/*
This file is part of GNUnet.
- (C)
+ Copyright (C) 2013-2016 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
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.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
-
/**
* @file peerstore/peerstore_api.c
* @brief API for peerstore
* @author Omar Tarabai
+ * @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "peerstore.h"
+#include "peerstore_common.h"
#define LOG(kind,...) GNUNET_log_from (kind, "peerstore-api",__VA_ARGS__)
const struct GNUNET_CONFIGURATION_Handle *cfg;
/**
- * Connection to the service.
+ * Message queue
+ */
+ struct GNUNET_MQ_Handle *mq;
+
+ /**
+ * Head of active STORE requests.
+ */
+ struct GNUNET_PEERSTORE_StoreContext *store_head;
+
+ /**
+ * Tail of active STORE requests.
+ */
+ struct GNUNET_PEERSTORE_StoreContext *store_tail;
+
+ /**
+ * Head of active ITERATE requests.
*/
- struct GNUNET_CLIENT_Connection *client;
+ struct GNUNET_PEERSTORE_IterateContext *iterate_head;
+
+ /**
+ * Tail of active ITERATE requests.
+ */
+ struct GNUNET_PEERSTORE_IterateContext *iterate_tail;
+
+ /**
+ * Hashmap of watch requests
+ */
+ struct GNUNET_CONTAINER_MultiHashMap *watches;
+
+ /**
+ * Are we in the process of disconnecting but need to sync first?
+ */
+ int disconnecting;
};
*/
struct GNUNET_PEERSTORE_StoreContext
{
+ /**
+ * Kept in a DLL.
+ */
+ struct GNUNET_PEERSTORE_StoreContext *next;
+
+ /**
+ * Kept in a DLL.
+ */
+ struct GNUNET_PEERSTORE_StoreContext *prev;
/**
* Handle to the PEERSTORE service.
GNUNET_PEERSTORE_Continuation cont;
/**
- * Closure for 'cont'
+ * Closure for @e cont
*/
void *cont_cls;
+ /**
+ * Which subsystem does the store?
+ */
+ char *sub_system;
+
+ /**
+ * Key for the store operation.
+ */
+ char *key;
+
+ /**
+ * Contains @e size bytes.
+ */
+ void *value;
+
+ /**
+ * Peer the store is for.
+ */
+ struct GNUNET_PeerIdentity peer;
+
+ /**
+ * Number of bytes in @e value.
+ */
+ size_t size;
+
+ /**
+ * When does the value expire?
+ */
+ struct GNUNET_TIME_Absolute expiry;
+
+ /**
+ * Options for the store operation.
+ */
+ enum GNUNET_PEERSTORE_StoreOption options;
+
+};
+
+/**
+ * Context for a iterate request
+ */
+struct GNUNET_PEERSTORE_IterateContext
+{
+ /**
+ * Kept in a DLL.
+ */
+ struct GNUNET_PEERSTORE_IterateContext *next;
+
+ /**
+ * Kept in a DLL.
+ */
+ struct GNUNET_PEERSTORE_IterateContext *prev;
+
+ /**
+ * Handle to the PEERSTORE service.
+ */
+ struct GNUNET_PEERSTORE_Handle *h;
+
+ /**
+ * Which subsystem does the store?
+ */
+ char *sub_system;
+
+ /**
+ * Peer the store is for.
+ */
+ struct GNUNET_PeerIdentity peer;
+
+ /**
+ * Key for the store operation.
+ */
+ char *key;
+
+ /**
+ * Operation timeout
+ */
+ struct GNUNET_TIME_Relative timeout;
+
+ /**
+ * Callback with each matching record
+ */
+ GNUNET_PEERSTORE_Processor callback;
+
+ /**
+ * Closure for @e callback
+ */
+ void *callback_cls;
+
+ /**
+ * #GNUNET_YES if we are currently processing records.
