| // Copyright 2014 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 "components/metrics/cloned_install_detector.h" |
| |
| #include <stdint.h> |
| |
| #include <string> |
| |
| #include "base/bind.h" |
| #include "base/location.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/metrics/metrics_hashes.h" |
| #include "base/single_thread_task_runner.h" |
| #include "base/task/post_task.h" |
| #include "base/task_runner_util.h" |
| #include "components/metrics/machine_id_provider.h" |
| #include "components/metrics/metrics_pref_names.h" |
| #include "components/prefs/pref_registry_simple.h" |
| #include "components/prefs/pref_service.h" |
| |
| namespace metrics { |
| |
| namespace { |
| |
| uint32_t HashRawId(const std::string& value) { |
| uint64_t hash = base::HashMetricName(value); |
| |
| // Only use 24 bits from the 64-bit hash. |
| return hash & ((1 << 24) - 1); |
| } |
| |
| // State of the generated machine id in relation to the previously stored value. |
| // Note: UMA histogram enum - don't re-order or remove entries |
| enum MachineIdState { |
| ID_GENERATION_FAILED, |
| ID_NO_STORED_VALUE, |
| ID_CHANGED, |
| ID_UNCHANGED, |
| ID_ENUM_SIZE |
| }; |
| |
| // Logs the state of generating a machine id and comparing it to a stored value. |
| void LogMachineIdState(MachineIdState state) { |
| UMA_HISTOGRAM_ENUMERATION("UMA.MachineIdState", state, ID_ENUM_SIZE); |
| } |
| |
| } // namespace |
| |
| ClonedInstallDetector::ClonedInstallDetector() : weak_ptr_factory_(this) {} |
| |
| ClonedInstallDetector::~ClonedInstallDetector() { |
| } |
| |
| void ClonedInstallDetector::CheckForClonedInstall(PrefService* local_state) { |
| base::PostTaskWithTraitsAndReplyWithResult( |
| FROM_HERE, |
| {base::MayBlock(), base::TaskPriority::BEST_EFFORT, |
| base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN}, |
| base::Bind(&MachineIdProvider::GetMachineId), |
| base::Bind(&ClonedInstallDetector::SaveMachineId, |
| weak_ptr_factory_.GetWeakPtr(), local_state)); |
| } |
| |
| void ClonedInstallDetector::SaveMachineId(PrefService* local_state, |
| const std::string& raw_id) { |
| if (raw_id.empty()) { |
| LogMachineIdState(ID_GENERATION_FAILED); |
| local_state->ClearPref(prefs::kMetricsMachineId); |
| return; |
| } |
| |
| int hashed_id = HashRawId(raw_id); |
| |
| MachineIdState id_state = ID_NO_STORED_VALUE; |
| if (local_state->HasPrefPath(prefs::kMetricsMachineId)) { |
| if (local_state->GetInteger(prefs::kMetricsMachineId) != hashed_id) { |
| id_state = ID_CHANGED; |
| // TODO(jwd): Use a callback to set the reset pref. That way |
| // ClonedInstallDetector doesn't need to know about this pref. |
| local_state->SetBoolean(prefs::kMetricsResetIds, true); |
| } else { |
| id_state = ID_UNCHANGED; |
| } |
| } |
| |
| LogMachineIdState(id_state); |
| |
| local_state->SetInteger(prefs::kMetricsMachineId, hashed_id); |
| } |
| |
| // static |
| void ClonedInstallDetector::RegisterPrefs(PrefRegistrySimple* registry) { |
| registry->RegisterIntegerPref(prefs::kMetricsMachineId, 0); |
| } |
| |
| } // namespace metrics |