/*
This file is part of GNUnet
- (C) 2004, 2005, 2006, 2007, 2009 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2004-2013, 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
- by the Free Software Foundation; either version 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
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 datastore/datastore_api.c
- * @brief Management for the datastore for files stored on a GNUnet node
+ * @brief Management for the datastore for files stored on a GNUnet node. Implements
+ * a priority queue for requests
* @author Christian Grothoff
*/
-
#include "platform.h"
+#include "gnunet_arm_service.h"
+#include "gnunet_constants.h"
#include "gnunet_datastore_service.h"
+#include "gnunet_statistics_service.h"
#include "datastore.h"
+#define LOG(kind,...) GNUNET_log_from (kind, "datastore-api",__VA_ARGS__)
+
+/**
+ * Collect an instane number of statistics? May cause excessive IPC.
+ */
+#define INSANE_STATISTICS GNUNET_NO
+
+/**
+ * If a client stopped asking for more results, how many more do
+ * we receive from the DB before killing the connection? Trade-off
+ * between re-doing TCP handshakes and (needlessly) receiving
+ * useless results.
+ */
+#define MAX_EXCESS_RESULTS 8
+
+/**
+ * Context for processing status messages.
+ */
+struct StatusContext
+{
+ /**
+ * Continuation to call with the status.
+ */
+ GNUNET_DATASTORE_ContinuationWithStatus cont;
+
+ /**
+ * Closure for @e cont.
+ */
+ void *cont_cls;
+
+};
+
+
+/**
+ * Context for processing result messages.
+ */
+struct ResultContext
+{
+ /**
+ * Function to call with the result.
+ */
+ GNUNET_DATASTORE_DatumProcessor proc;
+
+ /**
+ * Closure for @e proc.
+ */
+ void *proc_cls;
+
+};
+
+
+/**
+ * Context for a queue operation.
+ */
+union QueueContext
+{
+
+ struct StatusContext sc;
+
+ struct ResultContext rc;
+
+};
+
+
+/**
+ * Entry in our priority queue.
+ */
+struct GNUNET_DATASTORE_QueueEntry
+{
+
+ /**
+ * This is a linked list.
+ */
+ struct GNUNET_DATASTORE_QueueEntry *next;
+
+ /**
+ * This is a linked list.
+ */
+ struct GNUNET_DATASTORE_QueueEntry *prev;
+
+ /**
+ * Handle to the master context.
+ */
+ struct GNUNET_DATASTORE_Handle *h;
+
+ /**
+ * Function to call after transmission of the request.
+ */
+ GNUNET_DATASTORE_ContinuationWithStatus cont;
+
+ /**
+ * Closure for @e cont.
+ */
+ void *cont_cls;
+
+ /**
+ * Context for the operation.
+ */
+ union QueueContext qc;
+
+ /**
+ * Envelope of the request to transmit, NULL after
+ * transmission.
+ */
+ struct GNUNET_MQ_Envelope *env;
+
+ /**
+ * Priority in the queue.
+ */
+ unsigned int priority;
+
+ /**
+ * Maximum allowed length of queue (otherwise
+ * this request should be discarded).
+ */
+ unsigned int max_queue;
+
+ /**
+ * Expected response type.
+ */
+ uint16_t response_type;
+
+};
+
+
/**
* Handle to the datastore service.
*/
struct GNUNET_DATASTORE_Handle
{
+
+ /**
+ * Our configuration.
+ */
+ const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+ /**
+ * Current connection to the datastore service.
+ */
+ struct GNUNET_MQ_Handle *mq;
+
+ /**
+ * Handle for statistics.
+ */
+ struct GNUNET_STATISTICS_Handle *stats;
+
+ /**
+ * Current head of priority queue.
+ */
+ struct GNUNET_DATASTORE_QueueEntry *queue_head;
+
+ /**
+ * Current tail of priority queue.
+ */
+ struct GNUNET_DATASTORE_QueueEntry *queue_tail;
+
+ /**
+ * Task for trying to reconnect.
+ */
+ struct GNUNET_SCHEDULER_Task *reconnect_task;
+
+ /**
+ * How quickly should we retry? Used for exponential back-off on
+ * connect-errors.
+ */
+ struct GNUNET_TIME_Relative retry_time;
+
+ /**
+ * Number of entries in the queue.
+ */
+ unsigned int queue_size;
+
+ /**
+ * Number of results we're receiving for the current query
+ * after application stopped to care. Used to determine when
+ * to reset the connection.
+ */
+ unsigned int result_count;
+
+ /**
+ * We should ignore the next message(s) from the service.
+ */
+ unsigned int skip_next_messages;
+
};
+/**
+ * Try reconnecting to the datastore service.
+ *
+ * @param cls the `struct GNUNET_DATASTORE_Handle`
+ */
+static void
+try_reconnect (void *cls);
+
+
+/**
+ * Disconnect from the service and then try reconnecting to the datastore service
+ * after some delay.
