2 This file is part of GNUnet
3 (C) 2004, 2005, 2006, 2007, 2009 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 2, 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 * @file datastore/datastore_api.c
23 * @brief Management for the datastore for files stored on a GNUnet node
24 * @author Christian Grothoff
27 #include "gnunet_datastore_service.h"
28 #include "datastore.h"
31 * Handle to the datastore service. Followed
32 * by 65536 bytes used for storing messages.
34 struct GNUNET_DATASTORE_Handle
40 const struct GNUNET_CONFIGURATION_Handle *cfg;
45 struct GNUNET_SCHEDULER_Handle *sched;
48 * Current connection to the datastore service.
50 struct GNUNET_CLIENT_Connection *client;
53 * Current response processor (NULL if we are not waiting for a
54 * response). The specific type depends on the kind of message we
60 * Closure for response_proc.
62 void *response_proc_cls;
65 * Timeout for the current operation.
67 struct GNUNET_TIME_Absolute timeout;
70 * Number of bytes in the message following
71 * this struct, 0 if we have no request pending.
79 * Connect to the datastore service.
81 * @param cfg configuration to use
82 * @param sched scheduler to use
83 * @return handle to use to access the service
85 struct GNUNET_DATASTORE_Handle *GNUNET_DATASTORE_connect (const struct
86 GNUNET_CONFIGURATION_Handle
89 GNUNET_SCHEDULER_Handle
92 struct GNUNET_CLIENT_Connection *c;
93 struct GNUNET_DATASTORE_Handle *h;
95 c = GNUNET_CLIENT_connect (sched, "datastore", cfg);
97 return NULL; /* oops */
98 h = GNUNET_malloc (sizeof(struct GNUNET_DATASTORE_Handle) +
99 GNUNET_SERVER_MAX_MESSAGE_SIZE);
108 * Transmit DROP message to datastore service.
111 transmit_drop (void *cls,
112 size_t size, void *buf)
114 struct GNUNET_DATASTORE_Handle *h = cls;
115 struct GNUNET_MessageHeader *hdr;
119 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
120 _("Failed to transmit request to drop database.\n"));
121 GNUNET_DATASTORE_disconnect (h, GNUNET_NO);
124 GNUNET_assert (size >= sizeof(struct GNUNET_MessageHeader));
126 hdr->size = htons(sizeof(struct GNUNET_MessageHeader));
127 hdr->type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_DROP);
128 GNUNET_DATASTORE_disconnect (h, GNUNET_NO);
129 return sizeof(struct GNUNET_MessageHeader);
134 * Disconnect from the datastore service (and free
135 * associated resources).
137 * @param h handle to the datastore
138 * @param drop set to GNUNET_YES to delete all data in datastore (!)
140 void GNUNET_DATASTORE_disconnect (struct GNUNET_DATASTORE_Handle *h,
143 GNUNET_assert (0 == h->message_size);
144 GNUNET_assert (NULL == h->response_proc);
145 if ( (GNUNET_YES == drop) &&
146 (h->client != NULL) )
149 GNUNET_CLIENT_notify_transmit_ready (h->client,
150 sizeof(struct GNUNET_MessageHeader),
151 GNUNET_TIME_UNIT_MINUTES,
157 if (h->client != NULL)
158 GNUNET_CLIENT_disconnect (h->client);
164 * Type of a function to call when we receive a message
165 * from the service. This specific function is used
166 * to handle messages of type "struct StatusMessage".
