Reorganize net/disk_cache into backend specific directories.

net/disk_cache/mem_backend_impl.h

-// Copyright (c) 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.
-
-// See net/disk_cache/disk_cache.h for the public interface of the cache.
-
-#ifndef NET_DISK_CACHE_MEM_BACKEND_IMPL_H__
-#define NET_DISK_CACHE_MEM_BACKEND_IMPL_H__
-
-#include "base/compiler_specific.h"
-#include "base/containers/hash_tables.h"
-#include "net/disk_cache/disk_cache.h"
-#include "net/disk_cache/mem_rankings.h"
-
-namespace net {
-class NetLog;
-}  // namespace net
-
-namespace disk_cache {
-
-class MemEntryImpl;
-
-// This class implements the Backend interface. An object of this class handles
-// the operations of the cache without writing to disk.
-class NET_EXPORT_PRIVATE MemBackendImpl : public Backend {
- public:
-  explicit MemBackendImpl(net::NetLog* net_log);
-  virtual ~MemBackendImpl();
-
-  // Returns an instance of a Backend implemented only in memory. The returned
-  // object should be deleted when not needed anymore. max_bytes is the maximum
-  // size the cache can grow to. If zero is passed in as max_bytes, the cache
-  // will determine the value to use based on the available memory. The returned
-  // pointer can be NULL if a fatal error is found.
-  static scoped_ptr<Backend> CreateBackend(int max_bytes, net::NetLog* net_log);
-
-  // Performs general initialization for this current instance of the cache.
-  bool Init();
-
-  // Sets the maximum size for the total amount of data stored by this instance.
-  bool SetMaxSize(int max_bytes);
-
-  // Permanently deletes an entry.
-  void InternalDoomEntry(MemEntryImpl* entry);
-
-  // Updates the ranking information for an entry.
-  void UpdateRank(MemEntryImpl* node);
-
-  // A user data block is being created, extended or truncated.
-  void ModifyStorageSize(int32 old_size, int32 new_size);
-
-  // Returns the maximum size for a file to reside on the cache.
-  int MaxFileSize() const;
-
-  // Insert an MemEntryImpl into the ranking list. This method is only called
-  // from MemEntryImpl to insert child entries. The reference can be removed
-  // by calling RemoveFromRankingList(|entry|).
-  void InsertIntoRankingList(MemEntryImpl* entry);
-
-  // Remove |entry| from ranking list. This method is only called from
-  // MemEntryImpl to remove a child entry from the ranking list.
-  void RemoveFromRankingList(MemEntryImpl* entry);
-
-  // Backend interface.
-  virtual net::CacheType GetCacheType() const OVERRIDE;
-  virtual int32 GetEntryCount() const OVERRIDE;
-  virtual int OpenEntry(const std::string& key, Entry** entry,
-                        const CompletionCallback& callback) OVERRIDE;
-  virtual int CreateEntry(const std::string& key, Entry** entry,
-                          const CompletionCallback& callback) OVERRIDE;
-  virtual int DoomEntry(const std::string& key,
-                        const CompletionCallback& callback) OVERRIDE;
-  virtual int DoomAllEntries(const CompletionCallback& callback) OVERRIDE;
-  virtual int DoomEntriesBetween(base::Time initial_time,
-                                 base::Time end_time,
-                                 const CompletionCallback& callback) OVERRIDE;
-  virtual int DoomEntriesSince(base::Time initial_time,
-                               const CompletionCallback& callback) OVERRIDE;
-  virtual int OpenNextEntry(void** iter, Entry** next_entry,
-                            const CompletionCallback& callback) OVERRIDE;
-  virtual void EndEnumeration(void** iter) OVERRIDE;
-  virtual void GetStats(
-      std::vector<std::pair<std::string, std::string> >* stats) OVERRIDE {}
-  virtual void OnExternalCacheHit(const std::string& key) OVERRIDE;
-
- private:
-  typedef base::hash_map<std::string, MemEntryImpl*> EntryMap;
-
-  // Old Backend interface.
-  bool OpenEntry(const std::string& key, Entry** entry);
-  bool CreateEntry(const std::string& key, Entry** entry);
-  bool DoomEntry(const std::string& key);
-  bool DoomAllEntries();
-  bool DoomEntriesBetween(const base::Time initial_time,
-                          const base::Time end_time);
-  bool DoomEntriesSince(const base::Time initial_time);
-  bool OpenNextEntry(void** iter, Entry** next_entry);
-
-  // Deletes entries from the cache until the current size is below the limit.
-  // If empty is true, the whole cache will be trimmed, regardless of being in
-  // use.
-  void TrimCache(bool empty);
-
-  // Handles the used storage count.
-  void AddStorageSize(int32 bytes);
-  void SubstractStorageSize(int32 bytes);
-
-  EntryMap entries_;
-  MemRankings rankings_;  // Rankings to be able to trim the cache.
-  int32 max_size_;        // Maximum data size for this instance.
-  int32 current_size_;
-
-  net::NetLog* net_log_;
-
-  DISALLOW_COPY_AND_ASSIGN(MemBackendImpl);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_MEM_BACKEND_IMPL_H__