Added caching

README.md

@@ -1,6 +1,6 @@
 # angel_static
 
-[![version 1.1.2](https://img.shields.io/badge/pub-1.1.2-brightgreen.svg)](https://pub.dartlang.org/packages/angel_static)
+[![version 1.1.3](https://img.shields.io/badge/pub-1.1.3-brightgreen.svg)](https://pub.dartlang.org/packages/angel_static)
 [![build status](https://travis-ci.org/angel-dart/static.svg?branch=master)](https://travis-ci.org/angel-dart/static)
 
 Static server middleware for Angel.
@@ -24,7 +24,13 @@ import 'package:angel_static/angel_static.dart';
 
 main() async {
   final app = new Angel();
+
+  // Normal static server
   await app.configure(new VirtualDirectory(source: new Directory('./public')));
+
+  // Send Cache-Control, ETag, etc. as well
+  await app.configure(new CachingVirtualDirectory(source: new Directory('./public')));
+
   await app.startServer();
 }
 ```

lib/angel_static.dart

@@ -1,4 +1,5 @@
 library angel_static;
 
+export 'src/cache.dart';
 export 'src/serve_static.dart';
 export 'src/virtual_directory.dart';

lib/src/cache.dart

@@ -0,0 +1,177 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:crypto/crypto.dart';
+import 'package:intl/intl.dart';
+import 'package:mime/mime.dart';
+import 'virtual_directory.dart';
+
+final DateFormat _fmt = new DateFormat('EEE, d MMM yyyy HH:mm:ss');
+
+/// Formats a date (converted to UTC), ex: `Sun, 03 May 2015 23:02:37 GMT`.
+String formatDateForHttp(DateTime dt) => _fmt.format(dt.toUtc()) + ' GMT';
+
+/// Generates an ETag from the given buffer.
+String generateEtag(List<int> buf, {bool weak: true, Hash hash}) {
+  if (weak == false) {
+    Hash h = hash ?? md5;
+    return new String.fromCharCodes(h.convert(buf).bytes);
+  } else {
+    // length + first 50 bytes as base64url
+    return 'W/${buf.length}' + BASE64URL.encode(buf.take(50).toList());
+  }
+}
+
+/// Returns a string representation of the given [CacheAccessLevel].
+String accessLevelToString(CacheAccessLevel accessLevel) {
+  switch (accessLevel) {
+    case CacheAccessLevel.PRIVATE:
+      return 'private';
+    case CacheAccessLevel.PUBLIC:
+      return 'public';
+    default:
+      throw new ArgumentError('Unrecognized cache access level: $accessLevel');
+  }
+}
+
+/// A static server plug-in that also sets `Cache-Control` headers.
+class CachingVirtualDirectory extends VirtualDirectory {
+  final Map<String, String> _etags = {};
+
+  /// Either `PUBLIC` or `PRIVATE`.
+  final CacheAccessLevel accessLevel;
+
+  /// Used to generate strong ETags, if [useWeakEtags] is false.
+  ///
+  /// Default: `md5`.
+  final Hash hash;
+
+  /// If `true`, responses will always have `private, max-age=0` as their `Cache-Control` header.
+  final bool noCache;
+
+  /// If `true` (default), `Cache-Control` headers will only be set if the application is in production mode.
+  final bool onlyInProduction;
+
+  /// If `true` (default), ETags will be computed and sent along with responses.
+  final bool useEtags;
+
+  /// If `false` (default: `true`), ETags will be generated via MD5 hash.
+  final bool useWeakEtags;
+
+  /// The `max-age` for `Cache-Control`.
+  final int maxAge;
+
+  CachingVirtualDirectory(
+      {this.accessLevel: CacheAccessLevel.PUBLIC,
+      Directory source,
+      bool debug,
+      this.hash,
+      Iterable<String> indexFileNames,
+      this.maxAge: 0,
+      this.noCache: false,
+      this.onlyInProduction: false,
+      this.useEtags: true,
+      this.useWeakEtags: true,
+      String publicPath,
+      StaticFileCallback callback,
+      bool streamToIO: false})
+      : super(
+            source: source,
+            debug: debug == true,
+            indexFileNames: indexFileNames ?? ['index.html'],
+            publicPath: publicPath ?? '/',
+            callback: callback,
+            streamToIO: streamToIO == true);
+
+  @override
+  Future<bool> serveFile(
+      File file, FileStat stat, RequestContext req, ResponseContext res) {
+    if (onlyInProduction == true && req.app.isProduction == true) {
+      return super.serveFile(file, stat, req, res);
+    }
+
+    if (noCache == true) {
+      res.headers[HttpHeaders.CACHE_CONTROL] = 'private, max-age=0, no-cache';