169 * @param msg message received, NULL on timeout or fatal error
172 with_status_response_handler (void *cls,
174 GNUNET_MessageHeader * msg)
176 struct GNUNET_DATASTORE_Handle *h = cls;
177 GNUNET_DATASTORE_ContinuationWithStatus cont = h->response_proc;
178 const struct StatusMessage *sm;
184 h->response_proc = NULL;
185 GNUNET_CLIENT_disconnect (h->client);
186 h->client = GNUNET_CLIENT_connect (h->sched, "datastore", h->cfg);
187 cont (h->response_proc_cls,
189 _("Timeout trying to read response from datastore service\n"));
192 if ( (ntohs(msg->size) < sizeof(struct StatusMessage)) ||
193 (ntohs(msg->type) != GNUNET_MESSAGE_TYPE_DATASTORE_STATUS) )
196 h->response_proc = NULL;
197 GNUNET_CLIENT_disconnect (h->client);
198 h->client = GNUNET_CLIENT_connect (h->sched, "datastore", h->cfg);
199 cont (h->response_proc_cls,
201 _("Error reading response from datastore service\n"));
204 sm = (const struct StatusMessage*) msg;
205 status = ntohl(sm->status);
207 if (ntohs(msg->size) > sizeof(struct StatusMessage))
209 emsg = (const char*) &sm[1];
210 if (emsg[ntohs(msg->size) - sizeof(struct StatusMessage) - 1] != '\0')
213 emsg = _("Invalid error message received from datastore service");
216 if ( (status == GNUNET_SYSERR) &&
220 emsg = _("Invalid error message received from datastore service");
222 h->response_proc = NULL;
224 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
225 "Received status %d/%s\n",
229 cont (h->response_proc_cls,
236 * Transmit message to datastore service and then
237 * read a status message.
239 * @param cls closure with handle to datastore
240 * @param size number of bytes we can transmit at most
241 * @param buf where to write transmission, NULL on
243 * @return number of bytes copied to buf
246 transmit_get_status (void *cls,
250 struct GNUNET_DATASTORE_Handle *h = cls;
251 GNUNET_DATASTORE_ContinuationWithStatus cont = h->response_proc;
257 h->response_proc = NULL;
258 cont (h->response_proc_cls,
260 gettext_noop ("Error transmitting message to datastore service.\n"));
263 msize = h->message_size;
264 GNUNET_assert (msize <= size);
265 memcpy (buf, &h[1], msize);
267 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
268 "Transmitted %u byte message to datastore service, now waiting for status.\n",
272 GNUNET_CLIENT_receive (h->client,
273 &with_status_response_handler,
275 GNUNET_TIME_absolute_get_remaining (h->timeout));
281 * Helper function that will initiate the
282 * transmission of a message to the datastore
283 * service. The message must already be prepared
284 * and stored in the buffer at the end of the
285 * handle. The message must be of a type that
286 * expects a "StatusMessage" in response.
288 * @param h handle to the service with prepared message
289 * @param cont function to call with result
290 * @param cont_cls closure
291 * @param timeout timeout for the operation
294 transmit_for_status (struct GNUNET_DATASTORE_Handle *h,
295 GNUNET_DATASTORE_ContinuationWithStatus cont,
297 struct GNUNET_TIME_Relative timeout)
299 const struct GNUNET_MessageHeader *hdr;
302 GNUNET_assert (cont != NULL);
303 hdr = (const struct GNUNET_MessageHeader*) &h[1];
304 msize = ntohs(hdr->size);
306 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
307 "Transmitting %u byte message of type %u to datastore service\n",
311 GNUNET_assert (h->response_proc == NULL);
312 h->response_proc = cont;
313 h->response_proc_cls = cont_cls;
314 h->timeout = GNUNET_TIME_relative_to_absolute (timeout);
315 h->message_size = msize;
316 if (NULL == GNUNET_CLIENT_notify_transmit_ready (h->client,
319 &transmit_get_status,
323 h->response_proc = NULL;
327 gettext_noop ("Not ready to transmit request to datastore service"));
333 * Store an item in the datastore. If the item is already present,
334 * the priorities are summed up and the higher expiration time and
335 * lower anonymity level is used.
