/* This file is part of GNUnet. (C) 2009, 2010, 2011 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 statistics/statistics_api.c * @brief API of the statistics service * @author Christian Grothoff */ #include "platform.h" #include "gnunet_client_lib.h" #include "gnunet_constants.h" #include "gnunet_container_lib.h" #include "gnunet_protocols.h" #include "gnunet_server_lib.h" #include "gnunet_statistics_service.h" #include "gnunet_strings_lib.h" #include "statistics.h" /** * How long do we wait until a statistics request for setting * a value times out? (The update will be lost if the * service does not react within this timeframe). */ #define SET_TRANSMIT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 2) #define LOG(kind,...) GNUNET_log_from (kind, "statistics-api",__VA_ARGS__) /** * Types of actions. */ enum ActionType { /** * Get a value. */ ACTION_GET, /** * Set a value. */ ACTION_SET, /** * Update a value. */ ACTION_UPDATE, /** * Watch a value. */ ACTION_WATCH }; /** * Entry kept for each value we are watching. */ struct GNUNET_STATISTICS_WatchEntry { /** * What subsystem is this action about? (never NULL) */ char *subsystem; /** * What value is this action about? (never NULL) */ char *name; /** * Function to call */ GNUNET_STATISTICS_Iterator proc; /** * Closure for proc */ void *proc_cls; }; /** * Linked list of things we still need to do. */ struct GNUNET_STATISTICS_GetHandle { /** * This is a doubly linked list. */ struct GNUNET_STATISTICS_GetHandle *next; /** * This is a doubly linked list. */ struct GNUNET_STATISTICS_GetHandle *prev; /** * Main statistics handle. */ struct GNUNET_STATISTICS_Handle *sh; /** * What subsystem is this action about? (can be NULL) */ char *subsystem; /** * What value is this action about? (can be NULL) */ char *name; /** * Continuation to call once action is complete. */ GNUNET_STATISTICS_Callback cont; /** * Function to call (for GET actions only). */ GNUNET_STATISTICS_Iterator proc; /** * Closure for proc and cont. */ void *cls; /** * Timeout for this action. */ struct GNUNET_TIME_Absolute timeout; /** * Associated value. */ uint64_t value; /** * Flag for SET/UPDATE actions. */ int make_persistent; /** * Has the current iteration been aborted; for GET actions. */ int aborted; /** * Is this a GET, SET, UPDATE or WATCH? */ enum ActionType type; /** * Size of the message that we will be transmitting. */ uint16_t msize; }; /** * Handle for the service. */ struct GNUNET_STATISTICS_Handle { /** * Name of our subsystem. */ char *subsystem; /** * Configuration to use. */ const struct GNUNET_CONFIGURATION_Handle *cfg; /** * Socket (if available). */ struct GNUNET_CLIENT_Connection *client; /** * Currently pending transmission request. */ struct GNUNET_CLIENT_TransmitHandle *th; /** * Head of the linked list of pending actions (first action * to be performed). */ struct GNUNET_STATISTICS_GetHandle *action_head; /** * Tail of the linked list of actions (for fast append). */ struct GNUNET_STATISTICS_GetHandle *action_tail; /** * Action we are currently busy with (action request has been * transmitted, we're now receiving the response from the * service). */ struct GNUNET_STATISTICS_GetHandle *current; /** * Array of watch entries. */ struct GNUNET_STATISTICS_WatchEntry **watches; /** * Task doing exponential back-off trying to reconnect. */ GNUNET_SCHEDULER_TaskIdentifier backoff_task; /** * Time for next connect retry. */ struct GNUNET_TIME_Relative backoff; /** * Size of the 'watches' array. */ unsigned int watches_size; /** * Should this handle auto-destruct once all actions have * been processed? */ int do_destroy; /** * Are we currently receiving from the service? */ int receiving; }; /** * Schedule the next action to be performed. * * @param h statistics handle to reconnect */ static void schedule_action (struct GNUNET_STATISTICS_Handle *h); /** * Transmit request to service that we want to watch * the development of a particular value. * * @param h statistics handle * @param watch watch entry of the value to watch */ static void schedule_watch_request (struct GNUNET_STATISTICS_Handle *h, struct GNUNET_STATISTICS_WatchEntry *watch) { struct GNUNET_STATISTICS_GetHandle *ai; size_t slen; size_t nlen; size_t nsize; GNUNET_assert (NULL != h); GNUNET_assert (NULL != watch); slen = strlen (watch->subsystem) + 1; nlen = strlen (watch->name) + 1; nsize = sizeof (struct GNUNET_MessageHeader) + slen + nlen; if (nsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break (0); return; } ai = GNUNET_malloc (sizeof (struct GNUNET_STATISTICS_GetHandle)); ai->sh = h; ai->subsystem = GNUNET_strdup (watch->subsystem); ai->name = GNUNET_strdup (watch->name); ai->timeout = GNUNET_TIME_UNIT_FOREVER_ABS; ai->msize = nsize; ai->type = ACTION_WATCH; ai->proc = watch->proc; ai->cls = watch->proc_cls; GNUNET_CONTAINER_DLL_insert_tail (h->action_head, h->action_tail, ai); schedule_action (h); } /** * Free memory associated with the given action item. * * @param gh action item to free */ static void free_action_item (struct GNUNET_STATISTICS_GetHandle *gh) { GNUNET_free_non_null (gh->subsystem); GNUNET_free_non_null (gh->name); GNUNET_free (gh); } /** * Disconnect from the statistics service. * * @param h statistics handle to disconnect from */ static void do_disconnect (struct GNUNET_STATISTICS_Handle *h) { struct GNUNET_STATISTICS_GetHandle *c; if (NULL != h->th) { GNUNET_CLIENT_notify_transmit_ready_cancel (h->th); h->th = NULL; } if (NULL != h->client) { GNUNET_CLIENT_disconnect (h->client); h->client = NULL; } h->receiving = GNUNET_NO; if (NULL != (c = h->current)) { h->current = NULL; if (NULL != c->cont) c->cont (c->cls, GNUNET_SYSERR); free_action_item (c); } } /** * Try to (re)connect to the statistics service. * * @param h statistics handle to reconnect * @return GNUNET_YES on success, GNUNET_NO on failure. */ static int try_connect (struct GNUNET_STATISTICS_Handle *h) { struct GNUNET_STATISTICS_GetHandle *gh; struct GNUNET_STATISTICS_GetHandle *gn; unsigned int i; if (GNUNET_SCHEDULER_NO_TASK != h->backoff_task) return GNUNET_NO; if (NULL != h->client) return GNUNET_YES; h->client = GNUNET_CLIENT_connect ("statistics", h->cfg); if (NULL != h->client) { gn = h->action_head; while (NULL != (gh = gn)) { gn = gh->next; if (gh->type == ACTION_WATCH) { GNUNET_CONTAINER_DLL_remove (h->action_head, h->action_tail, gh); free_action_item (gh); } } for (i = 0; i < h->watches_size; i++) { if (NULL != h->watches[i]) schedule_watch_request (h, h->watches[i]); } return GNUNET_YES; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Failed to connect to statistics service!\n"); return GNUNET_NO; } /** * We've waited long enough, reconnect now. * * @param cls the 'struct GNUNET_STATISTICS_Handle' to reconnect * @param tc scheduler context (unused) */ static void reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_STATISTICS_Handle *h = cls; h->backoff_task = GNUNET_SCHEDULER_NO_TASK; schedule_action (h); } /** * Task used by 'reconnect_later' to shutdown the handle * * @param cls the statistics handle * @param tc scheduler context */ static void do_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_STATISTICS_Handle *h = cls; GNUNET_STATISTICS_destroy (h, GNUNET_NO); } /** * Reconnect at a later time, respecting back-off. * * @param h statistics handle */ static void reconnect_later (struct GNUNET_STATISTICS_Handle *h) { int loss; struct GNUNET_STATISTICS_GetHandle *gh; GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == h->backoff_task); if (GNUNET_YES == h->do_destroy) { /* So we are shutting down and the service is not reachable. * Chances are that it's down for good and we are not going to connect to * it