+ */
+ int iterating;
+
+ /**
+ * Task identifier for the function called
+ * on iterate request timeout
+ */
+ struct GNUNET_SCHEDULER_Task *timeout_task;
+
+};
+
+/**
+ * Context for a watch request
+ */
+struct GNUNET_PEERSTORE_WatchContext
+{
+ /**
+ * Kept in a DLL.
+ */
+ struct GNUNET_PEERSTORE_WatchContext *next;
+
+ /**
+ * Kept in a DLL.
+ */
+ struct GNUNET_PEERSTORE_WatchContext *prev;
+
+ /**
+ * Handle to the PEERSTORE service.
+ */
+ struct GNUNET_PEERSTORE_Handle *h;
+
+ /**
+ * Callback with each record received
+ */
+ GNUNET_PEERSTORE_Processor callback;
+
+ /**
+ * Closure for @e callback
+ */
+ void *callback_cls;
+
+ /**
+ * Hash of the combined key
+ */
+ struct GNUNET_HashCode keyhash;
+
};
/******************************************************************************/
-/******************* CONNECTION FUNCTIONS *********************/
+/******************* DECLARATIONS *********************/
/******************************************************************************/
/**
* @param h handle to the service
*/
static void
-reconnect (struct GNUNET_PEERSTORE_Handle *h)
+reconnect (struct GNUNET_PEERSTORE_Handle *h);
+
+
+/**
+ * Callback after MQ envelope is sent
+ *
+ * @param cls a `struct GNUNET_PEERSTORE_StoreContext *`
+ */
+static void
+store_request_sent (void *cls)
+{
+ struct GNUNET_PEERSTORE_StoreContext *sc = cls;
+ GNUNET_PEERSTORE_Continuation cont;
+ void *cont_cls;
+
+ cont = sc->cont;
+ cont_cls = sc->cont_cls;
+ GNUNET_PEERSTORE_store_cancel (sc);
+ if (NULL != cont)
+ cont (cont_cls, GNUNET_OK);
+}
+
+
+/******************************************************************************/
+/******************* CONNECTION FUNCTIONS *********************/
+/******************************************************************************/
+
+static void
+handle_client_error (void *cls,
+ enum GNUNET_MQ_Error error)
+{
+ struct GNUNET_PEERSTORE_Handle *h = cls;
+
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("Received an error notification from MQ of type: %d\n"),
+ error);
+ reconnect (h);
+}
+
+
+/**
+ * Iterator over previous watches to resend them
+ *
+ * @param cls the `struct GNUNET_PEERSTORE_Handle`
+ * @param key key for the watch
+ * @param value the `struct GNUNET_PEERSTORE_WatchContext *`
+ * @return #GNUNET_YES (continue to iterate)
+ */
+static int
+rewatch_it (void *cls,
+ const struct GNUNET_HashCode *key,
+ void *value)
+{
+ struct GNUNET_PEERSTORE_Handle *h = cls;
+ struct GNUNET_PEERSTORE_WatchContext *wc = value;
+ struct StoreKeyHashMessage *hm;
+ struct GNUNET_MQ_Envelope *ev;
+
+ ev = GNUNET_MQ_msg (hm, GNUNET_MESSAGE_TYPE_PEERSTORE_WATCH);
+ hm->keyhash = wc->keyhash;
+ GNUNET_MQ_send (h->mq, ev);
+ return GNUNET_YES;
+}
+
+
+/**
+ * Called when the iterate request is timedout
+ *
+ * @param cls a `struct GNUNET_PEERSTORE_IterateContext *`
+ */
+static void
+iterate_timeout (void *cls)
+{
+ struct GNUNET_PEERSTORE_IterateContext *ic = cls;
+ GNUNET_PEERSTORE_Processor callback;
+ void *callback_cls;
+
+ ic->timeout_task = NULL;
+ callback = ic->callback;
+ callback_cls = ic->callback_cls;
+ GNUNET_PEERSTORE_iterate_cancel (ic);
+ if (NULL != callback)
+ callback (callback_cls, NULL, _("timeout"));
+}
+
+
+/**
+ * Iterator over watch requests to cancel them.
