media/midi/midi_manager_mac.cc - chromium/src - Git at Google

 // 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 "media/midi/midi_manager_mac.h"

 #include <algorithm>

 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/sys_string_conversions.h"

 #include <CoreAudio/HostTime.h>
 #include <stddef.h>

 using base::IntToString;
 using base::SysCFStringRefToUTF8;
 using std::string;

 // NB: System MIDI types are pointer types in 32-bit and integer types in
 // 64-bit. Therefore, the initialization is the simplest one that satisfies both
 // (if possible).

 namespace media {
 namespace midi {

 namespace {

 // Maximum buffer size that CoreMIDI can handle for MIDIPacketList.
 const size_t kCoreMIDIMaxPacketListSize = 65536;
 // Pessimistic estimation on available data size of MIDIPacketList.
 const size_t kEstimatedMaxPacketDataSize = kCoreMIDIMaxPacketListSize / 2;

 MidiPortInfo GetPortInfoFromEndpoint(MIDIEndpointRef endpoint) {
   string manufacturer;
   CFStringRef manufacturer_ref = NULL;
   OSStatus result = MIDIObjectGetStringProperty(
       endpoint, kMIDIPropertyManufacturer, &manufacturer_ref);
   if (result == noErr) {
     manufacturer = SysCFStringRefToUTF8(manufacturer_ref);
   } else {
     // kMIDIPropertyManufacturer is not supported in IAC driver providing
     // endpoints, and the result will be kMIDIUnknownProperty (-10835).
     DLOG(WARNING) << "Failed to get kMIDIPropertyManufacturer with status "
                   << result;
   }

   string name;
   CFStringRef name_ref = NULL;
   result = MIDIObjectGetStringProperty(endpoint, kMIDIPropertyDisplayName,
                                        &name_ref);
   if (result == noErr) {
     name = SysCFStringRefToUTF8(name_ref);
   } else {
     DLOG(WARNING) << "Failed to get kMIDIPropertyDisplayName with status "
                   << result;
   }

   string version;
   SInt32 version_number = 0;
   result = MIDIObjectGetIntegerProperty(
       endpoint, kMIDIPropertyDriverVersion, &version_number);
   if (result == noErr) {
     version = IntToString(version_number);
   } else {
     // kMIDIPropertyDriverVersion is not supported in IAC driver providing
     // endpoints, and the result will be kMIDIUnknownProperty (-10835).
     DLOG(WARNING) << "Failed to get kMIDIPropertyDriverVersion with status "
                   << result;
   }

   string id;
   SInt32 id_number = 0;
   result = MIDIObjectGetIntegerProperty(
       endpoint, kMIDIPropertyUniqueID, &id_number);
   if (result == noErr) {
     id = IntToString(id_number);
   } else {
     // On connecting some devices, e.g., nano KONTROL2, unknown endpoints
     // appear and disappear quickly and they fail on queries.
     // Let's ignore such ghost devices.
     // Same problems will happen if the device is disconnected before finishing
     // all queries.
     DLOG(WARNING) << "Failed to get kMIDIPropertyUniqueID with status "
                   << result;
   }

   const MidiPortState state = MIDI_PORT_OPENED;
   return MidiPortInfo(id, manufacturer, name, version, state);
 }

 double MIDITimeStampToSeconds(MIDITimeStamp timestamp) {
   UInt64 nanoseconds = AudioConvertHostTimeToNanos(timestamp);
   return static_cast<double>(nanoseconds) / 1.0e9;
 }

 MIDITimeStamp SecondsToMIDITimeStamp(double seconds) {
   UInt64 nanos = UInt64(seconds * 1.0e9);
   return AudioConvertNanosToHostTime(nanos);
 }

 }  // namespace

 MidiManager* MidiManager::Create() {
   return new MidiManagerMac();
 }

 MidiManagerMac::MidiManagerMac()
     : midi_client_(0),
       coremidi_input_(0),
       coremidi_output_(0),
       client_thread_("MidiClientThread"),
       shutdown_(false) {
 }

