Support optimistic Create and Write operations on the SimpleCache.

net/disk_cache/simple/simple_entry_impl.h

Index: net/disk_cache/simple/simple_entry_impl.h
diff --git a/net/disk_cache/simple/simple_entry_impl.h b/net/disk_cache/simple/simple_entry_impl.h
index aa5b55c1ff32538419cc9109e261aedbef27bb8f..a11d1af3b05f8ffa4773d6b23b0c202caa401c54 100644
--- a/net/disk_cache/simple/simple_entry_impl.h
+++ b/net/disk_cache/simple/simple_entry_impl.h
@@ -104,6 +104,10 @@ class SimpleEntryImpl : public Entry, public base::RefCounted<SimpleEntryImpl>,
     // IO is currently in flight, operations must wait for completion before
     // launching.
     STATE_IO_PENDING,
+
+    // A failure occurred in the current or previous operation. All operations
+    // after that must fail too.
+    STATE_FAILURE,
   };
 
   virtual ~SimpleEntryImpl();
@@ -130,11 +134,10 @@ class SimpleEntryImpl : public Entry, public base::RefCounted<SimpleEntryImpl>,
   // the last reference.
   void RunNextOperationIfNeeded();
 
-  void OpenEntryInternal(Entry** entry,
-                         const CompletionCallback& callback);
+  void OpenEntryInternal(const CompletionCallback& callback, Entry** out_entry);
 
-  void CreateEntryInternal(Entry** entry,
-                           const CompletionCallback& callback);
+  void CreateEntryInternal(const CompletionCallback& callback,
+                           Entry** out_entry);
 
   void CloseInternal();
 
@@ -234,6 +237,9 @@ class SimpleEntryImpl : public Entry, public base::RefCounted<SimpleEntryImpl>,
   SimpleSynchronousEntry* synchronous_entry_;
 
   std::queue<base::Closure> pending_operations_;
+
+  // Flag to turn On or Off Create and Write optimistic operations.
+  bool optimistic_;

[gavinp, 2013/05/01 13:11:22]

I think we should either test with this flag (since i expect other cache users,
like APP_CACHE might want it off), or we should remove this flag. WDYT?

[felipeg, 2013/05/02 09:49:27]

I will remove it and we add it later if we need it.

 };
 
 }  // namespace disk_cache