From f2adbeb2a41430f28a3427ddb4365c4075e9296a Mon Sep 17 00:00:00 2001
From: Frederic Guillot <contact@fredericguillot.com>
Date: Sat, 6 Apr 2013 21:15:42 -0400
Subject: [PATCH] Add support for HTTP caching with Etag and LastModified

---
 miniflux/common.php |   2 +-
 miniflux/model.php  | 112 ++++++++++++++++++++++++++++----------------
 miniflux/schema.php |  11 ++++-
 3 files changed, 82 insertions(+), 43 deletions(-)

diff --git a/miniflux/common.php b/miniflux/common.php
index 6f1f988..806aab6 100644
--- a/miniflux/common.php
+++ b/miniflux/common.php
@@ -9,7 +9,7 @@ require 'schema.php';
 require 'model.php';
 
 
-const DB_VERSION = 1;
+const DB_VERSION = 2;
 const APP_VERSION = 'master';
 const APP_USERAGENT = 'Miniflux - http://miniflux.net';
 const HTTP_TIMEOUT = 5;
diff --git a/miniflux/model.php b/miniflux/model.php
index 5f83a77..8f4cecb 100644
--- a/miniflux/model.php
+++ b/miniflux/model.php
@@ -64,7 +64,7 @@ function import_feeds($content)
 function import_feed($url)
 {
     $reader = new Reader;
-    $reader->download($url, HTTP_TIMEOUT, APP_USERAGENT);
+    $resource = $reader->download($url, '', '', HTTP_TIMEOUT, APP_USERAGENT);
 
     $parser = $reader->getParser();
 
@@ -72,15 +72,14 @@ function import_feed($url)
 
         $feed = $parser->execute();
 
-        if (! $feed->title || ! $feed->url) {
-
-            return false;
-        }
+        if ($feed === false) return false;
+        if (! $feed->title || ! $feed->url) return false;
 
         $db = \PicoTools\singleton('db');
 
         if (! $db->table('feeds')->eq('feed_url', $reader->getUrl())->count()) {
 
+            // Etag and LastModified are added the next update
             $rs = $db->table('feeds')->save(array(
                 'title' => $feed->title,
                 'site_url' => $feed->url,
@@ -101,6 +100,62 @@ function import_feed($url)
 }
 
 
+function update_feeds()
+{
+    foreach (get_feeds_id() as $feed_id) {
+
+        update_feed($feed_id);
+    }
+}
+
+
+function update_feed($feed_id)
+{
+    $feed = get_feed($feed_id);
+
+    $reader = new Reader;
+
+    $resource = $reader->download(
+        $feed['feed_url'],
+        $feed['last_modified'],
+        $feed['etag'],
+        HTTP_TIMEOUT,
+        APP_USERAGENT
+    );
+
+    if (! $resource->isModified()) {
+
+        return true;
+    }
+
+    $parser = $reader->getParser();
+
+    if ($parser !== false) {
+
+        $feed = $parser->execute();
+
+        if ($feed !== false) {
+
+            update_feed_cache_infos($feed_id, $resource->getLastModified(), $resource->getEtag());
+            update_items($feed_id, $feed->items);
+
+            return true;
+        }
+    }
+
+    return false;
+}
+
+
+function get_feeds_id()
+{
+    return \PicoTools\singleton('db')
+        ->table('feeds')
+        ->asc('updated')
+        ->listing('id', 'id');
+}
+
+
 function get_feeds()
 {
     return \PicoTools\singleton('db')
@@ -119,10 +174,21 @@ function get_feed($feed_id)
 }
 
 
+function update_feed_cache_infos($feed_id, $last_modified, $etag)
+{
+    \PicoTools\singleton('db')
+        ->table('feeds')
+        ->eq('id', $feed_id)
+        ->save(array(
+            'last_modified' => $last_modified,
+            'etag' => $etag
+        ));
+}
+
+
 function remove_feed($feed_id)
 {
     $db = \PicoTools\singleton('db');
-
     $db->table('items')->eq('feed_id', $feed_id)->remove();
 
     return $db->table('feeds')->eq('id', $feed_id)->remove();
@@ -263,40 +329,6 @@ function flush_read()
 }
 
 
-function update_feeds()
-{
-    foreach (get_feeds() as $feed) {
-
-        $reader = new Reader;
-        $reader->download($feed['feed_url'], HTTP_TIMEOUT, APP_USERAGENT);
-        $parser = $reader->getParser();
-
-        if ($parser !== false) {
-
-            update_items($feed['id'], $parser->execute()->items);
-        }
-    }
-}
-
-
-function update_feed($feed_id)
-{
-    $feed = get_feed($feed_id);
-
-    $reader = new Reader;
-    $reader->download($feed['feed_url'], HTTP_TIMEOUT, APP_USERAGENT);
-    $parser = $reader->getParser();
-
-    if ($parser !== false) {
-
-        update_items($feed['id'], $parser->execute()->items);
-        return true;
-    }
-
-    return false;
-}
-
-
 function update_items($feed_id, array $items)
 {
     $db = \PicoTools\singleton('db');
diff --git a/miniflux/schema.php b/miniflux/schema.php
index c47f16d..e446af3 100644
--- a/miniflux/schema.php
+++ b/miniflux/schema.php
@@ -2,13 +2,20 @@
 
 namespace Schema;
 
+
+function version_2($pdo)
+{
+    $pdo->exec('ALTER TABLE feeds ADD COLUMN last_modified TEXT');
+    $pdo->exec('ALTER TABLE feeds ADD COLUMN etag TEXT');
+}
+
+
 function version_1($pdo)
 {
     $pdo->exec("
         CREATE TABLE config (
             username TEXT DEFAULT 'admin',
-            password TEXT,
-            history INTEGER DEFAULT '15'
+            password TEXT
         )
     ");