DeePeer

DeePeer — Finds other objects with the same swarm-name on the bus.

Synopsis

#include <dee.h>

#define             DEE_PEER_DBUS_IFACE
struct              DeePeer;
struct              DeePeerClass;
DeePeer *           dee_peer_new                        (const gchar *swarm_name);
const gboolean      dee_peer_is_swarm_leader            (DeePeer *self);
const gchar *       dee_peer_get_swarm_leader           (DeePeer *self);
const gchar *       dee_peer_get_swarm_name             (DeePeer *self);
                    DeePeerPrivate;

Object Hierarchy

  GObject
   +----DeePeer

Properties

  "swarm-leader"             gchar*                : Read
  "swarm-name"               gchar*                : Read / Write / Construct

Signals

  "peer-found"                                     : Run Last
  "peer-lost"                                      : Run Last

Description

DeePeer allows you to build objects that can rendevouz on DBus without the need for an central registration service. Think of it like peer-to-peer for your application. The DBus session bus will also implicitly elect a swarm leader - namely the one owning the swarm name on the bus, but it's up to the consumer of this API to determine whether swarm leadership has any concrete responsibilities associated.

Peers find eachother through a well-known "swarm-name", which is a well known DBus name, such as: org.myapp.MyPeers. Choose a namespaced name that would not normally be used outside of your program.

For example:

{
  DeePeer *peer;

  peer = g_object_new (DBUS_TYPE_PEER,
                       "swarm-name", "org.myapp.MyPeers",
                       NULL);

  g_signal_connect (peer, "peer-found",
                    G_CALLBACK (on_peer_found), NULL);
  g_signal_connect (peer, "peer-lost",
                    G_CALLBACK (on_peer_lost), NULL);
}

Details

DEE_PEER_DBUS_IFACE

#define DEE_PEER_DBUS_IFACE "com.canonical.Dee.Peer"


struct DeePeer

struct DeePeer;

All fields in the DeePeer structure are private and should never be accessed directly


struct DeePeerClass

struct DeePeerClass {
  /*< signals >*/
  void (*connected)  (DeePeer *peer, const gchar *peer_name);
  void (*peer_found) (DeePeer *peer, const gchar *name);
  void (*peer_lost)  (DeePeer *peer, const gchar *name);

  /*< vtable >*/
};


dee_peer_new ()

DeePeer *           dee_peer_new                        (const gchar *swarm_name);

Create a new DeePeer. The peer will immediately connect to the swarm and start the peer discovery.

swarm_name :

The name of the swarm to join. Fx "org.example.DataProviders"

Returns :

A newly constructed DeePeer. Free with g_object_unref(). [transfer full]

dee_peer_is_swarm_leader ()

const gboolean      dee_peer_is_swarm_leader            (DeePeer *self);

self :

a DeePeer

Returns :

TRUE if and only if this peer owns the swarm name on the session bus

dee_peer_get_swarm_leader ()

const gchar *       dee_peer_get_swarm_leader           (DeePeer *self);

Gets the unique DBus address of the current swarm leader.

This function can only be used after dee_peer_connect() has been called.

self :

a DeePeer

Returns :

Unique DBus address of the current swarm leader, possibly NULL if the leader has not been detected yet

dee_peer_get_swarm_name ()

const gchar *       dee_peer_get_swarm_name             (DeePeer *self);

Gets the unique name for this swarm. The swarm leader is the Peer owning this name on the session bus.

self :

a DeePeer

Returns :

The swarm name

DeePeerPrivate

typedef struct _DeePeerPrivate DeePeerPrivate;

Ignore this structure.

Property Details

The "swarm-leader" property

  "swarm-leader"             gchar*                : Read

Unique DBus address of the swarm leader.

Default value: NULL


The "swarm-name" property

  "swarm-name"               gchar*                : Read / Write / Construct

Well-known name to find other peers with.

Default value: NULL

Signal Details

The "peer-found" signal

void                user_function                      (DeePeer *self,
                                                        gchar   *name,
                                                        gpointer user_data)      : Run Last

Connect to this signal to be notified of existing and new peers that are in your swarm.

self :

the DeePeer on which the signal is emitted

name :

the DBus name of the object found

user_data :

user data set when the signal handler was connected.

The "peer-lost" signal

void                user_function                      (DeePeer *self,
                                                        gchar   *name,
                                                        gpointer user_data)      : Run Last

Connect to this signal to be notified when peers disconnect from the swarm

self :

the DeePeer on which the signal is emitted

name :

the DBus name of the object that disconnected

user_data :

user data set when the signal handler was connected.