337 * @param h handle to the datastore
338 * @param key key for the value
339 * @param size number of bytes in data
340 * @param data content stored
341 * @param type type of the content
342 * @param priority priority of the content
343 * @param anonymity anonymity-level for the content
344 * @param expiration expiration time for the content
345 * @param timeout timeout for the operation
346 * @param cont continuation to call when done
347 * @param cont_cls closure for cont
350 GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
352 const GNUNET_HashCode * key,
358 struct GNUNET_TIME_Absolute expiration,
359 struct GNUNET_TIME_Relative timeout,
360 GNUNET_DATASTORE_ContinuationWithStatus cont,
363 struct DataMessage *dm;
367 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
368 "Asked to put %u bytes of data\n",
371 msize = sizeof(struct DataMessage) + size;
372 GNUNET_assert (msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE);
373 dm = (struct DataMessage*) &h[1];
374 dm->header.type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_PUT);
375 dm->header.size = htons(msize);
376 dm->rid = htonl(rid);
377 dm->size = htonl(size);
378 dm->type = htonl(type);
379 dm->priority = htonl(priority);
380 dm->anonymity = htonl(anonymity);
381 dm->uid = GNUNET_htonll(0);
382 dm->expiration = GNUNET_TIME_absolute_hton(expiration);
384 memcpy (&dm[1], data, size);
385 transmit_for_status (h, cont, cont_cls, timeout);
390 * Reserve space in the datastore. This function should be used
391 * to avoid "out of space" failures during a longer sequence of "put"
392 * operations (for example, when a file is being inserted).
394 * @param h handle to the datastore
395 * @param amount how much space (in bytes) should be reserved (for content only)
396 * @param entries how many entries will be created (to calculate per-entry overhead)
397 * @param cont continuation to call when done; "success" will be set to
398 * a positive reservation value if space could be reserved.
399 * @param cont_cls closure for cont
400 * @param timeout how long to wait at most for a response
403 GNUNET_DATASTORE_reserve (struct GNUNET_DATASTORE_Handle *h,
406 GNUNET_DATASTORE_ContinuationWithStatus cont,
408 struct GNUNET_TIME_Relative timeout)
410 struct ReserveMessage *rm;
412 rm = (struct ReserveMessage*) &h[1];
413 rm->header.type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_RESERVE);
414 rm->header.size = htons(sizeof (struct ReserveMessage));
415 rm->entries = htonl(entries);
416 rm->amount = GNUNET_htonll(amount);
417 transmit_for_status (h, cont, cont_cls, timeout);
422 * Signal that all of the data for which a reservation was made has
423 * been stored and that whatever excess space might have been reserved
424 * can now be released.
426 * @param h handle to the datastore
427 * @param rid reservation ID (value of "success" in original continuation
428 * from the "reserve" function).
429 * @param cont continuation to call when done
430 * @param cont_cls closure for cont
431 * @param timeout how long to wait at most for a response
434 GNUNET_DATASTORE_release_reserve (struct GNUNET_DATASTORE_Handle *h,
436 GNUNET_DATASTORE_ContinuationWithStatus cont,
438 struct GNUNET_TIME_Relative timeout)
440 struct ReleaseReserveMessage *rrm;
442 rrm = (struct ReleaseReserveMessage*) &h[1];
443 rrm->header.type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_RELEASE_RESERVE);
444 rrm->header.size = htons(sizeof (struct ReleaseReserveMessage));
445 rrm->rid = htonl(rid);
446 transmit_for_status (h, cont, cont_cls, timeout);
451 * Update a value in the datastore.
453 * @param h handle to the datastore
454 * @param uid identifier for the value
455 * @param priority how much to increase the priority of the value
456 * @param expiration new expiration value should be MAX of existing and this argument
457 * @param cont continuation to call when done
458 * @param cont_cls closure for cont
459 * @param timeout how long to wait at most for a response
462 GNUNET_DATASTORE_update (struct GNUNET_DATASTORE_Handle *h,
463 unsigned long long uid,
465 struct GNUNET_TIME_Absolute expiration,
466 GNUNET_DATASTORE_ContinuationWithStatus cont,
468 struct GNUNET_TIME_Relative timeout)
470 struct UpdateMessage *um;
472 um = (struct UpdateMessage*) &h[1];
473 um->header.type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_UPDATE);
474 um->header.size = htons(sizeof (struct UpdateMessage));
475 um->priority = htonl(priority);
476 um->expiration = GNUNET_TIME_absolute_hton(expiration);
477 um->uid = GNUNET_htonll(uid);
478 transmit_for_status (h, cont, cont_cls, timeout);
485 * Type of a function to call when we receive a message
486 * from the service. This specific function is used
487 * to handle messages of type "struct DataMessage".
