| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| part of bindings; |
| |
| abstract class Stub extends core.MojoEventStreamListener { |
| int _outstandingResponseFutures = 0; |
| bool _isClosing = false; |
| Completer _closeCompleter; |
| |
| Stub.fromEndpoint(core.MojoMessagePipeEndpoint endpoint) |
| : super.fromEndpoint(endpoint); |
| |
| Stub.fromHandle(core.MojoHandle handle) : super.fromHandle(handle); |
| |
| Stub.unbound() : super.unbound(); |
| |
| Future<Message> handleMessage(ServiceMessage message); |
| |
| void handleRead() { |
| // Query how many bytes are available. |
| var result = endpoint.query(); |
| assert(result.status.isOk || result.status.isResourceExhausted); |
| if (result.bytesRead == 0) { |
| throw new MojoCodecError('Unexpected empty message.'); |
| } |
| |
| // Read the data and view as a message. |
| var bytes = new ByteData(result.bytesRead); |
| var handles = new List<core.MojoHandle>(result.handlesRead); |
| result = endpoint.read(bytes, result.bytesRead, handles); |
| assert(result.status.isOk || result.status.isResourceExhausted); |
| |
| // Prepare the response. |
| var message; |
| var responseFuture; |
| try { |
| message = new ServiceMessage.fromMessage(new Message(bytes, handles)); |
| responseFuture = _isClosing ? null : handleMessage(message); |
| } catch (e, s) { |
| handles.forEach((h) => h.close()); |
| rethrow; |
| } |
| |
| // If there's a response, send it. |
| if (responseFuture != null) { |
| _outstandingResponseFutures++; |
| responseFuture.then((response) { |
| _outstandingResponseFutures--; |
| if (isOpen) { |
| endpoint.write( |
| response.buffer, response.buffer.lengthInBytes, response.handles); |
| // FailedPrecondition is only used to indicate that the other end of |
| // the pipe has been closed. We can ignore the close here and wait for |
| // the PeerClosed signal on the event stream. |
| assert(endpoint.status.isOk || endpoint.status.isFailedPrecondition); |
| if (_isClosing && (_outstandingResponseFutures == 0)) { |
| // This was the final response future for which we needed to send |
| // a response. It is safe to close. |
| super.close().then((_) { |
| if (_isClosing) { |
| _isClosing = false; |
| _closeCompleter.complete(null); |
| _closeCompleter = null; |
| } |
| }); |
| } |
| } |
| }); |
| } else if (_isClosing && (_outstandingResponseFutures == 0)) { |
| // We are closing, there is no response to send for this message, and |
| // there are no outstanding response futures. Do the close now. |
| super.close().then((_) { |
| if (_isClosing) { |
| _isClosing = false; |
| _closeCompleter.complete(null); |
| _closeCompleter = null; |
| } |
| }); |
| } |
| } |
| |
| void handleWrite() { |
| throw 'Unexpected write signal in client.'; |
| } |
| |
| // NB: |immediate| should only be true when calling close() while handling an |
| // exception thrown from handleRead(), e.g. when we receive a malformed |
| // message, or when we have received the PEER_CLOSED event. |
| @override |
| Future close({bool immediate: false}) { |
| if (isOpen && |
| !immediate && |
| (isInHandler || (_outstandingResponseFutures > 0))) { |
| // Either close() is being called from within handleRead() or |
| // handleWrite(), or close() is being called while there are outstanding |
| // response futures. Defer the actual close until all response futures |
| // have been resolved. |
| _isClosing = true; |
| _closeCompleter = new Completer(); |
| return _closeCompleter.future; |
| } else { |
| return super.close(immediate: immediate).then((_) { |
| if (_isClosing) { |
| _isClosing = false; |
| _closeCompleter.complete(null); |
| _closeCompleter = null; |
| } |
| }); |
| } |
| } |
| |
| Message buildResponse(Struct response, int name) { |
| var header = new MessageHeader(name); |
| return response.serializeWithHeader(header); |
| } |
| |
| Message buildResponseWithId(Struct response, int name, int id, int flags) { |
| var header = new MessageHeader.withRequestId(name, flags, id); |
| return response.serializeWithHeader(header); |
| } |
| |
| String toString() { |
| var superString = super.toString(); |
| return "Stub(${superString})"; |
| } |
| |
| int get version; |
| } |