TpBaseConnection

TpBaseConnection — base class for TpSvcConnection implementations

Synopsis


#include <telepathy-glib/base-connection.h>


#define             TP_INTERNAL_CONNECTION_STATUS_NEW
                    TpBaseConnection;
                    TpBaseConnectionClass;
GPtrArray*          (*TpBaseConnectionCreateChannelFactoriesImpl)
                                                        (TpBaseConnection *self);
void                (*TpBaseConnectionCreateHandleReposImpl)
                                                        (TpBaseConnection *self,
                                                         TpHandleRepoIface *repos[NUM_TP_HANDLE_TYPES]);
gchar*              (*TpBaseConnectionGetUniqueConnectionNameImpl)
                                                        (TpBaseConnection *self);
void                (*TpBaseConnectionProc)             (TpBaseConnection *self);
gboolean            (*TpBaseConnectionStartConnectingImpl)
                                                        (TpBaseConnection *self,
                                                         GError **error);
gboolean            tp_base_connection_register         (TpBaseConnection *self,
                                                         const gchar *cm_name,
                                                         gchar **bus_name,
                                                         gchar **object_path,
                                                         GError **error);
TpHandleRepoIface*  tp_base_connection_get_handles      (TpBaseConnection *self,
                                                         TpHandleType handle_type);
void                tp_base_connection_change_status    (TpBaseConnection *self,
                                                         TpConnectionStatus status,
                                                         TpConnectionStatusReason reason);
void                tp_base_connection_finish_shutdown  (TpBaseConnection *self);
void                tp_base_connection_add_interfaces   (TpBaseConnection *self,
                                                         const gchar **interfaces);
void                tp_base_connection_dbus_request_handles
                                                        (TpSvcConnection *iface,
                                                         guint handle_type,
                                                         const gchar **names,
                                                         DBusGMethodInvocation *context);
#define             TP_BASE_CONNECTION_ERROR_IF_NOT_CONNECTED(conn, context)

Object Hierarchy


  GObject
   +----TpBaseConnection

Implemented Interfaces

TpBaseConnection implements TpSvcConnection.

Properties


  "protocol"                 gchararray            : Read / Write / Construct Only

Signals


  "shutdown-finished"                              : Run Last / Has Details

Description

This base class makes it easier to write TpSvcConnection implementations by managing connection status, channel factories and handle tracking. A subclass should often not need to implement any of the Connection methods itself.

However, methods may be reimplemented if needed: for instance, Gabble overrides RequestHandles so it can validate MUC rooms, which must be done asynchronously.

Details

TP_INTERNAL_CONNECTION_STATUS_NEW

#   define TP_INTERNAL_CONNECTION_STATUS_NEW ((TpConnectionStatus)(-1))

A special value for TpConnectionStatus, used within GLib connection managers to indicate that the connection is disconnected because connection has never been attempted (as distinct from disconnected after connection has started, either by user request or an error).

Must never be visible on the D-Bus - TP_CONNECTION_STATUS_DISCONNECTED is sent instead.

TpBaseConnection

typedef struct {
    GObject parent;

    gchar *bus_name;
    gchar *object_path;

    TpConnectionStatus status;

    TpHandle self_handle;
} TpBaseConnection;

Data structure representing a generic TpSvcConnection implementation.

In addition to the fields documented here, there are four gpointer fields which must currently be NULL (a meaning may be defined for these in a future version of telepathy-glib), and a pointer to opaque private data.

GObject parent;

 Fields shared by the superclass.

gchar *bus_name;

 A D-Bus well-known bus name, owned by the connection manager process and associated with this connection. Set by tp_base_connection_register; should be considered read-only by subclasses.

gchar *object_path;

 The object-path of this connection. Set by tp_base_connection_register; should be considered read-only by subclasses.