490 * @param msg message received, NULL on timeout or fatal error
493 with_result_response_handler (void *cls,
495 GNUNET_MessageHeader * msg)
497 static struct GNUNET_TIME_Absolute zero;
498 struct GNUNET_DATASTORE_Handle *h = cls;
499 GNUNET_DATASTORE_Iterator cont = h->response_proc;
500 const struct DataMessage *dm;
505 h->response_proc = NULL;
506 GNUNET_CLIENT_disconnect (h->client);
507 h->client = GNUNET_CLIENT_connect (h->sched, "datastore", h->cfg);
508 cont (h->response_proc_cls,
509 NULL, 0, NULL, 0, 0, 0, zero, 0);
512 if (ntohs(msg->type) == GNUNET_MESSAGE_TYPE_DATASTORE_DATA_END)
514 GNUNET_break (ntohs(msg->size) == sizeof(struct GNUNET_MessageHeader));
515 h->response_proc = NULL;
517 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
518 "Received end of result set\n");
520 cont (h->response_proc_cls,
521 NULL, 0, NULL, 0, 0, 0, zero, 0);
524 if ( (ntohs(msg->size) < sizeof(struct DataMessage)) ||
525 (ntohs(msg->type) != GNUNET_MESSAGE_TYPE_DATASTORE_DATA) )
528 GNUNET_CLIENT_disconnect (h->client);
529 h->client = GNUNET_CLIENT_connect (h->sched, "datastore", h->cfg);
530 h->response_proc = NULL;
531 cont (h->response_proc_cls,
532 NULL, 0, NULL, 0, 0, 0, zero, 0);
535 dm = (const struct DataMessage*) msg;
536 msize = ntohl(dm->size);
537 if (ntohs(msg->size) != msize + sizeof(struct DataMessage))
540 GNUNET_CLIENT_disconnect (h->client);
541 h->client = GNUNET_CLIENT_connect (h->sched, "datastore", h->cfg);
542 h->response_proc = NULL;
543 cont (h->response_proc_cls,
544 NULL, 0, NULL, 0, 0, 0, zero, 0);
548 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
549 "Received result %llu with type %u and size %u with key %s\n",
550 (unsigned long long) GNUNET_ntohll(dm->uid),
553 GNUNET_h2s(&dm->key));
555 cont (h->response_proc_cls,
561 ntohl(dm->anonymity),
562 GNUNET_TIME_absolute_ntoh(dm->expiration),
563 GNUNET_ntohll(dm->uid));
564 GNUNET_CLIENT_receive (h->client,
565 &with_result_response_handler,
567 GNUNET_TIME_absolute_get_remaining (h->timeout));
572 * Transmit message to datastore service and then
573 * read a result message.
575 * @param cls closure with handle to datastore
576 * @param size number of bytes we can transmit at most
577 * @param buf where to write transmission, NULL on
579 * @return number of bytes copied to buf
582 transmit_get_result (void *cls,
586 struct GNUNET_DATASTORE_Handle *h = cls;
587 GNUNET_DATASTORE_ContinuationWithStatus cont = h->response_proc;
592 h->response_proc = NULL;
594 cont (h->response_proc_cls,
596 gettext_noop ("Error transmitting message to datastore service.\n"));
599 msize = h->message_size;
600 GNUNET_assert (msize <= size);
601 memcpy (buf, &h[1], msize);
603 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
604 "Transmitted %u byte message to datastore service, now waiting for result.\n",
608 GNUNET_CLIENT_receive (h->client,
609 &with_result_response_handler,
611 GNUNET_TIME_absolute_get_remaining (h->timeout));
617 * Helper function that will initiate the
618 * transmission of a message to the datastore
619 * service. The message must already be prepared
620 * and stored in the buffer at the end of the
621 * handle. The message must be of a type that
622 * expects a "DataMessage" in response.
