Add DBus Bindings for leaderd

chromeos/dbus/leadership_daemon_manager_client.cc

+// 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.
+
+#include "chromeos/dbus/leadership_daemon_manager_client.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "base/observer_list.h"
+#include "dbus/bus.h"
+#include "dbus/message.h"
+#include "dbus/object_manager.h"
+#include "dbus/object_proxy.h"
+#include "dbus/values_util.h"
+
+namespace chromeos {
+
+// TODO(benchan): Move these constants to system_api.
+namespace leaderd {
+const char kLeaderdServiceName[] = "org.chromium.leaderd";
+const char kLeaderdObjectManagerServicePath[] = "/org/chromium/leaderd";
+const char kLeaderdManagerPath[] = "/org/chromium/leaderd/Manager";
+const char kManagerInterface[] = "org.chromium.leaderd.Manager";
+const char kGroupInterface[] = "org.chromium.leaderd.Group";
+const char kJoinGroupMethod[] = "JoinGroup";
+const char kLeaveGroupMethod[] = "LeaveGroup";
+const char kSetScoreMethod[] = "SetScore";
+const char kPokeLeaderMethod[] = "PokeLeader";
+const char kPingMethod[] = "Ping";
+const char kLeaderUUID[] = "LeaderUUID";
+const char kGroupMembers[] = "GroupMembers";
+}
+// namespace leaderd
+
+namespace {
+
+// Since there is no property associated with Manager objects, an empty callback
+// is used.
+void DoNothing(const std::string& property_name) {
+}
+
+// The LeadershipDaemonManagerClient implementation used in production.
+class LeadershipDaemonManagerClientImpl
+    : public LeadershipDaemonManagerClient,
+      public dbus::ObjectManager::Interface {
+ public:
+  LeadershipDaemonManagerClientImpl();
+  ~LeadershipDaemonManagerClientImpl() override;
+
+  // LeadershipDaemonManagerClient overrides.
+  void AddObserver(Observer* observer) override;
+  void RemoveObserver(Observer* observer) override;
+  void JoinGroup(const std::string& group,
+                 const base::DictionaryValue& options,
+                 const StringDBusMethodCallback& callback) override;
+  void LeaveGroup(const std::string& object_path,
+                  const VoidDBusMethodCallback& callback) override;
+  void SetScore(const std::string& object_path,
+                int score,
+                const VoidDBusMethodCallback& callback) override;
+  void PokeLeader(const std::string& object_path,
+                  const VoidDBusMethodCallback& callback) override;
+  void Ping(const StringDBusMethodCallback& callback) override;
+  GroupProperties* GetGroupProperties(
+      const dbus::ObjectPath& object_path) override;
+
+  // DBusClient overrides:
+  void Init(dbus::Bus* bus) override;
+
+  // dbus::ObjectManager::Interface override.
+  dbus::PropertySet* CreateProperties(
+      dbus::ObjectProxy* object_proxy,
+      const dbus::ObjectPath& object_path,
+      const std::string& interface_name) override;
+  void ObjectAdded(const dbus::ObjectPath& object_path,
+                   const std::string& interface_name) override;
+  void ObjectRemoved(const dbus::ObjectPath& object_path,
+                     const std::string& interface_name) override;
+
+ private:
+  // Called by dbus::PropertySet when a property value is changed,
+  // either by result of a signal or response to a GetAll() or Get()
+  // call. Informs observers.
+  void OnGroupPropertyChanged(const dbus::ObjectPath& object_path,
+                              const std::string& property_name);
+
+  void OnStringDBusMethod(const StringDBusMethodCallback& callback,
+                          dbus::Response* response);
+  void OnVoidDBusMethod(const VoidDBusMethodCallback& callback,
+                        dbus::Response* response);
+
+  // List of observers interested in event notifications from us.