+ *
+ * @param cls unsused
+ * @param key key to the watch request
+ * @param value watch context
+ * @return #GNUNET_YES to continue iteration
+ */
+static int
+destroy_watch (void *cls,
+ const struct GNUNET_HashCode *key,
+ void *value)
{
+ struct GNUNET_PEERSTORE_WatchContext *wc = value;
+
+ GNUNET_PEERSTORE_watch_cancel (wc);
+ return GNUNET_YES;
+}
+
- LOG(GNUNET_ERROR_TYPE_DEBUG, "Reconnecting...\n");
- if (NULL != h->client)
+/**
+ * Kill the connection to the service. This can be delayed in case of pending
+ * STORE requests and the user explicitly asked to sync first. Otherwise it is
+ * performed instantly.
+ *
+ * @param h Handle to the service.
+ */
+static void
+do_disconnect (struct GNUNET_PEERSTORE_Handle *h)
+{
+ if (NULL != h->mq)
{
- GNUNET_CLIENT_disconnect (h->client);
- h->client = NULL;
+ GNUNET_MQ_destroy (h->mq);
+ h->mq = NULL;
}
- h->client = GNUNET_CLIENT_connect ("peerstore", h->cfg);
-
+ GNUNET_free (h);
}
+
/**
* Connect to the PEERSTORE service.
*
+ * @param cfg configuration to use
* @return NULL on error
*/
struct GNUNET_PEERSTORE_Handle *
GNUNET_PEERSTORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
{
- struct GNUNET_CLIENT_Connection *client;
struct GNUNET_PEERSTORE_Handle *h;
- client = GNUNET_CLIENT_connect ("peerstore", cfg);
- if(NULL == client)
- return NULL;
h = GNUNET_new (struct GNUNET_PEERSTORE_Handle);
- h->client = client;
h->cfg = cfg;
- LOG(GNUNET_ERROR_TYPE_DEBUG, "New connection created\n");
+ h->disconnecting = GNUNET_NO;
+ reconnect (h);
+ if (NULL == h->mq)
+ {
+ GNUNET_free (h);
+ return NULL;
+ }
return h;
}
+
/**
- * Disconnect from the PEERSTORE service
- * Do not call in case of pending requests
+ * Disconnect from the PEERSTORE service. Any pending ITERATE and WATCH requests
+ * will be canceled.
+ * Any pending STORE requests will depend on @e snyc_first flag.
*
* @param h handle to disconnect
+ * @param sync_first send any pending STORE requests before disconnecting
*/
void
-GNUNET_PEERSTORE_disconnect(struct GNUNET_PEERSTORE_Handle *h)
+GNUNET_PEERSTORE_disconnect (struct GNUNET_PEERSTORE_Handle *h,
+ int sync_first)
{
- if (NULL != h->client)
+ struct GNUNET_PEERSTORE_IterateContext *ic;
+ struct GNUNET_PEERSTORE_StoreContext *sc;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting.\n");
+ if (NULL != h->watches)
+ {
+ GNUNET_CONTAINER_multihashmap_iterate (h->watches, &destroy_watch, NULL);
+ GNUNET_CONTAINER_multihashmap_destroy (h->watches);
+ h->watches = NULL;
+ }
+ while (NULL != (ic = h->iterate_head))
+ {
+ GNUNET_break (0);
+ GNUNET_PEERSTORE_iterate_cancel (ic);
+ }
+ if (NULL != h->store_head)
{
- GNUNET_CLIENT_disconnect (h->client);
- h->client = NULL;
+ if (GNUNET_YES == sync_first)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Delaying disconnection due to pending store requests.\n");
+ h->disconnecting = GNUNET_YES;
+ return;
+ }
+ while (NULL != (sc = h->store_head))
+ GNUNET_PEERSTORE_store_cancel (sc);
}
- GNUNET_free(h);
- LOG(GNUNET_ERROR_TYPE_DEBUG, "Disconnected, BYE!\n");
+ do_disconnect (h);
