Web MIDI: introduce MidiService class

content/browser/media/midi_host.cc

 // 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/media/midi_host.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/process/process.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/bad_message.h"
 #include "content/browser/browser_main_loop.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/common/media/midi_messages.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/user_metrics.h"
 #include "media/midi/message_util.h"
-#include "media/midi/midi_manager.h"
 #include "media/midi/midi_message_queue.h"
+#include "media/midi/midi_service.h"
 
 namespace content {
 namespace {
 
 // The total number of bytes which we're allowed to send to the OS
 // before knowing that they have been successfully sent.
 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.
 const size_t kAcknowledgementThresholdBytes = 1024 * 1024;  // 1 MB.
 
 }  // namespace
 
 using midi::IsDataByte;
 using midi::IsSystemRealTimeMessage;
 using midi::IsValidWebMIDIData;
 using midi::MidiPortInfo;
 using midi::kSysExByte;
 using midi::kEndOfSysExByte;
 using midi::mojom::PortState;
 using midi::mojom::Result;
 
-MidiHost::MidiHost(int renderer_process_id,
-                   midi::MidiManager* midi_manager)
+MidiHost::MidiHost(int renderer_process_id, midi::MidiService* midi_service)
     : BrowserMessageFilter(MidiMsgStart),
       renderer_process_id_(renderer_process_id),
       has_sys_ex_permission_(false),
       is_session_requested_(false),
-      midi_manager_(midi_manager),
+      midi_service_(midi_service),
       sent_bytes_in_flight_(0),
       bytes_sent_since_last_acknowledgement_(0),
       output_port_count_(0) {
-  DCHECK(midi_manager_);
+  DCHECK(midi_service_);
 }
 
 MidiHost::~MidiHost() = default;
 
 void MidiHost::OnChannelClosing() {
-  // If we get here the MidiHost is going to be destroyed soon. Prevent any
-  // subsequent calls from MidiManager by closing our session.
+  // If we get here the MidiHost is going to be destroyed soon.  Prevent any
+  // subsequent calls from MidiService by closing our session.
   // If Send() is called from a different thread (e.g. a separate thread owned
-  // by the MidiManager implementation), it will get posted to the IO thread.
+  // by the MidiService implementation), it will get posted to the IO thread.
   // There is a race condition here if our refcount is 0 and we're about to or
   // have already entered OnDestruct().
-  if (is_session_requested_ && midi_manager_) {
-    midi_manager_->EndSession(this);
+  if (is_session_requested_ && midi_service_) {
+    midi_service_->EndSession(this);
     is_session_requested_ = false;
   }
 }
 
 void MidiHost::OnDestruct() const {
   BrowserThread::DeleteOnIOThread::Destruct(this);
 }
 
 // IPC Messages handler
 bool MidiHost::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(MidiHost, message)
     IPC_MESSAGE_HANDLER(MidiHostMsg_StartSession, OnStartSession)
     IPC_MESSAGE_HANDLER(MidiHostMsg_SendData, OnSendData)
     IPC_MESSAGE_HANDLER(MidiHostMsg_EndSession, OnEndSession)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled;
 }
 
 void MidiHost::OnStartSession() {
   is_session_requested_ = true;
-  if (midi_manager_)
-    midi_manager_->StartSession(this);
+  if (midi_service_)
+    midi_service_->StartSession(this);
 }
 
 void MidiHost::OnSendData(uint32_t port,
                           const std::vector<uint8_t>& data,
                           double timestamp) {
   {
     base::AutoLock auto_lock(output_port_count_lock_);
     if (output_port_count_ <= port) {
       bad_message::ReceivedBadMessage(this, bad_message::MH_INVALID_MIDI_PORT);
       return;
@@ skipping 17 matching lines @@
 
   {
     base::AutoLock auto_lock(in_flight_lock_);
     // Sanity check that we won't send too much data.
     // TODO(yukawa): Consider to send an error event back to the renderer
     // after some future discussion in W3C.
     if (data.size() + sent_bytes_in_flight_ > kMaxInFlightBytes)
       return;
     sent_bytes_in_flight_ += data.size();
   }
-  if (midi_manager_)
-    midi_manager_->DispatchSendMidiData(this, port, data, timestamp);
+  if (midi_service_)
+    midi_service_->DispatchSendMidiData(this, port, data, timestamp);
 }
 
 void MidiHost::OnEndSession() {
   is_session_requested_ = false;
-  if (midi_manager_)
-    midi_manager_->EndSession(this);
+  if (midi_service_)
+    midi_service_->EndSession(this);
 }
 
 void MidiHost::CompleteStartSession(Result result) {
   DCHECK(is_session_requested_);
   if (result == Result::OK) {
     // ChildSecurityPolicy is set just before OnStartSession by
     // MidiDispatcherHost. So we can safely cache the policy.
     has_sys_ex_permission_ = ChildProcessSecurityPolicyImpl::GetInstance()->
         CanSendMidiSysExMessage(renderer_process_id_);
   }
@@ skipping 66 matching lines @@
 
   if (bytes_sent_since_last_acknowledgement_ >=
       kAcknowledgementThresholdBytes) {
     Send(new MidiMsg_AcknowledgeSentData(
         bytes_sent_since_last_acknowledgement_));
     bytes_sent_since_last_acknowledgement_ = 0;
   }
 }
 
 void MidiHost::Detach() {
-  midi_manager_ = nullptr;
+  midi_service_ = nullptr;
 }
 
 }  // namespace content