EpcShell

EpcShell — library management functions

Stability Level

Private, unless otherwise indicated

Synopsis


#include <libepc/shell.h>


#define             EPC_DEBUG_LEVEL                     (level)
guint               epc_shell_get_debug_level           (void);

                    EpcShellProgressHooks;
void                epc_shell_progress_begin            (const gchar *title,
                                                         const gchar *message);
void                epc_shell_progress_end              (void);
void                epc_shell_progress_update           (gdouble percentage,
                                                         const gchar *message);
void                epc_shell_set_progress_hooks        (const EpcShellProgressHooks *hooks,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy_data);

#define             EPC_AVAHI_ERROR
guint               epc_shell_watch_avahi_client_state  (AvahiClientCallback callback,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy_data,
                                                         GError **error);
AvahiEntryGroup*    epc_shell_create_avahi_entry_group  (AvahiEntryGroupCallback callback,
                                                         gpointer user_data);
AvahiServiceBrowser* epc_shell_create_service_browser   (AvahiIfIndex interface,
                                                         AvahiProtocol protocol,
                                                         const gchar *type,
                                                         const gchar *domain,
                                                         AvahiLookupFlags flags,
                                                         AvahiServiceBrowserCallback callback,
                                                         gpointer user_data,
                                                         GError **error);
void                epc_shell_restart_avahi_client      (const gchar *strloc);
const gchar*        epc_shell_get_host_name             (GError **error);
void                epc_shell_watch_remove              (guint id);

Description

The methods of the EpcShell singleton are used to manage library resources.

Details

EPC_DEBUG_LEVEL()

#define EPC_DEBUG_LEVEL(level) G_UNLIKELY(epc_shell_get_debug_level () >= (level))

Checks if the library's debug level, which can be modified by setting the EPC_DEBUG environment variable, is above the value sepecified by level.

level : the minimum level to check for

epc_shell_get_debug_level ()

guint               epc_shell_get_debug_level           (void);

Query the library's debug level. The debug level can be modified by setting the external EPC_DEBUG environment variable. In most cases the EPC_DEBUG_LEVEL macro should be used, instead of calling this checking the return value of this function.

Returns : The library's current debugging level.

EpcShellProgressHooks

typedef struct {
  void (*begin)  (const gchar *title,
                  gpointer     user_data);
  void (*update) (gdouble      percentage,
                  const gchar *message,
                  gpointer     user_data);
  void (*end)    (gpointer     user_data);
} EpcShellProgressHooks;

This table is used by epc_shell_set_progress_hooks to install functions allowing the library to provide feedback during processing.

See also: epc_progress_window_install

begin () the function called by epc_shell_progress_begin
update () the function called by epc_shell_progress_update
end () the function called by epc_shell_progress_end

epc_shell_progress_begin ()

void                epc_shell_progress_begin            (const gchar *title,
                                                         const gchar *message);

Call this function before starting a lengthy operation to allow the application tp provide some visual feedback during the operation, and to generally keep its UI responsive.

This function calls your "begin" hook with title as argument and "update" with message.

See also: epc_shell_set_progress_hooks(), epc_progress_window_install, epc_shell_progress_update(), epc_shell_progress_end

title : the title of the lengthy operation
message : description of the lengthy operation

epc_shell_progress_end ()

void                epc_shell_progress_end              (void);

Call this function when your lengthy operation has finished.

See also: epc_shell_set_progress_hooks(), epc_progress_window_install, epc_shell_progress_begin(), epc_shell_progress_update


epc_shell_progress_update ()

void                epc_shell_progress_update           (gdouble percentage,
                                                         const gchar *message);

Called this function to inform about progress of a lengthy operation. The progress is expressed as percentage in the range [0..1], or -1 if the progress cannot be estimated.

See also: epc_shell_set_progress_hooks(), epc_progress_window_install, epc_shell_progress_begin, epc_shell_progress_end()

percentage : current progress of the operation, or -1
message : a description of the current progress

epc_shell_set_progress_hooks ()

void                epc_shell_set_progress_hooks        (const EpcShellProgressHooks *hooks,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy_data);

Installs functions which are called during processing, such as generating server keys. This allows the application to indicate progress and generally keep its UI responsive. If no progress callbacks are provided, or when NULL is passed for hooks, progress messages are written to the console.

