From 3540897a6f4f8bd8a069f6295bd19c7e872148ea Mon Sep 17 00:00:00 2001
From: Timo Tijhof <krinklemail@gmail.com>
Date: Sun, 24 Mar 2019 20:28:25 +0000
Subject: [PATCH] resources: Add caching for faster runs and offline use

Also honour any XDG variables if set (such as Wikimedia CI does)
so that gate jobs can automatically persist the cache.

Bug: T203694
Change-Id: I156af1c5097b8a87be228345fc0a0b80bb3ae338
---
 .gitignore                          |  1 +
 includes/ForeignResourceManager.php | 61 +++++++++++++++++++++++++----
 2 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/.gitignore b/.gitignore
index def5a08eca..8cacb1ee30 100644
--- a/.gitignore
+++ b/.gitignore
@@ -50,6 +50,7 @@ sftp-config.json
 # Building & testing
 npm-debug.log
 node_modules/
+/resources/lib/.foreign
 /tests/phpunit/phpunit.phar
 /tests/selenium/log
 .eslintcache
diff --git a/includes/ForeignResourceManager.php b/includes/ForeignResourceManager.php
index 297200e9ba..9fd1e4fe45 100644
--- a/includes/ForeignResourceManager.php
+++ b/includes/ForeignResourceManager.php
@@ -30,10 +30,12 @@ class ForeignResourceManager {
 	private $registryFile;
 	private $libDir;
 	private $tmpParentDir;
+	private $cacheDir;
 	private $infoPrinter;
 	private $errorPrinter;
 	private $verbosePrinter;
 	private $action;
+	private $registry;
 
 	/**
 	 * @param string $registryFile Path to YAML file
@@ -60,8 +62,11 @@ class ForeignResourceManager {
 
 		// Use a temporary directory under the destination directory instead
 		// of wfTempDir() because PHP's rename() does not work across file
-		// systems, as the user's /tmp and $IP may be on different filesystems.
-		$this->tmpParentDir = "{$this->libDir}/.tmp";
+		// systems, and the user's /tmp and $IP may be on different filesystems.
+		$this->tmpParentDir = "{$this->libDir}/.foreign/tmp";
+
+		$cacheHome = getenv( 'XDG_CACHE_HOME' ) ? realpath( getenv( 'XDG_CACHE_HOME' ) ) : false;
+		$this->cacheDir = $cacheHome ? "$cacheHome/mw-foreign" : "{$this->libDir}/.foreign/cache";
 	}
 
 	/**
@@ -76,14 +81,14 @@ class ForeignResourceManager {
 		}
 		$this->action = $action;
 
-		$registry = $this->parseBasicYaml( file_get_contents( $this->registryFile ) );
+		$this->registry = $this->parseBasicYaml( file_get_contents( $this->registryFile ) );
 		if ( $module === 'all' ) {
-			$modules = $registry;
-		} elseif ( isset( $registry[ $module ] ) ) {
-			$modules = [ $module => $registry[ $module ] ];
+			$modules = $this->registry;
+		} elseif ( isset( $this->registry[ $module ] ) ) {
+			$modules = [ $module => $this->registry[ $module ] ];
 		} else {
 			$this->error( "Unknown module name.\n\nMust be one of:\n" .
-				wordwrap( implode( ', ', array_keys( $registry ) ), 80 ) .
+				wordwrap( implode( ', ', array_keys( $this->registry ) ), 80 ) .
 				'.'
 			);
 			return false;
@@ -127,8 +132,8 @@ class ForeignResourceManager {
 			}
 		}
 
-		$this->cleanUp();
 		$this->output( "\nDone!\n" );
+		$this->cleanUp();
 		if ( $this->hasErrors ) {
 			// The verify mode should check all modules/files and fail after, not during.
 			return false;
@@ -137,7 +142,29 @@ class ForeignResourceManager {
 		return true;
 	}
 
+	private function cacheKey( $src, $integrity ) {
+		$key = basename( $src ) . '_' . substr( $integrity, -12 );
+		$key = preg_replace( '/[.\/+?=_-]+/', '_', $key );
+		return rtrim( $key, '_' );
+	}
+
+	/** @return string|false */
+	private function cacheGet( $key ) {
+		return Wikimedia\quietCall( 'file_get_contents', "{$this->cacheDir}/$key.data" );
+	}
+
+	private function cacheSet( $key, $data ) {
+		wfMkdirParents( $this->cacheDir );
+		file_put_contents( "{$this->cacheDir}/$key.data", $data, LOCK_EX );
+	}
+
 	private function fetch( $src, $integrity ) {
+		$key = $this->cacheKey( $src, $integrity );
+		$data = $this->cacheGet( $key );
+		if ( $data ) {
+			return $data;
+		}
+
 		$req = MWHttpRequest::factory( $src, [ 'method' => 'GET', 'followRedirects' => false ] );
 		if ( !$req->execute()->isOK() ) {
 			throw new Exception( "Failed to download resource at {$src}" );
@@ -150,6 +177,7 @@ class ForeignResourceManager {
 		$actualIntegrity = $algo . '-' . base64_encode( hash( $algo, $data, true ) );
 		if ( $integrity === $actualIntegrity ) {
 			$this->verbose( "... passed integrity check for {$src}\n" );
+			$this->cacheSet( $key, $data );
 		} else {
 			if ( $this->action === 'make-sri' ) {
 				$this->output( "Integrity for {$src}\n\tintegrity: ${actualIntegrity}\n" );
@@ -277,6 +305,23 @@ class ForeignResourceManager {
 
 	private function cleanUp() {
 		wfRecursiveRemoveDir( $this->tmpParentDir );
+
+		// Prune the cache of files we don't recognise.
+		$knownKeys = [];
+		foreach ( $this->registry as $info ) {
+			if ( $info['type'] === 'file' || $info['type'] === 'tar' ) {
+				$knownKeys[] = $this->cacheKey( $info['src'], $info['integrity'] );
+			} elseif ( $info['type'] === 'multi-file' ) {
+				foreach ( $info['files'] as $file ) {
+					$knownKeys[] = $this->cacheKey( $file['src'], $file['integrity'] );
+				}
+			}
+		}
+		foreach ( glob( "{$this->cacheDir}/*" ) as $cacheFile ) {
+			if ( !in_array( basename( $cacheFile, '.data' ), $knownKeys ) ) {
+				unlink( $cacheFile );
+			}
+		}
 	}
 
 	/**
-- 
2.20.1