+  ObserverList<Observer> observers_;
+  dbus::ObjectManager* object_manager_;
+  base::WeakPtrFactory<LeadershipDaemonManagerClientImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(LeadershipDaemonManagerClientImpl);
+};
+
+LeadershipDaemonManagerClientImpl::LeadershipDaemonManagerClientImpl()
+    : object_manager_(nullptr), weak_ptr_factory_(this) {
+}
+
+LeadershipDaemonManagerClientImpl::~LeadershipDaemonManagerClientImpl() {
+  if (object_manager_) {
+    object_manager_->UnregisterInterface(leaderd::kManagerInterface);
+    object_manager_->UnregisterInterface(leaderd::kGroupInterface);
+  }
+}
+
+void LeadershipDaemonManagerClientImpl::AddObserver(Observer* observer) {
+  DCHECK(observer);
+  observers_.AddObserver(observer);
+}
+
+void LeadershipDaemonManagerClientImpl::RemoveObserver(Observer* observer) {
+  DCHECK(observer);
+  observers_.RemoveObserver(observer);
+}
+
+void LeadershipDaemonManagerClientImpl::JoinGroup(
+    const std::string& group,
+    const base::DictionaryValue& options,
+    const StringDBusMethodCallback& callback) {
+  dbus::ObjectProxy* object_proxy = object_manager_->GetObjectProxy(
+      dbus::ObjectPath(leaderd::kLeaderdManagerPath));
+  if (!object_proxy) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&LeadershipDaemonManagerClientImpl::OnStringDBusMethod,
+                   weak_ptr_factory_.GetWeakPtr(), callback, nullptr));
+    return;
+  }
+
+  dbus::MethodCall method_call(leaderd::kManagerInterface,
+                               leaderd::kJoinGroupMethod);
+  dbus::MessageWriter writer(&method_call);
+  writer.AppendString(group);
+  dbus::AppendValueData(&writer, options);
+  object_proxy->CallMethod(
+      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+      base::Bind(&LeadershipDaemonManagerClientImpl::OnStringDBusMethod,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void LeadershipDaemonManagerClientImpl::LeaveGroup(
+    const std::string& object_path,
+    const VoidDBusMethodCallback& callback) {
+  dbus::ObjectProxy* object_proxy =
+      object_manager_->GetObjectProxy(dbus::ObjectPath(object_path));
+  if (!object_proxy) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&LeadershipDaemonManagerClientImpl::OnVoidDBusMethod,
+                   weak_ptr_factory_.GetWeakPtr(), callback, nullptr));
+    return;
+  }
+
+  dbus::MethodCall method_call(leaderd::kGroupInterface,
+                               leaderd::kLeaveGroupMethod);
+  dbus::MessageWriter writer(&method_call);
+  object_proxy->CallMethod(
+      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+      base::Bind(&LeadershipDaemonManagerClientImpl::OnVoidDBusMethod,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void LeadershipDaemonManagerClientImpl::SetScore(
+    const std::string& object_path,
+    int score,
+    const VoidDBusMethodCallback& callback) {
+  dbus::ObjectProxy* object_proxy =
+      object_manager_->GetObjectProxy(dbus::ObjectPath(object_path));
+  if (!object_proxy) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&LeadershipDaemonManagerClientImpl::OnVoidDBusMethod,
+                   weak_ptr_factory_.GetWeakPtr(), callback, nullptr));
+    return;
+  }
+
+  dbus::MethodCall method_call(leaderd::kGroupInterface,
+                               leaderd::kSetScoreMethod);
+  dbus::MessageWriter writer(&method_call);
+  writer.AppendInt32(score);
+  object_proxy->CallMethod(
+      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+      base::Bind(&LeadershipDaemonManagerClientImpl::OnVoidDBusMethod,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void LeadershipDaemonManagerClientImpl::PokeLeader(
+    const std::string& object_path,
+    const VoidDBusMethodCallback& callback) {
+  dbus::ObjectProxy* object_proxy =
+      object_manager_->GetObjectProxy(dbus::ObjectPath(object_path));
+  if (!object_proxy) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&LeadershipDaemonManagerClientImpl::OnVoidDBusMethod,
+                   weak_ptr_factory_.GetWeakPtr(), callback, nullptr));
+    return;
+  }
+
+  dbus::MethodCall method_call(leaderd::kGroupInterface,
+                               leaderd::kPokeLeaderMethod);
+  dbus::MessageWriter writer(&method_call);
+  object_proxy->CallMethod(
+      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+      base::Bind(&LeadershipDaemonManagerClientImpl::OnVoidDBusMethod,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void LeadershipDaemonManagerClientImpl::Ping(
+    const StringDBusMethodCallback& callback) {
+  dbus::ObjectProxy* object_proxy = object_manager_->GetObjectProxy(
+      dbus::ObjectPath(leaderd::kLeaderdManagerPath));
+  if (!object_proxy) {
