Improve metadata retrieval (performances and accuracy)

  - Use dedicated function to download headers to avoid apply multiple regexps on headers
  - Also try to extract title from meta tags

3 files changed, 91 insertions, 55 deletions

diff --git a/application/http/HttpAccess.php b/application/http/HttpAccess.php
index 81d9e076..646a5264 100644
--- a/application/http/HttpAccess.php
+++ b/application/http/HttpAccess.php
@@ -14,9 +14,14 @@ namespace Shaarli\Http;
  */
 class HttpAccess
 {
-    public function getHttpResponse($url, $timeout = 30, $maxBytes = 4194304, $curlWriteFunction = null)
-    {
-        return get_http_response($url, $timeout, $maxBytes, $curlWriteFunction);
+    public function getHttpResponse(
+        $url,
+        $timeout = 30,
+        $maxBytes = 4194304,
+        $curlHeaderFunction = null,
+        $curlWriteFunction = null
+    ) {
+        return get_http_response($url, $timeout, $maxBytes, $curlHeaderFunction, $curlWriteFunction);
     }
 
     public function getCurlDownloadCallback(
@@ -24,16 +29,19 @@ class HttpAccess
         &$title,
         &$description,
         &$keywords,
-        $retrieveDescription,
-        $curlGetInfo = 'curl_getinfo'
+        $retrieveDescription
     ) {
         return get_curl_download_callback(
             $charset,
             $title,
             $description,
             $keywords,
-            $retrieveDescription,
-            $curlGetInfo
+            $retrieveDescription
         );
     }
+
+    public function getCurlHeaderCallback(&$charset, $curlGetInfo = 'curl_getinfo')
+    {
+        return get_curl_header_callback($charset, $curlGetInfo);
+    }
 }
diff --git a/application/http/HttpUtils.php b/application/http/HttpUtils.php
index 9f414073..28c12969 100644
--- a/application/http/HttpUtils.php
+++ b/application/http/HttpUtils.php
@@ -6,12 +6,14 @@ use Shaarli\Http\Url;
  * GET an HTTP URL to retrieve its content
  * Uses the cURL library or a fallback method
  *
- * @param string          $url               URL to get (http://...)
- * @param int             $timeout           network timeout (in seconds)
- * @param int             $maxBytes          maximum downloaded bytes (default: 4 MiB)
- * @param callable|string $curlWriteFunction Optional callback called during the download (cURL CURLOPT_WRITEFUNCTION).
- *                                           Can be used to add download conditions on the
- *                                           headers (response code, content type, etc.).
+ * @param string          $url                URL to get (http://...)
+ * @param int             $timeout            network timeout (in seconds)
+ * @param int             $maxBytes           maximum downloaded bytes (default: 4 MiB)
+ * @param callable|string $curlHeaderFunction Optional callback called during the download of headers
+ *                                            (CURLOPT_HEADERFUNCTION)
+ * @param callable|string $curlWriteFunction  Optional callback called during the download (cURL CURLOPT_WRITEFUNCTION).
+ *                                            Can be used to add download conditions on the
+ *                                            headers (response code, content type, etc.).
  *
  * @return array HTTP response headers, downloaded content
  *
@@ -35,8 +37,13 @@ use Shaarli\Http\Url;
  * @see http://stackoverflow.com/q/9183178
  * @see http://stackoverflow.com/q/1462720
  */
-function get_http_response($url, $timeout = 30, $maxBytes = 4194304, $curlWriteFunction = null)
-{
+function get_http_response(
+    $url,
+    $timeout = 30,
+    $maxBytes = 4194304,
+    $curlHeaderFunction = null,
+    $curlWriteFunction = null
+) {
     $urlObj = new Url($url);
     $cleanUrl = $urlObj->idnToAscii();
 
@@ -70,7 +77,8 @@ function get_http_response($url, $timeout = 30, $maxBytes = 4194304, $curlWriteF
     // General cURL settings
     curl_setopt($ch, CURLOPT_AUTOREFERER, true);
     curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
-    curl_setopt($ch, CURLOPT_HEADER, true);
+    // Default header download if the $curlHeaderFunction is not defined
+    curl_setopt($ch, CURLOPT_HEADER, !is_callable($curlHeaderFunction));
     curl_setopt(
         $ch,
         CURLOPT_HTTPHEADER,
@@ -81,25 +89,21 @@ function get_http_response($url, $timeout = 30, $maxBytes = 4194304, $curlWriteF
     curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
     curl_setopt($ch, CURLOPT_USERAGENT, $userAgent);
 