624 * @param h handle to the service with prepared message
625 * @param cont function to call with result
626 * @param cont_cls closure
627 * @param timeout timeout for the operation
630 transmit_for_result (struct GNUNET_DATASTORE_Handle *h,
631 GNUNET_DATASTORE_Iterator cont,
633 struct GNUNET_TIME_Relative timeout)
635 static struct GNUNET_TIME_Absolute zero;
636 const struct GNUNET_MessageHeader *hdr;
639 GNUNET_assert (cont != NULL);
640 hdr = (const struct GNUNET_MessageHeader*) &h[1];
641 msize = ntohs(hdr->size);
643 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
644 "Transmitting %u byte message of type %u to datastore service\n",
648 GNUNET_assert (h->response_proc == NULL);
649 h->response_proc = cont;
650 h->response_proc_cls = cont_cls;
651 h->timeout = GNUNET_TIME_relative_to_absolute (timeout);
652 h->message_size = msize;
653 if (NULL == GNUNET_CLIENT_notify_transmit_ready (h->client,
656 &transmit_get_result,
660 h->response_proc = NULL;
662 cont (h->response_proc_cls,
663 NULL, 0, NULL, 0, 0, 0, zero, 0);
669 * Iterate over the results for a particular key
672 * @param h handle to the datastore
673 * @param key maybe NULL (to match all entries)
674 * @param type desired type, 0 for any
675 * @param iter function to call on each matching value;
676 * will be called once with a NULL value at the end
677 * @param iter_cls closure for iter
678 * @param timeout how long to wait at most for a response
681 GNUNET_DATASTORE_get (struct GNUNET_DATASTORE_Handle *h,
682 const GNUNET_HashCode * key,
684 GNUNET_DATASTORE_Iterator iter, void *iter_cls,
685 struct GNUNET_TIME_Relative timeout)
687 struct GetMessage *gm;
689 gm = (struct GetMessage*) &h[1];
690 gm->header.type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_GET);
691 gm->type = htonl(type);
694 gm->header.size = htons(sizeof (struct GetMessage));
699 gm->header.size = htons(sizeof (struct GetMessage) - sizeof(GNUNET_HashCode));
701 transmit_for_result (h, iter, iter_cls, timeout);
706 * Get a random value from the datastore.
708 * @param h handle to the datastore
709 * @param iter function to call on a random value; it
710 * will be called exactly once; if no values
711 * are available, the value will be NULL.
712 * @param iter_cls closure for iter
713 * @param timeout how long to wait at most for a response
716 GNUNET_DATASTORE_get_random (struct GNUNET_DATASTORE_Handle *h,
717 GNUNET_DATASTORE_Iterator iter, void *iter_cls,
718 struct GNUNET_TIME_Relative timeout)
720 struct GNUNET_MessageHeader *m;
722 m = (struct GNUNET_MessageHeader*) &h[1];
723 m->type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_GET_RANDOM);
724 m->size = htons(sizeof (struct GNUNET_MessageHeader));
725 transmit_for_result (h, iter, iter_cls, timeout);
730 * Explicitly remove some content from the database.
732 * @param h handle to the datastore
733 * @param key key for the value
734 * @param size number of bytes in data
735 * @param data content stored
736 * @param cont continuation to call when done
737 * @param cont_cls closure for cont
738 * @param timeout how long to wait at most for a response
741 GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
742 const GNUNET_HashCode * key,
743 uint32_t size, const void *data,
744 GNUNET_DATASTORE_ContinuationWithStatus cont,
746 struct GNUNET_TIME_Relative timeout)
748 struct DataMessage *dm;
751 msize = sizeof(struct DataMessage) + size;
752 GNUNET_assert (msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE);
753 dm = (struct DataMessage*) &h[1];
754 dm->header.type = htons(GNUNET_MESSAGE_TYPE_DATASTORE_REMOVE);
755 dm->header.size = htons(msize);
757 dm->size = htonl(size);
759 dm->priority = htonl(0);
760 dm->anonymity = htonl(0);
761 dm->uid = GNUNET_htonll(0);
762 dm->expiration.value = 0;
764 memcpy (&dm[1], data, size);
765 transmit_for_status (h, cont, cont_cls, timeout);
769 /* end of datastore_api.c */