Asynchronous initialization in Simple Index.

net/disk_cache/simple/simple_index.h

Index: net/disk_cache/simple/simple_index.h
diff --git a/net/disk_cache/simple/simple_index.h b/net/disk_cache/simple/simple_index.h
index f07476d2409d41988bbeba0dd91b1bc27f540ec6..154bdde6d4e5d0c7588aa7975eb94b0666ed7589 100644
--- a/net/disk_cache/simple/simple_index.h
+++ b/net/disk_cache/simple/simple_index.h
@@ -29,12 +29,12 @@ class SimpleIndex
  public:
   SimpleIndex(
       const scoped_refptr<base::TaskRunner>& cache_thread,
+      const scoped_refptr<base::TaskRunner>& io_thread,
       const base::FilePath& path);
 
   virtual ~SimpleIndex();
 
-  // Should be called on CacheThread.
-  bool Initialize();
+  void Initialize();
 
   void Insert(const std::string& key);
   void Remove(const std::string& key);
@@ -45,7 +45,7 @@ class SimpleIndex
   // iff the entry exist in the index.
   bool UseIfExists(const std::string& key);
 
-  void Cleanup();
+  void WriteToDisk();
 
   bool UpdateEntrySize(const std::string& key, uint64 entry_size);
 
@@ -56,10 +56,18 @@ class SimpleIndex
   // EntryMetadata itself.
   typedef base::hash_map<std::string, SimpleIndexFile::EntryMetadata> EntrySet;
 
-  void InsertInternal(const SimpleIndexFile::EntryMetadata& entry_metadata);
+  static void InsertInternal(
+      EntrySet* entry_set,
+      const SimpleIndexFile::EntryMetadata& entry_metadata);
+
+  // Load index file from disk, if file is corrupted it calls RestoreFromDisk().
+  void LoadFromDisk();
 
   // Enumerates all entries' files on disk and regenerates the index.
-  bool RestoreFromDisk();
+  void RestoreFromDisk();
+
+  // Must run on IO Thread.

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

Can you add a base::ThreadChecker to this class?

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

Done.

+  void MergeInitializingSet();
 
   // |out_buffer| needs to be pre-allocated. The serialized index is stored in
   // |out_buffer|.
@@ -77,13 +85,22 @@ class SimpleIndex
   EntrySet entries_set_;
   uint64 cache_size_;  // Total cache storage size in bytes.
 
+  // These sets are only used during initialization phase.
+  // They are merged back in the entries_set_ once it finishes.
+  EntrySet initializing_set_;
+  // This stores all the hash_key of entries that are removed during
+  // initialization.
+  base::hash_set<std::string> removals_set_;
+  bool initialized_;
+
   base::FilePath index_filename_;
   base::PlatformFile index_file_;
 
   // We keep the thread from where Initialize() method has been called so that
-  // we run the Cleanup method in the same thread. Usually that should be the
-  // CacheThread.
+  // we run the WriteToDisk method in the same thread. Usually that should be
+  // the Cache Thread.

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

Is this comment right anymore? I think these come from the constructor (which is
nicer anyway).

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

Done.

   scoped_refptr<base::TaskRunner> cache_thread_;
+  scoped_refptr<base::TaskRunner> io_thread_;
 };
 
 }  // namespace disk_cache