}
/******************************************************************************/
-/******************* ADD FUNCTIONS *********************/
+/******************* STORE FUNCTIONS *********************/
/******************************************************************************/
-/**
- * When a response for store request is received
- *
- * @param cls a 'struct GNUNET_PEERSTORE_StoreContext *'
- * @param msg message received, NULL on timeout or fatal error
- */
-void store_response_receiver (void *cls, const struct GNUNET_MessageHeader *msg)
-{
- struct GNUNET_PEERSTORE_StoreContext *sc = cls;
- uint16_t msg_type;
-
- if(NULL == sc->cont)
- return;
- if(NULL == msg)
- {
- sc->cont(sc->cont_cls, GNUNET_SYSERR);
- reconnect(sc->h);
- return;
- }
- msg_type = ntohs(msg->type);
- if(GNUNET_MESSAGE_TYPE_PEERSTORE_STORE_RESULT_OK == msg_type)
- sc->cont(sc->cont_cls, GNUNET_OK);
- else if(GNUNET_MESSAGE_TYPE_PEERSTORE_STORE_RESULT_FAIL == msg_type)
- sc->cont(sc->cont_cls, GNUNET_SYSERR);
- else
- {
- LOG(GNUNET_ERROR_TYPE_ERROR, "Invalid response from `PEERSTORE' service.\n");
- sc->cont(sc->cont_cls, GNUNET_SYSERR);
- }
-
-}
/**
* Cancel a store request
void
GNUNET_PEERSTORE_store_cancel (struct GNUNET_PEERSTORE_StoreContext *sc)
{
- sc->cont = NULL;
+ struct GNUNET_PEERSTORE_Handle *h = sc->h;
+
+ GNUNET_CONTAINER_DLL_remove (sc->h->store_head, sc->h->store_tail, sc);
+ GNUNET_free (sc->sub_system);
+ GNUNET_free (sc->value);
+ GNUNET_free (sc->key);
+ GNUNET_free (sc);
+ if ((GNUNET_YES == h->disconnecting) && (NULL == h->store_head))
+ do_disconnect (h);
}
+
/**
- * Store a new entry in the PEERSTORE
+ * Store a new entry in the PEERSTORE.
+ * Note that stored entries can be lost in some cases
+ * such as power failure.
*
* @param h Handle to the PEERSTORE service
* @param sub_system name of the sub system
* @param peer Peer Identity
* @param key entry key
* @param value entry value BLOB
- * @param size size of 'value'
- * @param lifetime relative time after which the entry is (possibly) deleted
- * @param cont Continuation function after the store request is processed
- * @param cont_cls Closure for 'cont'
+ * @param size size of @e value
+ * @param expiry absolute time after which the entry is (possibly) deleted
+ * @param options options specific to the storage operation
+ * @param cont Continuation function after the store request is sent
+ * @param cont_cls Closure for @a cont
*/
struct GNUNET_PEERSTORE_StoreContext *
GNUNET_PEERSTORE_store (struct GNUNET_PEERSTORE_Handle *h,
- const char *sub_system,
- const struct GNUNET_PeerIdentity *peer,
- const char *key,
- const void *value,
- size_t size,
- struct GNUNET_TIME_Relative lifetime,
- GNUNET_PEERSTORE_Continuation cont,
- void *cont_cls)
+ const char *sub_system,
+ const struct GNUNET_PeerIdentity *peer,
+ const char *key,
+ const void *value, size_t size,
+ struct GNUNET_TIME_Absolute expiry,
+ enum GNUNET_PEERSTORE_StoreOption options,
+ GNUNET_PEERSTORE_Continuation cont,
+ void *cont_cls)
{
+ struct GNUNET_MQ_Envelope *ev;
