From 9732d8fc9ff976bea480b663012c6c6ec6dc9f01 Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <noreply@fakecake.org>
Date: Wed, 23 Nov 2022 22:09:04 +0300
Subject: [PATCH] update_rss_feed: use DiskCache to store feed data

---
 classes/cache/adapter.php |  5 +++++
 classes/cache/local.php   |  4 ++++
 classes/diskcache.php     |  6 +++++-
 classes/rssutils.php      | 15 +++++++++------
 4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/classes/cache/adapter.php b/classes/cache/adapter.php
index da69c5bb1..88dca21b9 100644
--- a/classes/cache/adapter.php
+++ b/classes/cache/adapter.php
@@ -9,6 +9,11 @@ interface Cache_Adapter {
 	 * @return int|false -1 if the file doesn't exist, false if an error occurred, size in bytes otherwise
 	 */
 	public function get_size(string $filename);
+
+	/**
+	 * @return int|false -1 if the file doesn't exist, false if an error occurred, timestamp otherwise
+	 */
+	public function get_mtime(string $filename);
 	/**
 	 * @param mixed $data
 	 *
diff --git a/classes/cache/local.php b/classes/cache/local.php
index 20d97d9c0..4461ef4ca 100644
--- a/classes/cache/local.php
+++ b/classes/cache/local.php
@@ -2,6 +2,10 @@
 class Cache_Local implements Cache_Adapter {
 	private string $dir;
 
+	public function get_mtime(string $filename) {
+		return filemtime($this->get_full_path($filename));
+	}
+
 	public function set_dir(string $dir) : void {
 		$this->dir = Config::get(Config::CACHE_DIR) . "/" . basename(clean($dir));
 	}
diff --git a/classes/diskcache.php b/classes/diskcache.php
index 4cec77cde..69b48688c 100644
--- a/classes/diskcache.php
+++ b/classes/diskcache.php
@@ -200,7 +200,7 @@ class DiskCache implements Cache_Adapter {
 			if (implements_interface($p, "Cache_Adapter")) {
 
 				/** @var Cache_Adapter $p */
-				$this->adapter = $p;
+				$this->adapter = clone $p; // we need separate object instances for separate directories
 				$this->adapter->set_dir($dir);
 				return;
 			}
@@ -210,6 +210,10 @@ class DiskCache implements Cache_Adapter {
 		$this->adapter->set_dir($dir);
 	}
 
+	public function get_mtime(string $filename) {
+		return $this->adapter->get_mtime($filename);
+	}
+
 	public function set_dir(string $dir) : void {
 		$this->adapter->set_dir($dir);
 	}
diff --git a/classes/rssutils.php b/classes/rssutils.php
index fe295417a..2a82a35b0 100755
--- a/classes/rssutils.php
+++ b/classes/rssutils.php
@@ -338,6 +338,9 @@ class RSSUtils {
 
 		$pdo = Db::pdo();
 
+		/** @var DiskCache $cache */
+		$cache = new DiskCache('feeds');
+
 		if (Config::get(Config::DB_TYPE) == "pgsql") {
 			$favicon_interval_qpart = "favicon_last_checked < NOW() - INTERVAL '12 hour'";
 		} else {
@@ -387,7 +390,7 @@ class RSSUtils {
 
 		$date_feed_processed = date('Y-m-d H:i');
 
-		$cache_filename = Config::get(Config::CACHE_DIR) . "/feeds/" . sha1($feed_obj->feed_url) . ".xml";
+		$cache_filename = sha1($feed_obj->feed_url) . ".xml";
 
 		$pluginhost = new PluginHost();
 		$user_plugins = get_pref(Prefs::_ENABLED_PLUGINS, $feed_obj->owner_uid);
@@ -423,13 +426,13 @@ class RSSUtils {
 
 		// try cache
 		if (!$feed_data &&
-			is_readable($cache_filename) &&
+			$cache->exists($cache_filename) &&
 			!$feed_obj->auth_login && !$feed_obj->auth_pass &&
-			filemtime($cache_filename) > time() - 30) {
+			$cache->get_mtime($cache_filename) > time() - 30) {
 
 			Debug::log("using local cache: {$cache_filename}.", Debug::LOG_VERBOSE);
 
-			$feed_data = file_get_contents($cache_filename);
+			$feed_data = $cache->get($cache_filename);
 
 			if ($feed_data) {
 				$rss_hash = sha1($feed_data);
@@ -480,9 +483,9 @@ class RSSUtils {
 			if ($feed_data && !$feed_obj->auth_pass && !$feed_obj->auth_login && is_writable(Config::get(Config::CACHE_DIR) . "/feeds")) {
 				$new_rss_hash = sha1($feed_data);
 
-				if ($new_rss_hash != $rss_hash) {
+				if ($new_rss_hash != $rss_hash && $cache->is_writable()) {
 					Debug::log("saving to local cache: $cache_filename", Debug::LOG_VERBOSE);
-					file_put_contents($cache_filename, $feed_data);
+					$cache->put($cache_filename, $feed_data);
 				}
 			}
 		}