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// Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef LIBBRILLO_BRILLO_GLIB_DBUS_H_
#define LIBBRILLO_BRILLO_GLIB_DBUS_H_
// IMPORTANT: Do not use this in new code. Instead, use libchrome's D-Bus
// bindings. See https://goo.gl/EH3MmR for more details.
#include <dbus/dbus-glib.h>
#include <glib-object.h>
#include <algorithm>
#include <string>
#include <utility>
#include "base/logging.h"
#include <brillo/brillo_export.h>
#include <brillo/glib/object.h>
struct DBusMessage;
struct DBusConnection;
namespace brillo {
namespace dbus {
// \brief BusConnection manages the ref-count for a ::DBusGConnection*.
//
// A BusConnection has reference semantics bound to a particular communication
// bus.
//
// \models Copyable, Assignable
// \related GetSystemBusConnection()
class BRILLO_EXPORT BusConnection {
public:
typedef ::DBusGConnection* value_type;
BusConnection(const BusConnection& x) : object_(x.object_) {
if (object_)
::dbus_g_connection_ref(object_);
}
~BusConnection() {
if (object_)
::dbus_g_connection_unref(object_);
}
BusConnection& operator=(BusConnection x) {
swap(*this, x);
return *this;
}
const value_type& g_connection() const {
DCHECK(object_) << "referencing an empty connection";
return object_;
}
operator bool() const { return object_; }
bool HasConnection() const { return object_; }
private:
friend void swap(BusConnection& x, BusConnection& y);
friend class Proxy;
friend BusConnection GetSystemBusConnection();
friend BusConnection GetPrivateBusConnection(const char* address);
// Constructor takes ownership
BRILLO_PRIVATE explicit BusConnection(::DBusGConnection* x) : object_(x) {}
value_type object_;
};
inline void swap(BusConnection& x, BusConnection& y) {
std::swap(x.object_, y.object_);
}
// \brief Proxy manages the ref-count for a ::DBusGProxy*.
//
// Proxy has reference semantics and represents a connection to on object on
// the bus. A proxy object is constructed with a connection to a bus, a name
// to an entity on the bus, a path to an object owned by the entity, and an
// interface protocol name used to communicate with the object.
class BRILLO_EXPORT Proxy {
public:
typedef ::DBusGProxy* value_type;
Proxy();
// Set |connect_to_name_owner| true if you'd like to use
// dbus_g_proxy_new_for_name_owner() rather than dbus_g_proxy_new_for_name().
Proxy(const BusConnection& connection,
const char* name,
const char* path,
const char* interface,
bool connect_to_name_owner);
// Equivalent to Proxy(connection, name, path, interface, false).
Proxy(const BusConnection& connection,
const char* name,
const char* path,
const char* interface);
// Creates a peer proxy using dbus_g_proxy_new_for_peer.
Proxy(const BusConnection& connection,
const char* path,
const char* interface);
Proxy(const Proxy& x);
~Proxy();
Proxy& operator=(Proxy x) {
swap(*this, x);
return *this;
}
const char* path() const {
DCHECK(object_) << "referencing an empty proxy";
return ::dbus_g_proxy_get_path(object_);
}
// gproxy() returns a reference to the underlying ::DBusGProxy*. As this
// library evolves, the gproxy() will be moved to be private.
const value_type& gproxy() const {
DCHECK(object_) << "referencing an empty proxy";
return object_;
}
operator bool() const { return object_; }
private:
BRILLO_PRIVATE static value_type GetGProxy(const BusConnection& connection,
const char* name,
const char* path,
const char* interface,
bool connect_to_name_owner);
BRILLO_PRIVATE static value_type GetGPeerProxy(
const BusConnection& connection,
const char* path,
const char* interface);
BRILLO_PRIVATE operator int() const; // for safe bool cast
friend void swap(Proxy& x, Proxy& y);
value_type object_;
};
inline void swap(Proxy& x, Proxy& y) {
std::swap(x.object_, y.object_);
}
// \brief RegisterExclusiveService configures a GObject to run as a service on
// a supplied ::BusConnection.
//
// RegisterExclusiveService encapsulates the process of configuring the
// supplied \param object at \param service_path on the \param connection.
// Exclusivity is ensured by replacing any existing services at that named
// location and confirming that the connection is the primary owner.
//
// Type information for the \param object must be installed with
// dbus_g_object_type_install_info prior to use.