+ *
+ * @param h handle to datastore to disconnect and reconnect
+ */
+static void
+do_disconnect (struct GNUNET_DATASTORE_Handle *h)
+{
+ if (NULL == h->mq)
+ {
+ GNUNET_break (0);
+ return;
+ }
+ GNUNET_MQ_destroy (h->mq);
+ h->mq = NULL;
+ h->skip_next_messages = 0;
+ h->reconnect_task
+ = GNUNET_SCHEDULER_add_delayed (h->retry_time,
+ &try_reconnect,
+ h);
+}
+
+
+/**
+ * Free a queue entry. Removes the given entry from the
+ * queue and releases associated resources. Does NOT
+ * call the callback.
+ *
+ * @param qe entry to free.
+ */
+static void
+free_queue_entry (struct GNUNET_DATASTORE_QueueEntry *qe)
+{
+ struct GNUNET_DATASTORE_Handle *h = qe->h;
+
+ GNUNET_CONTAINER_DLL_remove (h->queue_head,
+ h->queue_tail,
+ qe);
+ h->queue_size--;
+ if (NULL != qe->env)
+ GNUNET_MQ_discard (qe->env);
+ GNUNET_free (qe);
+}
+
+
+/**
+ * Handle error in sending drop request to datastore.
+ *
+ * @param cls closure with the datastore handle
+ * @param error error code
+ */
+static void
+mq_error_handler (void *cls,
+ enum GNUNET_MQ_Error error)
+{
+ struct GNUNET_DATASTORE_Handle *h = cls;
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "MQ error, reconnecting to DATASTORE\n");
+ do_disconnect (h);
+ qe = h->queue_head;
+ if ( (NULL != qe) &&
+ (NULL == qe->env) )
+ {
+ union QueueContext qc = qe->qc;
+ uint16_t rt = qe->response_type;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Failed to receive response from database.\n");
+ free_queue_entry (qe);
+ switch (rt)
+ {
+ case GNUNET_MESSAGE_TYPE_DATASTORE_STATUS:
+ if (NULL != qc.sc.cont)
+ qc.sc.cont (qc.sc.cont_cls,
+ GNUNET_SYSERR,
+ GNUNET_TIME_UNIT_ZERO_ABS,
+ _("DATASTORE disconnected"));
+ break;
+ case GNUNET_MESSAGE_TYPE_DATASTORE_DATA:
+ if (NULL != qc.rc.proc)
+ qc.rc.proc (qc.rc.proc_cls,
+ NULL,
+ 0,
+ NULL, 0, 0, 0,
+ GNUNET_TIME_UNIT_ZERO_ABS,
+ 0);
+ break;
+ default:
+ GNUNET_break (0);
+ }
+ }
+}
+
+
/**
* Connect to the datastore service.
*
* @param cfg configuration to use
- * @param sched scheduler to use
* @return handle to use to access the service
*/
-struct GNUNET_DATASTORE_Handle *GNUNET_DATASTORE_connect (struct
- GNUNET_CONFIGURATION_Handle
- *cfg,
- struct
- GNUNET_SCHEDULER_Handle
- *sched)
+struct GNUNET_DATASTORE_Handle *
+GNUNET_DATASTORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
{
- return NULL;
+ struct GNUNET_DATASTORE_Handle *h;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Establishing DATASTORE connection!\n");
+ h = GNUNET_new (struct GNUNET_DATASTORE_Handle);
+ h->cfg = cfg;
+ try_reconnect (h);
+ if (NULL == h->mq)
+ {
+ GNUNET_free (h);
+ return NULL;
+ }
+ h->stats = GNUNET_STATISTICS_create ("datastore-api",
+ cfg);
+ return h;
+}
+
+
+/**
+ * Task used by to disconnect from the datastore after
+ * we send the #GNUNET_MESSAGE_TYPE_DATASTORE_DROP message.
+ *
+ * @param cls the datastore handle
+ */
+static void
+disconnect_after_drop (void *cls)
+{
+ struct GNUNET_DATASTORE_Handle *h = cls;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Drop sent, disconnecting\n");
+ GNUNET_DATASTORE_disconnect (h,
+ GNUNET_NO);
+}
+
+
+/**
+ * Handle error in sending drop request to datastore.
+ *
+ * @param cls closure with the datastore handle
+ * @param error error code
+ */
+static void
+disconnect_on_mq_error (void *cls,
+ enum GNUNET_MQ_Error error)
+{
+ struct GNUNET_DATASTORE_Handle *h = cls;
+
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ "Failed to ask datastore to drop tables\n");
+ GNUNET_DATASTORE_disconnect (h,
+ GNUNET_NO);
}
* associated resources).
*
* @param h handle to the datastore
- * @param drop set to GNUNET_YES to delete all data in datastore (!)
