Support different formats in the same resource pool.

cc/resources/resource_pool.cc

 // 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.
 
 #include "cc/resources/resource_pool.h"
 
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/scoped_resource.h"
 
 namespace cc {
 
 ResourcePool::ResourcePool(ResourceProvider* resource_provider,
                            GLenum target,
-                           ResourceFormat format)
+                           bool use_memory_efficient_format)
     : resource_provider_(resource_provider),
       target_(target),
-      format_(format),
+      use_memory_efficient_format_(use_memory_efficient_format),
       max_memory_usage_bytes_(0),
       max_unused_memory_usage_bytes_(0),
       max_resource_count_(0),
       memory_usage_bytes_(0),
       unused_memory_usage_bytes_(0),
       resource_count_(0) {}
 
 ResourcePool::~ResourcePool() {
   while (!busy_resources_.empty()) {
     DidFinishUsingResource(busy_resources_.front());
     busy_resources_.pop_front();
   }
 
   SetResourceUsageLimits(0, 0, 0);
-  DCHECK_EQ(0u, unused_resources_.size());
+  for (UnusedMap::const_iterator it = unused_resources_.begin();
+       it != unused_resources_.end();
+       ++it) {
+    DCHECK_EQ(0u, it->second.size());
+  }
   DCHECK_EQ(0u, memory_usage_bytes_);
   DCHECK_EQ(0u, unused_memory_usage_bytes_);
   DCHECK_EQ(0u, resource_count_);
 }
 
 scoped_ptr<ScopedResource> ResourcePool::AcquireResource(
-    const gfx::Size& size) {
-  for (ResourceList::iterator it = unused_resources_.begin();
-       it != unused_resources_.end();
-       ++it) {
+    const gfx::Size& size, ResourceFormat format) {
+  ResourceList& unused = unused_resources_[format];
+  for (ResourceList::iterator it = unused.begin(); it != unused.end(); ++it) {
     ScopedResource* resource = *it;
     DCHECK(resource_provider_->CanLockForWrite(resource->id()));
 
     if (resource->size() != size)
       continue;
 
-    unused_resources_.erase(it);
+    unused.erase(it);
     unused_memory_usage_bytes_ -= resource->bytes();
     return make_scoped_ptr(resource);
   }
 
   scoped_ptr<ScopedResource> resource =
       ScopedResource::Create(resource_provider_);
-  resource->AllocateManaged(size, target_, format_);
+  resource->AllocateManaged(size, target_, format);
 
   memory_usage_bytes_ += resource->bytes();
   ++resource_count_;
   return resource.Pass();
 }
 
+scoped_ptr<ScopedResource> ResourcePool::AcquireResource(
+    const gfx::Size& size, ResourceFormatUsage usage) {
+  return AcquireResource(size, resource_format(usage));
+}
+
 void ResourcePool::ReleaseResource(scoped_ptr<ScopedResource> resource) {
   busy_resources_.push_back(resource.release());
 }
 
 void ResourcePool::SetResourceUsageLimits(size_t max_memory_usage_bytes,
                                           size_t max_unused_memory_usage_bytes,
                                           size_t max_resource_count) {
   max_memory_usage_bytes_ = max_memory_usage_bytes;
   max_unused_memory_usage_bytes_ = max_unused_memory_usage_bytes;
   max_resource_count_ = max_resource_count;
 
   ReduceResourceUsage();
 }
 
 void ResourcePool::ReduceResourceUsage() {
-  while (!unused_resources_.empty()) {
-    if (!ResourceUsageTooHigh())
-      break;
+  for (UnusedMap::iterator it = unused_resources_.begin();
+       it != unused_resources_.end();
+       ++it) {
+    ResourceList& unused = it->second;
+    while (!unused.empty()) {
+      if (!ResourceUsageTooHigh())
+        break;
 
-    // LRU eviction pattern. Most recently used might be blocked by
-    // a read lock fence but it's still better to evict the least
-    // recently used as it prevents a resource that is hard to reuse
-    // because of unique size from being kept around. Resources that
-    // can't be locked for write might also not be truly free-able.
-    // We can free the resource here but it doesn't mean that the
-    // memory is necessarily returned to the OS.
-    ScopedResource* resource = unused_resources_.front();
-    unused_resources_.pop_front();
-    memory_usage_bytes_ -= resource->bytes();
-    unused_memory_usage_bytes_ -= resource->bytes();
-    --resource_count_;
-    delete resource;
+      // LRU eviction pattern. Most recently used might be blocked by
+      // a read lock fence but it's still better to evict the least
+      // recently used as it prevents a resource that is hard to reuse
+      // because of unique size from being kept around. Resources that
+      // can't be locked for write might also not be truly free-able.
+      // We can free the resource here but it doesn't mean that the
+      // memory is necessarily returned to the OS.
+      ScopedResource* resource = unused.front();
+      unused.pop_front();
+      memory_usage_bytes_ -= resource->bytes();
+      unused_memory_usage_bytes_ -= resource->bytes();
+      --resource_count_;
+      delete resource;
+    }
   }
 }
 
 bool ResourcePool::ResourceUsageTooHigh() {
   if (resource_count_ > max_resource_count_)
     return true;
   if (memory_usage_bytes_ > max_memory_usage_bytes_)
     return true;
   if (unused_memory_usage_bytes_ > max_unused_memory_usage_bytes_)
     return true;
   return false;
 }
 
+ResourceFormat ResourcePool::resource_format(ResourceFormatUsage usage) const {
+  if (use_memory_efficient_format_) {
+    return resource_provider_->memory_efficient_texture_format(usage);
+  } else {
+    return resource_provider_->best_texture_format();
+  }
+}
+
+size_t ResourcePool::acquired_resource_count() const {
+  size_t result = resource_count_;
+  for (UnusedMap::const_iterator it = unused_resources_.begin();
+       it != unused_resources_.end(); ++it) {
+    result -= it->second.size();
+  }
+  return result;
+}
+
 void ResourcePool::CheckBusyResources(bool wait_if_needed) {
   ResourceList::iterator it = busy_resources_.begin();
 
   while (it != busy_resources_.end()) {
     ScopedResource* resource = *it;
 
     if (wait_if_needed)
       resource_provider_->WaitReadLockIfNeeded(resource->id());
 
     if (resource_provider_->CanLockForWrite(resource->id())) {
       DidFinishUsingResource(resource);
       it = busy_resources_.erase(it);
     } else {
       ++it;
     }
   }
 }
 
 void ResourcePool::DidFinishUsingResource(ScopedResource* resource) {
   unused_memory_usage_bytes_ += resource->bytes();
-  unused_resources_.push_back(resource);
+  unused_resources_[resource->format()].push_back(resource);
 }
 
 }  // namespace cc