| // Copyright 2015 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_IMAGE_DECODE_CACHE_H_ |
| #define CC_TILES_IMAGE_DECODE_CACHE_H_ |
| |
| #include "base/memory/ref_counted.h" |
| #include "cc/paint/draw_image.h" |
| #include "cc/tiles/decoded_draw_image.h" |
| #include "cc/tiles/tile_priority.h" |
| |
| namespace cc { |
| |
| class TileTask; |
| |
| // ImageDecodeCache is responsible for generating decode tasks, decoding |
| // images, storing images in cache, and being able to return the decoded images |
| // when requested. |
| |
| // ImageDecodeCache is responsible for the following things: |
| // 1. Given a DrawImage, it can return an TileTask which when run will |
| // decode and cache the resulting image. If the image does not need a task to |
| // be decoded, then nullptr will be returned. The return value of the |
| // function indicates whether the image was or is going to be locked, so an |
| // unlock will be required. |
| // 2. Given a cache key and a DrawImage, it can decode the image and store it in |
| // the cache. Note that it is important that this function is only accessed |
| // via an image decode task. |
| // 3. Given a DrawImage, it can return a DecodedDrawImage, which represented the |
| // decoded version of the image. Note that if the image is not in the cache |
| // and it needs to be scaled/decoded, then this decode will happen as part of |
| // getting the image. As such, this should only be accessed from a raster |
| // thread. |
| class CC_EXPORT ImageDecodeCache { |
| public: |
| // This information should be used strictly in tracing, UMA, and any other |
| // reporting systems. |
| struct TracingInfo { |
| TracingInfo(uint64_t prepare_tiles_id, |
| TilePriority::PriorityBin requesting_tile_bin) |
| : prepare_tiles_id(prepare_tiles_id), |
| requesting_tile_bin(requesting_tile_bin) {} |
| TracingInfo() : TracingInfo(0, TilePriority::NOW) {} |
| |
| // ID for the current prepare tiles call. |
| const uint64_t prepare_tiles_id; |
| |
| // The bin of the tile that caused this image to be requested. |
| const TilePriority::PriorityBin requesting_tile_bin; |
| }; |
| |
| virtual ~ImageDecodeCache() {} |
| |
| // Fill in an TileTask which will decode the given image when run. In |
| // case the image is already cached, fills in nullptr. Returns true if the |
| // image needs to be unreffed when the caller is finished with it. |
| // |
| // This is called by the tile manager (on the compositor thread) when creating |
| // a raster task. |
| virtual bool GetTaskForImageAndRef(const DrawImage& image, |
| const TracingInfo& tracing_info, |
| scoped_refptr<TileTask>* task) = 0; |
| // Similar to GetTaskForImageAndRef, except that it returns tasks that are not |
| // meant to be run as part of raster. That is, this is part of a predecode |
| // API. Note that this should only return a task responsible for decoding (and |
| // not uploading), since it will be run on a worker thread which may not have |
| // the right GPU context for upload. |
| virtual bool GetOutOfRasterDecodeTaskForImageAndRef( |
| const DrawImage& image, |
| scoped_refptr<TileTask>* task) = 0; |
| |
| // Unrefs an image. When the tile is finished, this should be called for every |
| // GetTaskForImageAndRef call that returned true. |
| virtual void UnrefImage(const DrawImage& image) = 0; |
| |
| // Returns a decoded draw image. This may cause a decode if the image was not |
| // predecoded. |
| // |
| // This is called by a raster task (on a worker thread) when an image is |
| // required. |
| virtual DecodedDrawImage GetDecodedImageForDraw(const DrawImage& image) = 0; |
| // Unrefs an image. This should be called for every GetDecodedImageForDraw |
| // when the draw with the image is finished. |
| virtual void DrawWithImageFinished(const DrawImage& image, |
| const DecodedDrawImage& decoded_image) = 0; |
| |
| // This function informs the cache that now is a good time to clean up |
| // memory. This is called periodically from the compositor thread. |
| virtual void ReduceCacheUsage() = 0; |
| |
| // This function informs the cache that we are hidden and should not be |
| // retaining cached resources longer than needed. |
| virtual void SetShouldAggressivelyFreeResources( |
| bool aggressively_free_resources) = 0; |
| |
| // Clears all elements from the cache. |
| virtual void ClearCache() = 0; |
| |
| // Returns the maximum amount of memory we would be able to lock. This ignores |
| // any temporary states, such as throttled, and return the maximum possible |
| // memory. It is used as an esimate of whether an image can fit into the |
| // locked budget before creating a task. |
| virtual size_t GetMaximumMemoryLimitBytes() const = 0; |
| }; |
| |
| } // namespace cc |
| |
| #endif // CC_TILES_IMAGE_DECODE_CACHE_H_ |