TpConnectionStatus status;

 Connection status - may either be a valid TpConnectionStatus or TP_INTERNAL_CONNECTION_STATUS_NEW. Should be considered read-only by subclasses: use tp_base_connection_change_status() to set it.

TpHandle self_handle;

 The handle of type TP_HANDLE_TYPE_CONTACT representing the local user. Must be set nonzero by the subclass before moving to state CONNECTED. If nonzero, the connection must hold a reference to the handle.

TpBaseConnectionClass

typedef struct {
    GObjectClass parent_class;

    TpBaseConnectionCreateHandleReposImpl create_handle_repos;

    TpBaseConnectionCreateChannelFactoriesImpl create_channel_factories;

    TpBaseConnectionGetUniqueConnectionNameImpl get_unique_connection_name;

    TpBaseConnectionProc connecting;
    TpBaseConnectionProc connected;
    TpBaseConnectionProc disconnected;

    TpBaseConnectionProc shut_down;

    TpBaseConnectionStartConnectingImpl start_connecting;

    const gchar **interfaces_always_present;
} TpBaseConnectionClass;

The class of a TpBaseConnection. Many members are virtual methods etc. to be filled in in the subclass' class_init function.

In addition to the fields documented here, there are four gpointer fields which must currently be NULL (a meaning may be defined for these in a future version of telepathy-glib), and a pointer to opaque private data.

GObjectClass parent_class;

 The superclass' structure

TpBaseConnectionCreateHandleReposImpl create_handle_repos;

 Fill in suitable handle repositories in the given array for all those handle types this Connection supports. Must be set by subclasses to a non-NULL value; the function must create at least a CONTACT handle repository (failing to do so will cause a crash).

TpBaseConnectionCreateChannelFactoriesImpl create_channel_factories;

 Create an array of channel factories for this Connection. Must be set by subclasses to a non-NULL value.

TpBaseConnectionGetUniqueConnectionNameImpl get_unique_connection_name;

 Construct a unique name for this connection (for example using the protocol's format for usernames). If NULL (the default), a unique name will be generated. Subclasses should usually override this to get more obvious names, to aid debugging and prevent multiple connections to the same account.

TpBaseConnectionProc connecting;

 If set by subclasses, will be called just after the state changes to CONNECTING. May be NULL if nothing special needs to happen.

TpBaseConnectionProc connected;

 If set by subclasses, will be called just after the state changes to CONNECTED. May be NULL if nothing special needs to happen.

TpBaseConnectionProc disconnected;

 If set by subclasses, will be called just after the state changes to DISCONNECTED. May be NULL if nothing special needs to happen.

TpBaseConnectionProc shut_down;

 Called after disconnected() is called, to clean up the connection. Must start the shutdown process for the underlying network connection, and arrange for tp_base_connection_finish_shutdown() to be called after the underlying connection has been closed. May not be left as NULL.

TpBaseConnectionStartConnectingImpl start_connecting;

 Asynchronously start connecting - called to implement the Connect D-Bus method. See TpBaseConnectionStartConnectingImpl for details.

const gchar **interfaces_always_present;

 A strv of extra D-Bus interfaces which are always implemented by instances of this class, which may be filled in by subclasses. The default is to list no additional interfaces. Individual instances may detect which additional interfaces they support and signal them before going to state CONNECTED by calling tp_base_connection_add_interfaces().

TpBaseConnectionCreateChannelFactoriesImpl ()

GPtrArray*          (*TpBaseConnectionCreateChannelFactoriesImpl)
                                                        (TpBaseConnection *self);

Signature of an implementation of the create_handle_repos method of TpBaseConnection.

self :

 The implementation, a subclass of TpBaseConnection

Returns :

 a GPtrArray of objects implementing TpChannelFactoryIface which, between them, implement all channel types this Connection supports.