See also: EpcEntropyProgress

hooks : the function table to install, or NULL
user_data : custom data which shall be passed to the start hook
destroy_data : function to call on user_data when the hooks are replaced

EPC_AVAHI_ERROR

#define EPC_AVAHI_ERROR (epc_avahi_error_quark ())

Error domain for Avahi operations. Errors in this domain will be Avahi error codes. See GError for information on error domains.


epc_shell_watch_avahi_client_state ()

guint               epc_shell_watch_avahi_client_state  (AvahiClientCallback callback,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy_data,
                                                         GError **error);

Registers a function to watch state changes of the library's AvahiClient. On success the identifier of the newly created watch is returned. Pass it to epc_shell_watch_remove() to remove the watch. On failure it returns 0 and sets error. The error domain is EPC_AVAHI_ERROR. Possible error codes are those of the Avahi library.

Note

Usually there is no need in handling the AVAHI_CLIENT_FAILURE state for callback, as the callback dispatcher takes care already. This state is dispatched mostly for notification purposes.

callback : a callback function
user_data : data to pass to callback
destroy_data : a function for freeing user_data when removing the watch
error : return location for a GError, or NULL
Returns : The identifier of the newly created watch, or 0 on error.

epc_shell_create_avahi_entry_group ()

AvahiEntryGroup*    epc_shell_create_avahi_entry_group  (AvahiEntryGroupCallback callback,
                                                         gpointer user_data);

Creates a new AvahiEntryGroup for the library's shared AvahiClient. On success the newly created AvahiEntryGroup is returned, and NULL on failure.

callback : a callback function
user_data : data to pass to callback
Returns : The newly created AvahiEntryGroup, or NULL on error.

epc_shell_create_service_browser ()

AvahiServiceBrowser* epc_shell_create_service_browser   (AvahiIfIndex interface,
                                                         AvahiProtocol protocol,
                                                         const gchar *type,
                                                         const gchar *domain,
                                                         AvahiLookupFlags flags,
                                                         AvahiServiceBrowserCallback callback,
                                                         gpointer user_data,
                                                         GError **error);

Creates a new AvahiServiceBrowser for the library's shared AvahiClient. On success the newly created AvahiEntryGroup is returned. On failure NULL is returned and error is set. The error domain is EPC_AVAHI_ERROR. Possible error codes are those of the Avahi library.

interface : the index of the network interface to watch
protocol : the protocol of the services to watch
type : the DNS-SD service type to watch
domain : the DNS domain to watch, or NULL
flags : flags for creating the service browser
callback : a callback function
user_data : data to pass to callback
error : return location for a GError, or NULL
Returns : The newly created AvahiServiceBrowser, or NULL on error.

epc_shell_restart_avahi_client ()

void                epc_shell_restart_avahi_client      (const gchar *strloc);

Requests restart of the builtin Avahi client. Use this function to react on critical failures (like AVAHI_ENTRY_GROUP_FAILURE) reported to your Avahi callbacks. The strloc argument is used to prevent endless restart cycles.

Note

Do not call this function to react on AVAHI_CLIENT_FAILURE in a AvahiClientCallback. The builtin callback dispatcher deals with that situation.

strloc : code location of the callee (G_STRLOC)

epc_shell_get_host_name ()

const gchar*        epc_shell_get_host_name             (GError **error);

Retrieves the official host name of this machine. On failure the function returns NULL and sets error. The error domain is EPC_AVAHI_ERROR. Possible error codes are those of the Avahi library.

error : return location for a GError, or NULL
Returns : The official host name, or NULL on error.

epc_shell_watch_remove ()

void                epc_shell_watch_remove              (guint id);

Removes the watching callback identified by id.

See also: epc_shell_watch_avahi_client()

id : identifier of an watching callback