+ * @param drop set to #GNUNET_YES to delete all data in datastore (!)
+ */
+void
+GNUNET_DATASTORE_disconnect (struct GNUNET_DATASTORE_Handle *h,
+ int drop)
+{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Datastore disconnect\n");
+ if (NULL != h->mq)
+ {
+ GNUNET_MQ_destroy (h->mq);
+ h->mq = NULL;
+ }
+ if (NULL != h->reconnect_task)
+ {
+ GNUNET_SCHEDULER_cancel (h->reconnect_task);
+ h->reconnect_task = NULL;
+ }
+ while (NULL != (qe = h->queue_head))
+ {
+ switch (qe->response_type)
+ {
+ case GNUNET_MESSAGE_TYPE_DATASTORE_STATUS:
+ if (NULL != qe->qc.sc.cont)
+ qe->qc.sc.cont (qe->qc.sc.cont_cls,
+ GNUNET_SYSERR,
+ GNUNET_TIME_UNIT_ZERO_ABS,
+ _("Disconnected from DATASTORE"));
+ break;
+ case GNUNET_MESSAGE_TYPE_DATASTORE_DATA:
+ if (NULL != qe->qc.rc.proc)
+ qe->qc.rc.proc (qe->qc.rc.proc_cls,
+ NULL,
+ 0,
+ NULL, 0, 0, 0,
+ GNUNET_TIME_UNIT_ZERO_ABS,
+ 0);
+ break;
+ default:
+ GNUNET_break (0);
+ }
+ free_queue_entry (qe);
+ }
+ if (GNUNET_YES == drop)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Re-connecting to issue DROP!\n");
+ GNUNET_assert (NULL == h->mq);
+ h->mq = GNUNET_CLIENT_connect (h->cfg,
+ "datastore",
+ NULL,
+ &disconnect_on_mq_error,
+ h);
+ if (NULL != h->mq)
+ {
+ struct GNUNET_MessageHeader *hdr;
+ struct GNUNET_MQ_Envelope *env;
+
+ env = GNUNET_MQ_msg (hdr,
+ GNUNET_MESSAGE_TYPE_DATASTORE_DROP);
+ GNUNET_MQ_notify_sent (env,
+ &disconnect_after_drop,
+ h);
+ GNUNET_MQ_send (h->mq,
+ env);
+ return;
+ }
+ GNUNET_break (0);
+ }
+ GNUNET_STATISTICS_destroy (h->stats,
+ GNUNET_NO);
+ h->stats = NULL;
+ GNUNET_free (h);
+}
+
+
+/**
+ * Create a new entry for our priority queue (and possibly discard other entires if
+ * the queue is getting too long).
+ *
+ * @param h handle to the datastore
+ * @param env envelope with the message to queue
+ * @param queue_priority priority of the entry
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param expected_type which type of response do we expect,
+ * #GNUNET_MESSAGE_TYPE_DATASTORE_STATUS or
+ * #GNUNET_MESSAGE_TYPE_DATASTORE_DATA
+ * @param qc client context (NOT a closure for @a response_proc)
+ * @return NULL if the queue is full
*/
-void GNUNET_DATASTORE_disconnect (struct GNUNET_DATASTORE_Handle *h,
- int drop)
+static struct GNUNET_DATASTORE_QueueEntry *
+make_queue_entry (struct GNUNET_DATASTORE_Handle *h,
+ struct GNUNET_MQ_Envelope *env,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ uint16_t expected_type,
+ const union QueueContext *qc)
{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct GNUNET_DATASTORE_QueueEntry *pos;
+ unsigned int c;
+
+ if ( (NULL != h->queue_tail) &&
+ (h->queue_tail->priority >= queue_priority) )
+ {
+ c = h->queue_size;
+ pos = NULL;
+ }
+ else
+ {
+ c = 0;
+ pos = h->queue_head;
+ }
+ while ( (NULL != pos) &&
+ (c < max_queue_size) &&
+ (pos->priority >= queue_priority) )
+ {
+ c++;
+ pos = pos->next;
+ }
+ if (c >= max_queue_size)
+ {
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# queue overflows"),
+ 1,
+ GNUNET_NO);
+ GNUNET_MQ_discard (env);
+ return NULL;
+ }
+ qe = GNUNET_new (struct GNUNET_DATASTORE_QueueEntry);
+ qe->h = h;
+ qe->env = env;
+ qe->response_type = expected_type;
+ qe->qc = *qc;
+ qe->priority = queue_priority;
+ qe->max_queue = max_queue_size;
+ if (NULL == pos)
+ {
+ /* append at the tail */
+ pos = h->queue_tail;
+ }
+ else
+ {
+ pos = pos->prev;
+ /* do not insert at HEAD if HEAD query was already
+ * transmitted and we are still receiving replies! */
+ if ( (NULL == pos) &&
+ (NULL == h->queue_head->env) )
+ pos = h->queue_head;
+ }
+ c++;
+#if INSANE_STATISTICS
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# queue entries created"),
+ 1,
+ GNUNET_NO);
+#endif
+ GNUNET_CONTAINER_DLL_insert_after (h->queue_head,
+ h->queue_tail,
+ pos,
+ qe);
+ h->queue_size++;
+ return qe;
}
/**
- * Get the current on-disk size of the datastore.