anymore. * Give up and don't sync the rest of the data. */ loss = GNUNET_NO; for (gh = h->action_head; NULL != gh; gh = gh->next) if ( (gh->make_persistent) && (ACTION_SET == gh->type) ) loss = GNUNET_YES; if (GNUNET_YES == loss) GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Could not save some persistent statistics\n")); h->do_destroy = GNUNET_NO; GNUNET_SCHEDULER_add_continuation (&do_destroy, h, GNUNET_SCHEDULER_REASON_PREREQ_DONE); return; } h->backoff_task = GNUNET_SCHEDULER_add_delayed (h->backoff, &reconnect_task, h); h->backoff = GNUNET_TIME_relative_multiply (h->backoff, 2); h->backoff = GNUNET_TIME_relative_min (h->backoff, GNUNET_CONSTANTS_SERVICE_TIMEOUT); } /** * Process a 'GNUNET_MESSAGE_TYPE_STATISTICS_VALUE' message. * * @param h statistics handle * @param msg message received from the service, never NULL * @return GNUNET_OK if the message was well-formed */ static int process_statistics_value_message (struct GNUNET_STATISTICS_Handle *h, const struct GNUNET_MessageHeader *msg) { char *service; char *name; const struct GNUNET_STATISTICS_ReplyMessage *smsg; uint16_t size; if (h->current->aborted) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Iteration was aborted, ignoring VALUE\n"); return GNUNET_OK; /* don't bother */ } size = ntohs (msg->size); if (size < sizeof (struct GNUNET_STATISTICS_ReplyMessage)) { GNUNET_break (0); return GNUNET_SYSERR; } smsg = (const struct GNUNET_STATISTICS_ReplyMessage *) msg; size -= sizeof (struct GNUNET_STATISTICS_ReplyMessage); if (size != GNUNET_STRINGS_buffer_tokenize ((const char *) &smsg[1], size, 2, &service, &name)) { GNUNET_break (0); return GNUNET_SYSERR; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Received valid statistic on `%s:%s': %llu\n", service, name, GNUNET_ntohll (smsg->value)); if (GNUNET_OK != h->current->proc (h->current->cls, service, name, GNUNET_ntohll (smsg->value), 0 != (ntohl (smsg->uid) & GNUNET_STATISTICS_PERSIST_BIT))) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Processing of remaining statistics aborted by client.\n"); h->current->aborted = GNUNET_YES; } LOG (GNUNET_ERROR_TYPE_DEBUG, "VALUE processed successfully\n"); return GNUNET_OK; } /** * We have received a watch value from the service. Process it. * * @param h statistics handle * @param msg the watch value message * @return GNUNET_OK if the message was well-formed, GNUNET_SYSERR if not, * GNUNET_NO if this watch has been cancelled */ static int process_watch_value (struct GNUNET_STATISTICS_Handle *h, const struct GNUNET_MessageHeader *msg) { const struct GNUNET_STATISTICS_WatchValueMessage *wvm; struct GNUNET_STATISTICS_WatchEntry *w; uint32_t wid; if (sizeof (struct GNUNET_STATISTICS_WatchValueMessage) != ntohs (msg->size)) { GNUNET_break (0); return GNUNET_SYSERR; } wvm = (const struct GNUNET_STATISTICS_WatchValueMessage *) msg; GNUNET_break (0 == ntohl (wvm->reserved)); wid = ntohl (wvm->wid); if (wid >= h->watches_size) { GNUNET_break (0); return GNUNET_SYSERR; } w = h->watches[wid]; if (NULL == w) return GNUNET_NO; (void) w->proc (w->proc_cls, w->subsystem, w->name, GNUNET_ntohll (wvm->value), 0 != (ntohl (wvm->flags) & GNUNET_STATISTICS_PERSIST_BIT)); return GNUNET_OK; } static void destroy_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_STATISTICS_Handle *h = cls; GNUNET_STATISTICS_destroy (h, GNUNET_NO); } /** * Function called with messages from stats service. * * @param cls closure * @param msg message received, NULL on timeout or fatal error */ static void receive_stats (void *cls, const struct GNUNET_MessageHeader *msg) { struct GNUNET_STATISTICS_Handle *h = cls; struct GNUNET_STATISTICS_GetHandle *c; int ret; if (NULL == msg) { LOG (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK, "Error receiving statistics from service, is the service running?