Disk cache: Reference CL for the implementation of file format version 3.

net/disk_cache/mapped_file.h

Index: net/disk_cache/mapped_file.h
===================================================================
--- net/disk_cache/mapped_file.h	(revision 199883)
+++ net/disk_cache/mapped_file.h	(working copy)
@@ -8,7 +8,6 @@
 #define NET_DISK_CACHE_MAPPED_FILE_H_
 
 #include "net/base/net_export.h"
-#include "net/disk_cache/disk_format.h"
 #include "net/disk_cache/file.h"
 #include "net/disk_cache/file_block.h"
 
@@ -31,6 +30,11 @@
   // will be mapped in memory.
   void* Init(const base::FilePath& name, size_t size);
 
+  // Performs object initialization without actually mapping any portion of the
+  // file. It assumes that the bitmap and header (of the related block file) are
+  // mapped somewhere else.
+  bool InitNoMap(const base::FilePath& name);
+
   void* buffer() const {
     return buffer_;
   }
@@ -39,6 +43,11 @@
   bool Load(const FileBlock* block);
   bool Store(const FileBlock* block);
 
+  // Asynchronous versions of Load/Store, following the semantics of File::Read
+  // and File::Write.
+  bool Load(const FileBlock* block, FileIOCallback* callback, bool* completed);
+  bool Store(const FileBlock* block, FileIOCallback* callback, bool* completed);
+
   // Flush the memory-mapped section to disk (synchronously).
   void Flush();