// Copyright (c) 2012 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/common/gpu/client/command_buffer_proxy_impl.h"

#include <vector>

#include "base/callback.h"
#include "base/logging.h"
#include "base/memory/shared_memory.h"
#include "base/stl_util.h"
#include "base/trace_event/trace_event.h"
#include "content/common/child_process_messages.h"
#include "content/common/gpu/client/gpu_channel_host.h"
#include "content/common/gpu/client/gpu_video_decode_accelerator_host.h"
#include "content/common/gpu/client/gpu_video_encode_accelerator_host.h"
#include "content/common/gpu/gpu_messages.h"
#include "content/common/view_messages.h"
#include "gpu/command_buffer/client/gpu_memory_buffer_manager.h"
#include "gpu/command_buffer/common/cmd_buffer_common.h"
#include "gpu/command_buffer/common/command_buffer_shared.h"
#include "gpu/command_buffer/common/gpu_memory_allocation.h"
#include "gpu/command_buffer/service/image_factory.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gl/gl_bindings.h"

namespace content {

CommandBufferProxyImpl::CommandBufferProxyImpl(GpuChannelHost* channel,
                                               int route_id)
    : lock_(nullptr),
      channel_(channel),
      route_id_(route_id),
      flush_count_(0),
      last_put_offset_(-1),
      last_barrier_put_offset_(-1),
      next_signal_id_(0) {
}

CommandBufferProxyImpl::~CommandBufferProxyImpl() {
  FOR_EACH_OBSERVER(DeletionObserver,
                    deletion_observers_,
                    OnWillDeleteImpl());
}

bool CommandBufferProxyImpl::OnMessageReceived(const IPC::Message& message) {
  scoped_ptr<base::AutoLock> lock;
  if (lock_)
    lock.reset(new base::AutoLock(*lock_));
  bool handled = true;
  IPC_BEGIN_MESSAGE_MAP(CommandBufferProxyImpl, message)
    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_Destroyed, OnDestroyed);
    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_ConsoleMsg, OnConsoleMessage);
    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_SetMemoryAllocation,
                        OnSetMemoryAllocation);
    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_SignalSyncPointAck,
                        OnSignalSyncPointAck);
    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_SwapBuffersCompleted,
                        OnSwapBuffersCompleted);
    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_UpdateVSyncParameters,
                        OnUpdateVSyncParameters);
    IPC_MESSAGE_UNHANDLED(handled = false)
  IPC_END_MESSAGE_MAP()

  DCHECK(handled);
  return handled;
}

void CommandBufferProxyImpl::OnChannelError() {
  scoped_ptr<base::AutoLock> lock;
  if (lock_)
    lock.reset(new base::AutoLock(*lock_));
  OnDestroyed(gpu::error::kGpuChannelLost, gpu::error::kLostContext);
}

void CommandBufferProxyImpl::OnDestroyed(gpu::error::ContextLostReason reason,
                                         gpu::error::Error error) {
  CheckLock();
  // Prevent any further messages from being sent.
  channel_ = NULL;

  // When the client sees that the context is lost, they should delete this
  // CommandBufferProxyImpl and create a new one.
  last_state_.error = error;
  last_state_.context_lost_reason = reason;

  if (!context_lost_callback_.is_null()) {
    context_lost_callback_.Run();
    // Avoid calling the error callback more than once.
    context_lost_callback_.Reset();
  }
}

void CommandBufferProxyImpl::OnConsoleMessage(
    const GPUCommandBufferConsoleMessage& message) {
  if (!console_message_callback_.is_null()) {
    console_message_callback_.Run(message.message, message.id);
  }
}

void CommandBufferProxyImpl::SetMemoryAllocationChangedCallback(
    const MemoryAllocationChangedCallback& callback) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  memory_allocation_changed_callback_ = callback;
  Send(new GpuCommandBufferMsg_SetClientHasMemoryAllocationChangedCallback(
      route_id_, !memory_allocation_changed_callback_.is_null()));
}

void CommandBufferProxyImpl::AddDeletionObserver(DeletionObserver* observer) {
  CheckLock();
  deletion_observers_.AddObserver(observer);
}