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&LeadershipDaemonManagerClientImpl::OnStringDBusMethod,
+                   weak_ptr_factory_.GetWeakPtr(), callback, nullptr));
+    return;
+  }
+
+  dbus::MethodCall method_call(leaderd::kManagerInterface,
+                               leaderd::kPingMethod);
+  dbus::MessageWriter writer(&method_call);
+  object_proxy->CallMethod(
+      &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+      base::Bind(&LeadershipDaemonManagerClientImpl::OnStringDBusMethod,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+LeadershipDaemonManagerClient::GroupProperties*
+LeadershipDaemonManagerClientImpl::GetGroupProperties(
+    const dbus::ObjectPath& object_path) {
+  return static_cast<GroupProperties*>(
+      object_manager_->GetProperties(object_path, leaderd::kGroupInterface));
+}
+
+void LeadershipDaemonManagerClientImpl::Init(dbus::Bus* bus) {
+  object_manager_ = bus->GetObjectManager(
+      leaderd::kLeaderdServiceName,
+      dbus::ObjectPath(leaderd::kLeaderdObjectManagerServicePath));
+  object_manager_->RegisterInterface(leaderd::kManagerInterface, this);
+  object_manager_->RegisterInterface(leaderd::kGroupInterface, this);
+}
+
+dbus::PropertySet* LeadershipDaemonManagerClientImpl::CreateProperties(
+    dbus::ObjectProxy* object_proxy,
+    const dbus::ObjectPath& object_path,
+    const std::string& interface_name) {
+  dbus::PropertySet* properties = nullptr;
+  if (interface_name == leaderd::kManagerInterface) {
+    properties = new dbus::PropertySet(object_proxy, interface_name,
+                                       base::Bind(&DoNothing));
+  } else if (interface_name == leaderd::kGroupInterface) {
+    properties = new GroupProperties(
+        object_proxy, interface_name,
+        base::Bind(&LeadershipDaemonManagerClientImpl::OnGroupPropertyChanged,
+                   weak_ptr_factory_.GetWeakPtr(), object_path));
+  } else {
+    NOTREACHED() << "Unhandled interface name " << interface_name;
+  }
+  return properties;
+}
+
+void LeadershipDaemonManagerClientImpl::ObjectAdded(
+    const dbus::ObjectPath& object_path,
+    const std::string& interface_name) {
+  if (interface_name == leaderd::kManagerInterface) {
+    FOR_EACH_OBSERVER(Observer, observers_, ManagerAdded());
+  } else if (interface_name == leaderd::kGroupInterface) {
+    FOR_EACH_OBSERVER(Observer, observers_, GroupAdded(object_path));
+  } else {
+    NOTREACHED() << "Unhandled interface name " << interface_name;
+  }
+}
+
+void LeadershipDaemonManagerClientImpl::ObjectRemoved(
+    const dbus::ObjectPath& object_path,
+    const std::string& interface_name) {
+  if (interface_name == leaderd::kManagerInterface) {
+    FOR_EACH_OBSERVER(Observer, observers_, ManagerRemoved());
+  } else if (interface_name == leaderd::kGroupInterface) {
+    FOR_EACH_OBSERVER(Observer, observers_, GroupRemoved(object_path));
+  } else {
+    NOTREACHED() << "Unhandled interface name " << interface_name;
+  }
+}
+
+void LeadershipDaemonManagerClientImpl::OnGroupPropertyChanged(
+    const dbus::ObjectPath& object_path,
+    const std::string& property_name) {
+  FOR_EACH_OBSERVER(Observer, observers_,
+                    GroupPropertyChanged(object_path, property_name));
+}
+
+void LeadershipDaemonManagerClientImpl::OnStringDBusMethod(
+    const StringDBusMethodCallback& callback,
+    dbus::Response* response) {
+  if (!response) {
+    callback.Run(DBUS_METHOD_CALL_FAILURE, std::string());
+    return;
+  }
+
+  dbus::MessageReader reader(response);
+  std::string result;
+  if (!reader.PopString(&result)) {
+    callback.Run(DBUS_METHOD_CALL_FAILURE, std::string());
+    return;
+  }
+
+  callback.Run(DBUS_METHOD_CALL_SUCCESS, result);
+}
+
+void LeadershipDaemonManagerClientImpl::OnVoidDBusMethod(
+    const VoidDBusMethodCallback& callback,
+    dbus::Response* response) {
+  callback.Run(response ? DBUS_METHOD_CALL_SUCCESS : DBUS_METHOD_CALL_FAILURE);
+}
+
+}  // namespace
+
+LeadershipDaemonManagerClient::GroupProperties::GroupProperties(
+    dbus::ObjectProxy* object_proxy,
+    const std::string& interface_name,
+    const PropertyChangedCallback& callback)
+    : dbus::PropertySet(object_proxy, interface_name, callback) {
+  RegisterProperty(leaderd::kLeaderUUID, &leaderUUID_);
+  RegisterProperty(leaderd::kGroupMembers, &group_members_);
+}
+
+LeadershipDaemonManagerClient::GroupProperties::~GroupProperties() {
+}
+
+LeadershipDaemonManagerClient::LeadershipDaemonManagerClient() {
+}
+
+LeadershipDaemonManagerClient::~LeadershipDaemonManagerClient() {
+}
+
+// static
+LeadershipDaemonManagerClient* LeadershipDaemonManagerClient::Create() {
+  return new LeadershipDaemonManagerClientImpl();
+}
+
+}  // namespace chromeos