Adds ChromecastConfig to manage cast_shell's PrefService.

chromecast/common/chromecast_config.cc

Index: chromecast/common/chromecast_config.cc
diff --git a/chromecast/common/chromecast_config.cc b/chromecast/common/chromecast_config.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f016a683fcd522a5e4a9e68842eeb23dc587d7c2
--- /dev/null
+++ b/chromecast/common/chromecast_config.cc
@@ -0,0 +1,136 @@
+// 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 "chromecast/common/chromecast_config.h"
+
+#include <string>
+
+#include "base/command_line.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/path_service.h"
+#include "base/prefs/json_pref_store.h"
+#include "base/prefs/pref_registry_simple.h"
+#include "base/prefs/pref_service_factory.h"
+#include "base/prefs/pref_store.h"
+#include "base/strings/string_number_conversions.h"
+#include "chromecast/common/cast_paths.h"
+
+namespace chromecast {
+
+namespace {
+
+// Config file IO worker constants.
+const int kNumOfConfigFileIOWorkers = 1;
+const char kNameOfConfigFileIOWorkers[] = "ConfigFileIO";
+
+void UserPrefsLoadError(
+    PersistentPrefStore::PrefReadError* error_val,
+    PersistentPrefStore::PrefReadError error) {
+  DCHECK(error_val);
+  *error_val = error;
+}
+
+base::FilePath GetConfigPath() {
+  base::FilePath config_path;
+  CHECK(PathService::Get(FILE_CAST_CONFIG, &config_path));
+  return config_path;
+}
+
+}  // namespace
+
+// static
+ChromecastConfig* ChromecastConfig::g_instance_ = NULL;
+
+// static
+void ChromecastConfig::Create(PrefRegistrySimple* registry) {
+  DCHECK(g_instance_ == NULL);
+  g_instance_ = new ChromecastConfig();
+  g_instance_->Load(registry);
+}
+
+// static
+ChromecastConfig* ChromecastConfig::GetInstance() {
+  DCHECK(g_instance_ != NULL);
+  return g_instance_;
+}
+
+ChromecastConfig::ChromecastConfig()
+    : config_path_(GetConfigPath()),
+      worker_pool_(new base::SequencedWorkerPool(kNumOfConfigFileIOWorkers,
+                                                 kNameOfConfigFileIOWorkers)) {
+}
+
+ChromecastConfig::~ChromecastConfig() {
+  // Explict writing before worker_pool shutdown.
+  pref_service_->CommitPendingWrite();
+  worker_pool_->Shutdown();
+}
+
+bool ChromecastConfig::Load(PrefRegistrySimple* registry) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  VLOG(1) << "Loading config from " << config_path_.value();
+
+  RegisterPlatformPrefs(registry);
+
+  PersistentPrefStore::PrefReadError prefs_read_error =
+      PersistentPrefStore::PREF_READ_ERROR_NONE;
+  base::PrefServiceFactory prefServiceFactory;
+  prefServiceFactory.SetUserPrefsFile(config_path_,
+      JsonPrefStore::GetTaskRunnerForFile(config_path_, worker_pool_));
+  prefServiceFactory.set_async(false);
+  prefServiceFactory.set_read_error_callback(
+      base::Bind(&UserPrefsLoadError, &prefs_read_error));
+  pref_service_ = prefServiceFactory.Create(registry);
+
+  if (prefs_read_error == PersistentPrefStore::PREF_READ_ERROR_NONE) {
+    return true;
+  } else {
+    LOG(ERROR) << "Cannot initialize chromecast config: "
+               << config_path_.value()
+               << ", pref_error=" << prefs_read_error;
+    return false;
+  }
+}
+
+void ChromecastConfig::Save() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  VLOG(1) << "Saving config to: " << config_path_.value();
+  pref_service_->CommitPendingWrite();
+}
+
+const std::string ChromecastConfig::GetValue(const std::string& key) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return pref_service_->GetString(key.c_str());
+}
+
+const int ChromecastConfig::GetIntValue(const std::string& key) const {
+  return pref_service_->GetInteger(key.c_str());
+}
+
+void ChromecastConfig::SetValue(
+    const std::string& key,
+    const std::string& value) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (pref_service_->IsUserModifiablePreference(key.c_str())) {
+    VLOG(1) << "Set config: key=" << key << ", value=" << value;
+    pref_service_->SetString(key.c_str(), value);
+  } else {
+    LOG(ERROR) << "Cannot set read-only config: key=" << key
+               << ", value=" << value;
+  }
+}
+
+void ChromecastConfig::SetIntValue(const std::string& key, int value) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (pref_service_->IsUserModifiablePreference(key.c_str())) {
+    VLOG(1) << "Set config: key=" << key << ", value=" << value;
+    pref_service_->SetInteger(key.c_str(), value);
+  } else {
+    LOG(ERROR) << "Cannot set read-only config: key=" << key
+               << ", value=" << value;
+  }
+}
+
+}  // namespace chromecast