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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.
#include "content/browser/renderer_host/media/midi_host.h"
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/debug/trace_event.h"
#include "base/process/process.h"
#include "content/browser/browser_main_loop.h"
#include "content/browser/media/media_internals.h"
#include "content/common/media/midi_messages.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/browser/media_observer.h"
#include "media/midi/midi_manager.h"
using media::MIDIManager;
using media::MIDIPortInfoList;
// The total number of bytes which we're allowed to send to the OS
// before knowing that they have been successfully sent.
static const size_t kMaxInFlightBytes = 10 * 1024 * 1024; // 10 MB.
// We keep track of the number of bytes successfully sent to
// the hardware. Every once in a while we report back to the renderer
// the number of bytes sent since the last report. This threshold determines
// how many bytes will be sent before reporting back to the renderer.
static const size_t kAcknowledgementThresholdBytes = 1024 * 1024; // 1 MB.
static const uint8 kSysExMessage = 0xf0;
namespace content {
MIDIHost::MIDIHost(media::MIDIManager* midi_manager)
: midi_manager_(midi_manager),
sent_bytes_in_flight_(0),
bytes_sent_since_last_acknowledgement_(0) {
}
MIDIHost::~MIDIHost() {
if (midi_manager_)
midi_manager_->EndSession(this);
}
void MIDIHost::OnChannelClosing() {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
BrowserMessageFilter::OnChannelClosing();
}
void MIDIHost::OnDestruct() const {
BrowserThread::DeleteOnIOThread::Destruct(this);
}
///////////////////////////////////////////////////////////////////////////////
// IPC Messages handler
bool MIDIHost::OnMessageReceived(const IPC::Message& message,
bool* message_was_ok) {
bool handled = true;
IPC_BEGIN_MESSAGE_MAP_EX(MIDIHost, message, *message_was_ok)
IPC_MESSAGE_HANDLER(MIDIHostMsg_StartSession, OnStartSession)
IPC_MESSAGE_HANDLER(MIDIHostMsg_SendData, OnSendData)
IPC_MESSAGE_UNHANDLED(handled = false)
IPC_END_MESSAGE_MAP_EX()
return handled;
}
void MIDIHost::OnStartSession(int client_id) {
MIDIPortInfoList input_ports;
MIDIPortInfoList output_ports;
// Initialize devices and register to receive MIDI data.
bool success = false;
if (midi_manager_) {
success = midi_manager_->StartSession(this);
if (success) {
input_ports = midi_manager_->input_ports();
output_ports = midi_manager_->output_ports();
}
}
Send(new MIDIMsg_SessionStarted(
client_id,
success,
input_ports,
output_ports));
}
void MIDIHost::OnSendData(int port,
const std::vector<uint8>& data,
double timestamp) {
if (!midi_manager_)
return;
base::AutoLock auto_lock(in_flight_lock_);
// Sanity check that we won't send too much.
if (sent_bytes_in_flight_ > kMaxInFlightBytes ||
data.size() > kMaxInFlightBytes ||
data.size() + sent_bytes_in_flight_ > kMaxInFlightBytes)
return;
// For now disallow all System Exclusive messages even if we
// have permission.
// TODO(toyoshim): allow System Exclusive if browser has granted
// this client access. We'll likely need to pass a GURL
// here to compare against our permissions.
if (data.size() > 0 && data[0] >= kSysExMessage)
return;
#if defined(OS_ANDROID)
// TODO(toyoshim): figure out why data() method does not compile on Android.
NOTIMPLEMENTED();
#else
midi_manager_->DispatchSendMIDIData(
this,
port,
data.data(),
data.size(),
timestamp);
#endif
sent_bytes_in_flight_ += data.size();
}
void MIDIHost::ReceiveMIDIData(
int port_index,
const uint8* data,
size_t length,
double timestamp) {
TRACE_EVENT0("midi", "MIDIHost::ReceiveMIDIData");
// For now disallow all System Exclusive messages even if we
// have permission.
// TODO(toyoshim): allow System Exclusive if browser has granted
// this client access. We'll likely need to pass a GURL
// here to compare against our permissions.
if (length > 0 && data[0] >= kSysExMessage)
return;
// Send to the renderer.
std::vector<uint8> v(data, data + length);
Send(new MIDIMsg_DataReceived(port_index, v, timestamp));
}
void MIDIHost::AccumulateMIDIBytesSent(size_t n) {
{
base::AutoLock auto_lock(in_flight_lock_);
if (n <= sent_bytes_in_flight_)
sent_bytes_in_flight_ -= n;
}
if (bytes_sent_since_last_acknowledgement_ + n >=
bytes_sent_since_last_acknowledgement_)
bytes_sent_since_last_acknowledgement_ += n;
if (bytes_sent_since_last_acknowledgement_ >=
kAcknowledgementThresholdBytes) {
Send(new MIDIMsg_AcknowledgeSentData(
bytes_sent_since_last_acknowledgement_));
bytes_sent_since_last_acknowledgement_ = 0;
}
}
} // namespace content
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