struct GNUNET_PEERSTORE_StoreContext *sc;
- struct StoreRequestMessage *srm;
- size_t ss_size;
- size_t key_size;
- size_t request_size;
- void *dummy;
LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Storing value (size: %lu) for subsytem `%s', peer `%s', key `%s'\n",
- size, sub_system, GNUNET_i2s (peer), key);
- sc = GNUNET_new(struct GNUNET_PEERSTORE_StoreContext);
+ "Storing value (size: %lu) for subsytem `%s', peer `%s', key `%s'\n",
+ size, sub_system, GNUNET_i2s (peer), key);
+ ev = PEERSTORE_create_record_mq_envelope (sub_system, peer, key, value, size,
+ &expiry, options,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_STORE);
+ sc = GNUNET_new (struct GNUNET_PEERSTORE_StoreContext);
+
+ sc->sub_system = GNUNET_strdup (sub_system);
+ sc->peer = *peer;
+ sc->key = GNUNET_strdup (key);
+ sc->value = GNUNET_memdup (value, size);
+ sc->size = size;
+ sc->expiry = expiry;
+ sc->options = options;
sc->cont = cont;
sc->cont_cls = cont_cls;
sc->h = h;
- ss_size = strlen(sub_system) + 1;
- key_size = strlen(key) + 1;
- request_size = sizeof(struct StoreRequestMessage) +
- ss_size +
- key_size +
- size;
- srm = GNUNET_malloc(request_size);
- srm->header.size = htons(request_size);
- srm->header.type = htons(GNUNET_MESSAGE_TYPE_PEERSTORE_STORE);
- srm->key_size = htons(key_size);
- srm->lifetime = lifetime;
- srm->peer = *peer;
- srm->sub_system_size = htons(ss_size);
- srm->value_size = htons(size);
- dummy = &srm[1];
- memcpy(dummy, sub_system, ss_size);
- dummy += ss_size;
- memcpy(dummy, key, key_size);
- dummy += key_size;
- memcpy(dummy, value, size);
- GNUNET_CLIENT_transmit_and_get_response(h->client,
- (const struct GNUNET_MessageHeader *)srm,
- GNUNET_TIME_UNIT_FOREVER_REL,
- GNUNET_YES,
- &store_response_receiver,
- sc);
+
+ GNUNET_CONTAINER_DLL_insert_tail (h->store_head, h->store_tail, sc);
+ GNUNET_MQ_notify_sent (ev, &store_request_sent, sc);
+ GNUNET_MQ_send (h->mq, ev);
return sc;
}
+/******************************************************************************/
+/******************* ITERATE FUNCTIONS *********************/
+/******************************************************************************/
+
+
+/**
+ * When a response for iterate request is received
+ *
+ * @param cls a `struct GNUNET_PEERSTORE_Handle *`
+ * @param msg message received
+ */
+static void
+handle_iterate_end (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ struct GNUNET_PEERSTORE_Handle *h = cls;
+ struct GNUNET_PEERSTORE_IterateContext *ic;
+ GNUNET_PEERSTORE_Processor callback;
+ void *callback_cls;
+
+ ic = h->iterate_head;
+ if (NULL == ic)
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("Unexpected iteration response, this should not happen.\n"));
+ reconnect (h);
+ return;
+ }
+ callback = ic->callback;
+ callback_cls = ic->callback_cls;
+ ic->iterating = GNUNET_NO;
+ GNUNET_PEERSTORE_iterate_cancel (ic);
+ if (NULL != callback)
+ callback (callback_cls, NULL, NULL);
+}
+
+
+/**
+ * When a response for iterate request is received, check the
+ * message is well-formed.
