From c0a4b9c09a8178d4d6b032967137d6ca208fd0a8 Mon Sep 17 00:00:00 2001
From: gravel <gravel@noreply.codeberg.org>
Date: Tue, 6 Jun 2023 11:54:51 +0000
Subject: [PATCH] Cache fetched sources

---
 .gitignore              |  1 +
 .phpenv                 |  4 +++-
 CONTRIBUTING.md         |  2 +-
 Makefile                |  6 +++++-
 etc/.gitpreserve        | 10 ++++++++++
 php/servers/sources.php | 23 +++++++++++++++++++----
 6 files changed, 39 insertions(+), 7 deletions(-)
 create mode 100644 etc/.gitpreserve

diff --git a/.gitignore b/.gitignore
index 31c4439..1bbe701 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,6 +13,7 @@ listings/lp-output/*
 
 # Server-side cache
 cache
+cache-lt
 
 # Local tests
 .test
diff --git a/.phpenv b/.phpenv
index 9d86cc1..9162f73 100644
--- a/.phpenv
+++ b/.phpenv
@@ -11,6 +11,8 @@
 	$ROOM_ICONS_CACHE="$CACHE_ROOT/icons";
 	$ROOM_ICONS="$DOCUMENT_ROOT/icons";
 	$ROOM_ICONS_RELATIVE="icons";
+	$LONG_TERM_CACHE_ROOT="$PROJECT_ROOT/cache-lt";
+	$SOURCES_CACHE="$LONG_TERM_CACHE_ROOT/sources";
 
 	$LISTING_PROVIDER_ROOT="$PROJECT_ROOT/listings";
 	$LISTINGS_INI="$LISTING_PROVIDER_ROOT/listings.ini";
@@ -30,4 +32,4 @@
 	error_reporting(E_ALL & ~E_WARNING);
 
 	date_default_timezone_set('UTC');
-?>
\ No newline at end of file
+?>
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a745c5d..77eeeee 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -5,7 +5,7 @@
 ### Prerequisites
 
 - PHP 8.1+
-- `make`
+- `make`, `awk`, `xargs`
 - `entr` to watch for file changes
 - `xdg-open` link handler to invoke browser
 - `libgd` (`php-gd`, `phpX.Y-gd`) for downsizing images
diff --git a/Makefile b/Makefile
index 8fd541c..c1d3e91 100644
--- a/Makefile
+++ b/Makefile
@@ -68,7 +68,11 @@ watchdog:
 
 # Remove artefacts
 clean:
-	-git clean -dfX
+	-awk '/^[^#]/ { printf " -e \"!%s\"", $$0 }' <etc/.gitpreserve | xargs git clean -Xdf $(CLEANFLAGS)
+
+# Display files affected by artefact removal.
+would-clean: CLEANFLAGS="-n"
+would-clean: clean
 
 # Build everything from scratch and test functionality.
 test: FLAGS = --verbose
diff --git a/etc/.gitpreserve b/etc/.gitpreserve
new file mode 100644
index 0000000..be2b809
--- /dev/null
+++ b/etc/.gitpreserve
@@ -0,0 +1,10 @@
+# Preserve the following files when cleaning the directory:
+
+# Long-term cache
+cache-lt
+
+# Visual Studio Code
+.vscode
+
+# Kate
+.kate-swp
diff --git a/php/servers/sources.php b/php/servers/sources.php
index dfe6f2b..42ae533 100644
--- a/php/servers/sources.php
+++ b/php/servers/sources.php
@@ -242,18 +242,31 @@
 				str_replace("\\/", "/", $this->contents_sdir);
 		}
 
+		private static function source_cache_file(string $source_key) {
+			global $SOURCES_CACHE;
+			return "$SOURCES_CACHE/$source_key";
+		}
+
 		private static function fetch_source(string $source_key) {
 			$url = CommunitySources::SOURCES[$source_key];
 
 			$contents = file_get_contents($url);
 			log_debug($http_response_header[0]);
+			$cache_file = CommunitySources::source_cache_file($source_key);
 
-			if (!$contents) {
-				log_error("Could not fetch source from $url.");
-				return "";
+			if ($contents) {
+				file_put_contents($cache_file, $contents);
+				return $contents;
 			}
 
-			return $contents;
+			$contents = file_get_contents($cache_file);
+			if ($contents) {
+				log_warning("Could not fetch source from $url, using cache");
+				return $contents;
+			}
+
+			log_error("Could not fetch source from $url.");
+			return "";
 		}
 
 		/**
@@ -315,4 +328,6 @@
 			return $this->room_tags[$room_id];
 		}
 	}
+
+	file_exists($SOURCES_CACHE) or mkdir($SOURCES_CACHE, 0755, recursive: true);
 ?>