+ * Process entries in the queue (or do nothing if we are already
+ * doing so).
+ *
* @param h handle to the datastore
- * @return size estimate, -1 if datastore is not available (yet)
*/
-unsigned long long GNUNET_DATASTORE_size (struct GNUNET_DATASTORE_Handle *h)
+static void
+process_queue (struct GNUNET_DATASTORE_Handle *h)
+{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+
+ if (NULL == (qe = h->queue_head))
+ {
+ /* no entry in queue */
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Queue empty\n");
+ return;
+ }
+ if (NULL == qe->env)
+ {
+ /* waiting for replies */
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Head request already transmitted\n");
+ return;
+ }
+ if (NULL == h->mq)
+ {
+ /* waiting for reconnect */
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Not connected\n");
+ return;
+ }
+ GNUNET_MQ_send (h->mq,
+ qe->env);
+ qe->env = NULL;
+}
+
+
+
+
+/**
+ * Function called to check status message from the service.
+ *
+ * @param cls closure
+ * @param sm status message received
+ * @return #GNUNET_OK if the message is well-formed
+ */
+static int
+check_status (void *cls,
+ const struct StatusMessage *sm)
+{
+ uint16_t msize = ntohs (sm->header.size) - sizeof (*sm);
+ int32_t status = ntohl (sm->status);
+
+ if (msize > 0)
+ {
+ const char *emsg = (const char *) &sm[1];
+
+ if ('\0' != emsg[msize - 1])
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ }
+ else if (GNUNET_SYSERR == status)
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ return GNUNET_OK;
+}
+
+
+/**
+ * Function called to handle status message from the service.
+ *
+ * @param cls closure
+ * @param sm status message received
+ */
+static void
+handle_status (void *cls,
+ const struct StatusMessage *sm)
{
- return 0;
+ struct GNUNET_DATASTORE_Handle *h = cls;
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct StatusContext rc;
+ const char *emsg;
+ int32_t status = ntohl (sm->status);
+
+ if (h->skip_next_messages > 0)
+ {
+ h->skip_next_messages--;
+ process_queue (h);
+ return;
+ }
+ if (NULL == (qe = h->queue_head))
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ if (NULL != qe->env)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ if (GNUNET_MESSAGE_TYPE_DATASTORE_STATUS != qe->response_type)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ rc = qe->qc.sc;
+ free_queue_entry (qe);
+ if (ntohs (sm->header.size) > sizeof (struct StatusMessage))
+ emsg = (const char *) &sm[1];
+ else
+ emsg = NULL;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Received status %d/%s\n",
+ (int) status,
+ emsg);
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# status messages received"),
+ 1,
+ GNUNET_NO);
+ h->retry_time = GNUNET_TIME_UNIT_ZERO;
+ process_queue (h);
+ if (NULL != rc.cont)
+ rc.cont (rc.cont_cls,
+ status,
+ GNUNET_TIME_absolute_ntoh (sm->min_expiration),
+ emsg);
+}
+
+
+/**
+ * Check data message we received from the service.
+ *
+ * @param cls closure with the `struct GNUNET_DATASTORE_Handle *`
+ * @param dm message received
+ */
+static int
+check_data (void *cls,
+ const struct DataMessage *dm)
+{
+ uint16_t msize = ntohs (dm->header.size) - sizeof (*dm);
+
+ if (msize != ntohl (dm->size))
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ return GNUNET_OK;
+}
+
+
+/**
+ * Handle data message we got from the service.
+ *
+ * @param cls closure with the `struct GNUNET_DATASTORE_Handle *`
+ * @param dm message received
+ */
+static void
+handle_data (void *cls,
+ const struct DataMessage *dm)
+{
+ struct GNUNET_DATASTORE_Handle *h = cls;
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct ResultContext rc;
+
+ if (h->skip_next_messages > 0)
+ {
+ process_queue (h);
+ return;
+ }
+ qe = h->queue_head;
+ if (NULL == qe)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ if (NULL != qe->env)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ if (GNUNET_MESSAGE_TYPE_DATASTORE_DATA != qe->response_type)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+#if INSANE_STATISTICS
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# Results received"),
+ 1,
+ GNUNET_NO);
+#endif
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Received result %llu with type %u and size %u with key %s\n",
+ (unsigned long long) GNUNET_ntohll (dm->uid),
+ ntohl (dm->type),
+ ntohl (dm->size),
+ GNUNET_h2s (&dm->key));
+ rc = qe->qc.rc;
+ free_queue_entry (qe);
+ h->retry_time = GNUNET_TIME_UNIT_ZERO;
+ process_queue (h);
+ if (NULL != rc.proc)
+ rc.proc (rc.proc_cls,
+ &dm->key,
+ ntohl (dm->size),
+ &dm[1],
+ ntohl (dm->type),
+ ntohl (dm->priority),
+ ntohl (dm->anonymity),
+ GNUNET_TIME_absolute_ntoh (dm->expiration),
+ GNUNET_ntohll (dm->uid));
+}
+
+
+/**
+ * Type of a function to call when we receive a
+ * #GNUNET_MESSAGE_TYPE_DATASTORE_DATA_END message from the service.
