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// 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_BROWSER_MEDIA_MIDI_HOST_H_
#define CONTENT_BROWSER_MEDIA_MIDI_HOST_H_
#include <vector>
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
#include "base/synchronization/lock.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_message_filter.h"
#include "content/public/browser/browser_thread.h"
#include "media/midi/midi_manager.h"
namespace media {
class MidiManager;
class MidiMessageQueue;
}
namespace content {
class CONTENT_EXPORT MidiHost
: public BrowserMessageFilter,
public media::MidiManagerClient {
public:
// Called from UI thread from the owner of this object.
MidiHost(int renderer_process_id, media::MidiManager* midi_manager);
// BrowserMessageFilter implementation.
void OnDestruct() const override;
bool OnMessageReceived(const IPC::Message& message) override;
// MidiManagerClient implementation.
void CompleteStartSession(media::MidiResult result) override;
void AddInputPort(const media::MidiPortInfo& info) override;
void AddOutputPort(const media::MidiPortInfo& info) override;
void ReceiveMidiData(uint32 port,
const uint8* data,
size_t length,
double timestamp) override;
void AccumulateMidiBytesSent(size_t n) override;
// Start session to access MIDI hardware.
void OnStartSession();
// Data to be sent to a MIDI output port.
void OnSendData(uint32 port,
const std::vector<uint8>& data,
double timestamp);
void OnEndSession();
private:
FRIEND_TEST_ALL_PREFIXES(MidiHostTest, IsValidWebMIDIData);
friend class base::DeleteHelper<MidiHost>;
friend class BrowserThread;
~MidiHost() override;
// Returns true if |data| fulfills the requirements of MidiOutput.send API
// defined in the WebMIDI spec.
// - |data| must be any number of complete MIDI messages (data abbreviation
// called "running status" is disallowed).
// - 1-byte MIDI realtime messages can be placed at any position of |data|.
static bool IsValidWebMIDIData(const std::vector<uint8>& data);
int renderer_process_id_;
// Represents if the renderer has a permission to send/receive MIDI SysEX
// messages.
bool has_sys_ex_permission_;
// Represents if a session is requested to start.
bool is_session_requested_;
// |midi_manager_| talks to the platform-specific MIDI APIs.
// It can be NULL if the platform (or our current implementation)
// does not support MIDI. If not supported then a call to
// OnRequestAccess() will always refuse access and a call to
// OnSendData() will do nothing.
media::MidiManager* const midi_manager_;
// Buffers where data sent from each MIDI input port is stored.
ScopedVector<media::MidiMessageQueue> received_messages_queues_;
// Protects access to |received_messages_queues_|;
base::Lock messages_queues_lock_;
// The number of bytes sent to the platform-specific MIDI sending
// system, but not yet completed.
size_t sent_bytes_in_flight_;
// The number of bytes successfully sent since the last time
// we've acknowledged back to the renderer.
size_t bytes_sent_since_last_acknowledgement_;
// Protects access to |sent_bytes_in_flight_|.
base::Lock in_flight_lock_;
DISALLOW_COPY_AND_ASSIGN(MidiHost);
};
} // namespace content
#endif // CONTENT_BROWSER_MEDIA_MIDI_HOST_H_
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