\n"); do_disconnect (h); reconnect_later (h); return; } switch (ntohs (msg->type)) { case GNUNET_MESSAGE_TYPE_TEST: if (GNUNET_SYSERR != h->do_destroy) { /* not in shutdown, why do we get 'TEST'? */ GNUNET_break (0); do_disconnect (h); reconnect_later (h); return; } h->do_destroy = GNUNET_NO; GNUNET_SCHEDULER_add_continuation (&destroy_task, h, GNUNET_SCHEDULER_REASON_PREREQ_DONE); break; case GNUNET_MESSAGE_TYPE_STATISTICS_END: LOG (GNUNET_ERROR_TYPE_DEBUG, "Received end of statistics marker\n"); if (NULL == (c = h->current)) { GNUNET_break (0); do_disconnect (h); reconnect_later (h); return; } h->backoff = GNUNET_TIME_UNIT_MILLISECONDS; if (h->watches_size > 0) { GNUNET_CLIENT_receive (h->client, &receive_stats, h, GNUNET_TIME_UNIT_FOREVER_REL); } else { h->receiving = GNUNET_NO; } h->current = NULL; schedule_action (h); if (NULL != c->cont) c->cont (c->cls, GNUNET_OK); free_action_item (c); return; case GNUNET_MESSAGE_TYPE_STATISTICS_VALUE: if (GNUNET_OK != process_statistics_value_message (h, msg)) { do_disconnect (h); reconnect_later (h); return; } /* finally, look for more! */ LOG (GNUNET_ERROR_TYPE_DEBUG, "Processing VALUE done, now reading more\n"); GNUNET_CLIENT_receive (h->client, &receive_stats, h, GNUNET_TIME_absolute_get_remaining (h-> current->timeout)); h->backoff = GNUNET_TIME_UNIT_MILLISECONDS; return; case GNUNET_MESSAGE_TYPE_STATISTICS_WATCH_VALUE: if (GNUNET_OK != (ret = process_watch_value (h, msg))) { do_disconnect (h); if (GNUNET_NO == ret) h->backoff = GNUNET_TIME_UNIT_MILLISECONDS; reconnect_later (h); return; } h->backoff = GNUNET_TIME_UNIT_MILLISECONDS; GNUNET_assert (h->watches_size > 0); GNUNET_CLIENT_receive (h->client, &receive_stats, h, GNUNET_TIME_UNIT_FOREVER_REL); return; default: GNUNET_break (0); do_disconnect (h); reconnect_later (h); return; } } /** * Transmit a GET request (and if successful, start to receive * the response). * * @param handle statistics handle * @param size how many bytes can we write to buf * @param buf where to write requests to the service * @return number of bytes written to buf */ static size_t transmit_get (struct GNUNET_STATISTICS_Handle *handle, size_t size, void *buf) { struct GNUNET_STATISTICS_GetHandle *c; struct GNUNET_MessageHeader *hdr; size_t slen1; size_t slen2; uint16_t msize; GNUNET_assert (NULL != (c = handle->current)); if (NULL == buf) { /* timeout / error */ LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmission of request for statistics failed!\n"); do_disconnect (handle); reconnect_later (handle); return 0; } slen1 = strlen (c->subsystem) + 1; slen2 = strlen (c->name) + 1; msize = slen1 + slen2 + sizeof (struct GNUNET_MessageHeader); GNUNET_assert (msize <= size); hdr = (struct GNUNET_MessageHeader *) buf; hdr->size = htons (msize); hdr->type = htons (GNUNET_MESSAGE_TYPE_STATISTICS_GET); GNUNET_assert (slen1 + slen2 == GNUNET_STRINGS_buffer_fill ((char *) &hdr[1], slen1 + slen2, 2, c->subsystem, c->name)); if (GNUNET_YES != handle->receiving) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmission of GET done, now reading response\n"); handle->receiving = GNUNET_YES; GNUNET_CLIENT_receive (handle->client, &receive_stats, handle, GNUNET_TIME_absolute_get_remaining (c->timeout)); } return msize; } /** * Transmit a WATCH request (and if successful, start to receive * the response). * * @param handle statistics handle * @param size how many bytes can we write to buf * @param buf where to write requests to the service * @return number of bytes written to buf */ static size_t transmit_watch (struct GNUNET_STATISTICS_Handle *handle, size_t size, void *buf) { struct GNUNET_MessageHeader *hdr; size_t slen1; size_t slen2; uint16_t msize; if (NULL == buf) { /* timeout / error */ LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmission of request for statistics failed!