TpBaseConnectionCreateHandleReposImpl ()

void                (*TpBaseConnectionCreateHandleReposImpl)
                                                        (TpBaseConnection *self,
                                                         TpHandleRepoIface *repos[NUM_TP_HANDLE_TYPES]);

Signature of an implementation of the create_handle_repos method of TpBaseConnection.

self :

 The connection object

repos :

 An array of pointers to be filled in; the implementation may assume all are initially NULL.

TpBaseConnectionGetUniqueConnectionNameImpl ()

gchar*              (*TpBaseConnectionGetUniqueConnectionNameImpl)
                                                        (TpBaseConnection *self);

Signature of the get_unique_connection_name virtual method on TpBaseConnection.

self :

 The implementation, a subclass of TpBaseConnection

Returns :

 a name for this connection which will be unique within this connection manager process, as a string which the caller must free with g_free.

TpBaseConnectionProc ()

void                (*TpBaseConnectionProc)             (TpBaseConnection *self);

Signature of a virtual method on TpBaseConnection that takes no additional parameters and returns nothing.

self :

 The connection object

TpBaseConnectionStartConnectingImpl ()

gboolean            (*TpBaseConnectionStartConnectingImpl)
                                                        (TpBaseConnection *self,
                                                         GError **error);

Signature of an implementation of the start_connecting method of TpBaseConnection.

On entry, the implementation may assume that it is in state NEW.

If TRUE is returned, the Connect D-Bus method succeeds; the implementation must either have already set the status to CONNECTED by calling tp_base_connection_change_status(), or have arranged for a status change to either state DISCONNECTED or CONNECTED to be signalled by calling tp_base_connection_change_status() at some later time. If the status is still NEW after returning TRUE, TpBaseConnection will automatically change it to CONNECTING for reason REQUESTED.

If FALSE is returned, the error will be raised from Connect as an exception. If the status is not DISCONNECTED after FALSE is returned, TpBaseConnection will automatically change it to DISCONNECTED with a reason appropriate to the error; NetworkError results in NETWORK_ERROR, PermissionDenied results in AUTHENTICATION_FAILED, and all other errors currently result in NONE_SPECIFIED.

All except the simplest connection managers are expected to implement this asynchronously, returning TRUE in most cases and changing the status to CONNECTED or DISCONNECTED later.

self :

 The connection object

error :

 Set to the error if FALSE is returned

Returns :

 FALSE if failure has already occurred, else TRUE.

tp_base_connection_register ()

gboolean            tp_base_connection_register         (TpBaseConnection *self,
                                                         const gchar *cm_name,
                                                         gchar **bus_name,
                                                         gchar **object_path,
                                                         GError **error);

Make the connection object appear on the bus, returning the bus name and object path used. If TRUE is returned, the connection owns the bus name, and will release it when destroyed.

self :

 A connection

cm_name :

 The name of the connection manager in the Telepathy protocol

bus_name :

 Used to return the bus name corresponding to the connection if TRUE is returned; must not be NULL. To be freed by the caller.

object_path :

 Used to return the object path of the connection if TRUE is returned; must not be NULL. To be freed by the caller.

error :

 Used to return an error if FALSE is returned; may be NULL

Returns :

 TRUE on success, FALSE on error.

tp_base_connection_get_handles ()

TpHandleRepoIface*  tp_base_connection_get_handles      (TpBaseConnection *self,
                                                         TpHandleType handle_type);

self :

 A connection

handle_type :

 The handle type

Returns :

 the handle repository corresponding to the given handle type, or NULL if it's unsupported or invalid.

tp_base_connection_change_status ()

void                tp_base_connection_change_status    (TpBaseConnection *self,
                                                         TpConnectionStatus status,
                                                         TpConnectionStatusReason reason);

Change the status of the connection. The allowed state transitions are:

  • NEW -> CONNECTING
  • CONNECTING -> CONNECTED
  • NEW -> CONNECTED (equivalent to both of the above one after the other - see below)
  • (anything except DISCONNECTED) -> DISCONNECTED

Before the transition to CONNECTED, the implementation must have discovered the handle for the local user, obtained a reference to that handle and stored it in the self_handle member of TpBaseConnection.

