app_list: Search result launch history and boost.

chrome/browser/ui/app_list/search/history.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 CHROME_BROWSER_UI_APP_LIST_SEARCH_HISTORY_H_
+#define CHROME_BROWSER_UI_APP_LIST_SEARCH_HISTORY_H_
+
+#include <map>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/ui/app_list/search/history_data_observer.h"
+#include "chrome/browser/ui/app_list/search/history_types.h"
+#include "components/browser_context_keyed_service/browser_context_keyed_service.h"
+
+namespace content {
+class BrowserContext;
+}
+
+namespace app_list {
+
+class HistoryData;
+class HistoryDataStore;
+
+namespace test {
+class SearchHistoryTest;
+}
+
+// History tracks the launch events of the search results and uses HistoryData
+// to build user learning data out of these events. The learning data is stored
+// as associations between user typed query and launched result id. There are
+// primary and secondary associations. See HistoryData comments to see how
+// they are built. The learning data is sent to the mixer to boost results that
+// have been launched before.
+class History : public BrowserContextKeyedService,
+                public HistoryDataObserver {
+ public:
+  explicit History(content::BrowserContext* context);
+  virtual ~History();
+
+  // Returns true if the service is ready.
+  bool IsReady() const;
+
+  // Adds a launch event to the learning data.
+  void AddLaunchEvent(const std::string& query, const std::string& result_id);
+
+  // Gets all known search results that were launched using the given |query|
+  // or using queries that |query| is a prefix of.
+  scoped_ptr<KnownResults> GetKnownResults(const std::string& query) const;
+
+ private:
+  friend class app_list::test::SearchHistoryTest;
+
+  // HistoryDataObserver overrides:
+  virtual void OnHistoryDataLoadedFromStore() OVERRIDE;
+
+  content::BrowserContext* browser_context_;
+  scoped_ptr<HistoryData> data_;
+  scoped_refptr<HistoryDataStore> store_;
+  bool data_loaded_;
+
+  DISALLOW_COPY_AND_ASSIGN(History);
+};
+
+}  // namespace app_list
+
+#endif  // CHROME_BROWSER_UI_APP_LIST_SEARCH_HISTORY_H_