1 files changed, 59 insertions, 19 deletions

diff --git a/src/datastore/datastore_api.c b/src/datastore/datastore_api.c
index 916e6acae..26e1e501d 100644
--- a/src/datastore/datastore_api.c
+++ b/src/datastore/datastore_api.c
@@ -33,6 +33,8 @@
 
 #define LOG(kind,...) GNUNET_log_from (kind, "datastore-api",__VA_ARGS__)
 
+#define DELAY_WARN_TIMEOUT GNUNET_TIME_UNIT_MINUTES
+
 /**
  * Collect an instane number of statistics?  May cause excessive IPC.
  */
@@ -138,6 +140,12 @@ struct GNUNET_DATASTORE_QueueEntry
   struct GNUNET_MQ_Envelope *env;
 
   /**
+   * Task we run if this entry stalls the queue and we
+   * need to warn the user.
+   */
+  struct GNUNET_SCHEDULER_Task *delay_warn_task;
+
+  /**
    * Priority in the queue.
    */
   unsigned int priority;
@@ -269,11 +277,36 @@ free_queue_entry (struct GNUNET_DATASTORE_QueueEntry *qe)
   h->queue_size--;
   if (NULL != qe->env)
     GNUNET_MQ_discard (qe->env);
+  if (NULL != qe->delay_warn_task)
+    GNUNET_SCHEDULER_cancel (qe->delay_warn_task);
   GNUNET_free (qe);
 }
 
 
 /**
+ * Task that logs an error after some time.
+ *
+ * @param qe `struct GNUNET_DATASTORE_QueueEntry` about which the error is
+ */
+static void
+delay_warning (void *cls)
+{
+  struct GNUNET_DATASTORE_QueueEntry *qe = cls;
+
+  qe->delay_warn_task = NULL;
+  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+              "Request %p of type %u at head of datastore queue for more than %s\n",
+              qe,
+              (unsigned int) qe->response_type,
+              GNUNET_STRINGS_relative_time_to_string (DELAY_WARN_TIMEOUT,
+                                                      GNUNET_YES));
+  qe->delay_warn_task = GNUNET_SCHEDULER_add_delayed (DELAY_WARN_TIMEOUT,
+                                                      &delay_warning,
+                                                      qe);
+}
+
+
+/**
  * Handle error in sending drop request to datastore.
  *
  * @param cls closure with the datastore handle
@@ -290,8 +323,14 @@ mq_error_handler (void *cls,
        "MQ error, reconnecting to DATASTORE\n");
   do_disconnect (h);
   qe = h->queue_head;
-  if ( (NULL != qe) &&
-       (NULL == qe->env) )
+  if (NULL == qe)
+    return;
+  if (NULL != qe->delay_warn_task)
+  {
+    GNUNET_SCHEDULER_cancel (qe->delay_warn_task);
+    qe->delay_warn_task = NULL;
+  }
+  if (NULL == qe->env)
   {
     union QueueContext qc = qe->qc;
     uint16_t rt = qe->response_type;
@@ -594,6 +633,10 @@ process_queue (struct GNUNET_DATASTORE_Handle *h)
          "Not connected\n");
     return;
   }
+  GNUNET_assert (NULL == qe->delay_warn_task);
+  qe->delay_warn_task = GNUNET_SCHEDULER_add_delayed (DELAY_WARN_TIMEOUT,
+                                                      &delay_warning,
+                                                      qe);
   GNUNET_MQ_send (h->mq,
                   qe->env);
   qe->env = NULL;
@@ -958,7 +1001,7 @@ GNUNET_DATASTORE_put (struct GNUNET_DATASTORE_Handle *h,
   struct DataMessage *dm;
   union QueueContext qc;
 
-  if (size + sizeof (*dm) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  if (size + sizeof (*dm) >= GNUNET_MAX_MESSAGE_SIZE)
   {
     GNUNET_break (0);
     return NULL;
@@ -1169,7 +1212,7 @@ GNUNET_DATASTORE_remove (struct GNUNET_DATASTORE_Handle *h,
   struct GNUNET_MQ_Envelope *env;
   union QueueContext qc;
 
-  if (sizeof (*dm) + size >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  if (sizeof (*dm) + size >= GNUNET_MAX_MESSAGE_SIZE)
   {
     GNUNET_break (0);
     return NULL;
@@ -1282,10 +1325,7 @@ GNUNET_DATASTORE_get_for_replication (struct GNUNET_DATASTORE_Handle *h,
  * 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 next_uid return the result with lowest uid >= next_uid
  * @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)
@@ -1299,7 +1339,7 @@ GNUNET_DATASTORE_get_for_replication (struct GNUNET_DATASTORE_Handle *h,
  */
 struct GNUNET_DATASTORE_QueueEntry *
 GNUNET_DATASTORE_get_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
-                                     uint64_t offset,
+                                     uint64_t next_uid,
                                      unsigned int queue_priority,
                                      unsigned int max_queue_size,
                                      enum GNUNET_BLOCK_Type type,
@@ -1314,13 +1354,12 @@ GNUNET_DATASTORE_get_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
   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,
+       "Asked to get a zero-anonymity entry of type %d\n",
        type);
   env = GNUNET_MQ_msg (m,
                        GNUNET_MESSAGE_TYPE_DATASTORE_GET_ZERO_ANONYMITY);
   m->type = htonl ((uint32_t) type);
-  m->offset = GNUNET_htonll (offset);
+  m->next_uid = GNUNET_htonll (next_uid);
   qc.rc.proc = proc;
   qc.rc.proc_cls = proc_cls;
   qe = make_queue_entry (h,
@@ -1349,10 +1388,8 @@ GNUNET_DATASTORE_get_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
  * 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 next_uid return the result with lowest uid >= next_uid
+ * @param random if true, return a random result instead of using next_uid
  * @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
@@ -1366,7 +1403,8 @@ GNUNET_DATASTORE_get_zero_anonymity (struct GNUNET_DATASTORE_Handle *h,
  */
 struct GNUNET_DATASTORE_QueueEntry *
 GNUNET_DATASTORE_get_key (struct GNUNET_DATASTORE_Handle *h,
-                          uint64_t offset,
+                          uint64_t next_uid,
+                          bool random,
                           const struct GNUNET_HashCode *key,
                           enum GNUNET_BLOCK_Type type,
                           unsigned int queue_priority,
@@ -1390,14 +1428,16 @@ GNUNET_DATASTORE_get_key (struct GNUNET_DATASTORE_Handle *h,
     env = GNUNET_MQ_msg (gm,
                          GNUNET_MESSAGE_TYPE_DATASTORE_GET);
     gm->type = htonl (type);
-    gm->offset = GNUNET_htonll (offset);
+    gm->next_uid = GNUNET_htonll (next_uid);
+    gm->random = random;
   }
   else
   {
     env = GNUNET_MQ_msg (gkm,
                          GNUNET_MESSAGE_TYPE_DATASTORE_GET_KEY);
     gkm->type = htonl (type);
-    gkm->offset = GNUNET_htonll (offset);
+    gkm->next_uid = GNUNET_htonll (next_uid);
+    gkm->random = random;
     gkm->key = *key;
   }
   qc.rc.proc = proc;