+
+/**
+ * Function to obtain the last envelope in the queue.
+ *
+ * @param mq message queue to interrogate
+ * @return the last envelope in the queue
+ */
+struct GNUNET_MQ_Envelope *
+GNUNET_MQ_get_last_envelope (struct GNUNET_MQ_Handle *mq)
+{
+ if (NULL != mq->envelope_tail)
+ return mq->envelope_tail;
+
+ return mq->current_envelope;
+}
+
+
+/**
+ * Set application-specific options for this envelope.
+ * Overrides the options set for the queue with
+ * #GNUNET_MQ_set_options() for this message only.
+ *
+ * @param env message to set options for
+ * @param flags flags to use (meaning is queue-specific)
+ * @param extra additional buffer for further data (also queue-specific)
+ */
+void
+GNUNET_MQ_env_set_options (struct GNUNET_MQ_Envelope *env,
+ uint64_t flags,
+ const void *extra)
+{
+ env->flags = flags;
+ env->extra = extra;
+ env->have_custom_options = GNUNET_YES;
+}
+
+
+/**
+ * Get application-specific options for this envelope.
+ *
+ * @param env message to set options for
+ * @param[out] flags set to flags to use (meaning is queue-specific)
+ * @return extra additional buffer for further data (also queue-specific)
+ */
+const void *
+GNUNET_MQ_env_get_options (struct GNUNET_MQ_Envelope *env,
+ uint64_t *flags)
+{
+ struct GNUNET_MQ_Handle *mq = env->parent_queue;
+
+ if (GNUNET_YES == env->have_custom_options)
+ {
+ *flags = env->flags;
+ return env->extra;
+ }
+ if (NULL == mq)
+ {
+ *flags = 0;
+ return NULL;
+ }
+ *flags = mq->default_flags;
+ return mq->default_extra;
+}
+
+
+/**
+ * Set application-specific options for this queue.
+ *
+ * @param mq message queue to set options for
+ * @param flags flags to use (meaning is queue-specific)
+ * @param extra additional buffer for further data (also queue-specific)
+ */
+void
+GNUNET_MQ_set_options (struct GNUNET_MQ_Handle *mq,
+ uint64_t flags,
+ const void *extra)
+{
+ mq->default_flags = flags;
+ mq->default_extra = extra;
+}
+
+
+/**
+ * Obtain message contained in envelope.
+ *
+ * @param env the envelope
+ * @return message contained in the envelope
+ */
+const struct GNUNET_MessageHeader *
+GNUNET_MQ_env_get_msg (const struct GNUNET_MQ_Envelope *env)
+{
+ return env->mh;
+}
+
+
+/**
+ * Return next envelope in queue.
+ *
+ * @param env a queued envelope
+ * @return next one, or NULL
+ */
+const struct GNUNET_MQ_Envelope *
+GNUNET_MQ_env_next (const struct GNUNET_MQ_Envelope *env)
+{
+ return env->next;
+}
+
+
+/**
+ * Register function to be called whenever @a mq is being
+ * destroyed.
+ *
+ * @param mq message queue to watch
+ * @param cb function to call on @a mq destruction
+ * @param cb_cls closure for @a cb
+ * @return handle for #GNUNET_MQ_destroy_notify_cancel().
+ */
+struct GNUNET_MQ_DestroyNotificationHandle *
+GNUNET_MQ_destroy_notify (struct GNUNET_MQ_Handle *mq,
+ GNUNET_SCHEDULER_TaskCallback cb,
+ void *cb_cls)
+{
+ struct GNUNET_MQ_DestroyNotificationHandle *dnh;
+
+ dnh = GNUNET_new (struct GNUNET_MQ_DestroyNotificationHandle);
+ dnh->mq = mq;
+ dnh->cb = cb;
+ dnh->cb_cls = cb_cls;
+ GNUNET_CONTAINER_DLL_insert (mq->dnh_head,
+ mq->dnh_tail,
+ dnh);
+ return dnh;
+}
+
+
+/**
+ * Cancel registration from #GNUNET_MQ_destroy_notify().