BRILLO_EXPORT bool RegisterExclusiveService(const BusConnection& connection,
const char* interface_name,
const char* service_name,
const char* service_path,
GObject* object);
template<typename F> // F is a function signature
class MonitorConnection;
template<typename A1>
class MonitorConnection<void(A1)> {
public:
MonitorConnection(const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1),
void* object)
: proxy_(proxy), name_(name), monitor_(monitor), object_(object) {}
static void Run(::DBusGProxy*, A1 x, MonitorConnection* self) {
self->monitor_(self->object_, x);
}
const Proxy& proxy() const { return proxy_; }
const std::string& name() const { return name_; }
private:
Proxy proxy_;
std::string name_;
void (*monitor_)(void*, A1);
void* object_;
};
template<typename A1, typename A2>
class MonitorConnection<void(A1, A2)> {
public:
MonitorConnection(const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1, A2),
void* object)
: proxy_(proxy), name_(name), monitor_(monitor), object_(object) {}
static void Run(::DBusGProxy*, A1 x, A2 y, MonitorConnection* self) {
self->monitor_(self->object_, x, y);
}
const Proxy& proxy() const { return proxy_; }
const std::string& name() const { return name_; }
private:
Proxy proxy_;
std::string name_;
void (*monitor_)(void*, A1, A2);
void* object_;
};
template<typename A1, typename A2, typename A3>
class MonitorConnection<void(A1, A2, A3)> {
public:
MonitorConnection(const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1, A2, A3),
void* object)
: proxy_(proxy), name_(name), monitor_(monitor), object_(object) {}
static void Run(::DBusGProxy*, A1 x, A2 y, A3 z, MonitorConnection* self) {
self->monitor_(self->object_, x, y, z);
}
const Proxy& proxy() const { return proxy_; }
const std::string& name() const { return name_; }
private:
Proxy proxy_;
std::string name_;
void (*monitor_)(void*, A1, A2, A3);
void* object_;
};
template<typename A1, typename A2, typename A3, typename A4>
class MonitorConnection<void(A1, A2, A3, A4)> {
public:
MonitorConnection(const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1, A2, A3, A4),
void* object)
: proxy_(proxy), name_(name), monitor_(monitor), object_(object) {}
static void Run(::DBusGProxy*,
A1 x,
A2 y,
A3 z,
A4 w,
MonitorConnection* self) {
self->monitor_(self->object_, x, y, z, w);
}
const Proxy& proxy() const { return proxy_; }
const std::string& name() const { return name_; }
private:
Proxy proxy_;
std::string name_;
void (*monitor_)(void*, A1, A2, A3, A4);
void* object_;
};
template<typename A1>
MonitorConnection<void(A1)>* Monitor(const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1),
void* object) {
typedef MonitorConnection<void(A1)> ConnectionType;
ConnectionType* result = new ConnectionType(proxy, name, monitor, object);
::dbus_g_proxy_add_signal(
proxy.gproxy(), name, glib::type_to_gtypeid<A1>(), G_TYPE_INVALID);
::dbus_g_proxy_connect_signal(
proxy.gproxy(), name, G_CALLBACK(&ConnectionType::Run), result, nullptr);
return result;
}
template<typename A1, typename A2>
MonitorConnection<void(A1, A2)>* Monitor(const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1, A2),
void* object) {
typedef MonitorConnection<void(A1, A2)> ConnectionType;
ConnectionType* result = new ConnectionType(proxy, name, monitor, object);
::dbus_g_proxy_add_signal(proxy.gproxy(),
name,
glib::type_to_gtypeid<A1>(),
glib::type_to_gtypeid<A2>(),
G_TYPE_INVALID);
::dbus_g_proxy_connect_signal(
proxy.gproxy(), name, G_CALLBACK(&ConnectionType::Run), result, nullptr);
return result;
}
template<typename A1, typename A2, typename A3>
MonitorConnection<void(A1, A2, A3)>* Monitor(const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1, A2, A3),
void* object) {
typedef MonitorConnection<void(A1, A2, A3)> ConnectionType;
ConnectionType* result = new ConnectionType(proxy, name, monitor, object);
::dbus_g_proxy_add_signal(proxy.gproxy(),
name,
glib::type_to_gtypeid<A1>(),
glib::type_to_gtypeid<A2>(),
glib::type_to_gtypeid<A3>(),
G_TYPE_INVALID);
::dbus_g_proxy_connect_signal(
proxy.gproxy(), name, G_CALLBACK(&ConnectionType::Run), result, nullptr);
return result;
}
template<typename A1, typename A2, typename A3, typename A4>
MonitorConnection<void(A1, A2, A3, A4)>* Monitor(
const Proxy& proxy,
const char* name,
void (*monitor)(void*, A1, A2, A3, A4),
void* object) {
typedef MonitorConnection<void(A1, A2, A3, A4)> ConnectionType;
ConnectionType* result = new ConnectionType(proxy, name, monitor, object);
::dbus_g_proxy_add_signal(proxy.gproxy(),
name,
glib::type_to_gtypeid<A1>(),
glib::type_to_gtypeid<A2>(),
glib::type_to_gtypeid<A3>(),
glib::type_to_gtypeid<A4>(),
G_TYPE_INVALID);
::dbus_g_proxy_connect_signal(
proxy.gproxy(), name, G_CALLBACK(&ConnectionType::Run), result, nullptr);
return result;
}
template<typename F>
void Disconnect(MonitorConnection<F>* connection) {
typedef MonitorConnection<F> ConnectionType;
::dbus_g_proxy_disconnect_signal(connection->proxy().gproxy(),
connection->name().c_str(),
G_CALLBACK(&ConnectionType::Run),
connection);
delete connection;
}
// \brief call_PtrArray() invokes a method on a proxy returning a
// glib::PtrArray.
