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/*
This file is part of GNUnet.
(C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 2, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
/**
* @file include/gnunet_client_lib.h
* @brief functions related to accessing services
* @author Christian Grothoff
*/
#ifndef GNUNET_CLIENT_LIB_H
#define GNUNET_CLIENT_LIB_H
#ifdef __cplusplus
extern "C"
{
#if 0 /* keep Emacsens' auto-indent happy */
}
#endif
#endif
#include "gnunet_common.h"
#include "gnunet_configuration_lib.h"
#include "gnunet_connection_lib.h"
#include "gnunet_scheduler_lib.h"
#include "gnunet_time_lib.h"
/**
* Opaque handle for a connection to a service.
*/
struct GNUNET_CLIENT_Connection;
/**
* Get a connection with a service.
*
* @param service_name name of the service
* @param cfg configuration to use
* @return NULL on error (service unknown to configuration)
*/
struct GNUNET_CLIENT_Connection *
GNUNET_CLIENT_connect (const char *service_name,
const struct GNUNET_CONFIGURATION_Handle *cfg);
/**
* Destroy connection with the service. This will automatically
* cancel any pending "receive" request (however, the handler will
* *NOT* be called, not even with a NULL message). Any pending
* transmission request will also be cancelled UNLESS the callback for
* the transmission request has already been called, in which case the
* transmission 'finish_pending_write' argument determines whether or
* not the write is guaranteed to complete before the socket is fully
* destroyed (unless, of course, there is an error with the server in
* which case the message may still be lost).
*
* @param client handle to the service connection
*/
void
GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *client);
/**
* Type of a function to call when we receive a message
* from the service.
*
* @param cls closure
* @param msg message received, NULL on timeout or fatal error
*/
typedef void (*GNUNET_CLIENT_MessageHandler) (void *cls,
const struct GNUNET_MessageHeader
* msg);
/**
* Type of a function to call when we have finished shutting
* down a service, or failed.
*
* @param cls closure
* @param reason what is the result of the shutdown
* GNUNET_NO on shutdown (not running)
* GNUNET_YES on running
* GNUNET_SYSERR on failure to transmit message
*/
typedef void (*GNUNET_CLIENT_ShutdownTask) (void *cls, int reason);
/**
* Read from the service.
*
* @param client connection to the service
* @param handler function to call with the message
* @param handler_cls closure for handler
* @param timeout how long to wait until timing out
*/
void
GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *client,
GNUNET_CLIENT_MessageHandler handler, void *handler_cls,
struct GNUNET_TIME_Relative timeout);
/**
* Transmit handle for client connections.
*/
struct GNUNET_CLIENT_TransmitHandle;
/**
* Ask the client to call us once the specified number of bytes
* are free in the transmission buffer. May call the notify
* method immediately if enough space is available.
*
* @param client connection to the service
* @param size number of bytes to send
* @param timeout after how long should we give up (and call
* notify with buf NULL and size 0)?
* @param auto_retry if the connection to the service dies, should we
* automatically re-connect and retry (within the timeout period)
* or should we immediately fail in this case? Pass GNUNET_YES
* if the caller does not care about temporary connection errors,
* for example because the protocol is stateless
* @param notify function to call
* @param notify_cls closure for notify
* @return NULL if someone else is already waiting to be notified
* non-NULL if the notify callback was queued (can be used to cancel
* using GNUNET_CONNECTION_notify_transmit_ready_cancel)
*/
struct GNUNET_CLIENT_TransmitHandle *
GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
size_t size,
struct GNUNET_TIME_Relative timeout,
int auto_retry,
GNUNET_CONNECTION_TransmitReadyNotify
notify, void *notify_cls);
/**
* Cancel a request for notification.
*
* @param th handle from the original request.
*/
void
GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle
*th);
/**
* Convenience API that combines sending a request
* to the service and waiting for a response.
* If either operation times out, the callback
* will be called with a "NULL" response (in which
* case the connection should probably be destroyed).
*
* @param client connection to use
* @param hdr message to transmit
* @param timeout when to give up (for both transmission
* and for waiting for a response)
* @param auto_retry if the connection to the service dies, should we
* automatically re-connect and retry (within the timeout period)
* or should we immediately fail in this case? Pass GNUNET_YES
* if the caller does not care about temporary connection errors,
* for example because the protocol is stateless
* @param rn function to call with the response
* @param rn_cls closure for rn
* @return GNUNET_OK on success, GNUNET_SYSERR if a request
* is already pending
*/
int
GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection *client,
const struct GNUNET_MessageHeader *hdr,
struct GNUNET_TIME_Relative timeout,
int auto_retry,
GNUNET_CLIENT_MessageHandler rn,
void *rn_cls);
/**
* Wait until the service is running.
*
* @param service name of the service to wait for
* @param cfg configuration to use
* @param timeout how long to wait at most in ms
* @param task task to run if service is running
* (reason will be "PREREQ_DONE" (service running)
* or "TIMEOUT" (service not known to be running))
* @param task_cls closure for task
*/
void
GNUNET_CLIENT_service_test (const char *service,
const struct GNUNET_CONFIGURATION_Handle *cfg,
struct GNUNET_TIME_Relative timeout,
GNUNET_SCHEDULER_Task task, void *task_cls);
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif
/* ifndef GNUNET_CLIENT_LIB_H */
#endif
/* end of gnunet_client_lib.h */
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