Precache tracking database

components/precache/core/precache_database.h

+// Copyright 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 COMPONENTS_PRECACHE_CORE_PRECACHE_DATABASE_H_
+#define COMPONENTS_PRECACHE_CORE_PRECACHE_DATABASE_H_
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/non_thread_safe.h"
+#include "base/time/time.h"
+#include "url/gurl.h"
+
+namespace sql {
+class Connection;
+}
+
+namespace precache {
+
+class PrecacheURLTable;
+class PrecacheStatisticsTable;
+
+// Class that tracks information related to precaching. This class can be
+// constructed or destroyed on any threads, but all other methods must be called
+// on the same thread (e.g. the DB thread).
+class PrecacheDatabase : public base::RefCountedThreadSafe<PrecacheDatabase>,
+                         base::NonThreadSafe {
+ public:
+  // A PrecacheDatabase can be constructed on any thread.
+  PrecacheDatabase();
+
+  // Initializes the precache database with the specified connection. The
+  // PrecacheDatabase takes ownership of |db|. Init must be called before any
+  // other methods.
+  void Init(sql::Connection* db);

[mmenke, 2013/10/29 18:23:34]

May want to pass in the db as a scoped_ptr<sql::Connection> to make ownership
semantics clear at callsites.

[sclittle, 2013/10/29 23:40:45]

Done.

+
+  // Reports UMA of precache statistics for days up to and including the day of
+  // |end_date|. The precache statistics for these days are deleted from the
+  // database after they have been reported, and expired precache history is
+  // deleted from the precache URL table. |end_date| is passed by value and not
+  // by const reference so that this method can be posted on a thread.
+  void ReportAndDeleteOldStats(base::Time end_date);
+
+  // Update metrics in response to a URL being fetched. Parameters are passed by
+  // value and not by const reference so that this method can be posted on a
+  // thread.
+  void RecordURLFetched(GURL url, base::Time fetch_time, int64 size,
+                        bool was_cached, bool is_precaching, bool is_cellular);
+
+ private:
+  friend class base::RefCountedThreadSafe<PrecacheDatabase>;
+  friend class PrecacheDatabaseTest;
+  ~PrecacheDatabase();

[mmenke, 2013/10/29 18:23:34]

nit:  Think there should be a blank line between friend and method declarations.

[sclittle, 2013/10/29 23:40:45]

Done.

+
+  bool CantAccessDatabase();
+
+  scoped_ptr<sql::Connection> db_;
+  scoped_ptr<PrecacheURLTable> precache_url_table_;
+  scoped_ptr<PrecacheStatisticsTable> precache_statistics_table_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrecacheDatabase);
+};
+
+}  // namespace precache
+
+#endif  // COMPONENTS_PRECACHE_CORE_PRECACHE_DATABASE_H_