Track redirects followed by curl

README.md

@@ -45,6 +45,7 @@ The get/post/head functions will return an array with the following properties:
 * `headers` - array, the HTTP headers returned
 * `rels` - array, the parsed HTTP rel values from any `Link` headers
 * `body` - string, the body of the HTTP response, or false/omit for a HEAD request
+* `redirects` - array, the redirects followed, or omitted when not supported
 * `error` - string, an error string. see below for the enumerated list.
 * `error_description` - string,
 * `url` - string, the final URL retrieved after following any redirects
@@ -112,6 +113,31 @@ The `rels` key will be the parsed version of any HTTP `Link` headers that contai
         )
 ```
 
+#### `redirects`
+
+The `redirects` key will be an array of all the redirects followed to retrieve the final response. This key may be omitted if the transport does not support retrieving the data.
+
+```php
+Array
+(
+    [0] => Array
+        (
+            [code] => 301
+            [from] => http://aaronpk.com/
+            [to] => https://aaronpk.com/
+        )
+
+    [1] => Array
+        (
+            [code] => 301
+            [from] => https://aaronpk.com/
+            [to] => https://aaronparecki.com/
+        )
+
+)
+```
+
+The `code` key within a redirect array is the HTTP status code that came with it. This can be used for separating permanent redirects (301) from temporary ones (302).
 
 ### Options
 

src/p3k/HTTP/Curl.php

@@ -6,6 +6,11 @@ class Curl implements Transport {
   protected $_timeout = 4;
   protected $_max_redirects = 8;
   static protected $_http_version = null;
+  private $_last_seen_url = null;
+  private $_last_seen_code = null;
+  private $_current_headers = [];
+  private $_current_redirects = [];
+  private $_debug_header = '';
 
   public function set_max_redirects($max) {
     $this->_max_redirects = $max;
@@ -21,16 +26,15 @@ public function get($url, $headers=[]) {
     if($headers)
       curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
     $response = curl_exec($ch);
-    $header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
-    $header_str = trim(substr($response, 0, $header_size));
     return [
       'code' => curl_getinfo($ch, CURLINFO_HTTP_CODE),
-      'header' => $header_str,
-      'body' => substr($response, $header_size),
+      'header' => implode("\r\n", array_map(function ($a) { return $a[0] . ': ' . $a[1]; }, $this->_current_headers)),
+      'body' => $response,
+      'redirects' => $this->_current_redirects,
       'error' => self::error_string_from_code(curl_errno($ch)),
       'error_description' => curl_error($ch),
-      'url' => curl_getinfo($ch, CURLINFO_EFFECTIVE_URL),
-      'debug' => $response
+      'url' => $this->_last_seen_url,
+      'debug' => $this->_debug_header . "\r\n" . $response
     ];
   }
 
@@ -42,16 +46,15 @@ public function post($url, $body, $headers=[]) {
     if($headers)
       curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
     $response = curl_exec($ch);
-    $header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
-    $header_str = trim(substr($response, 0, $header_size));
     return [
       'code' => curl_getinfo($ch, CURLINFO_HTTP_CODE),
-      'header' => $header_str,
-      'body' => substr($response, $header_size),
+      'header' => implode("\r\n", array_map(function ($a) { return $a[0] . ': ' . $a[1]; }, $this->_current_headers)),
+      'body' => $response,
+      'redirects' => $this->_current_redirects,
       'error' => self::error_string_from_code(curl_errno($ch)),
       'error_description' => curl_error($ch),
-      'url' => curl_getinfo($ch, CURLINFO_EFFECTIVE_URL),
-      'debug' => $response
+      'url' => $this->_last_seen_url,
+      'debug' => $this->_debug_header . "\r\n" . $response
     ];
   }
 
@@ -64,23 +67,23 @@ public function head($url, $headers=[]) {
     $response = curl_exec($ch);
     return [
       'code' => curl_getinfo($ch, CURLINFO_HTTP_CODE),
-      'header' => trim($response),
+      'header' => implode("\r\n", array_map(function ($a) { return $a[0] . ': ' . $a[1]; }, $this->_current_headers)),
+      'redirects' => $this->_current_redirects,
       'error' => self::error_string_from_code(curl_errno($ch)),
       'error_description' => curl_error($ch),
-      'url' => curl_getinfo($ch, CURLINFO_EFFECTIVE_URL),
-      'debug' => $response
+      'url' => $this->_last_seen_url,
+      'debug' => $this->_debug_header . "\r\n" . $response
     ];
   }
 
   private function _set_curlopts($ch, $url) {
     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
-    curl_setopt($ch, CURLOPT_HEADER, true);
-    if($this->_max_redirects > 0)
-      curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
+    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $this->_max_redirects > 0);
     curl_setopt($ch, CURLOPT_MAXREDIRS, $this->_max_redirects);
     curl_setopt($ch, CURLOPT_TIMEOUT_MS, round($this->_timeout * 1000));
     curl_setopt($ch, CURLOPT_CONNECTTIMEOUT_MS, 2000);
     curl_setopt($ch, CURLOPT_HTTP_VERSION, $this->_http_version());
+    curl_setopt($ch, CURLOPT_HEADERFUNCTION, [$this, '_header_function']);
   }
 
   private function _http_version() {
@@ -96,6 +99,32 @@ private function _http_version() {
     return static::$_http_version;
   }
 
+  private function _header_function($curl, $header) {
+    $this->_debug_header .= $header;
+    $current_url = curl_getinfo($curl, CURLINFO_EFFECTIVE_URL);
+    if ($current_url !== $this->_last_seen_url) {
+        if ($this->_last_seen_url !== null) {
+            $this->_current_redirects[] = [
+                'code' => $this->_last_seen_code,
+                'from' => $this->_last_seen_url,
+                'to' => $current_url,
+            ];
+        } else {
+            $this->_current_redirects = [];
+        }
+        $this->_current_headers = [];
+        $this->_last_seen_url = $current_url;
+        $this->_last_seen_code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
+    }
+    $length = strlen($header);
+    $header = explode(':', $header, 2);
+    if (count($header) !== 2) {
+      return $length;
+    }
+    $this->_current_headers[] = array_map('trim', [$header[0], $header[1]]);
+    return $length;
+  }
+
   public static function error_string_from_code($code) {
     switch($code) {
       case 0: