// Copyright 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.

#ifndef CC_TILES_TILE_MANAGER_H_
#define CC_TILES_TILE_MANAGER_H_

#include <deque>
#include <queue>
#include <set>
#include <utility>
#include <vector>

#include "base/containers/hash_tables.h"
#include "base/memory/scoped_ptr.h"
#include "base/values.h"
#include "cc/base/unique_notifier.h"
#include "cc/playback/display_list_raster_source.h"
#include "cc/raster/tile_task_runner.h"
#include "cc/resources/memory_history.h"
#include "cc/resources/resource_pool.h"
#include "cc/tiles/eviction_tile_priority_queue.h"
#include "cc/tiles/image_decode_controller.h"
#include "cc/tiles/raster_tile_priority_queue.h"
#include "cc/tiles/tile.h"
#include "cc/tiles/tile_draw_info.h"

namespace base {
namespace trace_event {
class ConvertableToTraceFormat;
class TracedValue;
}
}

namespace cc {
class PictureLayerImpl;
class ResourceProvider;

class CC_EXPORT TileManagerClient {
 public:
  // Called when all tiles marked as required for activation are ready to draw.
  virtual void NotifyReadyToActivate() = 0;

  // Called when all tiles marked as required for draw are ready to draw.
  virtual void NotifyReadyToDraw() = 0;

  // Called when all tile tasks started by the most recent call to PrepareTiles
  // are completed.
  virtual void NotifyAllTileTasksCompleted() = 0;

  // Called when the visible representation of a tile might have changed. Some
  // examples are:
  // - Tile version initialized.
  // - Tile resources freed.
  // - Tile marked for on-demand raster.
  virtual void NotifyTileStateChanged(const Tile* tile) = 0;

  // Given an empty raster tile priority queue, this will build a priority queue
  // that will return tiles in order in which they should be rasterized.
  // Note if the queue was previous built, Reset must be called on it.
  virtual scoped_ptr<RasterTilePriorityQueue> BuildRasterQueue(
      TreePriority tree_priority,
      RasterTilePriorityQueue::Type type) = 0;

  // Given an empty eviction tile priority queue, this will build a priority
  // queue that will return tiles in order in which they should be evicted.
  // Note if the queue was previous built, Reset must be called on it.
  virtual scoped_ptr<EvictionTilePriorityQueue> BuildEvictionQueue(
      TreePriority tree_priority) = 0;

  // Informs the client that due to the currently rasterizing (or scheduled to
  // be rasterized) tiles, we will be in a position that will likely require a
  // draw. This can be used to preemptively start a frame.
  virtual void SetIsLikelyToRequireADraw(bool is_likely_to_require_a_draw) = 0;

 protected:
  virtual ~TileManagerClient() {}
};

struct RasterTaskCompletionStats {
  RasterTaskCompletionStats();

  size_t completed_count;
  size_t canceled_count;
};
scoped_refptr<base::trace_event::ConvertableToTraceFormat>
RasterTaskCompletionStatsAsValue(const RasterTaskCompletionStats& stats);

// This class manages tiles, deciding which should get rasterized and which
// should no longer have any memory assigned to them. Tile objects are "owned"
// by layers; they automatically register with the manager when they are
// created, and unregister from the manager when they are deleted.
class CC_EXPORT TileManager : public TileTaskRunnerClient {
 public:
  enum NamedTaskSet {
    REQUIRED_FOR_ACTIVATION,
    REQUIRED_FOR_DRAW,
    // PixelBufferTileTaskWorkerPool depends on ALL being last.
    ALL
    // Adding additional values requires increasing kNumberOfTaskSets in
    // tile_task_runner.h
  };

  static_assert(NamedTaskSet::ALL == (kNumberOfTaskSets - 1),
                "NamedTaskSet::ALL should be equal to kNumberOfTaskSets"
                "minus 1");

  static scoped_ptr<TileManager> Create(TileManagerClient* client,
                                        base::SequencedTaskRunner* task_runner,
                                        size_t scheduled_raster_task_limit,
                                        bool use_partial_raster);
  ~TileManager() override;

  // Assigns tile memory and schedules work to prepare tiles for drawing.
  // - Runs client_->NotifyReadyToActivate() when all tiles required for
  // activation are prepared, or failed to prepare due to OOM.
  // - Runs client_->NotifyReadyToDraw() when all tiles required draw are
  // prepared, or failed to prepare due to OOM.
  bool PrepareTiles(const GlobalStateThatImpactsTilePriority& state);

  // Synchronously finish any in progress work, cancel the rest, and clean up as
  // much resources as possible. Also, prevents any future work until a
  // SetResources call.
  void FinishTasksAndCleanUp();

  // Set the new given resource pool and tile task runner. Note that
  // FinishTasksAndCleanUp must be called in between consecutive calls to
  // SetResources.
  void SetResources(ResourcePool* resource_pool,
                    TileTaskRunner* tile_task_runner,
                    size_t scheduled_raster_task_limit);

  // This causes any completed raster work to finalize, so that tiles get up to
  // date draw information.
  void Flush();

  ScopedTilePtr CreateTile(const Tile::CreateInfo& info,
                           int layer_id,
                           int source_frame_number,
                           int flags);

  bool IsReadyToActivate() const;
  bool IsReadyToDraw() const;

  scoped_refptr<base::trace_event::ConvertableToTraceFormat> BasicStateAsValue()
      const;
  void BasicStateAsValueInto(base::trace_event::TracedValue* dict) const;
  const MemoryHistory::Entry& memory_stats_from_last_assign() const {
    return memory_stats_from_last_assign_;
  }

  // Public methods for testing.
  void InitializeTilesWithResourcesForTesting(const std::vector<Tile*>& tiles) {
    for (size_t i = 0; i < tiles.size(); ++i) {
      TileDrawInfo& draw_info = tiles[i]->draw_info();
      draw_info.resource_ = resource_pool_->AcquireResource(
          tiles[i]->desired_texture_size(),
          tile_task_runner_->GetResourceFormat(false));
    }
  }

  void ReleaseTileResourcesForTesting(const std::vector<Tile*>& tiles) {
    for (size_t i = 0; i < tiles.size(); ++i) {
      Tile* tile = tiles[i];
      FreeResourcesForTile(tile);
    }
  }

  void SetGlobalStateForTesting(
      const GlobalStateThatImpactsTilePriority& state) {
    global_state_ = state;
  }

  void SetTileTaskRunnerForTesting(TileTaskRunner* tile_task_runner);

  void FreeResourcesAndCleanUpReleasedTilesForTesting() {
    FreeResourcesForReleasedTiles();
    CleanUpReleasedTiles();
  }

  std::vector<Tile*> AllTilesForTesting() const {
    std::vector<Tile*> tiles;
    for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end();
         ++it) {
      tiles.push_back(it->second);
    }
    return tiles;
  }

  void SetScheduledRasterTaskLimitForTesting(size_t limit) {
    scheduled_raster_task_limit_ = limit;
  }

  void CheckIfMoreTilesNeedToBePreparedForTesting() {
    CheckIfMoreTilesNeedToBePrepared();
  }

  void SetMoreTilesNeedToBeRasterizedForTesting() {
    all_tiles_that_need_to_be_rasterized_are_scheduled_ = false;
  }

  bool HasScheduledTileTasksForTesting() const {
    return has_scheduled_tile_tasks_;
  }

 protected:
  TileManager(TileManagerClient* client,
              const scoped_refptr<base::SequencedTaskRunner>& task_runner,
              size_t scheduled_raster_task_limit,
              bool use_partial_raster);

  void FreeResourcesForReleasedTiles();
  void CleanUpReleasedTiles();

  friend class Tile;
  // Virtual for testing.
  virtual void Release(Tile* tile);
  Tile::Id GetUniqueTileId() { return ++next_tile_id_; }

  // Overriden from TileTaskRunnerClient:
  void DidFinishRunningTileTasks(TaskSet task_set) override;

  typedef std::vector<PrioritizedTile> PrioritizedTileVector;
  typedef std::set<Tile*> TileSet;

