Gather stability prefs into managing objects.

components/metrics/environment_recorder.cc

+// Copyright 2017 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/environment_recorder.h"
+
+#include "base/base64.h"
+#include "base/sha1.h"
+#include "base/strings/string_number_conversions.h"
+#include "components/metrics/metrics_pref_names.h"
+#include "components/metrics/proto/system_profile.pb.h"
+#include "components/prefs/pref_registry_simple.h"
+#include "components/prefs/pref_service.h"
+
+namespace metrics {
+
+namespace {
+
+// Computes a SHA-1 hash of |data| and returns it as a hex string.
+std::string ComputeSHA1(const std::string& data) {
+  const std::string sha1 = base::SHA1HashString(data);
+  return base::HexEncode(sha1.data(), sha1.size());
+}
+
+}  // namespace
+
+EnvironmentRecorder::EnvironmentRecorder(PrefService* local_state)
+    : local_state_(local_state) {}
+
+EnvironmentRecorder::~EnvironmentRecorder() = default;
+
+std::string EnvironmentRecorder::SerializeAndRecordEnvironmentToPrefs(
+    const SystemProfileProto& system_profile) {
+  std::string serialized_system_profile;
+  std::string base64_system_profile;
+  if (system_profile.SerializeToString(&serialized_system_profile)) {
+    // Persist the system profile to disk. In the event of an unclean shutdown,
+    // it will be used as part of the initial stability report.
+    base::Base64Encode(serialized_system_profile, &base64_system_profile);
+    local_state_->SetString(prefs::kStabilitySavedSystemProfile,
+                            base64_system_profile);
+    local_state_->SetString(prefs::kStabilitySavedSystemProfileHash,
+                            ComputeSHA1(serialized_system_profile));
+  }
+
+  return serialized_system_profile;
+}
+
+bool EnvironmentRecorder::LoadEnvironmentFromPrefs(
+    SystemProfileProto* system_profile) {
+  DCHECK(system_profile);
+
+  const std::string base64_system_profile =
+      local_state_->GetString(prefs::kStabilitySavedSystemProfile);
+  if (base64_system_profile.empty())
+    return false;
+  const std::string system_profile_hash =
+      local_state_->GetString(prefs::kStabilitySavedSystemProfileHash);
+
+  std::string serialized_system_profile;
+  return base::Base64Decode(base64_system_profile,
+                            &serialized_system_profile) &&
+         ComputeSHA1(serialized_system_profile) == system_profile_hash &&
+         system_profile->ParseFromString(serialized_system_profile);
+}
+
+void EnvironmentRecorder::ClearEnvironmentFromPrefs() {
+  local_state_->ClearPref(prefs::kStabilitySavedSystemProfile);
+  local_state_->ClearPref(prefs::kStabilitySavedSystemProfileHash);
+}
+
+int64_t EnvironmentRecorder::GetLastBuildtime() {
+  return local_state_->GetInt64(prefs::kStabilityStatsBuildTime);
+}
+
+std::string EnvironmentRecorder::GetLastVersion() {
+  return local_state_->GetString(prefs::kStabilityStatsVersion);
+}
+
+void EnvironmentRecorder::SetBuildtimeAndVersion(int64_t buildtime,
+                                                 const std::string& version) {
+  local_state_->SetInt64(prefs::kStabilityStatsBuildTime, buildtime);
+  local_state_->SetString(prefs::kStabilityStatsVersion, version);
+}
+
+// static
+void EnvironmentRecorder::RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterStringPref(prefs::kStabilitySavedSystemProfile,
+                               std::string());
+  registry->RegisterStringPref(prefs::kStabilitySavedSystemProfileHash,
+                               std::string());
+  registry->RegisterStringPref(prefs::kStabilityStatsVersion, std::string());
+  registry->RegisterInt64Pref(prefs::kStabilityStatsBuildTime, 0);
+}
+
+}  // namespace metrics