 MidiManagerMac::~MidiManagerMac() = default;

 void MidiManagerMac::StartInitialization() {
   // MIDIClient should be created on |client_thread_| to receive CoreMIDI event
   // notifications.
   RunOnClientThread(
       base::Bind(&MidiManagerMac::InitializeCoreMIDI, base::Unretained(this)));
 }

 void MidiManagerMac::Finalize() {
   // Wait for the termination of |client_thread_| before disposing MIDI ports.
   shutdown_ = true;
   client_thread_.Stop();

   if (coremidi_input_)
     MIDIPortDispose(coremidi_input_);
   if (coremidi_output_)
     MIDIPortDispose(coremidi_output_);
   if (midi_client_)
     MIDIClientDispose(midi_client_);
 }

 void MidiManagerMac::DispatchSendMidiData(MidiManagerClient* client,
                                           uint32_t port_index,
                                           const std::vector<uint8_t>& data,
                                           double timestamp) {
   RunOnClientThread(
       base::Bind(&MidiManagerMac::SendMidiData,
                  base::Unretained(this), client, port_index, data, timestamp));
 }

 void MidiManagerMac::RunOnClientThread(const base::Closure& closure) {
   if (shutdown_)
     return;

   if (!client_thread_.IsRunning())
     client_thread_.Start();

   client_thread_.task_runner()->PostTask(FROM_HERE, closure);
 }

 void MidiManagerMac::InitializeCoreMIDI() {
   DCHECK(client_thread_.task_runner()->BelongsToCurrentThread());

   // CoreMIDI registration.
   DCHECK_EQ(0u, midi_client_);
   OSStatus result =
       MIDIClientCreate(CFSTR("Chrome"), ReceiveMidiNotifyDispatch, this,
                        &midi_client_);
   if (result != noErr || midi_client_ == 0)
     return CompleteInitialization(Result::INITIALIZATION_ERROR);

   // Create input and output port.
   DCHECK_EQ(0u, coremidi_input_);
   result = MIDIInputPortCreate(
       midi_client_,
       CFSTR("MIDI Input"),
       ReadMidiDispatch,
       this,
       &coremidi_input_);
   if (result != noErr || coremidi_input_ == 0)
     return CompleteInitialization(Result::INITIALIZATION_ERROR);

   DCHECK_EQ(0u, coremidi_output_);
   result = MIDIOutputPortCreate(
       midi_client_,
       CFSTR("MIDI Output"),
       &coremidi_output_);
   if (result != noErr || coremidi_output_ == 0)
     return CompleteInitialization(Result::INITIALIZATION_ERROR);

   // Following loop may miss some newly attached devices, but such device will
   // be captured by ReceiveMidiNotifyDispatch callback.
   uint32_t destination_count = MIDIGetNumberOfDestinations();
   destinations_.resize(destination_count);
   for (uint32_t i = 0; i < destination_count; i++) {
     MIDIEndpointRef destination = MIDIGetDestination(i);
     if (destination == 0) {
       // One ore more devices may be detached.
       destinations_.resize(i);
       break;
     }

     // Keep track of all destinations (known as outputs by the Web MIDI API).
     // Cache to avoid any possible overhead in calling MIDIGetDestination().
     destinations_[i] = destination;

     MidiPortInfo info = GetPortInfoFromEndpoint(destination);
     AddOutputPort(info);
   }

   // Open connections from all sources. This loop also may miss new devices.
   uint32_t source_count = MIDIGetNumberOfSources();
   for (uint32_t i = 0; i < source_count; ++i) {
     // Receive from all sources.
     MIDIEndpointRef source = MIDIGetSource(i);
     if (source == 0)
       break;

     // Start listening.
     MIDIPortConnectSource(
         coremidi_input_, source, reinterpret_cast<void*>(source));

     // Keep track of all sources (known as inputs in Web MIDI API terminology).
     source_map_[source] = i;

     MidiPortInfo info = GetPortInfoFromEndpoint(source);
     AddInputPort(info);
   }

   // Allocate maximum size of buffer that CoreMIDI can handle.
   midi_buffer_.resize(kCoreMIDIMaxPacketListSize);

