Precache tracking database

components/precache/core/precache_url_table.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_URL_TABLE_H_
+#define COMPONENTS_PRECACHE_CORE_PRECACHE_URL_TABLE_H_
+
+#include <map>
+
+#include "base/basictypes.h"
+#include "base/time/time.h"
+#include "url/gurl.h"
+
+namespace sql {
+class Connection;
+}
+
+namespace precache {
+
+// Interface for database table that keeps track of the URLs that have been
+// precached but not used. Each row in this table represents a URL that was
+// precached over the network, and has not been fetched through user browsing
+// since then. Manages one table { URL (primary key), precache timestamp }.
+class PrecacheURLTable {
+ public:
+  PrecacheURLTable();
+  ~PrecacheURLTable();
+
+  // Initialize the precache URL table for use with the specified database
+  // connection. The caller keeps ownership of |db|, and |db| must not be NULL.
+  // Init must be called before any other methods.
+  bool Init(sql::Connection* db);
+
+  // Adds a precached URL to the table, using the current time as the
+  // precache timestamp. Replaces the row if one already exists.
+  void AddURL(const GURL& url, const base::Time& precache_time);
+
+  // Returns true if this URL exists in the table.
+  bool HasURL(const GURL& url);
+
+  // Deletes the row from the table that has the given URL, if it exists.
+  void DeleteURL(const GURL& url);
+
+  // Deletes entries that were precached before the time of |delete_end|.
+  void DeleteAllPrecachedBefore(const base::Time& delete_end);
+
+  // Used by tests to get the contents of the table.
+  void GetAllDataForTesting(std::map<GURL, base::Time>* map);
+
+ private:
+  bool CreateTableIfNonExistent();
+
+  // Non-owned pointer.
+  sql::Connection* db_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrecacheURLTable);
+};
+
+}  // namespace precache
+
+#endif  // COMPONENTS_PRECACHE_CORE_PRECACHE_URL_TABLE_H_