2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @author Florian Dold
24 * @brief general purpose request queue
27 #include "gnunet_util_lib.h"
29 #define LOG(kind,...) GNUNET_log_from (kind, "mq",__VA_ARGS__)
32 struct GNUNET_MQ_Envelope
35 * Messages are stored in a linked list.
36 * Each queue has its own list of envelopes.
38 struct GNUNET_MQ_Envelope *next;
41 * Messages are stored in a linked list
42 * Each queue has its own list of envelopes.
44 struct GNUNET_MQ_Envelope *prev;
47 * Actual allocated message header,
48 * usually points to the end of the containing GNUNET_MQ_Envelope
50 struct GNUNET_MessageHeader *mh;
53 * Queue the message is queued in, NULL if message is not queued.
55 struct GNUNET_MQ_Handle *parent_queue;
58 * Called after the message was sent irrevocably.
60 GNUNET_MQ_NotifyCallback sent_cb;
70 * Handle to a message queue.
72 struct GNUNET_MQ_Handle
75 * Handlers array, or NULL if the queue should not receive messages
77 const struct GNUNET_MQ_MessageHandler *handlers;
80 * Closure for the handler callbacks,
81 * as well as for the error handler.
86 * Actual implementation of message sending,
87 * called when a message is added
89 GNUNET_MQ_SendImpl send_impl;
92 * Implementation-dependent queue destruction function
94 GNUNET_MQ_DestroyImpl destroy_impl;
97 * Implementation-specific state
102 * Callback will be called when an error occurs.
104 GNUNET_MQ_ErrorHandler error_handler;
107 * Linked list of messages pending to be sent
109 struct GNUNET_MQ_Envelope *envelope_head;
112 * Linked list of messages pending to be sent
114 struct GNUNET_MQ_Envelope *envelope_tail;
117 * Message that is currently scheduled to be
118 * sent. Not the head of the message queue, as the implementation
119 * needs to know if sending has been already scheduled or not.
121 struct GNUNET_MQ_Envelope *current_envelope;
124 * Map of associations, lazily allocated
126 struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
129 * Next id that should be used for the assoc_map,
130 * initialized lazily to a random value together with
139 struct ServerClientSocketState
141 struct GNUNET_SERVER_Client *client;
142 struct GNUNET_SERVER_TransmitHandle* th;
146 struct ClientConnectionState
149 * Did we call receive alread alreadyy?
154 * Do we also want to receive?
156 int receive_requested;
157 struct GNUNET_CLIENT_Connection *connection;
158 struct GNUNET_CLIENT_TransmitHandle *th;
163 * Call the message message handler that was registered
164 * for the type of the given message in the given message queue.
166 * This function is indended to be used for the implementation
169 * @param mq message queue with the handlers
170 * @param mh message to dispatch
173 GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *mh)
175 const struct GNUNET_MQ_MessageHandler *handler;
176 int handled = GNUNET_NO;
178 handler = mq->handlers;
181 for (; NULL != handler->cb; handler++)
183 if (handler->type == ntohs (mh->type))
185 handler->cb (mq->handlers_cls, mh);
186 handled = GNUNET_YES;
190 if (GNUNET_NO == handled)
191 LOG (GNUNET_ERROR_TYPE_WARNING, "no handler for message of type %d\n", ntohs (mh->type));
196 * Call the error handler of a message queue with the given
197 * error code. If there is no error handler, log a warning.
199 * This function is intended to be used by the implementation
202 * @param mq message queue
203 * @param error the error type
206 GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq,
207 enum GNUNET_MQ_Error error)
209 if (NULL == mq->error_handler)
211 /* FIXME: log what kind of error occured */
212 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "mq: got error, but no handler installed\n");
215 mq->error_handler (mq->handlers_cls, error);
220 GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *mqm)
222 GNUNET_assert (NULL == mqm->parent_queue);
228 * Send a message with the give message queue.
229 * May only be called once per message.
231 * @param mq message queue
232 * @param ev the envelope with the message to send.
235 GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq, struct GNUNET_MQ_Envelope *ev)
237 GNUNET_assert (NULL != mq);
238 GNUNET_assert (NULL == ev->parent_queue);
240 /* is the implementation busy? queue it! */
241 if (NULL != mq->current_envelope)
243 GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head, mq->envelope_tail, ev);
246 mq->current_envelope = ev;
247 mq->send_impl (mq, ev->mh, mq->impl_state);
252 * Call the send implementation for the next queued message,
254 * Only useful for implementing message queues,
255 * results in undefined behavior if not used carefully.
257 * @param mq message queue to send the next message with
260 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
262 struct GNUNET_MQ_Envelope *current_envelope;
264 /* call is only valid if we're actually currently sending
266 current_envelope = mq->current_envelope;
267 GNUNET_assert (NULL != current_envelope);
268 if (NULL == mq->envelope_head)
270 mq->current_envelope = NULL;
274 mq->current_envelope = mq->envelope_head;
275 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
277 mq->current_envelope);
278 mq->send_impl (mq, mq->current_envelope->mh, mq->impl_state);
280 if (NULL != current_envelope->sent_cb)
281 current_envelope->sent_cb (current_envelope->sent_cls);
282 GNUNET_free (current_envelope);
287 * Create a message queue for the specified handlers.