void CommandBufferProxyImpl::RemoveDeletionObserver(
    DeletionObserver* observer) {
  CheckLock();
  deletion_observers_.RemoveObserver(observer);
}

void CommandBufferProxyImpl::OnSetMemoryAllocation(
    const gpu::MemoryAllocation& allocation) {
  if (!memory_allocation_changed_callback_.is_null())
    memory_allocation_changed_callback_.Run(allocation);
}

void CommandBufferProxyImpl::OnSignalSyncPointAck(uint32 id) {
  SignalTaskMap::iterator it = signal_tasks_.find(id);
  DCHECK(it != signal_tasks_.end());
  base::Closure callback = it->second;
  signal_tasks_.erase(it);
  callback.Run();
}

void CommandBufferProxyImpl::SetContextLostCallback(
    const base::Closure& callback) {
  CheckLock();
  context_lost_callback_ = callback;
}

bool CommandBufferProxyImpl::Initialize() {
  TRACE_EVENT0("gpu", "CommandBufferProxyImpl::Initialize");
  shared_state_shm_.reset(channel_->factory()->AllocateSharedMemory(
      sizeof(*shared_state())).release());
  if (!shared_state_shm_)
    return false;

  if (!shared_state_shm_->Map(sizeof(*shared_state())))
    return false;

  shared_state()->Initialize();

  // This handle is owned by the GPU process and must be passed to it or it
  // will leak. In otherwords, do not early out on error between here and the
  // sending of the Initialize IPC below.
  base::SharedMemoryHandle handle =
      channel_->ShareToGpuProcess(shared_state_shm_->handle());
  if (!base::SharedMemory::IsHandleValid(handle))
    return false;

  bool result = false;
  if (!Send(new GpuCommandBufferMsg_Initialize(
      route_id_, handle, &result, &capabilities_))) {
    LOG(ERROR) << "Could not send GpuCommandBufferMsg_Initialize.";
    return false;
  }

  if (!result) {
    LOG(ERROR) << "Failed to initialize command buffer service.";
    return false;
  }

  capabilities_.image = true;

  return true;
}

gpu::CommandBuffer::State CommandBufferProxyImpl::GetLastState() {
  return last_state_;
}

int32 CommandBufferProxyImpl::GetLastToken() {
  TryUpdateState();
  return last_state_.token;
}

void CommandBufferProxyImpl::Flush(int32 put_offset) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  TRACE_EVENT1("gpu",
               "CommandBufferProxyImpl::Flush",
               "put_offset",
               put_offset);

  bool put_offset_changed = last_put_offset_ != put_offset;
  last_put_offset_ = put_offset;
  last_barrier_put_offset_ = put_offset;

  if (channel_) {
    channel_->OrderingBarrier(route_id_, put_offset, ++flush_count_,
                              latency_info_, put_offset_changed, true);
  }

  if (put_offset_changed)
    latency_info_.clear();
}

void CommandBufferProxyImpl::OrderingBarrier(int32 put_offset) {
  if (last_state_.error != gpu::error::kNoError)
    return;

  TRACE_EVENT1("gpu", "CommandBufferProxyImpl::OrderingBarrier", "put_offset",
               put_offset);

  bool put_offset_changed = last_barrier_put_offset_ != put_offset;
  last_barrier_put_offset_ = put_offset;

  if (channel_) {
    channel_->OrderingBarrier(route_id_, put_offset, ++flush_count_,
                              latency_info_, put_offset_changed, false);
  }

  if (put_offset_changed)
    latency_info_.clear();
}

void CommandBufferProxyImpl::SetLatencyInfo(
    const std::vector<ui::LatencyInfo>& latency_info) {
  CheckLock();
  for (size_t i = 0; i < latency_info.size(); i++)
    latency_info_.push_back(latency_info[i]);
}

void CommandBufferProxyImpl::SetSwapBuffersCompletionCallback(
    const SwapBuffersCompletionCallback& callback) {
  CheckLock();
  swap_buffers_completion_callback_ = callback;
}

void CommandBufferProxyImpl::SetUpdateVSyncParametersCallback(
    const UpdateVSyncParametersCallback& callback) {
  CheckLock();
  update_vsync_parameters_completion_callback_ = callback;
}