+ *
+ * @param cls a `struct GNUNET_PEERSTORE_Handle *`
+ * @param msg message received
+ */
+static int
+check_iterate_result (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ /* we defer validation to #handle_iterate_result */
+ return GNUNET_OK;
+}
+
+
+/**
+ * When a response for iterate request is received
+ *
+ * @param cls a `struct GNUNET_PEERSTORE_Handle *`
+ * @param msg message received
+ */
+static void
+handle_iterate_result (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ struct GNUNET_PEERSTORE_Handle *h = cls;
+ struct GNUNET_PEERSTORE_IterateContext *ic;
+ GNUNET_PEERSTORE_Processor callback;
+ void *callback_cls;
+ struct GNUNET_PEERSTORE_Record *record;
+
+ ic = h->iterate_head;
+ if (NULL == ic)
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("Unexpected iteration response, this should not happen.\n"));
+ reconnect (h);
+ return;
+ }
+ ic->iterating = GNUNET_YES;
+ callback = ic->callback;
+ callback_cls = ic->callback_cls;
+ if (NULL == callback)
+ return;
+ record = PEERSTORE_parse_record_message (msg);
+ if (NULL == record)
+ {
+ callback (callback_cls,
+ NULL,
+ _("Received a malformed response from service."));
+ }
+ else
+ {
+ callback (callback_cls,
+ record,
+ NULL);
+ PEERSTORE_destroy_record (record);
+ }
+}
+
+
+/**
+ * Cancel an iterate request
+ * Please do not call after the iterate request is done
+ *
+ * @param ic Iterate request context as returned by GNUNET_PEERSTORE_iterate()
+ */
+void
+GNUNET_PEERSTORE_iterate_cancel (struct GNUNET_PEERSTORE_IterateContext *ic)
+{
+ if (NULL != ic->timeout_task)
+ {
+ GNUNET_SCHEDULER_cancel (ic->timeout_task);
+ ic->timeout_task = NULL;
+ }
+ if (GNUNET_NO == ic->iterating)
+ {
+ GNUNET_CONTAINER_DLL_remove (ic->h->iterate_head,
+ ic->h->iterate_tail,
+ ic);
+ GNUNET_free (ic->sub_system);
+ GNUNET_free_non_null (ic->key);
+ GNUNET_free (ic);
+ }
+ else
+ ic->callback = NULL;
+}
+
+
+/**
+ * Iterate over records matching supplied key information
+ *
+ * @param h handle to the PEERSTORE service
+ * @param sub_system name of sub system
+ * @param peer Peer identity (can be NULL)
+ * @param key entry key string (can be NULL)
+ * @param timeout time after which the iterate request is canceled
+ * @param callback function called with each matching record, all NULL's on end
+ * @param callback_cls closure for @a callback
+ * @return Handle to iteration request
+ */
+struct GNUNET_PEERSTORE_IterateContext *
+GNUNET_PEERSTORE_iterate (struct GNUNET_PEERSTORE_Handle *h,
+ const char *sub_system,
+ const struct GNUNET_PeerIdentity *peer,
+ const char *key,
+ struct GNUNET_TIME_Relative timeout,
+ GNUNET_PEERSTORE_Processor callback,
+ void *callback_cls)
+{
+ struct GNUNET_MQ_Envelope *ev;
+ struct GNUNET_PEERSTORE_IterateContext *ic;
+
+ ev = PEERSTORE_create_record_mq_envelope (sub_system, peer, key, NULL, 0,
+ NULL, 0,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_ITERATE);
+ ic = GNUNET_new (struct GNUNET_PEERSTORE_IterateContext);
+
+ ic->callback = callback;
+ ic->callback_cls = callback_cls;
+ ic->h = h;
+ ic->sub_system = GNUNET_strdup (sub_system);
+ if (NULL != peer)
+ ic->peer = *peer;
+ if (NULL != key)
+ ic->key = GNUNET_strdup (key);
+ ic->timeout = timeout;
+ GNUNET_CONTAINER_DLL_insert_tail (h->iterate_head,
+ h->iterate_tail,
+ ic);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Sending an iterate request for sub system `%s'\n",
+ sub_system);
+ GNUNET_MQ_send (h->mq, ev);
+ ic->timeout_task =
+ GNUNET_SCHEDULER_add_delayed (timeout,
+ &iterate_timeout,
+ ic);
+ return ic;
+}
+
+
+/******************************************************************************/
+/******************* WATCH FUNCTIONS *********************/
+/******************************************************************************/
+
+/**
+ * When a watch record is received, validate it is well-formed.
