/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef SRC_TRACE_PROCESSOR_SLICE_TRACKER_H_
#define SRC_TRACE_PROCESSOR_SLICE_TRACKER_H_

#include <stdint.h>

#include "src/trace_processor/args_tracker.h"
#include "src/trace_processor/storage/trace_storage.h"

namespace perfetto {
namespace trace_processor {

class ArgsTracker;
class TraceProcessorContext;

class SliceTracker {
 public:
  using SetArgsCallback = std::function<void(ArgsTracker::BoundInserter*)>;

  explicit SliceTracker(TraceProcessorContext*);
  virtual ~SliceTracker();

  // virtual for testing
  virtual base::Optional<uint32_t> Begin(
      int64_t timestamp,
      TrackId track_id,
      StringId category,
      StringId name,
      SetArgsCallback args_callback = SetArgsCallback());

  void BeginGpu(tables::GpuSliceTable::Row row,
                SetArgsCallback args_callback = SetArgsCallback());

  // virtual for testing
  virtual base::Optional<uint32_t> Scoped(
      int64_t timestamp,
      TrackId track_id,
      StringId category,
      StringId name,
      int64_t duration,
      SetArgsCallback args_callback = SetArgsCallback());

  void ScopedGpu(const tables::GpuSliceTable::Row& row,
                 SetArgsCallback args_callback = SetArgsCallback());

  // virtual for testing
  virtual base::Optional<uint32_t> End(
      int64_t timestamp,
      TrackId track_id,
      StringId opt_category = {},
      StringId opt_name = {},
      SetArgsCallback args_callback = SetArgsCallback());

  // TODO(lalitm): eventually this method should become End and End should
  // be renamed EndChrome.
  base::Optional<SliceId> EndGpu(
      int64_t ts,
      TrackId track_id,
      SetArgsCallback args_callback = SetArgsCallback());

  void FlushPendingSlices();

 private:
  using SlicesStack = std::vector<std::pair<uint32_t /* row */, ArgsTracker>>;
  using StackMap = std::unordered_map<TrackId, SlicesStack>;

  base::Optional<uint32_t> StartSlice(int64_t timestamp,
                                      TrackId track_id,
                                      SetArgsCallback args_callback,
                                      std::function<SliceId()> inserter);

  base::Optional<SliceId> CompleteSlice(
      int64_t timestamp,
      TrackId track_id,
      SetArgsCallback args_callback,
      std::function<base::Optional<uint32_t>(const SlicesStack&)> finder);

  void MaybeCloseStack(int64_t end_ts, SlicesStack*);

  base::Optional<uint32_t> MatchingIncompleteSliceIndex(
      const SlicesStack& stack,
      StringId name,
      StringId category);
  int64_t GetStackHash(const SlicesStack&);

  // Timestamp of the previous event. Used to discard events arriving out
  // of order.
  int64_t prev_timestamp_ = 0;

  TraceProcessorContext* const context_;
  StackMap stacks_;
};

}  // namespace trace_processor
}  // namespace perfetto

#endif  // SRC_TRACE_PROCESSOR_SLICE_TRACKER_H_