\n"); do_disconnect (handle); reconnect_later (handle); return 0; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmitting watch request for `%s'\n", handle->current->name); slen1 = strlen (handle->current->subsystem) + 1; slen2 = strlen (handle->current->name) + 1; msize = slen1 + slen2 + sizeof (struct GNUNET_MessageHeader); GNUNET_assert (msize <= size); hdr = (struct GNUNET_MessageHeader *) buf; hdr->size = htons (msize); hdr->type = htons (GNUNET_MESSAGE_TYPE_STATISTICS_WATCH); GNUNET_assert (slen1 + slen2 == GNUNET_STRINGS_buffer_fill ((char *) &hdr[1], slen1 + slen2, 2, handle->current->subsystem, handle->current->name)); if (GNUNET_YES != handle->receiving) { handle->receiving = GNUNET_YES; GNUNET_CLIENT_receive (handle->client, &receive_stats, handle, GNUNET_TIME_UNIT_FOREVER_REL); } GNUNET_assert (NULL == handle->current->cont); free_action_item (handle->current); handle->current = NULL; return msize; } /** * Transmit a SET/UPDATE request. * * @param handle statistics handle * @param size how many bytes can we write to buf * @param buf where to write requests to the service * @return number of bytes written to buf */ static size_t transmit_set (struct GNUNET_STATISTICS_Handle *handle, size_t size, void *buf) { struct GNUNET_STATISTICS_SetMessage *r; size_t slen; size_t nlen; size_t nsize; if (NULL == buf) { do_disconnect (handle); reconnect_later (handle); return 0; } slen = strlen (handle->current->subsystem) + 1; nlen = strlen (handle->current->name) + 1; nsize = sizeof (struct GNUNET_STATISTICS_SetMessage) + slen + nlen; if (size < nsize) { GNUNET_break (0); do_disconnect (handle); reconnect_later (handle); return 0; } r = buf; r->header.size = htons (nsize); r->header.type = htons (GNUNET_MESSAGE_TYPE_STATISTICS_SET); r->flags = 0; r->value = GNUNET_htonll (handle->current->value); if (handle->current->make_persistent) r->flags |= htonl (GNUNET_STATISTICS_SETFLAG_PERSISTENT); if (handle->current->type == ACTION_UPDATE) r->flags |= htonl (GNUNET_STATISTICS_SETFLAG_RELATIVE); GNUNET_assert (slen + nlen == GNUNET_STRINGS_buffer_fill ((char *) &r[1], slen + nlen, 2, handle->current->subsystem, handle->current->name)); GNUNET_assert (NULL == handle->current->cont); free_action_item (handle->current); handle->current = NULL; return nsize; } /** * Function called when we are ready to transmit a request to the service. * * @param cls the 'struct GNUNET_STATISTICS_Handle' * @param size how many bytes can we write to buf * @param buf where to write requests to the service * @return number of bytes written to buf */ static size_t transmit_action (void *cls, size_t size, void *buf) { struct GNUNET_STATISTICS_Handle *h = cls; size_t ret; h->th = NULL; ret = 0; if (NULL != h->current) switch (h->current->type) { case ACTION_GET: ret = transmit_get (h, size, buf); break; case ACTION_SET: case ACTION_UPDATE: ret = transmit_set (h, size, buf); break; case ACTION_WATCH: ret = transmit_watch (h, size, buf); break; default: GNUNET_assert (0); break; } schedule_action (h); return ret; } /** * Get handle for the statistics service. * * @param subsystem name of subsystem using the service * @param cfg services configuration in use * @return handle to use */ struct GNUNET_STATISTICS_Handle * GNUNET_STATISTICS_create (const char *subsystem, const struct GNUNET_CONFIGURATION_Handle *cfg) { struct GNUNET_STATISTICS_Handle *ret; GNUNET_assert (NULL != subsystem); GNUNET_assert (NULL != cfg); ret = GNUNET_malloc (sizeof (struct GNUNET_STATISTICS_Handle)); ret->cfg = cfg; ret->subsystem = GNUNET_strdup (subsystem); ret->backoff = GNUNET_TIME_UNIT_MILLISECONDS; return ret; } /** * Destroy a handle (free all state associated with * it). * * @param h statistics handle to destroy * @param sync_first set to GNUNET_YES if pending SET requests should * be completed */ void GNUNET_STATISTICS_destroy (struct GNUNET_STATISTICS_Handle *h, int sync_first) { struct