+      return super.serveFile(file, stat, req, res);
+    } else {
+      if (useEtags == true) {
+        var etags = req.headers[HttpHeaders.IF_NONE_MATCH];
+
+        if (etags?.isNotEmpty == true) {
+          bool hasBeenModified = false;
+
+          for (var etag in etags) {
+            if (etag == '*')
+              hasBeenModified = true;
+            else {
+              hasBeenModified = _etags.containsKey(file.absolute.path) &&
+                  _etags[file.absolute.path] == etag;
+            }
+          }
+
+          if (hasBeenModified) {
+            res.statusCode = HttpStatus.NOT_MODIFIED;
+            setCachedHeaders(file, stat, req, res);
+            return new Future.value(false);
+          }
+        }
+      }
+
+      if (req.headers[HttpHeaders.IF_MODIFIED_SINCE] != null) {
+        try {
+          var ifModifiedSince = _fmt.parse(req.headers
+              .value(HttpHeaders.IF_MODIFIED_SINCE)
+              .replaceAll('GMT', '')
+              .trim());
+
+          if (ifModifiedSince.compareTo(stat.changed) > 0) {
+            res.statusCode = HttpStatus.NOT_MODIFIED;
+            setCachedHeaders(file, stat, req, res);
+
+            if (_etags.containsKey(file.absolute.path))
+              res.headers[HttpHeaders.ETAG] = _etags[file.absolute.path];
+
+            return new Future.value(false);
+          }
+        } catch (_) {
+          throw new AngelHttpException.badRequest(
+              message: 'Invalid date for If-Modified-Since header.');
+        }
+      }
+
+      return file.readAsBytes().then((buf) {
+        var etag = _etags[file.absolute.path] =
+            generateEtag(buf, weak: useWeakEtags != false);
+        res.headers
+          ..[HttpHeaders.ETAG] = etag
+          ..[HttpHeaders.CONTENT_TYPE] = lookupMimeType(file.path);
+        setCachedHeaders(file, stat, req, res);
+
+        if (useWeakEtags == false) {
+          res
+            ..statusCode = 200
+            ..willCloseItself = false
+            ..buffer.add(buf)
+            ..end();
+          return new Future.value(false);
+        }
+
+        return super.serveFile(file, stat, req, res);
+      });
+    }
+  }
+
+  void setCachedHeaders(
+      File file, FileStat stat, RequestContext req, ResponseContext res) {
+    var privacy = accessLevelToString(accessLevel ?? CacheAccessLevel.PUBLIC);
+    var expiry = new DateTime.now()..add(new Duration(seconds: maxAge ?? 0));
+
+    res.headers
+      ..[HttpHeaders.CACHE_CONTROL] = '$privacy, max-age=${maxAge ?? 0}'
+      ..[HttpHeaders.EXPIRES] = formatDateForHttp(expiry)
+      ..[HttpHeaders.LAST_MODIFIED] = formatDateForHttp(stat.changed);
+  }
+}
+
+enum CacheAccessLevel { PUBLIC, PRIVATE }

lib/src/virtual_directory.dart

@@ -25,13 +25,22 @@ String _pathify(String path) {
   return p;
 }
 
+/// A static server plug-in.
 class VirtualDirectory implements AngelPlugin {
   final bool debug;
   String _prefix;
   Directory _source;
+
+  /// The directory to serve files from.
   Directory get source => _source;
+
+  /// An optional callback to run before serving files.
   final StaticFileCallback callback;
-  final List<String> indexFileNames;
+
+  /// Filenames to be resolved within directories as indices.
+  final Iterable<String> indexFileNames;
+
+  /// An optional public path to map requests to.
   final String publicPath;
 
   /// If set to `true`, files will be streamed to `res.io`, instead of added to `res.buffer`.
@@ -89,9 +98,9 @@ class VirtualDirectory implements AngelPlugin {
     if (stat.type == FileSystemEntityType.NOT_FOUND)
       return true;
     else if (stat.type == FileSystemEntityType.DIRECTORY)
-      return await serveDirectory(new Directory(absolute), req, res);
+      return await serveDirectory(new Directory(absolute), stat, req, res);
     else if (stat.type == FileSystemEntityType.FILE)
-      return await serveFile(new File(absolute), req, res);
+      return await serveFile(new File(absolute), stat, req, res);
     else if (stat.type == FileSystemEntityType.LINK) {
       var link = new Link(absolute);
       return await servePath(await link.resolveSymbolicLinks(), req, res);
@@ -100,7 +109,7 @@ class VirtualDirectory implements AngelPlugin {