void CommandBufferProxyImpl::WaitForTokenInRange(int32 start, int32 end) {
  CheckLock();
  TRACE_EVENT2("gpu",
               "CommandBufferProxyImpl::WaitForToken",
               "start",
               start,
               "end",
               end);
  TryUpdateState();
  if (!InRange(start, end, last_state_.token) &&
      last_state_.error == gpu::error::kNoError) {
    gpu::CommandBuffer::State state;
    if (Send(new GpuCommandBufferMsg_WaitForTokenInRange(
            route_id_, start, end, &state)))
      OnUpdateState(state);
  }
  DCHECK(InRange(start, end, last_state_.token) ||
         last_state_.error != gpu::error::kNoError);
}

void CommandBufferProxyImpl::WaitForGetOffsetInRange(int32 start, int32 end) {
  CheckLock();
  TRACE_EVENT2("gpu",
               "CommandBufferProxyImpl::WaitForGetOffset",
               "start",
               start,
               "end",
               end);
  TryUpdateState();
  if (!InRange(start, end, last_state_.get_offset) &&
      last_state_.error == gpu::error::kNoError) {
    gpu::CommandBuffer::State state;
    if (Send(new GpuCommandBufferMsg_WaitForGetOffsetInRange(
            route_id_, start, end, &state)))
      OnUpdateState(state);
  }
  DCHECK(InRange(start, end, last_state_.get_offset) ||
         last_state_.error != gpu::error::kNoError);
}

void CommandBufferProxyImpl::SetGetBuffer(int32 shm_id) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  Send(new GpuCommandBufferMsg_SetGetBuffer(route_id_, shm_id));
  last_put_offset_ = -1;
}

scoped_refptr<gpu::Buffer> CommandBufferProxyImpl::CreateTransferBuffer(
    size_t size,
    int32* id) {
  CheckLock();
  *id = -1;

  if (last_state_.error != gpu::error::kNoError)
    return NULL;

  int32 new_id = channel_->ReserveTransferBufferId();

  scoped_ptr<base::SharedMemory> shared_memory(
      channel_->factory()->AllocateSharedMemory(size));
  if (!shared_memory)
    return NULL;

  DCHECK(!shared_memory->memory());
  if (!shared_memory->Map(size))
    return NULL;

  // This handle is owned by the GPU process and must be passed to it or it
  // will leak. In otherwords, do not early out on error between here and the
  // sending of the RegisterTransferBuffer IPC below.
  base::SharedMemoryHandle handle =
      channel_->ShareToGpuProcess(shared_memory->handle());
  if (!base::SharedMemory::IsHandleValid(handle))
    return NULL;

  if (!Send(new GpuCommandBufferMsg_RegisterTransferBuffer(route_id_,
                                                           new_id,
                                                           handle,
                                                           size))) {
    return NULL;
  }

  *id = new_id;
  scoped_refptr<gpu::Buffer> buffer(
      gpu::MakeBufferFromSharedMemory(shared_memory.Pass(), size));
  return buffer;
}

void CommandBufferProxyImpl::DestroyTransferBuffer(int32 id) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  Send(new GpuCommandBufferMsg_DestroyTransferBuffer(route_id_, id));
}

gpu::Capabilities CommandBufferProxyImpl::GetCapabilities() {
  return capabilities_;
}

int32_t CommandBufferProxyImpl::CreateImage(ClientBuffer buffer,
                                            size_t width,
                                            size_t height,
                                            unsigned internalformat) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return -1;

  int32 new_id = channel_->ReserveImageId();

  gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager =
      channel_->gpu_memory_buffer_manager();
  gfx::GpuMemoryBuffer* gpu_memory_buffer =
      gpu_memory_buffer_manager->GpuMemoryBufferFromClientBuffer(buffer);
  DCHECK(gpu_memory_buffer);

  // This handle is owned by the GPU process and must be passed to it or it
  // will leak. In otherwords, do not early out on error between here and the
  // sending of the CreateImage IPC below.
  bool requires_sync_point = false;
  gfx::GpuMemoryBufferHandle handle =
      channel_->ShareGpuMemoryBufferToGpuProcess(gpu_memory_buffer->GetHandle(),
                                                 &requires_sync_point);

