Code quality and standards in SimpleBackend.

net/disk_cache/simple/simple_index.h

 // 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.
 
 #ifndef NET_DISK_CACHE_SIMPLE_SIMPLE_INDEX_H_
 #define NET_DISK_CACHE_SIMPLE_SIMPLE_INDEX_H_
 
 #include <map>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "base/time.h"
 #include "net/base/net_export.h"
 
 class Pickle;
 class PickleIterator;
 
 namespace base {
-class TaskRunner;
+class SingleThreadTaskRunner;
 }
 
 namespace disk_cache {
 
 class NET_EXPORT_PRIVATE EntryMetadata {
  public:
   EntryMetadata();
   EntryMetadata(uint64 hash_key,
                 base::Time last_used_time,
                 uint64 entry_size);
@@ skipping 24 matching lines @@
   // If you want to make calculations/comparisons, you should use the
   // base::Time() class. Use the GetLastUsedTime() method above.
   // TODO(felipeg): Use Time() here.
   int64 last_used_time_;
 
   uint64 entry_size_;  // Storage size in bytes.
 };
 
 // This class is not Thread-safe.
 class NET_EXPORT_PRIVATE SimpleIndex
-    : public base::RefCountedThreadSafe<SimpleIndex> {
-  friend class base::RefCountedThreadSafe<SimpleIndex>;
+    : public base::SupportsWeakPtr<SimpleIndex> {
  public:
   SimpleIndex(
-      const scoped_refptr<base::TaskRunner>& cache_thread,
-      const scoped_refptr<base::TaskRunner>& io_thread,
+      base::SingleThreadTaskRunner* cache_thread,
+      base::SingleThreadTaskRunner* io_thread,
       const base::FilePath& path);
 
+  virtual ~SimpleIndex();
+
   void Initialize();
 
   void Insert(const std::string& key);
   void Remove(const std::string& key);
 
   bool Has(const std::string& key) const;
 
   // Update the last used time of the entry with the given key and return true
   // iff the entry exist in the index.
   bool UseIfExists(const std::string& key);
 
   void WriteToDisk();
 
   // Update the size (in bytes) of an entry, in the metadata stored in the
   // index. This should be the total disk-file size including all streams of the
   // entry.
   bool UpdateEntrySize(const std::string& key, uint64 entry_size);
 
   // TODO(felipeg): This way we are storing the hash_key twice, as the
   // hash_map::key and as a member of EntryMetadata. We could save space if we
   // use a hash_set.
   typedef base::hash_map<uint64, EntryMetadata> EntrySet;
 
   static void InsertInEntrySet(const EntryMetadata& entry_metadata,
                                EntrySet* entry_set);
 
  private:
   typedef base::Callback<void(scoped_ptr<EntrySet>)> IndexCompletionCallback;
 
-  virtual ~SimpleIndex();
-
   static void LoadFromDisk(
       const base::FilePath& index_filename,
-      const scoped_refptr<base::TaskRunner>& io_thread,
+      base::SingleThreadTaskRunner* io_thread,
       const IndexCompletionCallback& completion_callback);
 
   // Enumerates all entries' files on disk and regenerates the index.
   static scoped_ptr<SimpleIndex::EntrySet> RestoreFromDisk(
       const base::FilePath& index_filename);
 
   static void WriteToDiskInternal(const base::FilePath& index_filename,
                                   scoped_ptr<Pickle> pickle);
 
   // Must run on IO Thread.
   void MergeInitializingSet(scoped_ptr<EntrySet> index_file_entries);
 
   EntrySet entries_set_;
   uint64 cache_size_;  // Total cache storage size in bytes.
 
   // This stores all the hash_key of entries that are removed during
   // initialization.
   base::hash_set<uint64> removed_entries_;
   bool initialized_;
 
   base::FilePath index_filename_;
 
-  scoped_refptr<base::TaskRunner> cache_thread_;
-  scoped_refptr<base::TaskRunner> io_thread_;
+  scoped_refptr<base::SingleThreadTaskRunner> cache_thread_;
+  scoped_refptr<base::SingleThreadTaskRunner> io_thread_;
 
   // All nonstatic SimpleEntryImpl methods should always be called on the IO
   // thread, in all cases. |io_thread_checker_| documents and enforces this.
   base::ThreadChecker io_thread_checker_;
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_INDEX_H_