Precache tracking database

components/precache/core/precache_database.h

Index: components/precache/core/precache_database.h
diff --git a/components/precache/core/precache_database.h b/components/precache/core/precache_database.h
new file mode 100644
index 0000000000000000000000000000000000000000..c26d9564c4d5809d74bf1779a9e8a8a3745ca23f
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+++ b/components/precache/core/precache_database.h
@@ -0,0 +1,79 @@
+// 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"
+
+class GURL;
+
+namespace base {
+class Time;
+}
+
+namespace sql {
+class Connection;
+}
+
+namespace precache {
+
+class PrecacheStatisticsTable;
+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>,
+                         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(scoped_ptr<sql::Connection> db);
+
+  // 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.
+  void ReportAndDeleteOldStats(const base::Time& end_date);
+
+  // Update precache-related metrics in response to a URL being fetched.
+  // |is_precache| indicates whether or not the fetch is a precache, and

[mmenke, 2013/10/31 16:45:00]

nit:  "is a precache" -> "is a precache request"

[sclittle, 2013/11/06 01:51:42]

Done.

+  // |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_precache,
+                        bool is_connection_cellular);

[mmenke, 2013/10/31 16:45:00]

We're assuming all requests made while the PrecacheManager is precaching files
is a precache attempt, which is not necessarily true.  We should comment on that
assumption where we call this function.

[sclittle, 2013/11/06 01:51:42]

Sure.

+
+ 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_;
+
+  // Table that keeps track of daily cumulative statistics that are relevant to
+  // precaching.
+  scoped_ptr<PrecacheStatisticsTable> precache_statistics_table_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrecacheDatabase);
+};
+
+}  // namespace precache
+
+#endif  // COMPONENTS_PRECACHE_CORE_PRECACHE_DATABASE_H_