// Copyright 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 "cc/trees/latency_info_swap_promise_monitor.h"

#include <stdint.h>
#include <memory>
#include <utility>

#include "cc/trees/latency_info_swap_promise.h"
#include "cc/trees/layer_tree_host_impl.h"
#include "cc/trees/layer_tree_impl.h"
#include "cc/trees/swap_promise_manager.h"

namespace {

bool AddRenderingScheduledComponent(ui::LatencyInfo* latency_info,
                                    bool on_main) {
  ui::LatencyComponentType type =
      on_main ? ui::INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_MAIN_COMPONENT
              : ui::INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_IMPL_COMPONENT;
  if (latency_info->FindLatency(type, nullptr))
    return false;
  latency_info->AddLatencyNumber(type);
  return true;
}

}  // namespace

namespace cc {

LatencyInfoSwapPromiseMonitor::LatencyInfoSwapPromiseMonitor(
    ui::LatencyInfo* latency,
    SwapPromiseManager* swap_promise_manager)
    : latency_(latency), swap_promise_manager_(swap_promise_manager) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(main_sequence_checker_);
  DCHECK(swap_promise_manager);
  swap_promise_manager_->InsertLatencyInfoSwapPromiseMonitor(this);
}

LatencyInfoSwapPromiseMonitor::LatencyInfoSwapPromiseMonitor(
    ui::LatencyInfo* latency,
    LayerTreeHostImpl* host_impl)
    : latency_(latency), host_impl_(host_impl) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(impl_sequence_checker_);
  DCHECK(host_impl);
  host_impl_->InsertLatencyInfoSwapPromiseMonitor(this);
}

LatencyInfoSwapPromiseMonitor::~LatencyInfoSwapPromiseMonitor() {
  if (swap_promise_manager_) {
    DCHECK_CALLED_ON_VALID_SEQUENCE(main_sequence_checker_);
    swap_promise_manager_->RemoveLatencyInfoSwapPromiseMonitor(this);
  } else if (host_impl_) {
    DCHECK_CALLED_ON_VALID_SEQUENCE(impl_sequence_checker_);
    host_impl_->RemoveLatencyInfoSwapPromiseMonitor(this);
  }
}

void LatencyInfoSwapPromiseMonitor::OnSetNeedsCommitOnMain() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(main_sequence_checker_);
  if (AddRenderingScheduledComponent(latency_, true /* on_main */)) {
    std::unique_ptr<SwapPromise> swap_promise(
        new LatencyInfoSwapPromise(*latency_));
    swap_promise_manager_->QueueSwapPromise(std::move(swap_promise));
  }
}

void LatencyInfoSwapPromiseMonitor::OnSetNeedsRedrawOnImpl() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(impl_sequence_checker_);
  if (AddRenderingScheduledComponent(latency_, false /* on_main */)) {
    std::unique_ptr<SwapPromise> swap_promise(
        new LatencyInfoSwapPromise(*latency_));
    // Queue a pinned swap promise on the active tree. This will allow
    // measurement of the time to the next SwapBuffers(). The swap
    // promise is pinned so that it is not interrupted by new incoming
    // activations (which would otherwise break the swap promise).
    host_impl_->active_tree()->QueuePinnedSwapPromise(std::move(swap_promise));
  }
}

}  // namespace cc