-    if (is_callable($curlWriteFunction)) {
-        curl_setopt($ch, CURLOPT_WRITEFUNCTION, $curlWriteFunction);
-    }
-
     // Max download size management
     curl_setopt($ch, CURLOPT_BUFFERSIZE, 1024*16);
     curl_setopt($ch, CURLOPT_NOPROGRESS, false);
+    if (is_callable($curlHeaderFunction)) {
+        curl_setopt($ch, CURLOPT_HEADERFUNCTION, $curlHeaderFunction);
+    }
+    if (is_callable($curlWriteFunction)) {
+        curl_setopt($ch, CURLOPT_WRITEFUNCTION, $curlWriteFunction);
+    }
     curl_setopt(
         $ch,
         CURLOPT_PROGRESSFUNCTION,
-        function ($arg0, $arg1, $arg2, $arg3, $arg4 = 0) use ($maxBytes) {
-            if (version_compare(phpversion(), '5.5', '<')) {
-                // PHP version lower than 5.5
-                // Callback has 4 arguments
-                $downloaded = $arg1;
-            } else {
-                // Callback has 5 arguments
-                $downloaded = $arg2;
-            }
+        function ($arg0, $arg1, $arg2, $arg3, $arg4) use ($maxBytes) {
+            $downloaded = $arg2;
+
             // Non-zero return stops downloading
             return ($downloaded > $maxBytes) ? 1 : 0;
         }
@@ -493,6 +497,46 @@ function is_https($server)
  * Get cURL callback function for CURLOPT_WRITEFUNCTION
  *
  * @param string $charset     to extract from the downloaded page (reference)
+ * @param string $curlGetInfo Optionally overrides curl_getinfo function
+ *
+ * @return Closure
+ */
+function get_curl_header_callback(
+    &$charset,
+    $curlGetInfo = 'curl_getinfo'
+) {
+    $isRedirected = false;
+
+    return function ($ch, $data) use ($curlGetInfo, &$charset, &$isRedirected) {
+        $responseCode = $curlGetInfo($ch, CURLINFO_RESPONSE_CODE);
+        $chunkLength = strlen($data);
+        if (!empty($responseCode) && in_array($responseCode, [301, 302])) {
+            $isRedirected = true;
+            return $chunkLength;
+        }
+        if (!empty($responseCode) && $responseCode !== 200) {
+            return false;
+        }
+        // After a redirection, the content type will keep the previous request value
+        // until it finds the next content-type header.
+        if (! $isRedirected || strpos(strtolower($data), 'content-type') !== false) {
+            $contentType = $curlGetInfo($ch, CURLINFO_CONTENT_TYPE);
+        }
+        if (!empty($contentType) && strpos($contentType, 'text/html') === false) {
+            return false;
+        }
+        if (!empty($contentType) && empty($charset)) {
+            $charset = header_extract_charset($contentType);
+        }
+
+        return $chunkLength;
+    };
+}
+
+/**
+ * Get cURL callback function for CURLOPT_WRITEFUNCTION
+ *
+ * @param string $charset     to extract from the downloaded page (reference)
  * @param string $title       to extract from the downloaded page (reference)
  * @param string $description to extract from the downloaded page (reference)
  * @param string $keywords    to extract from the downloaded page (reference)
@@ -506,10 +550,8 @@ function get_curl_download_callback(
     &$title,
     &$description,
     &$keywords,
-    $retrieveDescription,
-    $curlGetInfo = 'curl_getinfo'
+    $retrieveDescription
 ) {
-    $isRedirected = false;
     $currentChunk = 0;
     $foundChunk = null;
 
@@ -524,37 +566,18 @@ function get_curl_download_callback(
      *
      * @return int|bool length of $data or false if we need to stop the download
      */
-    return function (&$ch, $data) use (
+    return function ($ch, $data) use (
         $retrieveDescription,
-        $curlGetInfo,
         &$charset,
         &$title,
         &$description,
         &$keywords,
-        &$isRedirected,
         &$currentChunk,
         &$foundChunk
     ) {
+        $chunkLength = strlen($data);
         $currentChunk++;
-        $responseCode = $curlGetInfo($ch, CURLINFO_RESPONSE_CODE);
-        if (!empty($responseCode) && in_array($responseCode, [301, 302])) {
-            $isRedirected = true;
-            return strlen($data);
-        }
-        if (!empty($responseCode) && $responseCode !== 200) {
-            return false;
-        }
-        // After a redirection, the content type will keep the previous request value
-        // until it finds the next content-type header.
-        if (! $isRedirected || strpos(strtolower($data), 'content-type') !== false) {
-            $contentType = $curlGetInfo($ch, CURLINFO_CONTENT_TYPE);
-        }
-        if (!empty($contentType) && strpos($contentType, 'text/html') === false) {
-            return false;
-        }
-        if (!empty($contentType) && empty($charset)) {
-            $charset = header_extract_charset($contentType);
-        }
+
         if (empty($charset)) {
             $charset = html_extract_charset($data);
         }
@@ -562,6 +585,10 @@ function get_curl_download_callback(
             $title = html_extract_title($data);
             $foundChunk = ! empty($title) ? $currentChunk : $foundChunk;
         }
+        if (empty($title)) {
+            $title = html_extract_tag('title', $data);
+            $foundChunk = ! empty($title) ? $currentChunk : $foundChunk;
+        }
         if ($retrieveDescription && empty($description)) {
             $description = html_extract_tag('description', $data);
             $foundChunk = ! empty($description) ? $currentChunk : $foundChunk;
@@ -591,6 +618,6 @@ function get_curl_download_callback(
             return false;
         }
 
-        return strlen($data);
+        return $chunkLength;
     };
 }
diff --git a/application/http/MetadataRetriever.php b/application/http/MetadataRetriever.php
index 2ca982e2..ba9bd40c 100644
--- a/application/http/MetadataRetriever.php
+++ b/application/http/MetadataRetriever.php
@@ -46,6 +46,7 @@ class MetadataRetriever
             $url,
             $this->conf->get('general.download_timeout', 30),
             $this->conf->get('general.download_max_size', 4194304),
+            $this->httpAccess->getCurlHeaderCallback($charset),
             $this->httpAccess->getCurlDownloadCallback(
                 $charset,
                 $title,