Ensuring Google Update at user-level is installed alongside App Host, for the quick-enable App Host…

chrome/installer/util/google_update_util.cc

+// Copyright (c) 2012 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.
+
+#include "chrome/installer/util/google_update_util.h"
+
+#include "base/command_line.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/process_util.h"
+#include "base/string16.h"
+#include "base/time.h"
+#include "base/win/registry.h"
+#include "base/win/scoped_handle.h"
+#include "chrome/installer/launcher_support/chrome_launcher_support.h"
+#include "chrome/installer/util/google_update_constants.h"
+#include "chrome/installer/util/google_update_settings.h"
+
+using base::win::RegKey;
+
+namespace google_update {
+
+namespace {
+
+const int kGoogleUpdateTimeoutMs = 20 * 1000;
+
+// Returns true iff Google Update is present at the given level.

[grt (UTC plus 2), 2012/09/24 15:23:39]

imo, "iff" doesn't make sense here.  just use "if".

[huangs, 2012/09/24 15:50:59]

Done.

+bool IsGoogleUpdatePresent(bool system_install) {
+  // Using the existence of version key in the registry to decide.
+  return GoogleUpdateSettings::GetGoogleUpdateVersion(system_install).IsValid();
+}
+
+// Returns GoogleUpdateSetup.exe's executable path at specified level.
+// or an empty path if none is found.
+FilePath GetGoogleUpdateSetupExe(bool system_install) {
+  const HKEY root_key = system_install ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
+  RegKey update_key;
+
+  if (update_key.Open(root_key, kRegPathGoogleUpdate, KEY_QUERY_VALUE) ==
+          ERROR_SUCCESS) {
+    string16 path_str;
+    string16 version_str;
+    if ((update_key.ReadValue(kRegPathField, &path_str) == ERROR_SUCCESS) &&
+        (update_key.ReadValue(kRegGoogleUpdateVersion, &version_str) ==
+             ERROR_SUCCESS)) {
+      return FilePath(path_str).DirName().Append(version_str).
+          Append(kGoogleUpdateSetupExe);
+    }
+  }
+  return FilePath();
+}
+
+// If Google Update is present at system-level, sets |cmd_string| to the command
+// line to install Google Update at user-level and returns true.
+// Otherwise, clears |cmd_string| and returns false.
+bool GetUserLevelGoogleUpdateInstallCommandLine(string16* cmd_string) {
+  cmd_string->clear();
+  FilePath google_update_setup(GetGoogleUpdateSetupExe(true));  // system-level.
+  if (!google_update_setup.empty()) {
+    CommandLine cmd(google_update_setup);
+    // Appends parameter "/install runtime=true&needsadmin=false /silent"
+    // Constants are found in code.google.com/p/omaha/common/const_cmd_line.h.
+    cmd.AppendArg("/install");
+    // The "&" can be used in base::LaunchProcess() without quotation
+    // (this is problematic only if run from command prompt).
+    cmd.AppendArg("runtime=true&needsadmin=false");
+    cmd.AppendArg("/silent");
+    *cmd_string = cmd.GetCommandLineString();
+  }
+  return !cmd_string->empty();
+}
+
+// Launches command |cmd_string|, and waits for |timeout| milliseconds before
+// timing out.  To wait indefinitely, one can set
+// |timeout| to be base::TimeDelta::FromMilliseconds(INFINITE).
+// Returns true if this executes successfully.
+// Returns false if command execution fails to execute, or times out.
+bool LaunchProcessAndWaitWithTimeout(const string16& cmd_string,
+                                     base::TimeDelta timeout) {
+  bool success = false;
+  base::win::ScopedHandle process;
+  int exit_code = 0;
+  LOG(INFO) << "Launching: " << cmd_string;
+  if (!base::LaunchProcess(cmd_string, base::LaunchOptions(),
+                           process.Receive())) {
+    PLOG(ERROR) << "Failed to launch (" << cmd_string << ")";
+  } else if (!base::WaitForExitCodeWithTimeout(process, &exit_code, timeout)) {
+    // The GetExitCodeProcess failed or timed-out.
+    LOG(ERROR) <<"Command (" << cmd_string << ") is taking more than "
+               << timeout.InMilliseconds() << " milliseconds to complete.";
+  } else if (exit_code != 0) {
+    LOG(ERROR) << "Command (" << cmd_string << ") exited with code "
+               << exit_code;
+  } else {
+    success = true;
+  }
+  return success;
+}
+
+}  // namespace
+
+bool EnsureUserLevelGoogleUpdatePresent() {
+  LOG(INFO) << "Ensuring Google Update is present at user-level.";
+
+  bool success = false;
+  if (IsGoogleUpdatePresent(false)) {
+    success = true;
+  } else {
+    string16 cmd_string;
+    if (!GetUserLevelGoogleUpdateInstallCommandLine(&cmd_string)) {
+      LOG(ERROR) << "Cannot find Google Update at system-level.";
+    } else {
+      success = LaunchProcessAndWaitWithTimeout(cmd_string,
+          base::TimeDelta::FromMilliseconds(INFINITE));
+    }
+  }
+  return success;
+}
+
+bool UninstallGoogleUpdate(bool system_install) {
+  bool success = false;
+  string16 cmd_string(
+      GoogleUpdateSettings::GetUninstallCommandLine(system_install));
+  if (cmd_string.empty()) {
+    success = true;  // Nothing to; vacuous success.
+  } else {
+    success = LaunchProcessAndWaitWithTimeout(cmd_string,
+        base::TimeDelta::FromMilliseconds(kGoogleUpdateTimeoutMs));
+  }
+  return success;
+}
+
+}  // namespace google_update