   CompleteInitialization(Result::OK);
 }

 // static
 void MidiManagerMac::ReceiveMidiNotifyDispatch(const MIDINotification* message,
                                                void* refcon) {
   // This callback function is invoked on |client_thread_|.
   MidiManagerMac* manager = static_cast<MidiManagerMac*>(refcon);
   manager->ReceiveMidiNotify(message);
 }

 void MidiManagerMac::ReceiveMidiNotify(const MIDINotification* message) {
   DCHECK(client_thread_.task_runner()->BelongsToCurrentThread());

   if (kMIDIMsgObjectAdded == message->messageID) {
     // New device is going to be attached.
     const MIDIObjectAddRemoveNotification* notification =
         reinterpret_cast<const MIDIObjectAddRemoveNotification*>(message);
     MIDIEndpointRef endpoint =
         static_cast<MIDIEndpointRef>(notification->child);
     if (notification->childType == kMIDIObjectType_Source) {
       // Attaching device is an input device.
       auto it = source_map_.find(endpoint);
       if (it == source_map_.end()) {
         MidiPortInfo info = GetPortInfoFromEndpoint(endpoint);
         // If the device disappears before finishing queries, MidiPortInfo
         // becomes incomplete. Skip and do not cache such information here.
         // On kMIDIMsgObjectRemoved, the entry will be ignored because it
         // will not be found in the pool.
         if (!info.id.empty()) {
           uint32_t index = source_map_.size();
           source_map_[endpoint] = index;
           AddInputPort(info);
           MIDIPortConnectSource(
               coremidi_input_, endpoint, reinterpret_cast<void*>(endpoint));
         }
       } else {
         SetInputPortState(it->second, MIDI_PORT_OPENED);
       }
     } else if (notification->childType == kMIDIObjectType_Destination) {
       // Attaching device is an output device.
       auto it = std::find(destinations_.begin(), destinations_.end(), endpoint);
       if (it == destinations_.end()) {
         MidiPortInfo info = GetPortInfoFromEndpoint(endpoint);
         // Skip cases that queries are not finished correctly.
         if (!info.id.empty()) {
           destinations_.push_back(endpoint);
           AddOutputPort(info);
         }
       } else {
         SetOutputPortState(it - destinations_.begin(), MIDI_PORT_OPENED);
       }
     }
   } else if (kMIDIMsgObjectRemoved == message->messageID) {
     // Existing device is going to be detached.
     const MIDIObjectAddRemoveNotification* notification =
         reinterpret_cast<const MIDIObjectAddRemoveNotification*>(message);
     MIDIEndpointRef endpoint =
         static_cast<MIDIEndpointRef>(notification->child);
     if (notification->childType == kMIDIObjectType_Source) {
       // Detaching device is an input device.
       auto it = source_map_.find(endpoint);
       if (it != source_map_.end())
         SetInputPortState(it->second, MIDI_PORT_DISCONNECTED);
     } else if (notification->childType == kMIDIObjectType_Destination) {
       // Detaching device is an output device.
       auto it = std::find(destinations_.begin(), destinations_.end(), endpoint);
       if (it != destinations_.end())
         SetOutputPortState(it - destinations_.begin(), MIDI_PORT_DISCONNECTED);
     }
   }
 }

 // static
 void MidiManagerMac::ReadMidiDispatch(const MIDIPacketList* packet_list,
                                       void* read_proc_refcon,
                                       void* src_conn_refcon) {
   // This method is called on a separate high-priority thread owned by CoreMIDI.

   MidiManagerMac* manager = static_cast<MidiManagerMac*>(read_proc_refcon);
 #if __LP64__
   MIDIEndpointRef source = reinterpret_cast<uintptr_t>(src_conn_refcon);
 #else
   MIDIEndpointRef source = static_cast<MIDIEndpointRef>(src_conn_refcon);
 #endif

   // Dispatch to class method.
   manager->ReadMidi(source, packet_list);
 }

 void MidiManagerMac::ReadMidi(MIDIEndpointRef source,
                               const MIDIPacketList* packet_list) {
   // This method is called from ReadMidiDispatch() and runs on a separate
   // high-priority thread owned by CoreMIDI.