   }
 
   Future<bool> serveFile(
-      File file, RequestContext req, ResponseContext res) async {
+      File file, FileStat stat, RequestContext req, ResponseContext res) async {
     _printDebug('Sending file ${file.absolute.path}...');
     _printDebug('MIME type for ${file.path}: ${lookupMimeType(file.path)}');
     res.statusCode = 200;
@@ -120,13 +129,13 @@ class VirtualDirectory implements AngelPlugin {
     return false;
   }
 
-  Future<bool> serveDirectory(
-      Directory directory, RequestContext req, ResponseContext res) async {
+  Future<bool> serveDirectory(Directory directory, FileStat stat,
+      RequestContext req, ResponseContext res) async {
     for (String indexFileName in indexFileNames) {
       final index =
           new File.fromUri(directory.absolute.uri.resolve(indexFileName));
       if (await index.exists()) {
-        return await serveFile(index, req, res);
+        return await serveFile(index, stat, req, res);
       }
     }
 

pubspec.yaml

@@ -4,9 +4,10 @@ environment:
   sdk: ">=1.19.0"
 homepage: https://github.com/angel-dart/angel_static
 author: thosakwe <thosakwe@gmail.com>
-version: 1.1.2
+version: 1.1.3
 dependencies:
   angel_framework: ^1.0.0-dev
+  intl: ">=0.0.0 <1.0.0"
   mime: ^0.9.3
 dev_dependencies:
   http: ^0.11.3

test/cache_sample.dart

@@ -0,0 +1,24 @@
+import 'dart:io';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:angel_static/angel_static.dart';
+
+main() async {
+  Angel app;
+  Directory testDir = new Directory('test');
+  app = new Angel(debug: true);
+
+  await app.configure(new CachingVirtualDirectory(
+      source: testDir,
+      maxAge: 350,
+      onlyInProduction: false,
+      // useWeakEtags: false,
+      //publicPath: '/virtual',
+      indexFileNames: ['index.txt']));
+
+  app.get('*', 'Fallback');
+
+  app.dumpTree(showMatchers: true);
+
+  await app.startServer(InternetAddress.LOOPBACK_IP_V4, 0);
+  print('Open at http://${app.httpServer.address.host}:${app.httpServer.port}');
+}

test/cache_test.dart

@@ -0,0 +1,71 @@
+import 'dart:io';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:angel_static/angel_static.dart';
+import 'package:http/http.dart' show Client;
+import 'package:matcher/matcher.dart';
+import 'package:test/test.dart';
+
+main() {
+  Angel app;
+  Directory testDir = new Directory('test');
+  String url;
+  Client client = new Client();
+
+  setUp(() async {
+    app = new Angel(debug: true);
+
+    await app.configure(new CachingVirtualDirectory(
+        source: testDir, maxAge: 350, onlyInProduction: false,
+        //publicPath: '/virtual',
+        indexFileNames: ['index.txt']));
+
+    app.get('*', 'Fallback');
+
+    app.dumpTree(showMatchers: true);
+
+    await app.startServer(InternetAddress.LOOPBACK_IP_V4, 0);
+    url = "http://${app.httpServer.address.host}:${app.httpServer.port}";
+  });
+
+  tearDown(() async {
+    if (app.httpServer != null) await app.httpServer.close(force: true);
+  });
+
+  test('sets etag, cache-control, expires, last-modified', () async {
+    var response = await client.get("$url");
+
+    print('Response status: ${response.statusCode}');
+    print('Response body: ${response.body}');
+    print('Response headers: ${response.headers}');
+
+    expect(response.statusCode, equals(200));
+    expect(
+        [
+          HttpHeaders.ETAG,
+          HttpHeaders.CACHE_CONTROL,
+          HttpHeaders.EXPIRES,
+          HttpHeaders.LAST_MODIFIED
+        ],
+        everyElement(predicate(
+            response.headers.containsKey, 'contained in response headers')));
+  });
+
+  test('if-modified-since', () async {
+    var response = await client.get("$url", headers: {
+      HttpHeaders.IF_MODIFIED_SINCE:
+          formatDateForHttp(new DateTime.now()..add(new Duration(days: 365)))
+    });
+
+    print('Response status: ${response.statusCode}');
+
+    expect(response.statusCode, equals(304));
+    expect(
+        [
+          HttpHeaders.CACHE_CONTROL,
+          HttpHeaders.EXPIRES,
+          HttpHeaders.LAST_MODIFIED
+        ],
+        everyElement(predicate(
+            response.headers.containsKey, 'contained in response headers')));
+  });
+}