GNUNET_STATISTICS_GetHandle *pos; struct GNUNET_STATISTICS_GetHandle *next; struct GNUNET_TIME_Relative timeout; int i; if (NULL == h) return; GNUNET_assert (GNUNET_NO == h->do_destroy); // Don't call twice. if (GNUNET_SCHEDULER_NO_TASK != h->backoff_task) { GNUNET_SCHEDULER_cancel (h->backoff_task); h->backoff_task = GNUNET_SCHEDULER_NO_TASK; } if (sync_first) { if (NULL != h->current) { if (ACTION_GET == h->current->type) { GNUNET_CLIENT_notify_transmit_ready_cancel (h->th); h->th = NULL; free_action_item (h->current); h->current = NULL; } } next = h->action_head; while (NULL != (pos = next)) { next = pos->next; if (ACTION_GET == pos->type) { GNUNET_CONTAINER_DLL_remove (h->action_head, h->action_tail, pos); free_action_item (pos); } } if ( (NULL == h->current) && (NULL != (h->current = h->action_head)) ) GNUNET_CONTAINER_DLL_remove (h->action_head, h->action_tail, h->current); h->do_destroy = GNUNET_YES; if ((NULL != h->current) && (NULL == h->th) && (NULL != h->client)) { timeout = GNUNET_TIME_absolute_get_remaining (h->current->timeout); h->th = GNUNET_CLIENT_notify_transmit_ready (h->client, h->current->msize, timeout, GNUNET_YES, &transmit_action, h); GNUNET_assert (NULL != h->th); } if (NULL != h->th) return; /* do not finish destruction just yet */ } while (NULL != (pos = h->action_head)) { GNUNET_CONTAINER_DLL_remove (h->action_head, h->action_tail, pos); free_action_item (pos); } do_disconnect (h); for (i = 0; i < h->watches_size; i++) { if (NULL == h->watches[i]) continue; GNUNET_free (h->watches[i]->subsystem); GNUNET_free (h->watches[i]->name); GNUNET_free (h->watches[i]); } GNUNET_array_grow (h->watches, h->watches_size, 0); GNUNET_free (h->subsystem); GNUNET_free (h); } /** * Function called to transmit TEST message to service to * confirm that the service has received all of our 'SET' * messages (during statistics disconnect/shutdown). * * @param cls the 'struct GNUNET_STATISTICS_Handle' * @param size how many bytes can we write to buf * @param buf where to write requests to the service * @return number of bytes written to buf */ static size_t transmit_test_on_shutdown (void *cls, size_t size, void *buf) { struct GNUNET_STATISTICS_Handle *h = cls; struct GNUNET_MessageHeader hdr; h->th = NULL; if (NULL == buf) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Failed to receive acknowledgement from statistics service, some statistics might have been lost!\n")); h->do_destroy = GNUNET_NO; GNUNET_SCHEDULER_add_continuation (&destroy_task, h, GNUNET_SCHEDULER_REASON_PREREQ_DONE); return 0; } hdr.type = htons (GNUNET_MESSAGE_TYPE_TEST); hdr.size = htons (sizeof (struct GNUNET_MessageHeader)); memcpy (buf, &hdr, sizeof (hdr)); if (GNUNET_YES != h->receiving) { h->receiving = GNUNET_YES; GNUNET_CLIENT_receive (h->client, &receive_stats, h, GNUNET_TIME_UNIT_FOREVER_REL); } return sizeof (struct GNUNET_MessageHeader); } /** * Schedule the next action to be performed. * * @param h statistics handle */ static void schedule_action (struct GNUNET_STATISTICS_Handle *h) { struct GNUNET_TIME_Relative timeout; if ( (NULL != h->th) || (GNUNET_SCHEDULER_NO_TASK != h->backoff_task) ) return; /* action already pending */ if (GNUNET_YES != try_connect (h)) { reconnect_later (h); return; } if (NULL != h->current) return; /* action already pending */ /* schedule next action */ h->current = h->action_head; if (NULL == h->current) { if (GNUNET_YES == h->do_destroy) { h->do_destroy = GNUNET_SYSERR; /* in 'TEST' mode */ h->th = GNUNET_CLIENT_notify_transmit_ready (h->client, sizeof (struct GNUNET_MessageHeader), SET_TRANSMIT_TIMEOUT, GNUNET_NO, &transmit_test_on_shutdown, h); } return; } GNUNET_CONTAINER_DLL_remove (h->action_head, h->action_tail, h->current); timeout = GNUNET_TIME_absolute_get_remaining (h->current->timeout); if (NULL == (h->th = GNUNET_CLIENT_notify_transmit_ready (h->client, h->current->msize, timeout, GNUNET_YES, &transmit_action, h))) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Failed to transmit request to statistics service.