Changing from NEW to CONNECTED is implemented by doing the transition from NEW to CONNECTING, followed by the transition from CONNECTING to CONNECTED; it's exactly equivalent to calling tp_base_connection_change_status for those two transitions one after the other.

Any other valid transition does the following, in this order:

  • Update the status member of TpBaseConnection
  • If the new state is DISCONNECTED, call the close_all_channels callback on all channel factories
  • If the new state is DISCONNECTED, unref the self_handle, if any, and set it to 0
  • Emit the D-Bus StatusChanged signal
  • Call the subclass' status change callback
  • Call the channel factories' status change callbacks
  • If the new state is DISCONNECTED, call the subclass' shut_down callback

self :

 The connection

status :

 The new status

reason :

 The reason for the status change

tp_base_connection_finish_shutdown ()

void                tp_base_connection_finish_shutdown  (TpBaseConnection *self);

Tell the connection manager that this Connection has been disconnected, has emitted StatusChanged and is ready to be removed from D-Bus.

self :

 The connection

tp_base_connection_add_interfaces ()

void                tp_base_connection_add_interfaces   (TpBaseConnection *self,
                                                         const gchar **interfaces);

Add some interfaces to the list supported by this Connection. If you're going to call this function at all, you must do so before moving to state CONNECTED (or DISCONNECTED); if you don't call it, only the set of interfaces always present (interfaces_always_present in TpBaseConnectionClass) will be supported.

self :

 A TpBaseConnection in state TP_INTERNAL_CONNECTION_STATUS_NEW or TP_CONNECTION_STATUS_CONNECTING

interfaces :

 A NULL-terminated array of D-Bus interface names, which must remain valid at least until the connection enters state TP_CONNECTION_STATUS_DISCONNECTED (in practice, you should either use static strings, or use strdup'd strings and free them in the dispose callback).

tp_base_connection_dbus_request_handles ()

void                tp_base_connection_dbus_request_handles
                                                        (TpSvcConnection *iface,
                                                         guint handle_type,
                                                         const gchar **names,
                                                         DBusGMethodInvocation *context);

Implements D-Bus method RequestHandles on interface org.freedesktop.Telepathy.Connection. Exported so subclasses can use it as a basis for their own implementations (for instance, at the time of writing Gabble's GabbleConnection does its own processing for room handles, in order to validate them asynchronously, but delegates to this implementation for all other types).

iface :

 A pointer to TpBaseConnection, cast to a pointer to TpSvcConnection

handle_type :

 The handle type (TpHandleType) as a guint

names :

 A strv of handle names

context :

 The dbus-glib method invocation context

TP_BASE_CONNECTION_ERROR_IF_NOT_CONNECTED()

#define             TP_BASE_CONNECTION_ERROR_IF_NOT_CONNECTED(conn, context)

If conn is not in state TP_CONNECTION_STATUS_CONNECTED, complete the D-Bus method invocation context by raising the Telepathy error TP_ERROR_DISCONNECTED, and return from the current function (which must be void). For use in D-Bus method implementations.

conn :

 A TpBaseConnection

context :

 A DBusGMethodInvocation

Property Details

The "protocol" property

  "protocol"                 gchararray            : Read / Write / Construct Only

Identifier used in the Telepathy protocol when this connection's protocol name is required.

Default value: NULL

Signal Details

The "shutdown-finished" signal

void                user_function                      (TpBaseConnection *arg0,
                                                        gpointer          user_data)      : Run Last / Has Details

Emitted by tp_base_connection_finish_shutdown() when the underlying network connection has been closed; TpBaseConnectionManager listens for this signal and removes connections from its table of active connections when it is received.

user_data :

 user data set when the signal handler was connected.

See Also

TpBaseConnectionManager, TpSvcConnection