+ *
+ * @param cls closure with the `struct GNUNET_DATASTORE_Handle *`
+ * @param msg message received
+ */
+static void
+handle_data_end (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ struct GNUNET_DATASTORE_Handle *h = cls;
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct ResultContext rc;
+
+ if (h->skip_next_messages > 0)
+ {
+ h->skip_next_messages--;
+ process_queue (h);
+ return;
+ }
+ qe = h->queue_head;
+ if (NULL == qe)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ if (NULL != qe->env)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ if (GNUNET_MESSAGE_TYPE_DATASTORE_DATA != qe->response_type)
+ {
+ GNUNET_break (0);
+ do_disconnect (h);
+ return;
+ }
+ rc = qe->qc.rc;
+ free_queue_entry (qe);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Received end of result set, new queue size is %u\n",
+ h->queue_size);
+ h->retry_time = GNUNET_TIME_UNIT_ZERO;
+ h->result_count = 0;
+ process_queue (h);
+ /* signal end of iteration */
+ if (NULL != rc.proc)
+ rc.proc (rc.proc_cls,
+ NULL,
+ 0,
+ NULL,
+ 0,
+ 0,
+ 0,
+ GNUNET_TIME_UNIT_ZERO_ABS,
+ 0);
+}
+
+
+/**
+ * Try reconnecting to the datastore service.
+ *
+ * @param cls the `struct GNUNET_DATASTORE_Handle`
+ */
+static void
+try_reconnect (void *cls)
+{
+ struct GNUNET_DATASTORE_Handle *h = cls;
+ struct GNUNET_MQ_MessageHandler handlers[] = {
+ GNUNET_MQ_hd_var_size (status,
+ GNUNET_MESSAGE_TYPE_DATASTORE_STATUS,
+ struct StatusMessage,
+ h),
+ GNUNET_MQ_hd_var_size (data,
+ GNUNET_MESSAGE_TYPE_DATASTORE_DATA,
+ struct DataMessage,
+ h),
+ GNUNET_MQ_hd_fixed_size (data_end,
+ GNUNET_MESSAGE_TYPE_DATASTORE_DATA_END,
+ struct GNUNET_MessageHeader,
+ h),
+ GNUNET_MQ_handler_end ()
+ };
+
+ h->retry_time = GNUNET_TIME_STD_BACKOFF (h->retry_time);
+ h->reconnect_task = NULL;
+ GNUNET_assert (NULL == h->mq);
+ h->mq = GNUNET_CLIENT_connect (h->cfg,
+ "datastore",
+ handlers,
+ &mq_error_handler,
+ h);
+ if (NULL == h->mq)
+ return;
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# datastore connections (re)created"),
+ 1,
+ GNUNET_NO);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Reconnected to DATASTORE\n");
+ process_queue (h);
+}
+
+
+/**
+ * Dummy continuation used to do nothing (but be non-zero).
+ *
+ * @param cls closure
+ * @param result result
+ * @param min_expiration expiration time
+ * @param emsg error message
+ */
+static void
+drop_status_cont (void *cls,
+ int32_t result,
+ struct GNUNET_TIME_Absolute min_expiration,
+ const char *emsg)
+{
+ /* do nothing */
}
* lower anonymity level is used.
*
* @param h handle to the datastore
+ * @param rid reservation ID to use (from "reserve"); use 0 if no
+ * prior reservation was made
* @param key key for the value
* @param size number of bytes in data
* @param data content stored
* @param type type of the content
* @param priority priority of the content
* @param anonymity anonymity-level for the content
+ * @param replication how often should the content be replicated to other peers?
