| // Copyright (c) 2013 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. |
| |
| #ifndef CONTENT_RENDERER_MEDIA_MIDI_MIDI_MESSAGE_FILTER_H_ |
| #define CONTENT_RENDERER_MEDIA_MIDI_MIDI_MESSAGE_FILTER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <memory> |
| #include <set> |
| #include <vector> |
| |
| #include "base/macros.h" |
| #include "content/common/content_export.h" |
| #include "ipc/message_filter.h" |
| #include "media/midi/midi_service.mojom.h" |
| #include "third_party/blink/public/platform/modules/webmidi/web_midi_accessor_client.h" |
| |
| namespace base { |
| class SingleThreadTaskRunner; |
| } |
| |
| namespace content { |
| |
| // MessageFilter that handles MIDI messages. Created on render thread, and |
| // host multiple clients running on multiple frames on IO thread. |
| // Web MIDI intentionally uses MessageFilter (in a renderer process) and |
| // BrowserMessageFilter (in the browser process) to intercept MIDI messages and |
| // process them on IO thread in the browser process since these messages are |
| // time critical. Non-critical operations like permission management are |
| // handled in MidiDispatcher. |
| class CONTENT_EXPORT MidiMessageFilter : public IPC::MessageFilter { |
| public: |
| explicit MidiMessageFilter( |
| scoped_refptr<base::SingleThreadTaskRunner> io_task_runner); |
| |
| // Each client registers for MIDI access here. |
| // If permission is granted, then the client's |
| void AddClient(blink::WebMIDIAccessorClient* client); |
| void RemoveClient(blink::WebMIDIAccessorClient* client); |
| |
| // A client will only be able to call this method if it has a suitable |
| // output port (from addOutputPort()). |
| void SendMidiData(uint32_t port, |
| const uint8_t* data, |
| size_t length, |
| base::TimeTicks timestamp); |
| |
| // IO task runner associated with this message filter. |
| base::SingleThreadTaskRunner* io_task_runner() const { |
| return io_task_runner_.get(); |
| } |
| |
| protected: |
| ~MidiMessageFilter() override; |
| |
| private: |
| void StartSessionOnIOThread(); |
| |
| void SendMidiDataOnIOThread(uint32_t port, |
| const std::vector<uint8_t>& data, |
| base::TimeTicks timestamp); |
| |
| void EndSessionOnIOThread(); |
| |
| // Sends an IPC message using |sender_|. |
| void Send(IPC::Message* message); |
| |
| // IPC::MessageFilter override. Called on |io_task_runner|. |
| bool OnMessageReceived(const IPC::Message& message) override; |
| void OnFilterAdded(IPC::Channel* channel) override; |
| void OnFilterRemoved() override; |
| void OnChannelClosing() override; |
| |
| // Called when the browser process has approved (or denied) access to |
| // MIDI hardware. |
| void OnSessionStarted(midi::mojom::Result result); |
| |
| // These functions are called in 2 cases: |
| // (1) Just before calling |OnSessionStarted|, to notify the recipient about |
| // existing ports. |
| // (2) To notify the recipient that a new device was connected and that new |
| // ports have been created. |
| void OnAddInputPort(midi::mojom::PortInfo info); |
| void OnAddOutputPort(midi::mojom::PortInfo info); |
| |
| // These functions are called to notify the recipient that a device that is |
| // notified via OnAddInputPort() or OnAddOutputPort() gets disconnected, or |
| // connected again. |
| void OnSetInputPortState(uint32_t port, midi::mojom::PortState state); |
| void OnSetOutputPortState(uint32_t port, midi::mojom::PortState state); |
| |
| // Called when the browser process has sent MIDI data containing one or |
| // more messages. |
| void OnDataReceived(uint32_t port, |
| const std::vector<uint8_t>& data, |
| base::TimeTicks timestamp); |
| |
| // From time-to-time, the browser incrementally informs us of how many bytes |
| // it has successfully sent. This is part of our throttling process to avoid |
| // sending too much data before knowing how much has already been sent. |
| void OnAcknowledgeSentData(size_t bytes_sent); |
| |
| // Following methods, Handle*, run on |main_task_runner_|. |
| void HandleClientAdded(midi::mojom::Result result); |
| |
| void HandleAddInputPort(midi::mojom::PortInfo info); |
| void HandleAddOutputPort(midi::mojom::PortInfo info); |
| void HandleSetInputPortState(uint32_t port, midi::mojom::PortState state); |
| void HandleSetOutputPortState(uint32_t port, midi::mojom::PortState state); |
| |
| void HandleDataReceived(uint32_t port, |
| const std::vector<uint8_t>& data, |
| base::TimeTicks timestamp); |
| |
| void HandleAckknowledgeSentData(size_t bytes_sent); |
| |
| // IPC sender for Send(); must only be accessed on |io_task_runner_|. |
| IPC::Sender* sender_; |
| |
| // Task runner on which IPC calls are driven. |
| const scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_; |
| |
| // Main task runner. |
| scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_; |
| |
| /* |
| * Notice: Following members are designed to be accessed only on |
| * |main_task_runner_|. |
| */ |
| // Keeps track of all MIDI clients. This should be std::set so that various |
| // for-loops work correctly. To change the type, make sure that the new type |
| // is safe to modify the container inside for-loops. |
| typedef std::set<blink::WebMIDIAccessorClient*> ClientsSet; |
| ClientsSet clients_; |
| |
| // Represents clients that are waiting for a session being open. |
| // Note: std::vector is not safe to invoke callbacks inside iterator based |
| // for-loops. |
| typedef std::vector<blink::WebMIDIAccessorClient*> ClientsQueue; |
| ClientsQueue clients_waiting_session_queue_; |
| |
| // Represents a result on starting a session. Can be accessed only on |
| midi::mojom::Result session_result_; |
| |
| // Holds MidiPortInfoList for input ports and output ports. |
| std::vector<midi::mojom::PortInfo> inputs_; |
| std::vector<midi::mojom::PortInfo> outputs_; |
| |
| size_t unacknowledged_bytes_sent_; |
| |
| DISALLOW_COPY_AND_ASSIGN(MidiMessageFilter); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_RENDERER_MEDIA_MIDI_MIDI_MESSAGE_FILTER_H_ |