Asynchronous initialization in Simple Index.

net/disk_cache/simple/simple_disk_format.cc

 // Copyright (c) 2013 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.
 
 #include "net/disk_cache/simple/simple_disk_format.h"
 
 #include "base/hash.h"
 #include "base/logging.h"
 #include "base/sha1.h"
 #include "base/stringprintf.h"
@@ skipping 53 matching lines @@
 }
 
 // static
 void EntryMetadata::DeSerialize(const char* in_buffer,
                                 EntryMetadata* out_entry_metadata) {
   DCHECK(in_buffer);
   DCHECK(out_entry_metadata);
   memcpy(out_entry_metadata, in_buffer, kEntryMetadataSize);
 }
 
+// static
+void EntryMetadata::Merge(const EntryMetadata& entry_metadata,
+                          EntryMetadata* out_entry_metadata) {
+  if (out_entry_metadata->last_used_time == 0)
+    out_entry_metadata->last_used_time = entry_metadata.last_used_time;
+  if (out_entry_metadata->entry_size == 0)

[gavinp, 2013/04/10 10:51:56]

So 0 is both an invalid size, and the size of a 0 length datum?

[felipeg, 2013/04/10 14:21:45]

You said there should never be a valid entry with a 0 lenght datum

Since the size also includes the header, metadata, etc...

+    out_entry_metadata->entry_size = entry_metadata.entry_size;
+}
+
 }  // namespace SimpleIndexFile
 
 }  // namespace disk_cache