Merge branch 'patch-1' into 'dev'

Return image modification date on remote fetch for caching

See merge request hubzilla/core!1383

include/photo/photo_driver.php

@@ -485,11 +485,11 @@ function guess_image_type($filename, $headers = '') {
 		$h = explode("\n",$headers);
 		foreach ($h as $l) {
 			list($k,$v) = array_map("trim", explode(":", trim($l), 2));
-			$hdrs[$k] = $v;
+			$hdrs[strtolower($k)] = $v;
 		}
 		logger('Curl headers: '.var_export($hdrs, true), LOGGER_DEBUG);
-		if (array_key_exists('Content-Type', $hdrs))
+		if (array_key_exists('content-type', $hdrs))
-			$type = $hdrs['Content-Type'];
+			$type = $hdrs['content-type'];
 	}
 	if (is_null($type)){
 
@@ -570,22 +570,48 @@ function delete_thing_photo($url,$ob_hash) {
 
 
 
-function import_xchan_photo($photo,$xchan,$thing = false) {
+/**
+ * @brief fetches an photo from external site and prepares its miniatures.
+ *
+ * @param string $photo
+ *    external URL to fetch base image
+ * @param string $xchan
+ *    channel unique hash
+ * @param boolean $thing
+ *    TRUE if this is a thing URL
+ * @param boolean $force
+ *    TRUE if ignore image modification date check (force fetch)
+ *
+ * @return array of results
+ * * \e string \b 0 => local URL to full image
+ * * \e string \b 1 => local URL to standard thumbnail
+ * * \e string \b 2 => local URL to micro thumbnail
+ * * \e string \b 3 => image type
+ * * \e boolean \b 4 => TRUE if fetch failure
+ * * \e string \b 5 => modification date
+ */
+
+function import_xchan_photo($photo,$xchan,$thing = false,$force = false) {
+
+        $modified = '';
 
         $flags = (($thing) ? PHOTO_THING : PHOTO_XCHAN);
         $album = (($thing) ? 'Things' : 'Contact Photos');
 
         logger('import_xchan_photo: updating channel photo from ' . $photo . ' for ' . $xchan, LOGGER_DEBUG);
 
-	if($thing)
+        if($thing) {
                 $hash = photo_new_resource();
+        }
         else {
-		$r = q("select resource_id from photo where xchan = '%s' and photo_usage = %d and imgscale = 4 limit 1",
+                $r = q("select resource_id, edited, mimetype from photo where xchan = '%s' and photo_usage = %d and imgscale = 4 limit 1",
                         dbesc($xchan),
                         intval(PHOTO_XCHAN)
                 );
                 if($r) {
                         $hash = $r[0]['resource_id'];
+                        $modified = $r[0]['edited'];
+                        $type = $r[0]['mimetype'];
                 }
                 else {
                         $hash = photo_new_resource();
@@ -598,29 +624,37 @@ function import_xchan_photo($photo,$xchan,$thing = false) {
         if($photo) {
                 $filename = basename($photo);
 
+                if($force || $modified == '') {
                         $result = z_fetch_url($photo,true);
+                }
+                else {
+                        $h = array('headers' => array("If-Modified-Since: " . gmdate("D, d M Y H:i:s", strtotime($modified . "Z")) . " GMT"));
+                        $result = z_fetch_url($photo,true,0,$h);
+                }
 
                 if($result['success']) {
                         $img_str = $result['body'];
                         $type = guess_image_type($photo, $result['header']);
+                        $modified = gmdate('Y-m-d H:i:s', (preg_match('/last-modified: (.+) \S+/i', $result['header'], $o) ? strtotime($o[1] . 'Z') : time()));
 
-			$h = explode("\n",$result['header']);
+                        if(is_null($type))
-			if($h) {
-				foreach($h as $hl) {
-					if(stristr($hl,'content-type:')) {
-						if(! stristr($hl,'image/')) {
                                 $photo_failure = true;
                 }
-					}
+                elseif($result['return_code'] = 304) {
-				}
+                        $photo = z_root() . '/photo/' . $hash . '-4';
-			}
+                        $thumb = z_root() . '/photo/' . $hash . '-5';
-		}
+                        $micro = z_root() . '/photo/' . $hash . '-6';
                 }
                 else {
                         $photo_failure = true;
                 }
 
-	if(! $photo_failure) {
+        }
+        else {
+                $photo_failure = true;
+        }
+
+        if(! $photo_failure && $result['return_code'] != 304) {
                 $img = photo_factory($img_str, $type);
                 if($img->is_valid()) {
                         $width = $img->getWidth();
@@ -679,13 +713,15 @@ function import_xchan_photo($photo,$xchan,$thing = false) {
                 }
         }
         if($photo_failure) {
-		$photo = z_root() . '/' . get_default_profile_photo();
+                $default = get_default_profile_photo();
+                $photo = z_root() . '/' . $default;
                 $thumb = z_root() . '/' . get_default_profile_photo(80);
                 $micro = z_root() . '/' . get_default_profile_photo(48);
                 $type = 'image/png';
+                $modified = gmdate('Y-m-d H:i:s', filemtime($default));
         }
 
-	return(array($photo,$thumb,$micro,$type,$photo_failure));
+        return(array($photo,$thumb,$micro,$type,$photo_failure,$modified));
 
 }
 
@@ -700,18 +736,10 @@ function import_channel_photo_from_url($photo,$aid,$uid) {
 			$img_str = $result['body'];
 			$type = guess_image_type($photo, $result['header']);
 
-			$h = explode("\n",$result['header']);
+            if(is_null($type))
-			if($h) {
-				foreach($h as $hl) {
-					if(stristr($hl,'content-type:')) {
-						if(! stristr($hl,'image/')) {
                     $photo_failure = true;
 		}
 	}
-				}
-			}
-		}
-	}
 	else {
 		$photo_failure = true;
 	}