\n"); do_disconnect (h); reconnect_later (h); } } /** * Get statistic from the peer. * * @param handle identification of the statistics service * @param subsystem limit to the specified subsystem, NULL for our subsystem * @param name name of the statistic value, NULL for all values * @param timeout after how long should we give up (and call * cont with an error code)? * @param cont continuation to call when done (can be NULL) * @param proc function to call on each value * @param cls closure for cont and proc * @return NULL on error */ struct GNUNET_STATISTICS_GetHandle * GNUNET_STATISTICS_get (struct GNUNET_STATISTICS_Handle *handle, const char *subsystem, const char *name, struct GNUNET_TIME_Relative timeout, GNUNET_STATISTICS_Callback cont, GNUNET_STATISTICS_Iterator proc, void *cls) { size_t slen1; size_t slen2; struct GNUNET_STATISTICS_GetHandle *ai; if (NULL == handle) return NULL; GNUNET_assert (NULL != proc); GNUNET_assert (GNUNET_NO == handle->do_destroy); if (NULL == subsystem) subsystem = ""; if (NULL == name) name = ""; slen1 = strlen (subsystem) + 1; slen2 = strlen (name) + 1; GNUNET_assert (slen1 + slen2 + sizeof (struct GNUNET_MessageHeader) < GNUNET_SERVER_MAX_MESSAGE_SIZE); ai = GNUNET_malloc (sizeof (struct GNUNET_STATISTICS_GetHandle)); ai->sh = handle; ai->subsystem = GNUNET_strdup (subsystem); ai->name = GNUNET_strdup (name); ai->cont = cont; ai->proc = proc; ai->cls = cls; ai->timeout = GNUNET_TIME_relative_to_absolute (timeout); ai->type = ACTION_GET; ai->msize = slen1 + slen2 + sizeof (struct GNUNET_MessageHeader); GNUNET_CONTAINER_DLL_insert_tail (handle->action_head, handle->action_tail, ai); schedule_action (handle); return ai; } /** * Cancel a 'get' request. Must be called before the 'cont' * function is called. * * @param gh handle of the request to cancel */ void GNUNET_STATISTICS_get_cancel (struct GNUNET_STATISTICS_GetHandle *gh) { if (NULL == gh) return; if (gh->sh->current == gh) { gh->aborted = GNUNET_YES; } else { GNUNET_CONTAINER_DLL_remove (gh->sh->action_head, gh->sh->action_tail, gh); GNUNET_free (gh->name); GNUNET_free (gh->subsystem); GNUNET_free (gh); } } /** * Watch statistics from the peer (be notified whenever they change). * * @param handle identification of the statistics service * @param subsystem limit to the specified subsystem, never NULL * @param name name of the statistic value, never NULL * @param proc function to call on each value * @param proc_cls closure for proc * @return GNUNET_OK on success, GNUNET_SYSERR on error */ int GNUNET_STATISTICS_watch (struct GNUNET_STATISTICS_Handle *handle, const char *subsystem, const char *name, GNUNET_STATISTICS_Iterator proc, void *proc_cls) { struct GNUNET_STATISTICS_WatchEntry *w; if (NULL == handle) return GNUNET_SYSERR; w = GNUNET_malloc (sizeof (struct GNUNET_STATISTICS_WatchEntry)); w->subsystem = GNUNET_strdup (subsystem); w->name = GNUNET_strdup (name); w->proc = proc; w->proc_cls = proc_cls; GNUNET_array_append (handle->watches, handle->watches_size, w); schedule_watch_request (handle, w); return GNUNET_OK; } /** * Stop watching statistics from the peer. * * @param handle identification of the statistics service * @param subsystem limit to the specified subsystem, never NULL * @param name name of the statistic value, never NULL * @param proc function to call on each value * @param proc_cls closure for proc * @return GNUNET_OK on success, GNUNET_SYSERR on error (no such watch) */ int GNUNET_STATISTICS_watch_cancel (struct GNUNET_STATISTICS_Handle *handle, const char *subsystem, const char *name, GNUNET_STATISTICS_Iterator proc, void *proc_cls) { struct GNUNET_STATISTICS_WatchEntry *w; unsigned int i; if (NULL == handle) return GNUNET_SYSERR; for (i=0;iwatches_size;i++) { w = handle->watches[i]; if (NULL == w) continue; if ( (w->proc == proc) && (w->proc_cls == proc_cls) && (0 == strcmp (w->name, name)) && (0 == strcmp (w->subsystem, subsystem)) ) { GNUNET_free (w->name); GNUNET_free (w->subsystem); GNUNET_free (w); handle->watches[i] = NULL; return GNUNET_OK; } } return GNUNET_SYSERR; } /** * Queue a request to change a statistic. * * @param h statistics handle * @param name name of the value * @param make_persistent should the value be kept across restarts? * @param value new value or change * @param type type of the action (ACTION_SET or ACTION_UPDATE) */ static void add_setter_action (struct GNUNET_STATISTICS_Handle *h, const char *name, int make_persistent, uint64_t value, enum ActionType type) { struct GNUNET_STATISTICS_GetHandle *ai; size_t slen; size_t nlen; size_t nsize; int64_t delta; GNUNET_assert (NULL != h); GNUNET_assert (NULL != name); slen = strlen (h->subsystem) + 1; nlen = strlen (name) + 1; nsize = sizeof (struct GNUNET_STATISTICS_SetMessage) + slen + nlen; if (nsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break (0); return; } for (ai = h->action_head; NULL != ai; ai = ai->next) { if (! ( (0 == strcmp (ai->subsystem, h->subsystem)) && (0 == strcmp (ai->name, name)) && ( (ACTION_UPDATE == ai->type) || (ACTION_SET == ai->type) ) ) ) continue; if (ACTION_SET == ai->type) { if (ACTION_UPDATE == type) { delta = (int64_t) value; if (delta > 0) { /* update old set by new delta */ ai->value += delta; } else { /* update old set by new delta, but never go negative */ if (ai->value < -delta) ai->value = 0; else ai->value += delta; } } else { /* new set overrides old set */ ai->value = value; } } else { if (ACTION_UPDATE == type) { /* make delta cummulative */ delta = (int64_t) value; ai->value += delta; } else { /* drop old 'update', use new 'set' instead */ ai->value = value; ai->type = type; } } ai->timeout = GNUNET_TIME_relative_to_absolute (SET_TRANSMIT_TIMEOUT); ai->make_persistent = make_persistent; return; } /* no existing entry matches, create a fresh one */ ai = GNUNET_malloc (sizeof (struct GNUNET_STATISTICS_GetHandle)); ai->sh = h; ai->subsystem = GNUNET_strdup (h->subsystem); ai->name = GNUNET_strdup (name); ai->timeout = GNUNET_TIME_relative_to_absolute (SET_TRANSMIT_TIMEOUT); ai->make_persistent = make_persistent; ai->msize = nsize; ai->value = value; ai->type = type; GNUNET_CONTAINER_DLL_insert_tail (h->action_head, h->action_tail, ai); schedule_action (h); } /** * Set statistic value for the peer. Will always use our * subsystem (the argument used when "handle" was created). * * @param handle identification of the statistics service * @param name name of the statistic value * @param value new value to set * @param make_persistent should the value be kept across restarts? */ void GNUNET_STATISTICS_set (struct GNUNET_STATISTICS_Handle *handle, const char *name, uint64_t value, int make_persistent) { if (NULL == handle) return; GNUNET_assert (GNUNET_NO == handle->do_destroy); add_setter_action (handle, name, make_persistent, value, ACTION_SET); } /** * Set statistic value for the peer. Will always use our * subsystem (the argument used when "handle" was created). * * @param handle identification of the statistics service * @param name name of the statistic value * @param delta change in value (added to existing value) * @param make_persistent should the value be kept across restarts? */ void GNUNET_STATISTICS_update (struct GNUNET_STATISTICS_Handle *handle, const char *name, int64_t delta, int make_persistent) { if (NULL == handle) return; if (0 == delta) return; GNUNET_assert (GNUNET_NO == handle->do_destroy); add_setter_action (handle, name, make_persistent, (uint64_t) delta, ACTION_UPDATE); } /* end of statistics_api.c */