* @param expiration expiration time for the content
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param cont continuation to call when done
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
+struct GNUNET_DATASTORE_QueueEntry *
GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
- const GNUNET_HashCode * key,
- uint32_t size,
+ uint32_t rid,
+ const struct GNUNET_HashCode *key,
+ size_t size,
const void *data,
- uint32_t type,
+ enum GNUNET_BLOCK_Type type,
uint32_t priority,
uint32_t anonymity,
- struct GNUNET_TIME_Absolute expiration)
+ uint32_t replication,
+ struct GNUNET_TIME_Absolute expiration,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls)
{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct GNUNET_MQ_Envelope *env;
+ struct DataMessage *dm;
+ union QueueContext qc;
+
+ if (size + sizeof (*dm) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Asked to put %u bytes of data under key `%s' for %s\n",
+ size,
+ GNUNET_h2s (key),
+ GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (expiration),
+ GNUNET_YES));
+ env = GNUNET_MQ_msg_extra (dm,
+ size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_PUT);
+ dm->rid = htonl (rid);
+ dm->size = htonl ((uint32_t) size);
+ dm->type = htonl (type);
+ dm->priority = htonl (priority);
+ dm->anonymity = htonl (anonymity);
+ dm->replication = htonl (replication);
+ dm->reserved = htonl (0);
+ dm->uid = GNUNET_htonll (0);
+ dm->expiration = GNUNET_TIME_absolute_hton (expiration);
+ dm->key = *key;
+ GNUNET_memcpy (&dm[1],
+ data,
+ size);
+ qc.sc.cont = cont;
+ qc.sc.cont_cls = cont_cls;
+ qe = make_queue_entry (h,
+ env,
+ queue_priority,
+ max_queue_size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_STATUS,
+ &qc);
+ if (NULL == qe)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Could not create queue entry for PUT\n");
+ return NULL;
+ }
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# PUT requests executed"),
+ 1,
+ GNUNET_NO);
+ process_queue (h);
+ return qe;
}
/**
- * Iterate over the results for a particular key
- * in the datastore.
+ * Reserve space in the datastore. This function should be used
+ * to avoid "out of space" failures during a longer sequence of "put"
+ * operations (for example, when a file is being inserted).
*
* @param h handle to the datastore
- * @param key maybe NULL (to match all entries)
- * @param type desired type, 0 for any
- * @param iter function to call on each matching value;
- * will be called once with a NULL value at the end
- * @param iter_cls closure for iter
+ * @param amount how much space (in bytes) should be reserved (for content only)
+ * @param entries how many entries will be created (to calculate per-entry overhead)
+ * @param cont continuation to call when done; "success" will be set to
+ * a positive reservation value if space could be reserved.
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
-GNUNET_DATASTORE_get (struct GNUNET_DATASTORE_Handle *h,
- const GNUNET_HashCode * key,
- uint32_t type,
- GNUNET_DATASTORE_Iterator iter, void *iter_cls)
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_reserve (struct GNUNET_DATASTORE_Handle *h,
+ uint64_t amount,
+ uint32_t entries,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls)
{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct GNUNET_MQ_Envelope *env;
+ struct ReserveMessage *rm;
+ union QueueContext qc;
+
+ if (NULL == cont)
+ cont = &drop_status_cont;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Asked to reserve %llu bytes of data and %u entries\n",
+ (unsigned long long) amount,
+ (unsigned int) entries);
+ env = GNUNET_MQ_msg (rm,
+ GNUNET_MESSAGE_TYPE_DATASTORE_RESERVE);
+ rm->entries = htonl (entries);
+ rm->amount = GNUNET_htonll (amount);
+
+ qc.sc.cont = cont;
+ qc.sc.cont_cls = cont_cls;
+ qe = make_queue_entry (h,
+ env,
+ UINT_MAX,
+ UINT_MAX,
+ GNUNET_MESSAGE_TYPE_DATASTORE_STATUS,
+ &qc);
+ if (NULL == qe)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Could not create queue entry to reserve\n");
+ return NULL;
+ }
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# RESERVE requests executed"),
+ 1,
+ GNUNET_NO);
+ process_queue (h);
+ return qe;
}
/**
- * Get a random value from the datastore.
+ * Signal that all of the data for which a reservation was made has
+ * been stored and that whatever excess space might have been reserved
+ * can now be released.
*
* @param h handle to the datastore
- * @param iter function to call on each matching value;
- * will be called exactly once; if no values
- * are available, the value will be NULL.
- * @param iter_cls closure for iter
+ * @param rid reservation ID (value of "success" in original continuation
+ * from the "reserve" function).
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param cont continuation to call when done
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
-GNUNET_DATASTORE_get_random (struct GNUNET_DATASTORE_Handle *h,
- GNUNET_DATASTORE_Iterator iter, void *iter_cls)
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_release_reserve (struct GNUNET_DATASTORE_Handle *h,
+ uint32_t rid,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls)
{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct GNUNET_MQ_Envelope *env;
+ struct ReleaseReserveMessage *rrm;
+ union QueueContext qc;
+
+ if (NULL == cont)
+ cont = &drop_status_cont;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Asked to release reserve %d\n",
+ rid);
+ env = GNUNET_MQ_msg (rrm,
+ GNUNET_MESSAGE_TYPE_DATASTORE_RELEASE_RESERVE);
+ rrm->rid = htonl (rid);
+ qc.sc.cont = cont;
+ qc.sc.cont_cls = cont_cls;
+ qe = make_queue_entry (h,
+ env,
+ queue_priority,
+ max_queue_size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_STATUS,
+ &qc);
+ if (NULL == qe)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Could not create queue entry to release reserve\n");
+ return NULL;
+ }
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop
+ ("# RELEASE RESERVE requests executed"), 1,
+ GNUNET_NO);
+ process_queue (h);
+ return qe;
}
/**
* Explicitly remove some content from the database.