   // Lookup the port index based on the source.
   auto it = source_map_.find(source);
   if (it == source_map_.end())
     return;
   // This is safe since MidiManagerMac does not remove any existing
   // MIDIEndpointRef, and the order is saved.
   uint32_t port_index = it->second;

   // Go through each packet and process separately.
   const MIDIPacket* packet = &packet_list->packet[0];
   for (size_t i = 0; i < packet_list->numPackets; i++) {
     // Each packet contains MIDI data for one or more messages (like note-on).
     double timestamp_seconds = MIDITimeStampToSeconds(packet->timeStamp);

     ReceiveMidiData(
         port_index,
         packet->data,
         packet->length,
         timestamp_seconds);

     packet = MIDIPacketNext(packet);
   }
 }

 void MidiManagerMac::SendMidiData(MidiManagerClient* client,
                                   uint32_t port_index,
                                   const std::vector<uint8_t>& data,
                                   double timestamp) {
   DCHECK(client_thread_.task_runner()->BelongsToCurrentThread());

   // Lookup the destination based on the port index.
   if (static_cast<size_t>(port_index) >= destinations_.size())
     return;

   MIDITimeStamp coremidi_timestamp = SecondsToMIDITimeStamp(timestamp);
   MIDIEndpointRef destination = destinations_[port_index];

   size_t send_size;
   for (size_t sent_size = 0; sent_size < data.size(); sent_size += send_size) {
     MIDIPacketList* packet_list =
         reinterpret_cast<MIDIPacketList*>(midi_buffer_.data());
     MIDIPacket* midi_packet = MIDIPacketListInit(packet_list);
     // Limit the maximum payload size to kEstimatedMaxPacketDataSize that is
     // half of midi_buffer data size. MIDIPacketList and MIDIPacket consume
     // extra buffer areas for meta information, and available size is smaller
     // than buffer size. Here, we simply assume that at least half size is
     // available for data payload.
     send_size = std::min(data.size() - sent_size, kEstimatedMaxPacketDataSize);
     midi_packet = MIDIPacketListAdd(
         packet_list,
         kCoreMIDIMaxPacketListSize,
         midi_packet,
         coremidi_timestamp,
         send_size,
         &data[sent_size]);
     DCHECK(midi_packet);

     MIDISend(coremidi_output_, destination, packet_list);
   }

   AccumulateMidiBytesSent(client, data.size());
 }

 }  // namespace midi
 }  // namespace media
	// 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 "media/midi/midi_manager_mac.h"

	#include <algorithm>

	#include "base/bind.h"
	#include "base/message_loop/message_loop.h"
	#include "base/single_thread_task_runner.h"
	#include "base/strings/string_number_conversions.h"
	#include "base/strings/sys_string_conversions.h"

	#include <CoreAudio/HostTime.h>
	#include <stddef.h>

	using base::IntToString;
	using base::SysCFStringRefToUTF8;
	using std::string;

	// NB: System MIDI types are pointer types in 32-bit and integer types in
	// 64-bit. Therefore, the initialization is the simplest one that satisfies both
	// (if possible).

	namespace media {
	namespace midi {

	namespace {

	// Maximum buffer size that CoreMIDI can handle for MIDIPacketList.
	const size_t kCoreMIDIMaxPacketListSize = 65536;
	// Pessimistic estimation on available data size of MIDIPacketList.
	const size_t kEstimatedMaxPacketDataSize = kCoreMIDIMaxPacketListSize / 2;

	MidiPortInfo GetPortInfoFromEndpoint(MIDIEndpointRef endpoint) {
	string manufacturer;
	CFStringRef manufacturer_ref = NULL;
	OSStatus result = MIDIObjectGetStringProperty(
	endpoint, kMIDIPropertyManufacturer, &manufacturer_ref);
	if (result == noErr) {
	manufacturer = SysCFStringRefToUTF8(manufacturer_ref);
	} else {
	// kMIDIPropertyManufacturer is not supported in IAC driver providing
	// endpoints, and the result will be kMIDIUnknownProperty (-10835).
	DLOG(WARNING) << "Failed to get kMIDIPropertyManufacturer with status "
	<< result;
	}

	string name;
	CFStringRef name_ref = NULL;
	result = MIDIObjectGetStringProperty(endpoint, kMIDIPropertyDisplayName,
	&name_ref);
	if (result == noErr) {
	name = SysCFStringRefToUTF8(name_ref);
	} else {
	DLOG(WARNING) << "Failed to get kMIDIPropertyDisplayName with status "
	<< result;
	}