+ *
+ * @param cls a `struct GNUNET_PEERSTORE_Handle *`
+ * @param msg message received
+ */
+static int
+check_watch_record (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ /* we defer validation to #handle_watch_result */
+ return GNUNET_OK;
+}
+
+
+/**
+ * When a watch record is received, process it.
+ *
+ * @param cls a `struct GNUNET_PEERSTORE_Handle *`
+ * @param msg message received
+ */
+static void
+handle_watch_record (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ struct GNUNET_PEERSTORE_Handle *h = cls;
+ struct GNUNET_PEERSTORE_Record *record;
+ struct GNUNET_HashCode keyhash;
+ struct GNUNET_PEERSTORE_WatchContext *wc;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Received a watch record from service.\n");
+ record = PEERSTORE_parse_record_message (msg);
+ if (NULL == record)
+ {
+ reconnect (h);
+ return;
+ }
+ PEERSTORE_hash_key (record->sub_system,
+ record->peer,
+ record->key,
+ &keyhash);
+ // FIXME: what if there are multiple watches for the same key?
+ wc = GNUNET_CONTAINER_multihashmap_get (h->watches,
+ &keyhash);
+ if (NULL == wc)
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("Received a watch result for a non existing watch.\n"));
+ PEERSTORE_destroy_record (record);
+ reconnect (h);
+ return;
+ }
+ if (NULL != wc->callback)
+ wc->callback (wc->callback_cls,
+ record,
+ NULL);
+ PEERSTORE_destroy_record (record);
+}
+
+
+/**
+ * Close the existing connection to PEERSTORE and reconnect.
+ *
+ * @param h handle to the service
+ */
+static void
+reconnect (struct GNUNET_PEERSTORE_Handle *h)
+{
+ GNUNET_MQ_hd_fixed_size (iterate_end,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_ITERATE_END,
+ struct GNUNET_MessageHeader);
+ GNUNET_MQ_hd_var_size (iterate_result,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_ITERATE_RECORD,
+ struct GNUNET_MessageHeader);
+ GNUNET_MQ_hd_var_size (watch_record,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_WATCH_RECORD,
+ struct GNUNET_MessageHeader);
+ struct GNUNET_MQ_MessageHandler mq_handlers[] = {
+ make_iterate_end_handler (h),
+ make_iterate_result_handler (h),
+ make_watch_record_handler (h),
+ GNUNET_MQ_handler_end ()
+ };
+ struct GNUNET_PEERSTORE_IterateContext *ic;
+ struct GNUNET_PEERSTORE_IterateContext *next;
+ GNUNET_PEERSTORE_Processor icb;
+ void *icb_cls;
+ struct GNUNET_PEERSTORE_StoreContext *sc;
+ struct GNUNET_MQ_Envelope *ev;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Reconnecting...\n");
+ for (ic = h->iterate_head; NULL != ic; ic = next)
+ {
+ next = ic->next;
+ if (GNUNET_YES == ic->iterating)
+ {
+ icb = ic->callback;
+ icb_cls = ic->callback_cls;
+ GNUNET_PEERSTORE_iterate_cancel (ic);
+ if (NULL != icb)
+ icb (icb_cls,
+ NULL,
+ "Iteration canceled due to reconnection");
+ }
+ }
+ if (NULL != h->mq)
+ {
+ GNUNET_MQ_destroy (h->mq);
+ h->mq = NULL;
+ }
+ h->mq = GNUNET_CLIENT_connecT (h->cfg,
+ "peerstore",
+ mq_handlers,
+ &handle_client_error,
+ h);
+ if (NULL == h->mq)