+ * The @a cont continuation will be called with `status`
+ * #GNUNET_OK" if content was removed, #GNUNET_NO
+ * if no matching entry was found and #GNUNET_SYSERR
+ * on all other types of errors.
*
* @param h handle to the datastore
* @param key key for the value
* @param size number of bytes in data
* @param data content stored
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param cont continuation to call when done
+ * @param cont_cls closure for @a cont
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel; note that even if NULL is returned, the callback will be invoked
+ * (or rather, will already have been invoked)
*/
-void
+struct GNUNET_DATASTORE_QueueEntry *
GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
- const GNUNET_HashCode * key,
- uint32_t size, const void *data)
+ const struct GNUNET_HashCode *key,
+ size_t size,
+ const void *data,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_ContinuationWithStatus cont,
+ void *cont_cls)
+{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct DataMessage *dm;
+ struct GNUNET_MQ_Envelope *env;
+ union QueueContext qc;
+
+ if (sizeof (*dm) + size >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ if (NULL == cont)
+ cont = &drop_status_cont;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Asked to remove %u bytes under key `%s'\n",
+ size,
+ GNUNET_h2s (key));
+ env = GNUNET_MQ_msg_extra (dm,
+ size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_REMOVE);
+ dm->rid = htonl (0);
+ dm->size = htonl (size);
+ dm->type = htonl (0);
+ dm->priority = htonl (0);
+ dm->anonymity = htonl (0);
+ dm->uid = GNUNET_htonll (0);
+ dm->expiration = GNUNET_TIME_absolute_hton (GNUNET_TIME_UNIT_ZERO_ABS);
+ dm->key = *key;
+ GNUNET_memcpy (&dm[1],
+ data,
+ size);
+
+ qc.sc.cont = cont;
+ qc.sc.cont_cls = cont_cls;
+
+ qe = make_queue_entry (h,
+ env,
+ queue_priority,
+ max_queue_size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_STATUS,
+ &qc);
+ if (NULL == qe)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Could not create queue entry for REMOVE\n");
+ return NULL;
+ }
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# REMOVE requests executed"),
+ 1,
+ GNUNET_NO);
+ process_queue (h);
+ return qe;
+}
+
+
+
+/**
+ * Get a random value from the datastore for content replication.
+ * Returns a single, random value among those with the highest
+ * replication score, lowering positive replication scores by one for
+ * the chosen value (if only content with a replication score exists,
+ * a random value is returned and replication scores are not changed).
+ *
+ * @param h handle to the datastore
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param proc function to call on a random value; it
+ * will be called once with a value (if available)
+ * and always once with a value of NULL.
+ * @param proc_cls closure for @a proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel
+ */
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_get_for_replication (struct GNUNET_DATASTORE_Handle *h,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_DatumProcessor proc,
+ void *proc_cls)
+{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct GNUNET_MQ_Envelope *env;
+ struct GNUNET_MessageHeader *m;
+ union QueueContext qc;
+
+ GNUNET_assert (NULL != proc);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Asked to get replication entry\n");
+ env = GNUNET_MQ_msg (m,
+ GNUNET_MESSAGE_TYPE_DATASTORE_GET_REPLICATION);
+ qc.rc.proc = proc;
+ qc.rc.proc_cls = proc_cls;
+ qe = make_queue_entry (h,
+ env,
+ queue_priority,
+ max_queue_size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_DATA,
+ &qc);
+ if (NULL == qe)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Could not create queue entry for GET REPLICATION\n");
+ return NULL;
+ }
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop
+ ("# GET REPLICATION requests executed"), 1,
+ GNUNET_NO);
+ process_queue (h);
+ return qe;
+}
+
+
+/**
+ * Get a single zero-anonymity value from the datastore.
+ *
+ * @param h handle to the datastore
+ * @param offset offset of the result (modulo num-results); set to
+ * a random 64-bit value initially; then increment by
+ * one each time; detect that all results have been found by uid
+ * being again the first uid ever returned.
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param type allowed type for the operation (never zero)
+ * @param proc function to call on a random value; it
+ * will be called once with a value (if available)
+ * or with NULL if none value exists.
