curl->errorCode . ': ' . $curl->errorMessage . "\n";
+    echo 'attempts: ' . $curl->attempts . "\n";
+    echo 'retries: ' . $curl->retries . "\n";
+} else {
+    echo 'Response:' . "\n";
+    var_dump($curl->response);
+}

examples/multi_curl_get_with_callable_retry.php

@@ -0,0 +1,20 @@
+<?php
+require __DIR__ . '/../vendor/autoload.php';
+
+use \Curl\MultiCurl;
+
+$multi_curl = new MultiCurl();
+$multi_curl->setRetry(function ($instance) {
+    return $instance->retries < 3;
+});
+$multi_curl->complete(function ($instance) {
+    echo 'call to "' . $instance->url . '" completed.' . "\n";
+    echo 'attempts: ' . $instance->attempts . "\n";
+    echo 'retries: ' . $instance->retries . "\n";
+});
+
+$multi_curl->addGet('https://httpbin.org/status/503?a');
+$multi_curl->addGet('https://httpbin.org/status/503?b');
+$multi_curl->addGet('https://httpbin.org/status/503?c');
+
+$multi_curl->start();

examples/multi_curl_get_with_retry.php

@@ -0,0 +1,20 @@
+<?php
+require __DIR__ . '/../vendor/autoload.php';
+
+use \Curl\MultiCurl;
+
+$max_retries = 3;
+
+$multi_curl = new MultiCurl();
+$multi_curl->setRetry($max_retries);
+$multi_curl->complete(function ($instance) {
+    echo 'call to "' . $instance->url . '" completed.' . "\n";
+    echo 'attempts: ' . $instance->attempts . "\n";
+    echo 'retries: ' . $instance->retries . "\n";
+});
+
+$multi_curl->addGet('https://httpbin.org/status/503?a');
+$multi_curl->addGet('https://httpbin.org/status/503?b');
+$multi_curl->addGet('https://httpbin.org/status/503?c');
+
+$multi_curl->start();

src/Curl/Curl.php

@@ -41,6 +41,12 @@ class Curl
     public $completeFunction = null;
     public $fileHandle = null;
 
+    public $attempts = 0;
+    public $retries = 0;
+    public $isChildOfMultiCurl = false;
+    public $remainingRetries = 0;
+    public $retryDecider = null;
+
     private $cookies = array();
     private $headers = array();
     private $options = array();
@@ -335,6 +341,8 @@ public function error($callback)
      */
     public function exec($ch = null)
     {
+        $this->attempts += 1;
+
         if ($ch === null) {
             $this->responseCookies = array();
             $this->call($this->beforeSendFunction);
@@ -382,6 +390,22 @@ public function exec($ch = null)
         }
         $this->errorMessage = $this->curlError ? $this->curlErrorMessage : $this->httpErrorMessage;
 
+        // Allow multicurl to attempt retry as needed.
+        if ($this->isChildOfMultiCurl) {
+            return;
+        }
+
+        if ($this->attemptRetry()) {
+            return $this->exec($ch);
+        }
+
+        $this->execDone();
+
+        return $this->response;
+    }
+
+    public function execDone()
+    {
         if ($this->error) {
             $this->call($this->errorFunction);
         } else {
@@ -394,8 +418,6 @@ public function exec($ch = null)
         if (!($this->fileHandle === null)) {
             $this->downloadComplete($this->fileHandle);
         }
-
-        return $this->response;
     }
 
     /**
@@ -1010,6 +1032,25 @@ public function setReferrer($referrer)
         $this->setOpt(CURLOPT_REFERER, $referrer);
     }
 
