Disk cache: First pass to add support for sparse entries....

net/disk_cache/entry_impl.h

Index: net/disk_cache/entry_impl.h
===================================================================
--- net/disk_cache/entry_impl.h	(revision 18456)
+++ net/disk_cache/entry_impl.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2009 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.
 
@@ -13,11 +13,13 @@
 namespace disk_cache {
 
 class BackendImpl;
+class SparseControl;
 
 // This class implements the Entry interface. An object of this
 // class represents a single entry on the cache.
 class EntryImpl : public Entry, public base::RefCounted<EntryImpl> {
   friend class base::RefCounted<EntryImpl>;
+  friend class SparseControl;
  public:
   EntryImpl(BackendImpl* backend, Addr address);
 
@@ -98,9 +100,9 @@
   void SetTimes(base::Time last_used, base::Time last_modified);
 
  private:
-   enum {
-     NUM_STREAMS = 3
-   };
+  enum {
+    NUM_STREAMS = 3
+  };
 
   ~EntryImpl();
 
@@ -138,6 +140,9 @@
   // Flush the in-memory data to the backing storage.
   bool Flush(int index, int size, bool async);
 
+  // Initializes the sparse control object. Returns a net error code.
+  int InitSparseData();
+
   // Logs this entry to the internal trace buffer.
   void Log(const char* msg);
 
@@ -149,6 +154,8 @@
                                                 // data and key.
   int unreported_size_[NUM_STREAMS];  // Bytes not reported yet to the backend.
   bool doomed_;               // True if this entry was removed from the cache.
+  scoped_ptr<SparseControl> sparse_;  // Support for sparse entries.
+
   DISALLOW_EVIL_CONSTRUCTORS(EntryImpl);
 };