Shelf response ctx

lib/src/shelf_response.dart

@@ -0,0 +1,120 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:shelf/shelf.dart' as shelf;
+import 'shelf_request.dart';
+
+class ShelfResponseContext extends ResponseContext<ShelfResponseContext> {
+  final Angel app;
+  final ShelfRequestContext correspondingRequest;
+  final StreamController<List<int>> _ctrl = StreamController();
+  bool _isOpen = true, _isDetached = false;
+
+  ShelfResponseContext(this.app, this.correspondingRequest);
+
+  shelf.Response get shelfResponse {
+    return shelf.Response(statusCode, body: _ctrl.stream, headers: headers);
+  }
+
+  @override
+  Future<void> close() {
+    _isOpen = false;
+    _ctrl.close();
+    return super.close();
+  }
+
+  Iterable<String> __allowedEncodings;
+
+  Iterable<String> get _allowedEncodings {
+    return __allowedEncodings ??= correspondingRequest.headers
+        .value('accept-encoding')
+        ?.split(',')
+        ?.map((s) => s.trim())
+        ?.where((s) => s.isNotEmpty)
+        ?.map((str) {
+      // Ignore quality specifications in accept-encoding
+      // ex. gzip;q=0.8
+      if (!str.contains(';')) return str;
+      return str.split(';')[0];
+    });
+  }
+
+  @override
+  Future addStream(Stream<List<int>> stream) {
+    if (!isOpen && isBuffered) throw ResponseContext.closed();
+    Stream<List<int>> output = stream;
+
+    if (encoders.isNotEmpty && correspondingRequest != null) {
+      if (_allowedEncodings != null) {
+        for (var encodingName in _allowedEncodings) {
+          Converter<List<int>, List<int>> encoder;
+          String key = encodingName;
+
+          if (encoders.containsKey(encodingName)) {
+            encoder = encoders[encodingName];
+          } else if (encodingName == '*') {
+            encoder = encoders[key = encoders.keys.first];
+          }
+
+          if (encoder != null) {
+            output = encoders[key].bind(output);
+            break;
+          }
+        }
+      }
+    }
+
+    return _ctrl.addStream(output);
+  }
+
+  @override
+  void add(List<int> data) {
+    if (!isOpen && isBuffered) {
+      throw ResponseContext.closed();
+    } else if (_isOpen) {
+      if (encoders.isNotEmpty && correspondingRequest != null) {
+        if (_allowedEncodings != null) {
+          for (var encodingName in _allowedEncodings) {
+            Converter<List<int>, List<int>> encoder;
+            String key = encodingName;
+
+            if (encoders.containsKey(encodingName)) {
+              encoder = encoders[encodingName];
+            } else if (encodingName == '*') {
+              encoder = encoders[key = encoders.keys.first];
+            }
+
+            if (encoder != null) {
+              data = encoders[key].convert(data);
+              break;
+            }
+          }
+        }
+      }
+
+      _ctrl.add(data);
+    }
+  }
+
+  @override
+  BytesBuilder get buffer => null;
+
+  @override
+  FutureOr<ShelfResponseContext> detach() {
+    _isDetached = true;
+    return this;
+  }
+
+  @override
+  bool get isBuffered => false;
+
+  @override
+  bool get isOpen => _isOpen && !_isDetached;
+
+  @override
+  void useBuffer() {}
+
+  @override
+  ShelfResponseContext get rawResponse => this;
+}