	string version;
	SInt32 version_number = 0;
	result = MIDIObjectGetIntegerProperty(
	endpoint, kMIDIPropertyDriverVersion, &version_number);
	if (result == noErr) {
	version = IntToString(version_number);
	} else {
	// kMIDIPropertyDriverVersion is not supported in IAC driver providing
	// endpoints, and the result will be kMIDIUnknownProperty (-10835).
	DLOG(WARNING) << "Failed to get kMIDIPropertyDriverVersion with status "
	<< result;
	}

	string id;
	SInt32 id_number = 0;
	result = MIDIObjectGetIntegerProperty(
	endpoint, kMIDIPropertyUniqueID, &id_number);
	if (result == noErr) {
	id = IntToString(id_number);
	} else {
	// On connecting some devices, e.g., nano KONTROL2, unknown endpoints
	// appear and disappear quickly and they fail on queries.
	// Let's ignore such ghost devices.
	// Same problems will happen if the device is disconnected before finishing
	// all queries.
	DLOG(WARNING) << "Failed to get kMIDIPropertyUniqueID with status "
	<< result;
	}

	const MidiPortState state = MIDI_PORT_OPENED;
	return MidiPortInfo(id, manufacturer, name, version, state);
	}

	double MIDITimeStampToSeconds(MIDITimeStamp timestamp) {
	UInt64 nanoseconds = AudioConvertHostTimeToNanos(timestamp);
	return static_cast<double>(nanoseconds) / 1.0e9;
	}

	MIDITimeStamp SecondsToMIDITimeStamp(double seconds) {
	UInt64 nanos = UInt64(seconds * 1.0e9);
	return AudioConvertNanosToHostTime(nanos);
	}

	} // namespace

	MidiManager* MidiManager::Create() {
	return new MidiManagerMac();
	}

	MidiManagerMac::MidiManagerMac()
	: midi_client_(0),
	coremidi_input_(0),
	coremidi_output_(0),
	client_thread_("MidiClientThread"),
	shutdown_(false) {
	}

	MidiManagerMac::~MidiManagerMac() = default;

	void MidiManagerMac::StartInitialization() {
	// MIDIClient should be created on \|client_thread_\| to receive CoreMIDI event
	// notifications.
	RunOnClientThread(
	base::Bind(&MidiManagerMac::InitializeCoreMIDI, base::Unretained(this)));
	}

	void MidiManagerMac::Finalize() {
	// Wait for the termination of \|client_thread_\| before disposing MIDI ports.
	shutdown_ = true;
	client_thread_.Stop();

	if (coremidi_input_)
	MIDIPortDispose(coremidi_input_);
	if (coremidi_output_)
	MIDIPortDispose(coremidi_output_);
	if (midi_client_)
	MIDIClientDispose(midi_client_);
	}

	void MidiManagerMac::DispatchSendMidiData(MidiManagerClient* client,
	uint32_t port_index,
	const std::vector<uint8_t>& data,
	double timestamp) {
	RunOnClientThread(
	base::Bind(&MidiManagerMac::SendMidiData,
	base::Unretained(this), client, port_index, data, timestamp));
	}

	void MidiManagerMac::RunOnClientThread(const base::Closure& closure) {
	if (shutdown_)
	return;

	if (!client_thread_.IsRunning())
	client_thread_.Start();

	client_thread_.task_runner()->PostTask(FROM_HERE, closure);
	}

	void MidiManagerMac::InitializeCoreMIDI() {
	DCHECK(client_thread_.task_runner()->BelongsToCurrentThread());

	// CoreMIDI registration.
	DCHECK_EQ(0u, midi_client_);
	OSStatus result =
	MIDIClientCreate(CFSTR("Chrome"), ReceiveMidiNotifyDispatch, this,
	&midi_client_);
	if (result != noErr \|\| midi_client_ == 0)
	return CompleteInitialization(Result::INITIALIZATION_ERROR);

	// Create input and output port.
	DCHECK_EQ(0u, coremidi_input_);
	result = MIDIInputPortCreate(
	midi_client_,
	CFSTR("MIDI Input"),
	ReadMidiDispatch,
	this,
	&coremidi_input_);
	if (result != noErr \|\| coremidi_input_ == 0)
	return CompleteInitialization(Result::INITIALIZATION_ERROR);