289 * @param send function the implements sending messages
290 * @param destroy function that implements destroying the queue
291 * @param cancel function that implements canceling a message
292 * @param impl_state for the queue, passed to 'send' and 'destroy'
293 * @param handlers array of message handlers
294 * @param error_handler handler for read and write errors
295 * @param cls closure for message handlers and error handler
296 * @return a new message queue
298 struct GNUNET_MQ_Handle *
299 GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
300 GNUNET_MQ_DestroyImpl destroy,
301 GNUNET_MQ_CancelImpl cancel,
303 const struct GNUNET_MQ_MessageHandler *handlers,
304 GNUNET_MQ_ErrorHandler error_handler,
307 struct GNUNET_MQ_Handle *mq;
309 mq = GNUNET_new (struct GNUNET_MQ_Handle);
310 mq->send_impl = send;
311 mq->destroy_impl = destroy;
312 mq->handlers = handlers;
313 mq->handlers_cls = cls;
314 mq->impl_state = impl_state;
321 * Get the message that should currently be sent.
322 * Fails if there is no current message.
323 * Only useful for implementing message queues,
324 * results in undefined behavior if not used carefully.
326 * @param mq message queue with the current message
327 * @return message to send, never NULL
329 const struct GNUNET_MessageHeader *
330 GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq)
332 if (NULL == mq->current_envelope)
334 if (NULL == mq->current_envelope->mh)
336 return mq->current_envelope->mh;
341 * Get the implementation state associated with the
344 * While the GNUNET_MQ_Impl* callbacks receive the
345 * implementation state, continuations that are scheduled
346 * by the implementation function often only have one closure
347 * argument, with this function it is possible to get at the
348 * implementation state when only passing the GNUNET_MQ_Handle
351 * @param mq message queue with the current message
352 * @return message to send, never NULL
355 GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq)
357 return mq->impl_state;
361 struct GNUNET_MQ_Envelope *
362 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type)
364 struct GNUNET_MQ_Envelope *mqm;
366 mqm = GNUNET_malloc (sizeof *mqm + size);
367 mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
368 mqm->mh->size = htons (size);
369 mqm->mh->type = htons (type);
377 * Implementation of the GNUNET_MQ_msg_nested_mh macro.
379 * @param mhp pointer to the message header pointer that will be changed to allocate at
380 * the newly allocated space for the message.
381 * @param base_size size of the data before the nested message
382 * @param type type of the message in the envelope
383 * @param nested_mh the message to append to the message after base_size
385 struct GNUNET_MQ_Envelope *
386 GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp, uint16_t base_size, uint16_t type,
387 const struct GNUNET_MessageHeader *nested_mh)
389 struct GNUNET_MQ_Envelope *mqm;
392 if (NULL == nested_mh)
393 return GNUNET_MQ_msg_ (mhp, base_size, type);
395 size = base_size + ntohs (nested_mh->size);
397 /* check for uint16_t overflow */
398 if (size < base_size)
401 mqm = GNUNET_MQ_msg_ (mhp, size, type);
402 memcpy ((char *) mqm->mh + base_size, nested_mh, ntohs (nested_mh->size));
409 * Transmit a queued message to the session's client.
411 * @param cls consensus session
412 * @param size number of bytes available in buf
413 * @param buf where the callee should write the message
414 * @return number of bytes written to buf
417 transmit_queued (void *cls, size_t size,
420 struct GNUNET_MQ_Handle *mq = cls;
421 struct ServerClientSocketState *state = GNUNET_MQ_impl_state (mq);
422 const struct GNUNET_MessageHeader *msg = GNUNET_MQ_impl_current (mq);
425 GNUNET_assert (NULL != buf);
427 msg_size = ntohs (msg->size);
428 GNUNET_assert (size >= msg_size);
429 memcpy (buf, msg, msg_size);
432 GNUNET_MQ_impl_send_continue (mq);
440 server_client_destroy_impl (struct GNUNET_MQ_Handle *mq,
443 struct ServerClientSocketState *state = impl_state;
445 GNUNET_assert (NULL != mq);
446 GNUNET_assert (NULL != state);
447 GNUNET_SERVER_client_drop (state->client);
452 server_client_send_impl (struct GNUNET_MQ_Handle *mq,
453 const struct GNUNET_MessageHeader *msg, void *impl_state)
455 struct ServerClientSocketState *state = impl_state;
457 GNUNET_assert (NULL != mq);
458 GNUNET_assert (NULL != state);
460 GNUNET_SERVER_notify_transmit_ready (state->client, ntohs (msg->size),
461 GNUNET_TIME_UNIT_FOREVER_REL,
462 &transmit_queued, mq);
466 struct GNUNET_MQ_Handle *
467 GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client)
469 struct GNUNET_MQ_Handle *mq;
470 struct ServerClientSocketState *scss;
472 mq = GNUNET_new (struct GNUNET_MQ_Handle);
473 scss = GNUNET_new (struct ServerClientSocketState);
474 mq->impl_state = scss;
475 scss->client = client;
476 GNUNET_SERVER_client_keep (client);
477 mq->send_impl = server_client_send_impl;
478 mq->destroy_impl = server_client_destroy_impl;
484 * Type of a function to call when we receive a message
488 * @param msg message received, NULL on timeout or fatal error
491 handle_client_message (void *cls,
492 const struct GNUNET_MessageHeader *msg)
494 struct GNUNET_MQ_Handle *mq = cls;
495 struct ClientConnectionState *state;
497 state = mq->impl_state;
501 GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
505 GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
506 GNUNET_TIME_UNIT_FOREVER_REL);
508 GNUNET_MQ_inject_message (mq, msg);
513 * Transmit a queued message to the session's client.
