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/thread_checker.h"
+
+class GURL;
+
+namespace base {
+class FilePath;
+class Time;
+}
+
+namespace sql {
+class Connection;
+}
+
+namespace precache {
+
+class PrecacheURLTable;
+
+// 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> {
+ public:
+  // A PrecacheDatabase can be constructed on any thread.
+  PrecacheDatabase();
+
+  // Initializes the precache database, using the specified database file path.
+  // Init must be called before any other methods.
+  bool Init(const base::FilePath& db_path);
+
+  // Deletes precache history from the precache URL table that is more than 60
+  // days older than |current_time|.
+  void DeleteExpiredPrecacheHistory(const base::Time& current_time);
+
+  // Report precache-related metrics in response to a URL being fetched, where
+  // the fetch was motivated by precaching.
+  void RecordURLPrecached(const GURL& url, const base::Time& fetch_time,
+                          int64 size, bool was_cached);
+
+  // Report precache-related metrics in response to a URL being fetched, where
+  // the fetch was not motivated by precaching. |is_connection_cellular|
+  // indicates whether the current network connection is a cellular network.
+  void RecordURLFetched(const GURL& url, const base::Time& fetch_time,
+                        int64 size, bool was_cached,
+                        bool is_connection_cellular);
+
+ private:
+  friend class base::RefCountedThreadSafe<PrecacheDatabase>;
+  friend class PrecacheDatabaseTest;
+
+  ~PrecacheDatabase();
+
+  bool IsDatabaseAccessible() const;
+
+  scoped_ptr<sql::Connection> db_;
+
+  // Table that keeps track of URLs that are in the cache because of precaching,
+  // and wouldn't be in the cache otherwise.
+  scoped_ptr<PrecacheURLTable> precache_url_table_;
+
+  // ThreadChecker used to ensure that all methods other than the constructor
+  // or destructor are called on the same thread.
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrecacheDatabase);
+};
+
+}  // namespace precache
+
+#endif  // COMPONENTS_PRECACHE_CORE_PRECACHE_DATABASE_H_