//
// CallPtrArray is the first instance of what is likely to be a general
// way to make method calls to a proxy. It will likely be replaced with
// something like Call(proxy, method, arg1, arg2, ..., ResultType*) in the
// future. However, I don't yet have enough cases to generalize from.
BRILLO_EXPORT bool CallPtrArray(const Proxy& proxy,
const char* method,
glib::ScopedPtrArray<const char*>* result);
// \brief RetrieveProperty() retrieves a property of an object associated with a
// proxy.
//
// Given a proxy to an object supporting the org.freedesktop.DBus.Properties
// interface, the RetrieveProperty() call will retrieve a property of the
// specified interface on the object storing it in \param result and returning
// \true. If the dbus call fails or the object returned is not of type \param T,
// then \false is returned and \param result is unchanged.
//
// \example
// Proxy proxy(GetSystemBusConnection(),
// "org.freedesktop.DeviceKit.Power", // A named entity on the bus
// battery_name, // Path to a battery on the bus
// "org.freedesktop.DBus.Properties") // Properties interface
//
// double x;
// if (RetrieveProperty(proxy,
// "org.freedesktop.DeviceKit.Power.Device",
// "percentage")
// std::cout << "Battery charge is " << x << "% of capacity.";
// \end_example
template<typename T>
inline bool RetrieveProperty(const Proxy& proxy,
const char* interface,
const char* property,
T* result) {
glib::ScopedError error;
glib::Value value;
if (!::dbus_g_proxy_call(proxy.gproxy(), "Get", &Resetter(&error).lvalue(),
G_TYPE_STRING, interface,
G_TYPE_STRING, property,
G_TYPE_INVALID,
G_TYPE_VALUE, &value,
G_TYPE_INVALID)) {
LOG(ERROR) << "Getting property failed: "
<< (error->message ? error->message : "Unknown Error.");
return false;
}
return glib::Retrieve(value, result);
}
// \brief RetrieveProperties returns a HashTable of all properties for the
// specified interface.
BRILLO_EXPORT bool RetrieveProperties(const Proxy& proxy,
const char* interface,
glib::ScopedHashTable* result);
// \brief Returns a connection to the system bus.
BRILLO_EXPORT BusConnection GetSystemBusConnection();
// \brief Returns a private connection to a bus at |address|.
BRILLO_EXPORT BusConnection GetPrivateBusConnection(const char* address);
// \brief Calls a method |method_name| with no arguments per the given |path|
// and |interface_name|. Ignores return value.
BRILLO_EXPORT void CallMethodWithNoArguments(const char* service_name,
const char* path,
const char* interface_name,
const char* method_name);
// \brief Low-level signal monitor base class.
//
// Used when there is no definite named signal sender (that Proxy
// could be used for).
class BRILLO_EXPORT SignalWatcher {
public:
SignalWatcher() {}
~SignalWatcher();
void StartMonitoring(const std::string& interface, const std::string& signal);
private:
// Callback invoked on the given signal arrival.
virtual void OnSignal(DBusMessage* message) = 0;
// Returns a string matching the D-Bus messages that we want to listen for.
BRILLO_PRIVATE std::string GetDBusMatchString() const;
// A D-Bus message filter to receive signals.
BRILLO_PRIVATE static DBusHandlerResult FilterDBusMessage(
DBusConnection* dbus_conn,
DBusMessage* message,
void* data);
std::string interface_;
std::string signal_;
};
} // namespace dbus
} // namespace brillo
#endif // LIBBRILLO_BRILLO_GLIB_DBUS_H_