  DCHECK(gpu::ImageFactory::IsGpuMemoryBufferFormatSupported(
      gpu_memory_buffer->GetFormat(), capabilities_));
  DCHECK(gpu::ImageFactory::IsImageSizeValidForGpuMemoryBufferFormat(
      gfx::Size(width, height), gpu_memory_buffer->GetFormat()));
  DCHECK(gpu::ImageFactory::IsImageFormatCompatibleWithGpuMemoryBufferFormat(
      internalformat, gpu_memory_buffer->GetFormat()));
  if (!Send(new GpuCommandBufferMsg_CreateImage(route_id_,
                                                new_id,
                                                handle,
                                                gfx::Size(width, height),
                                                gpu_memory_buffer->GetFormat(),
                                                internalformat))) {
    return -1;
  }

  if (requires_sync_point) {
    gpu_memory_buffer_manager->SetDestructionSyncPoint(gpu_memory_buffer,
                                                       InsertSyncPoint());
  }

  return new_id;
}

void CommandBufferProxyImpl::DestroyImage(int32 id) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  Send(new GpuCommandBufferMsg_DestroyImage(route_id_, id));
}

int32_t CommandBufferProxyImpl::CreateGpuMemoryBufferImage(
    size_t width,
    size_t height,
    unsigned internalformat,
    unsigned usage) {
  CheckLock();
  scoped_ptr<gfx::GpuMemoryBuffer> buffer(
      channel_->gpu_memory_buffer_manager()->AllocateGpuMemoryBuffer(
          gfx::Size(width, height),
          gpu::ImageFactory::ImageFormatToGpuMemoryBufferFormat(internalformat),
          gpu::ImageFactory::ImageUsageToGpuMemoryBufferUsage(usage)));
  if (!buffer)
    return -1;

  return CreateImage(buffer->AsClientBuffer(), width, height, internalformat);
}

int CommandBufferProxyImpl::GetRouteID() const {
  return route_id_;
}

uint32 CommandBufferProxyImpl::CreateStreamTexture(uint32 texture_id) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return 0;

  int32 stream_id = channel_->GenerateRouteID();
  bool succeeded = false;
  Send(new GpuCommandBufferMsg_CreateStreamTexture(
      route_id_, texture_id, stream_id, &succeeded));
  if (!succeeded) {
    DLOG(ERROR) << "GpuCommandBufferMsg_CreateStreamTexture returned failure";
    return 0;
  }
  return stream_id;
}

void CommandBufferProxyImpl::SetLock(base::Lock* lock) {
  lock_ = lock;
}

uint32 CommandBufferProxyImpl::InsertSyncPoint() {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return 0;

  uint32 sync_point = 0;
  Send(new GpuCommandBufferMsg_InsertSyncPoint(route_id_, true, &sync_point));
  return sync_point;
}

uint32_t CommandBufferProxyImpl::InsertFutureSyncPoint() {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return 0;

  uint32 sync_point = 0;
  Send(new GpuCommandBufferMsg_InsertSyncPoint(route_id_, false, &sync_point));
  return sync_point;
}

void CommandBufferProxyImpl::RetireSyncPoint(uint32_t sync_point) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  Send(new GpuCommandBufferMsg_RetireSyncPoint(route_id_, sync_point));
}

void CommandBufferProxyImpl::SignalSyncPoint(uint32 sync_point,
                                             const base::Closure& callback) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  uint32 signal_id = next_signal_id_++;
  if (!Send(new GpuCommandBufferMsg_SignalSyncPoint(route_id_,
                                                    sync_point,
                                                    signal_id))) {
    return;
  }

  signal_tasks_.insert(std::make_pair(signal_id, callback));
}

void CommandBufferProxyImpl::SignalQuery(uint32 query,
                                         const base::Closure& callback) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  // Signal identifiers are hidden, so nobody outside of this class will see
  // them. (And thus, they cannot save them.) The IDs themselves only last
  // until the callback is invoked, which will happen as soon as the GPU
  // catches upwith the command buffer.
  // A malicious caller trying to create a collision by making next_signal_id
  // would have to make calls at an astounding rate (300B/s) and even if they
  // could do that, all they would do is to prevent some callbacks from getting
  // called, leading to stalled threads and/or memory leaks.
  uint32 signal_id = next_signal_id_++;
  if (!Send(new GpuCommandBufferMsg_SignalQuery(route_id_,
                                                query,
                                                signal_id))) {
    return;
  }

  signal_tasks_.insert(std::make_pair(signal_id, callback));
}

void CommandBufferProxyImpl::SetSurfaceVisible(bool visible) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return;