+    /**
+     * Set Retry
+     *
+     * Number of retries to attempt or decider callable. Maximum number of
+     * attempts is $maximum_number_of_retries + 1.
+     *
+     * @access public
+     * @param  $mixed
+     */
+    public function setRetry($mixed)
+    {
+        if (is_callable($mixed)) {
+            $this->retryDecider = $mixed;
+        } elseif (is_int($mixed)) {
+            $maximum_number_of_retries = $mixed;
+            $this->remainingRetries = $maximum_number_of_retries;
+        }
+    }
+
     /**
      * Set Timeout
      *
@@ -1046,6 +1087,31 @@ public function setUserAgent($user_agent)
         $this->setOpt(CURLOPT_USERAGENT, $user_agent);
     }
 
+    /**
+     * Attempt Retry
+     *
+     * @access public
+     */
+    public function attemptRetry()
+    {
+        $attempt_retry = false;
+        if ($this->error) {
+            if ($this->retryDecider === null) {
+                $attempt_retry = $this->remainingRetries >= 1;
+            } else {
+                $func = $this->retryDecider;
+                $attempt_retry = $func($this);
+            }
+            if ($attempt_retry) {
+                $this->retries += 1;
+                if ($this->remainingRetries) {
+                    $this->remainingRetries -= 1;
+                }
+            }
+        }
+        return $attempt_retry;
+    }
+
     /**
      * Success
      *

src/Curl/MultiCurl.php

@@ -18,6 +18,8 @@ class MultiCurl
     private $errorFunction = null;
     private $completeFunction = null;
 
+    private $retry = null;
+
     private $cookies = array();
     private $headers = array();
     private $options = array();
@@ -587,6 +589,20 @@ public function setReferrer($referrer)
         $this->setOpt(CURLOPT_REFERER, $referrer);
     }
 
+    /**
+     * Set Retry
+     *
+     * Number of retries to attempt or decider callable. Maximum number of
+     * attempts is $maximum_number_of_retries + 1.
+     *
+     * @access public
+     * @param  $mixed
+     */
+    public function setRetry($mixed)
+    {
+        $this->retry = $mixed;
+    }
+
     /**
      * Set Timeout
      *
@@ -661,17 +677,31 @@ public function start()
                             $ch->curlErrorCode = $info_array['result'];
                             $ch->exec($ch->curl);
 
-                            // Remove completed instance from active curls.
-                            unset($this->activeCurls[$key]);
-
-                            // Start a new request before removing the handle of the completed one.
-                            if (count($this->curls) >= 1) {
-                                $this->initHandle(array_shift($this->curls));
+                            if ($ch->attemptRetry()) {
+                                // Remove completed handle before adding again in order to retry request.
+                                curl_multi_remove_handle($this->multiCurl, $ch->curl);
+
+                                $curlm_error_code = curl_multi_add_handle($this->multiCurl, $ch->curl);
+                                if (!($curlm_error_code === CURLM_OK)) {
+                                    throw new \ErrorException(
+                                        'cURL multi add handle error: ' . curl_multi_strerror($curlm_error_code)
+                                    );
+                                }
+                            } else {
+                                $ch->execDone();
+
+                                // Remove completed instance from active curls.
+                                unset($this->activeCurls[$key]);
+
+                                // Start a new request before removing the handle of the completed one.
+                                if (count($this->curls) >= 1) {
+                                    $this->initHandle(array_shift($this->curls));
+                                }
+                                curl_multi_remove_handle($this->multiCurl, $ch->curl);
+
+                                // Clean up completed instance.
+                                $ch->close();
                             }
-                            curl_multi_remove_handle($this->multiCurl, $ch->curl);
-
-                            // Clean up completed instance.
-                            $ch->close();
 
                             break;
                         }
@@ -763,6 +793,7 @@ private function queueHandle($curl)
     {
         // Use sequential ids to allow for ordered post processing.
         $curl->id = $this->nextCurlId++;
+        $curl->isChildOfMultiCurl = true;
         $this->curls[$curl->id] = $curl;
     }
 
@@ -791,6 +822,7 @@ private function initHandle($curl)
 
         $curl->setOpts($this->options);
         $curl->setHeaders($this->headers);
+        $curl->setRetry($this->retry);
 
         foreach ($this->cookies as $key => $value) {
             $curl->setCookie($key, $value);