	DCHECK_EQ(0u, coremidi_output_);
	result = MIDIOutputPortCreate(
	midi_client_,
	CFSTR("MIDI Output"),
	&coremidi_output_);
	if (result != noErr \|\| coremidi_output_ == 0)
	return CompleteInitialization(Result::INITIALIZATION_ERROR);

	// Following loop may miss some newly attached devices, but such device will
	// be captured by ReceiveMidiNotifyDispatch callback.
	uint32_t destination_count = MIDIGetNumberOfDestinations();
	destinations_.resize(destination_count);
	for (uint32_t i = 0; i < destination_count; i++) {
	MIDIEndpointRef destination = MIDIGetDestination(i);
	if (destination == 0) {
	// One ore more devices may be detached.
	destinations_.resize(i);
	break;
	}

	// Keep track of all destinations (known as outputs by the Web MIDI API).
	// Cache to avoid any possible overhead in calling MIDIGetDestination().
	destinations_[i] = destination;

	MidiPortInfo info = GetPortInfoFromEndpoint(destination);
	AddOutputPort(info);
	}

	// Open connections from all sources. This loop also may miss new devices.
	uint32_t source_count = MIDIGetNumberOfSources();
	for (uint32_t i = 0; i < source_count; ++i) {
	// Receive from all sources.
	MIDIEndpointRef source = MIDIGetSource(i);
	if (source == 0)
	break;

	// Start listening.
	MIDIPortConnectSource(
	coremidi_input_, source, reinterpret_cast<void*>(source));

	// Keep track of all sources (known as inputs in Web MIDI API terminology).
	source_map_[source] = i;

	MidiPortInfo info = GetPortInfoFromEndpoint(source);
	AddInputPort(info);
	}

	// Allocate maximum size of buffer that CoreMIDI can handle.
	midi_buffer_.resize(kCoreMIDIMaxPacketListSize);

	CompleteInitialization(Result::OK);
	}

	// static
	void MidiManagerMac::ReceiveMidiNotifyDispatch(const MIDINotification* message,
	void* refcon) {
	// This callback function is invoked on \|client_thread_\|.
	MidiManagerMac* manager = static_cast<MidiManagerMac*>(refcon);
	manager->ReceiveMidiNotify(message);
	}

	void MidiManagerMac::ReceiveMidiNotify(const MIDINotification* message) {
	DCHECK(client_thread_.task_runner()->BelongsToCurrentThread());

	if (kMIDIMsgObjectAdded == message->messageID) {
	// New device is going to be attached.
	const MIDIObjectAddRemoveNotification* notification =
	reinterpret_cast<const MIDIObjectAddRemoveNotification*>(message);
	MIDIEndpointRef endpoint =
	static_cast<MIDIEndpointRef>(notification->child);
	if (notification->childType == kMIDIObjectType_Source) {
	// Attaching device is an input device.
	auto it = source_map_.find(endpoint);
	if (it == source_map_.end()) {
	MidiPortInfo info = GetPortInfoFromEndpoint(endpoint);
	// If the device disappears before finishing queries, MidiPortInfo
	// becomes incomplete. Skip and do not cache such information here.
	// On kMIDIMsgObjectRemoved, the entry will be ignored because it
	// will not be found in the pool.
	if (!info.id.empty()) {
	uint32_t index = source_map_.size();
	source_map_[endpoint] = index;
	AddInputPort(info);
	MIDIPortConnectSource(
	coremidi_input_, endpoint, reinterpret_cast<void*>(endpoint));
	}
	} else {
	SetInputPortState(it->second, MIDI_PORT_OPENED);
	}
	} else if (notification->childType == kMIDIObjectType_Destination) {
	// Attaching device is an output device.
	auto it = std::find(destinations_.begin(), destinations_.end(), endpoint);
	if (it == destinations_.end()) {
	MidiPortInfo info = GetPortInfoFromEndpoint(endpoint);
	// Skip cases that queries are not finished correctly.
	if (!info.id.empty()) {
	destinations_.push_back(endpoint);
	AddOutputPort(info);
	}
	} else {
	SetOutputPortState(it - destinations_.begin(), MIDI_PORT_OPENED);
	}
	}
	} else if (kMIDIMsgObjectRemoved == message->messageID) {
	// Existing device is going to be detached.
	const MIDIObjectAddRemoveNotification* notification =
	reinterpret_cast<const MIDIObjectAddRemoveNotification*>(message);
	MIDIEndpointRef endpoint =
	static_cast<MIDIEndpointRef>(notification->child);
	if (notification->childType == kMIDIObjectType_Source) {
	// Detaching device is an input device.
	auto it = source_map_.find(endpoint);
	if (it != source_map_.end())
	SetInputPortState(it->second, MIDI_PORT_DISCONNECTED);
	} else if (notification->childType == kMIDIObjectType_Destination) {
	// Detaching device is an output device.
	auto it = std::find(destinations_.begin(), destinations_.end(), endpoint);
	if (it != destinations_.end())
	SetOutputPortState(it - destinations_.begin(), MIDI_PORT_DISCONNECTED);
	}
	}
	}