+ return;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Resending pending requests after reconnect.\n");
+ if (NULL != h->watches)
+ GNUNET_CONTAINER_multihashmap_iterate (h->watches,
+ &rewatch_it,
+ h);
+ for (ic = h->iterate_head; NULL != ic; ic = ic->next)
+ {
+ ev = PEERSTORE_create_record_mq_envelope (ic->sub_system,
+ &ic->peer,
+ ic->key,
+ NULL, 0,
+ NULL, 0,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_ITERATE);
+ GNUNET_MQ_send (h->mq, ev);
+ ic->timeout_task
+ = GNUNET_SCHEDULER_add_delayed (ic->timeout,
+ &iterate_timeout,
+ ic);
+ }
+ for (sc = h->store_head; NULL != sc; sc = sc->next)
+ {
+ ev = PEERSTORE_create_record_mq_envelope (sc->sub_system,
+ &sc->peer,
+ sc->key,
+ sc->value,
+ sc->size,
+ &sc->expiry,
+ sc->options,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_STORE);
+ GNUNET_MQ_notify_sent (ev,
+ &store_request_sent,
+ sc);
+ GNUNET_MQ_send (h->mq,
+ ev);
+ }
+}
+
+
+/**
+ * Cancel a watch request
+ *
+ * @param wc handle to the watch request
+ */
+void
+GNUNET_PEERSTORE_watch_cancel (struct GNUNET_PEERSTORE_WatchContext *wc)
+{
+ struct GNUNET_PEERSTORE_Handle *h = wc->h;
+ struct GNUNET_MQ_Envelope *ev;
+ struct StoreKeyHashMessage *hm;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Canceling watch.\n");
+ ev = GNUNET_MQ_msg (hm,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_WATCH_CANCEL);
+ hm->keyhash = wc->keyhash;
+ GNUNET_MQ_send (h->mq, ev);
+ GNUNET_CONTAINER_multihashmap_remove (h->watches,
+ &wc->keyhash,
+ wc);
+ GNUNET_free (wc);
+}
+
+
+/**
+ * Request watching a given key
+ * User will be notified with any new values added to key
+ *
+ * @param h handle to the PEERSTORE service
+ * @param sub_system name of sub system
+ * @param peer Peer identity
+ * @param key entry key string
+ * @param callback function called with each new value
+ * @param callback_cls closure for @a callback
+ * @return Handle to watch request
+ */
+struct GNUNET_PEERSTORE_WatchContext *
+GNUNET_PEERSTORE_watch (struct GNUNET_PEERSTORE_Handle *h,
+ const char *sub_system,
+ const struct GNUNET_PeerIdentity *peer,
+ const char *key,
+ GNUNET_PEERSTORE_Processor callback,
+ void *callback_cls)
+{
+ struct GNUNET_MQ_Envelope *ev;
+ struct StoreKeyHashMessage *hm;
+ struct GNUNET_PEERSTORE_WatchContext *wc;
+
+ ev = GNUNET_MQ_msg (hm,
+ GNUNET_MESSAGE_TYPE_PEERSTORE_WATCH);
+ PEERSTORE_hash_key (sub_system,
+ peer,
+ key,
+ &hm->keyhash);
+ wc = GNUNET_new (struct GNUNET_PEERSTORE_WatchContext);
+ wc->callback = callback;
+ wc->callback_cls = callback_cls;
+ wc->h = h;
+ wc->keyhash = hm->keyhash;
+ if (NULL == h->watches)
+ h->watches = GNUNET_CONTAINER_multihashmap_create (5, GNUNET_NO);
+ GNUNET_assert (GNUNET_OK ==
+ GNUNET_CONTAINER_multihashmap_put (h->watches,
+ &wc->keyhash,
+ wc,
+ GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Sending a watch request for ss `%s', peer `%s', key `%s'.\n",
+ sub_system,
+ GNUNET_i2s (peer),
+ key);
+ GNUNET_MQ_send (h->mq, ev);
+ return wc;
+}
+
/* end of peerstore_api.c */
projects / oweals / gnunet.git / blobdiff