515 * @param cls consensus session
516 * @param size number of bytes available in buf
517 * @param buf where the callee should write the message
518 * @return number of bytes written to buf
521 connection_client_transmit_queued (void *cls, size_t size,
524 struct GNUNET_MQ_Handle *mq = cls;
525 const struct GNUNET_MessageHeader *msg;
526 struct ClientConnectionState *state = mq->impl_state;
529 GNUNET_assert (NULL != mq);
530 msg = GNUNET_MQ_impl_current (mq);
534 GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
538 if ( (GNUNET_YES == state->receive_requested) &&
539 (GNUNET_NO == state->receive_active) )
541 state->receive_active = GNUNET_YES;
542 GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
543 GNUNET_TIME_UNIT_FOREVER_REL);
547 msg_size = ntohs (msg->size);
548 GNUNET_assert (size >= msg_size);
549 memcpy (buf, msg, msg_size);
552 GNUNET_MQ_impl_send_continue (mq);
560 connection_client_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state)
562 GNUNET_free (impl_state);
566 connection_client_send_impl (struct GNUNET_MQ_Handle *mq,
567 const struct GNUNET_MessageHeader *msg, void *impl_state)
569 struct ClientConnectionState *state = impl_state;
571 GNUNET_assert (NULL != state);
572 GNUNET_assert (NULL == state->th);
574 GNUNET_CLIENT_notify_transmit_ready (state->connection, ntohs (msg->size),
575 GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
576 &connection_client_transmit_queued, mq);
577 GNUNET_assert (NULL != state->th);
581 struct GNUNET_MQ_Handle *
582 GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
583 const struct GNUNET_MQ_MessageHandler *handlers,
584 GNUNET_MQ_ErrorHandler error_handler,
587 struct GNUNET_MQ_Handle *mq;
588 struct ClientConnectionState *state;
590 GNUNET_assert (NULL != connection);
592 mq = GNUNET_new (struct GNUNET_MQ_Handle);
593 mq->handlers = handlers;
594 mq->error_handler = error_handler;
595 mq->handlers_cls = cls;
596 state = GNUNET_new (struct ClientConnectionState);
597 state->connection = connection;
598 mq->impl_state = state;
599 mq->send_impl = connection_client_send_impl;
600 mq->destroy_impl = connection_client_destroy_impl;
601 if (NULL != handlers)
602 state->receive_requested = GNUNET_YES;
609 GNUNET_MQ_replace_handlers (struct GNUNET_MQ_Handle *mq,
610 const struct GNUNET_MQ_MessageHandler *new_handlers,
613 /* FIXME: notify implementation? */
614 /* FIXME: what about NULL handlers? abort receive? */
615 mq->handlers = new_handlers;
616 mq->handlers_cls = cls;
621 * Associate the assoc_data in mq with a unique request id.
623 * @param mq message queue, id will be unique for the queue
624 * @param assoc_data to associate
627 GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
632 if (NULL == mq->assoc_map)
634 mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
638 GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map, id, assoc_data,
639 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
646 GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
648 if (NULL == mq->assoc_map)
650 return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
655 GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
659 if (NULL == mq->assoc_map)
661 val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
662 GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map, request_id);
668 GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *mqm,
669 GNUNET_MQ_NotifyCallback cb,
678 GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
680 if (NULL != mq->destroy_impl)
682 mq->destroy_impl (mq, mq->impl_state);
685 while (NULL != mq->envelope_head)
687 struct GNUNET_MQ_Envelope *ev;
688 ev = mq->envelope_head;
689 GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, ev);
690 GNUNET_MQ_discard (ev);
693 if (NULL != mq->current_envelope)
695 GNUNET_MQ_discard (mq->current_envelope);
696 mq->current_envelope = NULL;
699 if (NULL != mq->assoc_map)
701 GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
702 mq->assoc_map = NULL;
709 struct GNUNET_MessageHeader *
710 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size)
713 uint16_t nested_size;
714 struct GNUNET_MessageHeader *nested_msg;
716 whole_size = ntohs (mh->size);
717 GNUNET_assert (whole_size >= base_size);
719 nested_size = whole_size - base_size;
721 if (0 == nested_size)
724 if (nested_size < sizeof (struct GNUNET_MessageHeader))
730 nested_msg = (struct GNUNET_MessageHeader *) ((char *) mh + base_size);
732 if (ntohs (nested_msg->size) != nested_size)
735 nested_msg->size = htons (nested_size);