Add the ability to clear the shader disk cache.

content/browser/gpu/shader_disk_cache.h

 // Copyright (c) 2013 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 CONTENT_BROWSER_GPU_SHADER_DISK_CACHE_H_
 #define CONTENT_BROWSER_GPU_SHADER_DISK_CACHE_H_
 
 #include <map>
+#include <queue>
 #include <string>
 
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/singleton.h"
+#include "content/common/content_export.h"
 #include "net/disk_cache/disk_cache.h"
 
 namespace content {
 
 class ShaderDiskCacheEntry;
 class ShaderDiskReadHelper;
+class ShaderClearHelper;
 
 // ShaderDiskCache is the interface to the on disk cache for
 // GL shaders.
 //
 // While this class is both RefCounted and SupportsWeakPtr
 // when using this class you should work with the RefCounting.
 // The WeakPtr is needed interally.
-class ShaderDiskCache
+class CONTENT_EXPORT ShaderDiskCache
     : public base::RefCounted<ShaderDiskCache>,
       public base::SupportsWeakPtr<ShaderDiskCache> {
  public:
   void Init();
 
   void set_host_id(int host_id) { host_id_ = host_id; }
   void set_max_cache_size(size_t max_cache_size) {
     max_cache_size_ = max_cache_size;
   }
 
+  // Store the |shader| into the cache under |key|.
   void Cache(const std::string& key, const std::string& shader);
 
+  // Clear a range of entries. This supports unbounded deletes in either
+  // direction by using null Time values for either |begin_time| or |end_time|.
+  // The return value is a net error code. If this method returns
+  // ERR_IO_PENDING, the |completion_callback| will be invoked when the
+  // operation completes.
+  int Clear(
+      const base::Time begin_time,
+      const base::Time end_time,
+      const net::CompletionCallback& completion_callback);
+
+  // Sets a callback for when the cache is available. If the cache is
+  // already available the callback will not be called and net::OK is returned.
+  // If the callback is set net::ERR_IO_PENDING is returned and the callback
+  // will be executed when the cache is available.
+  int SetAvailableCallback(const net::CompletionCallback& callback);
+
+  // Returns the number of elements currently in the cache.
+  int32 Size();
+
+  // Set a callback notification for when all current entries have been
+  // written to the cache.
+  // The return value is a net error code. If this method returns
+  // ERR_IO_PENDING, the |callback| will be invoked when all entries have
+  // been written to the cache.
+  int SetCacheCompleteCallback(const net::CompletionCallback& callback);
+
  private:
   friend class base::RefCounted<ShaderDiskCache>;
   friend class ShaderDiskCacheEntry;
   friend class ShaderDiskReadHelper;
   friend class ShaderCacheFactory;
 
   explicit ShaderDiskCache(const base::FilePath& cache_path);
   ~ShaderDiskCache();
 
   void CacheCreatedCallback(int rv);
 
   disk_cache::Backend* backend() { return backend_; }
 
   void EntryComplete(void* entry);
   void ReadComplete();
 
   bool cache_available_;
   size_t max_cache_size_;
   int host_id_;
   base::FilePath cache_path_;
   bool is_initialized_;
+  net::CompletionCallback available_callback_;
+  net::CompletionCallback cache_complete_callback_;
 
   disk_cache::Backend* backend_;
 
   scoped_refptr<ShaderDiskReadHelper> helper_;
   std::map<void*, scoped_refptr<ShaderDiskCacheEntry> > entry_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ShaderDiskCache);
 };
 
 // ShaderCacheFactory maintains a cache of ShaderDiskCache objects
 // so we only create one per profile directory.
-class ShaderCacheFactory {
+class CONTENT_EXPORT ShaderCacheFactory {
  public:
   static ShaderCacheFactory* GetInstance();
 
+  // Clear the shader disk cache for the given |path|. This supports unbounded
+  // deletes in either direction by using null Time values for either
+  // |begin_time| or |end_time|. The |callback| will be executed when the
+  // clear is complete.
+  void ClearByPath(const base::FilePath& path,
+                   const base::Time& begin_time,
+                   const base::Time& end_time,
+                   const base::Closure& callback);
+
+  // Retrieve the shader disk cache for the provided |client_id|.
   scoped_refptr<ShaderDiskCache> Get(int32 client_id);
 
+  // Set the |path| to be used for the disk cache for |client_id|.
   void SetCacheInfo(int32 client_id, const base::FilePath& path);
+
+  // Remove the path mapping for |client_id|.
   void RemoveCacheInfo(int32 client_id);
 
+  // Set the provided |cache| into the cache map for the given |path|.
   void AddToCache(const base::FilePath& path, ShaderDiskCache* cache);
+
+  // Remove the provided |path| from our cache map.
   void RemoveFromCache(const base::FilePath& path);
 
  private:
   friend struct DefaultSingletonTraits<ShaderCacheFactory>;
+  friend class ShaderClearHelper;
 
   ShaderCacheFactory();
   ~ShaderCacheFactory();
 
+  scoped_refptr<ShaderDiskCache> GetByPath(const base::FilePath& path);
+  void CacheCleared(const base::FilePath& path);
+
   typedef std::map<base::FilePath, ShaderDiskCache*> ShaderCacheMap;
   ShaderCacheMap shader_cache_map_;
 
   typedef std::map<int32, base::FilePath> ClientIdToPathMap;
   ClientIdToPathMap client_id_to_path_map_;
 
+  typedef std::queue<scoped_refptr<ShaderClearHelper> > ShaderClearQueue;
+  typedef std::map<base::FilePath, ShaderClearQueue> ShaderClearMap;
+  ShaderClearMap shader_clear_map_;
+
   DISALLOW_COPY_AND_ASSIGN(ShaderCacheFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_GPU_SHADER_DISK_CACHE_H_