Disk cache: Keep a map of all open entries....

net/disk_cache/entry_impl.h

 // 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.
 
 #ifndef NET_DISK_CACHE_ENTRY_IMPL_H_
 #define NET_DISK_CACHE_ENTRY_IMPL_H_
 
 #include "base/scoped_ptr.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/disk_cache/storage_block.h"
@@ skipping 58 matching lines @@
   // hash.
   CacheAddr GetNextAddress();
 
   // Sets the address of the next entry on the list of entries with the same
   // hash.
   void SetNextAddress(Addr address);
 
   // Reloads the rankings node information.
   bool LoadNodeAddress();
 
-  // Reloads the data for this entry. If there is already an object in memory
-  // for the entry, the returned value is a pointer to that entry, otherwise
-  // it is the passed in entry. On failure returns NULL.
-  static EntryImpl* Update(EntryImpl* entry);
+  // Updates the stored data to reflect the run-time information for this entry.
+  // Returns false if the data could not be updated. The purpose of this method
+  // is to be able to detect entries that are currently in use.
+  bool Update();
 
   // Returns true if this entry is marked as dirty on disk.
   bool IsDirty(int32 current_id);
   void ClearDirtyFlag();
 
   // Fixes this entry so it can be treated as valid (to delete it).
   void SetPointerForInvalidEntry(int32 new_id);
 
   // Returns false if the entry is clearly invalid.
   bool SanityCheck();
@@ skipping 72 matching lines @@
   int unreported_size_[kNumStreams];  // 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);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_ENTRY_IMPL_H_