cc: Separate RasterWorkerPool interface from implementation details.

cc/resources/rasterizer.h

+// Copyright 2014 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_RESOURCES_RASTERIZER_H_
+#define CC_RESOURCES_RASTERIZER_H_
+
+#include <vector>
+
+#include "base/callback.h"
+#include "cc/resources/resource_format.h"
+#include "cc/resources/task_graph_runner.h"
+
+class SkCanvas;
+
+namespace cc {
+class Resource;
+
+namespace internal {
+class RasterTask;
+
+class CC_EXPORT RasterizerTaskClient {
+ public:
+  virtual SkCanvas* AcquireCanvasForRaster(RasterTask* task) = 0;
+  virtual void ReleaseCanvasForRaster(RasterTask* task) = 0;
+
+ protected:
+  virtual ~RasterizerTaskClient() {}
+};
+
+class ImageDecodeTask;
+
+class CC_EXPORT RasterizerTask : public Task {
+ public:
+  typedef std::vector<scoped_refptr<RasterizerTask> > Vector;
+
+  virtual void ScheduleOnOriginThread(RasterizerTaskClient* client) = 0;
+  virtual void RunOnOriginThread() = 0;
+  virtual void CompleteOnOriginThread(RasterizerTaskClient* client) = 0;
+  virtual void RunReplyOnOriginThread() = 0;
+
+  // Type-checking downcast routines.
+  virtual ImageDecodeTask* AsImageDecodeTask();
+  virtual RasterTask* AsRasterTask();
+
+  void WillSchedule();
+  void DidSchedule();
+  bool HasBeenScheduled() const;
+
+  void WillComplete();
+  void DidComplete();
+  bool HasCompleted() const;
+
+ protected:
+  RasterizerTask();
+  virtual ~RasterizerTask();
+
+  bool did_schedule_;
+  bool did_complete_;
+};
+
+class CC_EXPORT ImageDecodeTask : public RasterizerTask {
+ public:
+  typedef std::vector<scoped_refptr<ImageDecodeTask> > Vector;
+
+  // Overridden from RasterizerTask:
+  virtual ImageDecodeTask* AsImageDecodeTask() OVERRIDE;
+
+ protected:
+  ImageDecodeTask();
+  virtual ~ImageDecodeTask();
+};
+
+class CC_EXPORT RasterTask : public RasterizerTask {
+ public:
+  typedef std::vector<scoped_refptr<RasterTask> > Vector;
+
+  // Overridden from RasterizerTask:
+  virtual RasterTask* AsRasterTask() OVERRIDE;
+
+  const Resource* resource() const { return resource_; }
+  const ImageDecodeTask::Vector& dependencies() const { return dependencies_; }
+
+ protected:
+  RasterTask(const Resource* resource, ImageDecodeTask::Vector* dependencies);
+  virtual ~RasterTask();
+
+ private:
+  const Resource* resource_;
+  ImageDecodeTask::Vector dependencies_;
+};
+
+}  // namespace internal
+
+class CC_EXPORT RasterizerClient {
+ public:
+  virtual bool ShouldForceTasksRequiredForActivationToComplete() const = 0;
+  virtual void DidFinishRunningTasks() = 0;
+  virtual void DidFinishRunningTasksRequiredForActivation() = 0;
+
+ protected:
+  virtual ~RasterizerClient() {}
+};
+
+struct CC_EXPORT RasterTaskQueue {
+  struct CC_EXPORT Item {
+    class TaskComparator {
+     public:
+      explicit TaskComparator(const internal::RasterTask* task) : task_(task) {}
+
+      bool operator()(const Item& item) const { return item.task == task_; }
+
+     private:
+      const internal::RasterTask* task_;
+    };
+
+    typedef std::vector<Item> Vector;
+
+    Item(internal::RasterTask* task, bool required_for_activation);
+    ~Item();
+
+    static bool IsRequiredForActivation(const Item& item) {
+      return item.required_for_activation;
+    }
+
+    internal::RasterTask* task;
+    bool required_for_activation;
+  };
+
+  RasterTaskQueue();
+  ~RasterTaskQueue();
+
+  void Swap(RasterTaskQueue* other);
+  void Reset();
+
+  Item::Vector items;
+  size_t required_for_activation_count;
+};
+
+// This interface can be used to schedule and run raster tasks. The client will
+// be notified asynchronously when the set of tasks marked as "required for
+// activation" have finished running and when all scheduled tasks have finished
+// running. The client can call CheckForCompletedTasks() at any time to dispatch
+// pending completion callbacks for all tasks that have finished running.
+class CC_EXPORT Rasterizer {
+ public:
+  // Set the client instance to be notified when finished running tasks.
+  virtual void SetClient(RasterizerClient* client) = 0;
+
+  // Tells the worker pool to shutdown after canceling all previously scheduled
+  // tasks. Reply callbacks are still guaranteed to run when
+  // CheckForCompletedTasks() is called.
+  virtual void Shutdown() = 0;
+
+  // Schedule running of raster tasks in |queue| and all dependencies.
+  // Previously scheduled tasks that are not in |queue| will be canceled unless
+  // already running. Once scheduled, reply callbacks are guaranteed to run for
+  // all tasks even if they later get canceled by another call to
+  // ScheduleTasks().
+  virtual void ScheduleTasks(RasterTaskQueue* queue) = 0;
+
+  // Check for completed tasks and dispatch reply callbacks.
+  virtual void CheckForCompletedTasks() = 0;
+
+  // Returns the target that needs to be used for raster task resources.
+  virtual unsigned GetResourceTarget() const = 0;
+
+  // Returns the format that needs to be used for raster task resources.
+  virtual ResourceFormat GetResourceFormat() const = 0;
+
+ protected:
+  virtual ~Rasterizer() {}
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_RASTERIZER_H_