Implement the logic to kick off image decoding jobs for TileManager

cc/tile_manager.h

Index: cc/tile_manager.h
diff --git a/cc/tile_manager.h b/cc/tile_manager.h
index 2d57f7d04312d5607630b68a75f7b5845c921e5b..98beb6faa19406494f8eb97f92bbf9f9014ef2d7 100644
--- a/cc/tile_manager.h
+++ b/cc/tile_manager.h
@@ -12,12 +12,24 @@
 #include "cc/resource_pool.h"
 #include "cc/tile_priority.h"
 
+#if defined(COMPILER_GCC)
+namespace BASE_HASH_NAMESPACE {
+template<>
+struct hash<SkPixelRef*> {

[nduca, 2012/12/06 08:46:53]

Can we make SkLazyPixelRef have an id() field on it that we allocate in the same
way as image id? IDs are super super useful for debugging and it sidesteps this
stuff.

[qinmin, 2012/12/07 05:06:28]

SkPixelRef has getGenerationId() call. But the reverse lookup is not there. I
added a map in tilemanager to do this.

On 2012/12/06 08:46:53, nduca wrote:

+  size_t operator()(SkPixelRef* ptr) const {
+    return hash<size_t>()(reinterpret_cast<size_t>(ptr));
+  }
+};
+} // namespace BASE_HASH_NAMESPACE
+#endif // COMPILER_GCC
+
 namespace base {
 class SequencedWorkerPool;
 }
 
 namespace cc {
 
+class Image;
 class Tile;
 class TileVersion;
 struct RenderingStats;
@@ -42,6 +54,13 @@ enum TileManagerBin {
   NUM_BINS = 4
 };
 
+// Current progress of image decoding jobs.
+enum ImageDecodingProgress {
+  NOT_STARTED = 0,
+  IN_PROGRESS = 1,
+  FINISHED = 2
+};
+
 // This is state that is specific to a tile that is
 // managed by the TileManager.
 class CC_EXPORT ManagedTileState {
@@ -60,6 +79,7 @@ class CC_EXPORT ManagedTileState {
   TileManagerBin bin;
   TileResolution resolution;
   float time_to_needed_in_seconds;
+  std::vector<SkPixelRef*> pixel_refs;

[nduca, 2012/12/06 08:46:53]

hmm.... isn't it sufficient to track num_pending_decode_jobs here? When you
pre-dispatch the tile, you bump this each time you enqueue a decode job or find
a decode job pending for that pixel ref id.

Then, all you need to know on the decode-ack side is to decrement this. When the
counter reaches zero, the tile can be dispatched for raster.

[qinmin, 2012/12/07 05:06:28]

Then we need a map in TileManager to map from skpixelref to all tiles.
Otherwise, when an image decoding job finishes, I have no ideas how many tiles
this job would affect as it can impact more than 1 tiles. Currently I can loop
over all tiles to find those affected tiles.

On 2012/12/06 08:46:53, nduca wrote:

 };
 
 // This class manages tiles, deciding which should get rasterized and which
@@ -97,6 +117,9 @@ class CC_EXPORT TileManager {
       scoped_refptr<PicturePileImpl>,
       RenderingStats*);
   void DidFinishTileInitialization(Tile*, ResourceProvider::ResourceId);
+  bool HasUndecodedImages(Tile*, std::vector<SkPixelRef*>&);

[Alpha Left Google, 2012/12/05 20:24:28]

This seems to be called over and over again, does this do caching?

[qinmin, 2012/12/07 05:06:28]

No, this just check if the tile has undecoded images. If so, we will wait for
all the decoding jobs to finish before kicking off the raster task. Also, this
function returns a list of skpixelRefs that we need to kick off the decoding
job.

On 2012/12/05 20:24:28, Alpha wrote:

+  void OnImageDecoded(scoped_refptr<Image> image);
+  void SpawnImageDecodingTask(SkPixelRef*);

[reveman, 2012/12/05 19:48:46]

Maybe DispatchOneImageDecodingTask/OnImageDecodingTaskCompleted to be consistent
other functions in this class?

[qinmin, 2012/12/07 05:06:28]

Done.

 
   TileManagerClient* client_;
   scoped_ptr<ResourcePool> resource_pool_;
@@ -110,6 +133,12 @@ class CC_EXPORT TileManager {
   TileVector tiles_;
   TileVector tiles_that_need_to_be_rasterized_;
 
+  typedef base::hash_map<uint32_t, scoped_refptr<Tile> > TileMap;

[reveman, 2012/12/05 19:48:46]

where is TileMap used?

[qinmin, 2012/12/07 05:06:28]

This is originally wrote to map SkPixelRef* to tiles, but i think i forgot to
remove it.

On 2012/12/05 19:48:46, David Reveman wrote:

+
+  typedef base::hash_map<SkPixelRef*, ImageDecodingProgress>
+      PixelRefDecodingProgress;
+  PixelRefDecodingProgress decoding_progress_;

[nduca, 2012/12/06 08:46:53]

All you need is IsDecodeTaskPending. Finished is not useful to you because it
might already be evicted.

pixel_ref_ids_with_pending_decode_task: map of ids. or hash map. But thats it.

[qinmin, 2012/12/07 05:06:28]

changed it to pending_decode_tasks_ hashmap here.

On 2012/12/06 08:46:53, nduca wrote:

+
   RenderingStats rendering_stats_;
 };