support If-Modified-Since

[tt-rss.git] / include / rssfuncs.php

diff --git a/include/rssfuncs.php b/include/rssfuncs.php
index e82e94b099f1d99ed665df7acd27a3c0e94a1e73..7c668f69f3122d8083b7f72900014894b7478eec 100644 (file)
--- a/include/rssfuncs.php
+++ b/include/rssfuncs.php
@@ -239,6 +239,7 @@
 
                $rss = false;
                $rss_hash = false;
+               $cache_timestamp = file_exists($cache_filename) ? filemtime($cache_filename) : 0;
 
                if (file_exists($cache_filename) &&
                        is_readable($cache_filename) &&
@@ -261,11 +262,11 @@
 
                        if (!$feed_data) {
                                if ($debug_enabled) {
-                                       _debug("update_rss_feed: fetching [$fetch_url]...");
+                                       _debug("update_rss_feed: fetching [$fetch_url] (ts: $cache_timestamp)");
                                }
 
                                $feed_data = fetch_file_contents($fetch_url, false,
-                                       $auth_login, $auth_pass, false, $no_cache ? 15 : 45);
+                                       $auth_login, $auth_pass, false, $no_cache ? 15 : 45, $cache_timestamp);
 
                                if ($debug_enabled) {
                                        _debug("update_rss_feed: fetch done.");
@@ -275,12 +276,22 @@
 
                        if (!$feed_data) {
                                global $fetch_last_error;
+                               global $fetch_last_error_code;
 
                                if ($debug_enabled) {
-                                       _debug("update_rss_feed: unable to fetch: $fetch_last_error");
+                                       _debug("update_rss_feed: unable to fetch: $fetch_last_error [$fetch_last_error_code]");
                                }
 
-                               $error_escaped = db_escape_string($link, $fetch_last_error);
+                               $error_escaped = '';
+
+                               // If-Modified-Since
+                               if ($fetch_last_error_code != 304) {
+                                       $error_escaped = db_escape_string($link, $fetch_last_error);
+                               } else {
+                                       if ($debug_enabled) {
+                                               _debug("update_rss_feed: source claims data not modified, nothing to do.");
+                                       }
+                               }
 
                                db_query($link,
                                        "UPDATE ttrss_feeds SET last_error = '$error_escaped',