  Send(new GpuCommandBufferMsg_SetSurfaceVisible(route_id_, visible));
}

bool CommandBufferProxyImpl::ProduceFrontBuffer(const gpu::Mailbox& mailbox) {
  CheckLock();
  if (last_state_.error != gpu::error::kNoError)
    return false;

  return Send(new GpuCommandBufferMsg_ProduceFrontBuffer(route_id_, mailbox));
}

scoped_ptr<media::VideoDecodeAccelerator>
CommandBufferProxyImpl::CreateVideoDecoder() {
  if (!channel_)
    return scoped_ptr<media::VideoDecodeAccelerator>();
  return scoped_ptr<media::VideoDecodeAccelerator>(
      new GpuVideoDecodeAcceleratorHost(channel_, this));
}

scoped_ptr<media::VideoEncodeAccelerator>
CommandBufferProxyImpl::CreateVideoEncoder() {
  if (!channel_)
    return scoped_ptr<media::VideoEncodeAccelerator>();
  return scoped_ptr<media::VideoEncodeAccelerator>(
      new GpuVideoEncodeAcceleratorHost(channel_, this));
}

gpu::error::Error CommandBufferProxyImpl::GetLastError() {
  return last_state_.error;
}

bool CommandBufferProxyImpl::Send(IPC::Message* msg) {
  // Caller should not intentionally send a message if the context is lost.
  DCHECK(last_state_.error == gpu::error::kNoError);

  if (channel_) {
    if (channel_->Send(msg)) {
      return true;
    } else {
      // Flag the command buffer as lost. Defer deleting the channel until
      // OnChannelError is called after returning to the message loop in case
      // it is referenced elsewhere.
      DVLOG(1) << "CommandBufferProxyImpl::Send failed. Losing context.";
      last_state_.error = gpu::error::kLostContext;
      return false;
    }
  }

  // Callee takes ownership of message, regardless of whether Send is
  // successful. See IPC::Sender.
  delete msg;
  return false;
}

void CommandBufferProxyImpl::OnUpdateState(
    const gpu::CommandBuffer::State& state) {
  // Handle wraparound. It works as long as we don't have more than 2B state
  // updates in flight across which reordering occurs.
  if (state.generation - last_state_.generation < 0x80000000U)
    last_state_ = state;
}

void CommandBufferProxyImpl::SetOnConsoleMessageCallback(
    const GpuConsoleMessageCallback& callback) {
  CheckLock();
  console_message_callback_ = callback;
}

void CommandBufferProxyImpl::TryUpdateState() {
  if (last_state_.error == gpu::error::kNoError)
    shared_state()->Read(&last_state_);
}

gpu::CommandBufferSharedState* CommandBufferProxyImpl::shared_state() const {
  return reinterpret_cast<gpu::CommandBufferSharedState*>(
      shared_state_shm_->memory());
}

void CommandBufferProxyImpl::OnSwapBuffersCompleted(
    const std::vector<ui::LatencyInfo>& latency_info) {
  if (!swap_buffers_completion_callback_.is_null()) {
    if (!ui::LatencyInfo::Verify(
            latency_info, "CommandBufferProxyImpl::OnSwapBuffersCompleted")) {
      swap_buffers_completion_callback_.Run(std::vector<ui::LatencyInfo>());
      return;
    }
    swap_buffers_completion_callback_.Run(latency_info);
  }
}

void CommandBufferProxyImpl::OnUpdateVSyncParameters(base::TimeTicks timebase,
                                                     base::TimeDelta interval) {
  if (!update_vsync_parameters_completion_callback_.is_null())
    update_vsync_parameters_completion_callback_.Run(timebase, interval);
}

}  // namespace content