Disk cache: Add a hash to the entry's internal data.

net/disk_cache/storage_block.h

 // Copyright (c) 2010 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.
 
 #ifndef NET_DISK_CACHE_STORAGE_BLOCK_H__
 #define NET_DISK_CACHE_STORAGE_BLOCK_H__
 #pragma once
 
@@ skipping 43 matching lines @@
 
   // Sets the object to lazily save the in-memory data on destruction.
   void set_modified();
 
   // Gets a pointer to the internal storage (allocates storage if needed).
   T* Data();
 
   // Returns true if there is data associated with this object.
   bool HasData() const;
 
+  // Returns true if the internal hash is correct.
+  bool VerifyHash() const;
+
   // Returns true if this object owns the data buffer, false if it is shared.
   bool own_data() const;
 
   const Addr address() const;
 
   // Loads and store the data.
   bool Load();
   bool Store();
 
  private:
   void AllocateData();
   void DeleteData();
+  uint32 CalculateHash() const;
 
   T* data_;
   MappedFile* file_;
   Addr address_;
   bool modified_;
   bool own_data_;  // Is data_ owned by this object or shared with someone else.
   bool extended_;  // Used to store an entry of more than one block.
 
   DISALLOW_COPY_AND_ASSIGN(StorageBlock);
 };
 
 typedef StorageBlock<EntryStore> CacheEntryBlock;
 typedef StorageBlock<RankingsNode> CacheRankingsBlock;
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_STORAGE_BLOCK_H__