  // Virtual for test
  virtual void ScheduleTasks(
      const PrioritizedTileVector& tiles_that_need_to_be_rasterized);

  void AssignGpuMemoryToTiles(
      RasterTilePriorityQueue* raster_priority_queue,
      size_t scheduled_raser_task_limit,
      PrioritizedTileVector* tiles_that_need_to_be_rasterized);

 private:
  class MemoryUsage {
   public:
    MemoryUsage();
    MemoryUsage(size_t memory_bytes, size_t resource_count);

    static MemoryUsage FromConfig(const gfx::Size& size, ResourceFormat format);
    static MemoryUsage FromTile(const Tile* tile);

    MemoryUsage& operator+=(const MemoryUsage& other);
    MemoryUsage& operator-=(const MemoryUsage& other);
    MemoryUsage operator-(const MemoryUsage& other);

    bool Exceeds(const MemoryUsage& limit) const;
    int64 memory_bytes() const { return memory_bytes_; }

   private:
    int64 memory_bytes_;
    int resource_count_;
  };

  void OnRasterTaskCompleted(
      Tile::Id tile,
      Resource* resource,
      const DisplayListRasterSource::SolidColorAnalysis& analysis,
      bool was_canceled);
  void UpdateTileDrawInfo(
      Tile* tile,
      Resource* resource,
      const DisplayListRasterSource::SolidColorAnalysis& analysis);

  void FreeResourcesForTile(Tile* tile);
  void FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(Tile* tile);
  scoped_refptr<RasterTask> CreateRasterTask(
      const PrioritizedTile& prioritized_tile);

  scoped_ptr<EvictionTilePriorityQueue>
  FreeTileResourcesUntilUsageIsWithinLimit(
      scoped_ptr<EvictionTilePriorityQueue> eviction_priority_queue,
      const MemoryUsage& limit,
      MemoryUsage* usage);
  scoped_ptr<EvictionTilePriorityQueue>
  FreeTileResourcesWithLowerPriorityUntilUsageIsWithinLimit(
      scoped_ptr<EvictionTilePriorityQueue> eviction_priority_queue,
      const MemoryUsage& limit,
      const TilePriority& oother_priority,
      MemoryUsage* usage);
  bool TilePriorityViolatesMemoryPolicy(const TilePriority& priority);
  bool AreRequiredTilesReadyToDraw(RasterTilePriorityQueue::Type type) const;
  void CheckIfMoreTilesNeedToBePrepared();
  void CheckAndIssueSignals();

  ResourceFormat DetermineResourceFormat(const Tile* tile) const;
  bool DetermineResourceRequiresSwizzle(const Tile* tile) const;

  TileManagerClient* client_;
  scoped_refptr<base::SequencedTaskRunner> task_runner_;
  ResourcePool* resource_pool_;
  TileTaskRunner* tile_task_runner_;
  GlobalStateThatImpactsTilePriority global_state_;
  size_t scheduled_raster_task_limit_;
  const bool use_partial_raster_;

  typedef base::hash_map<Tile::Id, Tile*> TileMap;
  TileMap tiles_;

  bool all_tiles_that_need_to_be_rasterized_are_scheduled_;
  MemoryHistory::Entry memory_stats_from_last_assign_;

  bool did_check_for_completed_tasks_since_last_schedule_tasks_;
  bool did_oom_on_last_assign_;

  ImageDecodeController image_decode_controller_;

  RasterTaskCompletionStats flush_stats_;

  std::vector<Tile*> released_tiles_;

  // Queue used when scheduling raster tasks.
  TileTaskQueue raster_queue_;

  std::vector<scoped_refptr<RasterTask>> orphan_raster_tasks_;

  UniqueNotifier more_tiles_need_prepare_check_notifier_;

  struct Signals {
    Signals();

    void reset();

    bool ready_to_activate;
    bool did_notify_ready_to_activate;
    bool ready_to_draw;
    bool did_notify_ready_to_draw;
    bool all_tile_tasks_completed;
    bool did_notify_all_tile_tasks_completed;
  } signals_;

  UniqueNotifier signals_check_notifier_;

  bool has_scheduled_tile_tasks_;

  uint64_t prepare_tiles_count_;
  uint64_t next_tile_id_;

  DISALLOW_COPY_AND_ASSIGN(TileManager);
};

}  // namespace cc

#endif  // CC_TILES_TILE_MANAGER_H_