cc::ResourcePool - Re-use larger resources for smaller requests

cc/resources/resource_pool.h

 // 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_RESOURCES_RESOURCE_POOL_H_
 #define CC_RESOURCES_RESOURCE_POOL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 15 matching lines @@
 class CC_EXPORT ResourcePool : public base::trace_event::MemoryDumpProvider,
                                public base::MemoryCoordinatorClient {
  public:
   // Delay before a resource is considered expired.
   static base::TimeDelta kDefaultExpirationDelay;
 
   static std::unique_ptr<ResourcePool> CreateForGpuMemoryBufferResources(
       ResourceProvider* resource_provider,
       base::SingleThreadTaskRunner* task_runner,
       gfx::BufferUsage usage,
-      const base::TimeDelta& expiration_delay) {
+      const base::TimeDelta& expiration_delay,
+      bool disallow_non_exact_reuse) {
     return base::WrapUnique(new ResourcePool(resource_provider, task_runner,
-                                             usage, expiration_delay));
+                                             usage, expiration_delay,
+                                             disallow_non_exact_reuse));
   }
 
   static std::unique_ptr<ResourcePool> Create(
       ResourceProvider* resource_provider,
       base::SingleThreadTaskRunner* task_runner,
       ResourceProvider::TextureHint hint,
-      const base::TimeDelta& expiration_delay) {
+      const base::TimeDelta& expiration_delay,
+      bool disallow_non_exact_reuse) {
     return base::WrapUnique(new ResourcePool(resource_provider, task_runner,
-                                             hint, expiration_delay));
+                                             hint, expiration_delay,
+                                             disallow_non_exact_reuse));
   }
 
   ~ResourcePool() override;
 
   // Tries to reuse a resource. If none are available, makes a new one.
   Resource* AcquireResource(const gfx::Size& size,
                             ResourceFormat format,
                             const gfx::ColorSpace& color_space);
 
   // Tries to acquire the resource with |previous_content_id| for us in partial
@@ skipping 37 matching lines @@
   }
   size_t GetBusyResourceCountForTesting() const {
     return busy_resources_.size();
   }
 
  protected:
   // Constructor for creating GPU memory buffer resources.
   ResourcePool(ResourceProvider* resource_provider,
                base::SingleThreadTaskRunner* task_runner,
                gfx::BufferUsage usage,
-               const base::TimeDelta& expiration_delay);
+               const base::TimeDelta& expiration_delay,
+               bool disallow_non_exact_reuse);
 
   // Constructor for creating standard resources.
   ResourcePool(ResourceProvider* resource_provider,
                base::SingleThreadTaskRunner* task_runner,
                ResourceProvider::TextureHint hint,
-               const base::TimeDelta& expiration_delay);
+               const base::TimeDelta& expiration_delay,
+               bool disallow_non_exact_reuse);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(ResourcePoolTest, ReuseResource);
+  FRIEND_TEST_ALL_PREFIXES(ResourcePoolTest, ExactRequestsRespected);
   class PoolResource : public ScopedResource {
    public:
     static std::unique_ptr<PoolResource> Create(
         ResourceProvider* resource_provider) {
       return base::WrapUnique(new PoolResource(resource_provider));
     }
     void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd,
                       const ResourceProvider* resource_provider,
                       bool is_free) const;
 
@@ skipping 54 matching lines @@
   using ResourceDeque = std::deque<std::unique_ptr<PoolResource>>;
   ResourceDeque unused_resources_;
   ResourceDeque busy_resources_;
 
   using InUseResourceMap = std::map<ResourceId, std::unique_ptr<PoolResource>>;
   InUseResourceMap in_use_resources_;
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   bool evict_expired_resources_pending_ = false;
   const base::TimeDelta resource_expiration_delay_;
+  const bool disallow_non_exact_reuse_ = false;
 
   base::WeakPtrFactory<ResourcePool> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourcePool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_POOL_H_