	// static
	void MidiManagerMac::ReadMidiDispatch(const MIDIPacketList* packet_list,
	void* read_proc_refcon,
	void* src_conn_refcon) {
	// This method is called on a separate high-priority thread owned by CoreMIDI.

	MidiManagerMac* manager = static_cast<MidiManagerMac*>(read_proc_refcon);
	#if __LP64__
	MIDIEndpointRef source = reinterpret_cast<uintptr_t>(src_conn_refcon);
	#else
	MIDIEndpointRef source = static_cast<MIDIEndpointRef>(src_conn_refcon);
	#endif

	// Dispatch to class method.
	manager->ReadMidi(source, packet_list);
	}

	void MidiManagerMac::ReadMidi(MIDIEndpointRef source,
	const MIDIPacketList* packet_list) {
	// This method is called from ReadMidiDispatch() and runs on a separate
	// high-priority thread owned by CoreMIDI.

	// Lookup the port index based on the source.
	auto it = source_map_.find(source);
	if (it == source_map_.end())
	return;
	// This is safe since MidiManagerMac does not remove any existing
	// MIDIEndpointRef, and the order is saved.
	uint32_t port_index = it->second;

	// Go through each packet and process separately.
	const MIDIPacket* packet = &packet_list->packet[0];
	for (size_t i = 0; i < packet_list->numPackets; i++) {
	// Each packet contains MIDI data for one or more messages (like note-on).
	double timestamp_seconds = MIDITimeStampToSeconds(packet->timeStamp);

	ReceiveMidiData(
	port_index,
	packet->data,
	packet->length,
	timestamp_seconds);

	packet = MIDIPacketNext(packet);
	}
	}

	void MidiManagerMac::SendMidiData(MidiManagerClient* client,
	uint32_t port_index,
	const std::vector<uint8_t>& data,
	double timestamp) {
	DCHECK(client_thread_.task_runner()->BelongsToCurrentThread());

	// Lookup the destination based on the port index.
	if (static_cast<size_t>(port_index) >= destinations_.size())
	return;

	MIDITimeStamp coremidi_timestamp = SecondsToMIDITimeStamp(timestamp);
	MIDIEndpointRef destination = destinations_[port_index];

	size_t send_size;
	for (size_t sent_size = 0; sent_size < data.size(); sent_size += send_size) {
	MIDIPacketList* packet_list =
	reinterpret_cast<MIDIPacketList*>(midi_buffer_.data());
	MIDIPacket* midi_packet = MIDIPacketListInit(packet_list);
	// Limit the maximum payload size to kEstimatedMaxPacketDataSize that is
	// half of midi_buffer data size. MIDIPacketList and MIDIPacket consume
	// extra buffer areas for meta information, and available size is smaller
	// than buffer size. Here, we simply assume that at least half size is
	// available for data payload.
	send_size = std::min(data.size() - sent_size, kEstimatedMaxPacketDataSize);
	midi_packet = MIDIPacketListAdd(
	packet_list,
	kCoreMIDIMaxPacketListSize,
	midi_packet,
	coremidi_timestamp,
	send_size,
	&data[sent_size]);
	DCHECK(midi_packet);

	MIDISend(coremidi_output_, destination, packet_list);
	}

	AccumulateMidiBytesSent(client, data.size());
	}

	} // namespace midi
	} // namespace media