// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cc/trees/presentation_time_callback_buffer.h"

#include <utility>
#include <vector>

#include "components/viz/common/quads/compositor_frame_metadata.h"

namespace cc {

PresentationTimeCallbackBuffer::PresentationTimeCallbackBuffer() = default;

PresentationTimeCallbackBuffer::PresentationTimeCallbackBuffer(
    PresentationTimeCallbackBuffer&& other)
    : frame_token_infos_(std::move(other.frame_token_infos_)) {}

PresentationTimeCallbackBuffer& PresentationTimeCallbackBuffer::operator=(
    PresentationTimeCallbackBuffer&& other) {
  if (this != &other) {
    frame_token_infos_ = std::move(other.frame_token_infos_);
  }
  return *this;
}

PresentationTimeCallbackBuffer::~PresentationTimeCallbackBuffer() = default;

PresentationTimeCallbackBuffer::FrameTokenInfo::FrameTokenInfo(uint32_t token)
    : token(token) {}

PresentationTimeCallbackBuffer::FrameTokenInfo::FrameTokenInfo(
    FrameTokenInfo&&) = default;
PresentationTimeCallbackBuffer::FrameTokenInfo&
PresentationTimeCallbackBuffer::FrameTokenInfo::operator=(FrameTokenInfo&&) =
    default;
PresentationTimeCallbackBuffer::FrameTokenInfo::~FrameTokenInfo() = default;

void PresentationTimeCallbackBuffer::RegisterMainThreadCallbacks(
    uint32_t frame_token,
    std::vector<Callback> callbacks) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (callbacks.empty())
    return;

  // Splice the given `callbacks` onto the vector of existing callbacks.
  auto& sink = GetOrMakeRegistration(frame_token).main_callbacks;
  sink.reserve(sink.size() + callbacks.size());
  std::ranges::move(callbacks, std::back_inserter(sink));
}

void PresentationTimeCallbackBuffer::RegisterMainThreadSuccessfulCallbacks(
    uint32_t frame_token,
    std::vector<SuccessfulCallbackWithDetails> callbacks) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (callbacks.empty())
    return;

  // Splice the given `callbacks` onto the vector of existing callbacks.
  auto& sink = GetOrMakeRegistration(frame_token).main_successful_callbacks;
  sink.reserve(sink.size() + callbacks.size());
  std::ranges::move(callbacks, std::back_inserter(sink));
}

void PresentationTimeCallbackBuffer::
    RegisterCompositorThreadSuccessfulCallbacks(
        uint32_t frame_token,
        std::vector<SuccessfulCallback> callbacks) {
  if (callbacks.empty())
    return;

  // Splice the given |callbacks| onto the vector of existing callbacks.
  std::vector<SuccessfulCallback>& sink =
      GetOrMakeRegistration(frame_token).compositor_successful_callbacks;
  sink.reserve(sink.size() + callbacks.size());
  std::ranges::move(callbacks, std::back_inserter(sink));
}

PresentationTimeCallbackBuffer::PendingCallbacks::PendingCallbacks() = default;
PresentationTimeCallbackBuffer::PendingCallbacks::PendingCallbacks(
    PendingCallbacks&&) = default;
PresentationTimeCallbackBuffer::PendingCallbacks&
PresentationTimeCallbackBuffer::PendingCallbacks::operator=(
    PendingCallbacks&&) = default;
PresentationTimeCallbackBuffer::PendingCallbacks::~PendingCallbacks() = default;

PresentationTimeCallbackBuffer::PendingCallbacks
PresentationTimeCallbackBuffer::PopPendingCallbacks(uint32_t frame_token,
                                                    bool presentation_failed) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  PendingCallbacks result;

  for (auto info = frame_token_infos_.begin();
       info != frame_token_infos_.end();) {
    if (viz::FrameTokenGT(info->token, frame_token))
      break;

    // Presentation time callbacks should be run whether presentation was
    // successful or not.
    std::ranges::move(info->main_callbacks,
                      std::back_inserter(result.main_callbacks));
    info->main_callbacks.clear();

    const bool should_keep_info =
        presentation_failed && (!info->main_successful_callbacks.empty() ||
                                !info->compositor_successful_callbacks.empty());

    if (should_keep_info) {
      ++info;
    } else {
      // Successful presentation time callbacks should only be run when the
      // presentation was successful.
      std::ranges::move(info->main_successful_callbacks,
                        std::back_inserter(result.main_successful_callbacks));
      std::ranges::move(
          info->compositor_successful_callbacks,
          std::back_inserter(result.compositor_successful_callbacks));
      info = frame_token_infos_.erase(info);
    }
  }

  return result;
}

PresentationTimeCallbackBuffer::FrameTokenInfo&
PresentationTimeCallbackBuffer::GetOrMakeRegistration(uint32_t frame_token) {
  // If the freshest registration is for an earlier frame token, add a new
  // entry to the queue.
  if (frame_token_infos_.empty() ||
      viz::FrameTokenGT(frame_token, frame_token_infos_.back().token)) {
    frame_token_infos_.emplace_back(frame_token);
    DCHECK_LE(frame_token_infos_.size(), kMaxBufferSize);
  }

  // Registrations should use monotonically increasing frame tokens.
  DCHECK_EQ(frame_token_infos_.back().token, frame_token);

  return frame_token_infos_.back();
}

}  // namespace cc