Beacons for tracking default browser status.

chrome/installer/util/beacons.h

+// Copyright 2015 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_INSTALLER_UTIL_BEACONS_H_
+#define CHROME_INSTALLER_UTIL_BEACONS_H_
+
+#include <windows.h>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_piece.h"
+#include "base/time/time.h"
+#include "chrome/installer/util/shell_util.h"
+
+class AppRegistrationData;
+class BrowserDistribution;
+
+namespace base {
+class FilePath;
+}
+
+// Checks the default state of the browser for the current user and updates the
+// appropriate beacon (last was default or first not default).
+void UpdateDefaultBrowserBeaconForPath(const base::FilePath& chrome_exe);
+
+// Updates the last was default or first not default beacon for the current user
+// based on |default_state|.
+void UpdateDefaultBrowserBeaconWithState(const base::FilePath& chrome_exe,
+                                         BrowserDistribution* distribution,
+                                         ShellUtil::DefaultState default_state);
+
+// Updates the last OS upgrade beacon for the install.
+void UpdateOsUpgradeBeacon(bool system_install,
+                           BrowserDistribution* distribution);
+
+namespace installer_util {
+
+class Beacon;
+
+// Returns a Beacon representing the last time the machine's OS was ugpraded.
+scoped_ptr<Beacon> MakeLastOsUpgradeBeacon(
+    bool system_install,
+    const AppRegistrationData& registration_data);
+
+// Returns a Beacon representing the last time Chrome was the user's default
+// browser.
+scoped_ptr<Beacon> MakeLastWasDefaultBeacon(
+    bool system_install,
+    const AppRegistrationData& registration_data);
+
+// Returns a Beacon representing the first time Chrome was not the user's
+// default browser.
+scoped_ptr<Beacon> MakeFirstNotDefaultBeacon(

[gab, 2015/06/01 18:43:12]

s/Make/Get ?

To me "Make" sounds like you'll actually set the state whereas you're only
getting an item representing the state.

[grt (UTC plus 2), 2015/06/01 19:49:43]

I chose Make since it returns an instance distinct from any other (Create would
also work, but Make is shorter :-) ). Get doesn't sound right to me for a
factory function since it sounds like it returns the one Beacon instance.

+    bool system_install,
+    const AppRegistrationData& registration_data);
+
+// A named beacon stored in the registry representing the first or last time at
+// which some event took place. A beacon may apply to a per-user event or a
+// per-install event. In general, beacons should be created via factory methods
+// such as those above.
+class Beacon {
+ public:
+  enum class BeaconType {
+    // A beacon that marks the first occurrence of an event.
+    FIRST,
+    // A beacon that marks the last occurrence of an event.
+    LAST,
+  };
+
+  enum class BeaconScope {
+    // A beacon that applies to a per-user event.
+    PER_USER,
+    // A beacon that applies to a per-install event.
+    PER_INSTALL,
+  };
+
+  // Creates a beacon named |name| for the product identified by
+  // |registration_data| installed as either a per-user or a per-machine app
+  // according to |system_install|.
+  Beacon(base::StringPiece16 name,
+         BeaconType type,
+         BeaconScope scope,
+         bool system_install,
+         const AppRegistrationData& registration_data);
+  ~Beacon();
+
+  // Updates the beacon. For a type LAST beacon, the current time is written
+  // unconditionally. For a type FIRST beacon, the beacon is only updated if it
+  // does not already exist.
+  void Update();
+
+  // Removes the beacon.
+  void Remove();
+
+  // Returns the beacon's value or a null time if not found.
+  base::Time Get();
+
+ private:
+  // Initializes the key_path_ and value_name_ fields of the beacon.
+  void Initialize(base::StringPiece16 name,
+                  bool system_install,
+                  const AppRegistrationData& registration_data);
+
+  // The type of beacon.
+  const BeaconType type_;
+
+  // The root key in the registry where this beacon is stored.
+  const HKEY root_;
+
+  // The scope of the beacon.
+  const BeaconScope scope_;
+
+  // The path to the registry key holding the beacon.
+  base::string16 key_path_;
+
+  // The name of the registry value holding the beacon.
+  base::string16 value_name_;
+
+  DISALLOW_COPY_AND_ASSIGN(Beacon);
+};
+
+}  // namespace installer_util
+
+#endif  // CHROME_INSTALLER_UTIL_BEACONS_H_