+ * @param proc_cls closure for @a proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel
+ */
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_get_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
+ uint64_t offset,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ enum GNUNET_BLOCK_Type type,
+ GNUNET_DATASTORE_DatumProcessor proc,
+ void *proc_cls)
{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct GNUNET_MQ_Envelope *env;
+ struct GetZeroAnonymityMessage *m;
+ union QueueContext qc;
+
+ GNUNET_assert (NULL != proc);
+ GNUNET_assert (type != GNUNET_BLOCK_TYPE_ANY);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Asked to get %llu-th zero-anonymity entry of type %d\n",
+ (unsigned long long) offset,
+ type);
+ env = GNUNET_MQ_msg (m,
+ GNUNET_MESSAGE_TYPE_DATASTORE_GET_ZERO_ANONYMITY);
+ m->type = htonl ((uint32_t) type);
+ m->offset = GNUNET_htonll (offset);
+ qc.rc.proc = proc;
+ qc.rc.proc_cls = proc_cls;
+ qe = make_queue_entry (h,
+ env,
+ queue_priority,
+ max_queue_size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_DATA,
+ &qc);
+ if (NULL == qe)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Could not create queue entry for zero-anonymity procation\n");
+ return NULL;
+ }
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop
+ ("# GET ZERO ANONYMITY requests executed"), 1,
+ GNUNET_NO);
+ process_queue (h);
+ return qe;
+}
+
+
+/**
+ * Get a result for a particular key from the datastore. The processor
+ * will only be called once.
+ *
+ * @param h handle to the datastore
+ * @param offset offset of the result (modulo num-results); set to
+ * a random 64-bit value initially; then increment by
+ * one each time; detect that all results have been found by uid
+ * being again the first uid ever returned.
+ * @param key maybe NULL (to match all entries)
+ * @param type desired type, 0 for any
+ * @param queue_priority ranking of this request in the priority queue
+ * @param max_queue_size at what queue size should this request be dropped
+ * (if other requests of higher priority are in the queue)
+ * @param proc function to call on each matching value;
+ * will be called once with a NULL value at the end
+ * @param proc_cls closure for @a proc
+ * @return NULL if the entry was not queued, otherwise a handle that can be used to
+ * cancel
+ */
+struct GNUNET_DATASTORE_QueueEntry *
+GNUNET_DATASTORE_get_key (struct GNUNET_DATASTORE_Handle *h,
+ uint64_t offset,
+ const struct GNUNET_HashCode *key,
+ enum GNUNET_BLOCK_Type type,
+ unsigned int queue_priority,
+ unsigned int max_queue_size,
+ GNUNET_DATASTORE_DatumProcessor proc,
+ void *proc_cls)
+{
+ struct GNUNET_DATASTORE_QueueEntry *qe;
+ struct GNUNET_MQ_Envelope *env;
+ struct GetKeyMessage *gkm;
+ struct GetMessage *gm;
+ union QueueContext qc;
+
+ GNUNET_assert (NULL != proc);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Asked to look for data of type %u under key `%s'\n",
+ (unsigned int) type,
+ GNUNET_h2s (key));
+ if (NULL == key)
+ {
+ env = GNUNET_MQ_msg (gm,
+ GNUNET_MESSAGE_TYPE_DATASTORE_GET);
+ gm->type = htonl (type);
+ gm->offset = GNUNET_htonll (offset);
+ }
+ else
+ {
+ env = GNUNET_MQ_msg (gkm,
+ GNUNET_MESSAGE_TYPE_DATASTORE_GET_KEY);
+ gkm->type = htonl (type);
+ gkm->offset = GNUNET_htonll (offset);
+ gkm->key = *key;
+ }
+ qc.rc.proc = proc;
+ qc.rc.proc_cls = proc_cls;
+ qe = make_queue_entry (h,
+ env,
+ queue_priority,
+ max_queue_size,
+ GNUNET_MESSAGE_TYPE_DATASTORE_DATA,
+ &qc);
+ if (NULL == qe)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Could not queue request for `%s'\n",
+ GNUNET_h2s (key));
+ return NULL;
+ }
+#if INSANE_STATISTICS
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop ("# GET requests executed"),
+ 1,
+ GNUNET_NO);
+#endif
+ process_queue (h);
+ return qe;
+}
+
+
+/**
+ * Cancel a datastore operation. The final callback from the
+ * operation must not have been done yet.
+ *
+ * @param qe operation to cancel
+ */
+void
+GNUNET_DATASTORE_cancel (struct GNUNET_DATASTORE_QueueEntry *qe)
+{
+ struct GNUNET_DATASTORE_Handle *h = qe->h;
+
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Pending DATASTORE request %p cancelled (%d, %d)\n",
+ qe,
+ NULL == qe->env,
+ h->queue_head == qe);
+ if (NULL == qe->env)
+ {
+ free_queue_entry (qe);
+ h->skip_next_messages++;
+ return;
+ }
+ free_queue_entry (qe);
+ process_queue (h);
}