+ *
+ * @param dnh handle for registration to cancel
+ */
+void
+GNUNET_MQ_destroy_notify_cancel (struct GNUNET_MQ_DestroyNotificationHandle *dnh)
+{
+ struct GNUNET_MQ_Handle *mq = dnh->mq;
+
+ GNUNET_CONTAINER_DLL_remove (mq->dnh_head,
+ mq->dnh_tail,
+ dnh);
+ GNUNET_free (dnh);
+}
+
+
+/**
+ * Insert @a env into the envelope DLL starting at @a env_head
+ * Note that @a env must not be in any MQ while this function
+ * is used with DLLs defined outside of the MQ module. This
+ * is just in case some application needs to also manage a
+ * FIFO of envelopes independent of MQ itself and wants to
+ * re-use the pointers internal to @a env. Use with caution.
+ *
+ * @param[in|out] env_head of envelope DLL
+ * @param[in|out] env_tail tail of envelope DLL
+ * @param[in|out] env element to insert at the tail
+ */
+void
+GNUNET_MQ_dll_insert_tail (struct GNUNET_MQ_Envelope **env_head,
+ struct GNUNET_MQ_Envelope **env_tail,
+ struct GNUNET_MQ_Envelope *env)
+{
+ GNUNET_CONTAINER_DLL_insert_tail (*env_head,
+ *env_tail,
+ env);
+}
+
+
+/**
+ * Remove @a env from the envelope DLL starting at @a env_head.
+ * Note that @a env must not be in any MQ while this function
+ * is used with DLLs defined outside of the MQ module. This
+ * is just in case some application needs to also manage a
+ * FIFO of envelopes independent of MQ itself and wants to
+ * re-use the pointers internal to @a env. Use with caution.
+ *
+ * @param[in|out] env_head of envelope DLL
+ * @param[in|out] env_tail tail of envelope DLL
+ * @param[in|out] env element to remove from the DLL
+ */
+void
+GNUNET_MQ_dll_remove (struct GNUNET_MQ_Envelope **env_head,
+ struct GNUNET_MQ_Envelope **env_tail,
+ struct GNUNET_MQ_Envelope *env)
+{
+ GNUNET_CONTAINER_DLL_remove (*env_head,
+ *env_tail,
+ env);
+}
+
+
+/**
+ * Copy an array of handlers.
+ *
+ * Useful if the array has been delared in local memory and needs to be
+ * persisted for future use.
+ *
+ * @param handlers Array of handlers to be copied. Can be NULL (nothing done).
+ * @return A newly allocated array of handlers.
+ * Needs to be freed with #GNUNET_free.
+ */
+struct GNUNET_MQ_MessageHandler *
+GNUNET_MQ_copy_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
+{
+ struct GNUNET_MQ_MessageHandler *copy;
+ unsigned int count;
+
+ if (NULL == handlers)
+ return NULL;
+
+ count = GNUNET_MQ_count_handlers (handlers);
+ copy = GNUNET_new_array (count + 1,
+ struct GNUNET_MQ_MessageHandler);
+ GNUNET_memcpy (copy,
+ handlers,
+ count * sizeof (struct GNUNET_MQ_MessageHandler));
+ return copy;
+}
+
+
+/**
+ * Copy an array of handlers, appending AGPL handler.
+ *
+ * Useful if the array has been delared in local memory and needs to be
+ * persisted for future use.
+ *
+ * @param handlers Array of handlers to be copied. Can be NULL (nothing done).
+ * @param agpl_handler function to call for AGPL handling
+ * @param agpl_cls closure for @a agpl_handler
+ * @return A newly allocated array of handlers.
+ * Needs to be freed with #GNUNET_free.
+ */
+struct GNUNET_MQ_MessageHandler *
+GNUNET_MQ_copy_handlers2 (const struct GNUNET_MQ_MessageHandler *handlers,
+ GNUNET_MQ_MessageCallback agpl_handler,
+ void *agpl_cls)
+{
+ struct GNUNET_MQ_MessageHandler *copy;
+ unsigned int count;
+
+ if (NULL == handlers)
+ return NULL;
+ count = GNUNET_MQ_count_handlers (handlers);
+ copy = GNUNET_new_array (count + 2,
+ struct GNUNET_MQ_MessageHandler);
+ GNUNET_memcpy (copy,
+ handlers,
+ count * sizeof (struct GNUNET_MQ_MessageHandler));
+ copy[count].mv = NULL;
+ copy[count].cb = agpl_handler;
+ copy[count].cls = agpl_cls;
+ copy[count].type = GNUNET_MESSAGE_TYPE_REQUEST_AGPL;
+ copy[count].expected_size = sizeof (struct GNUNET_MessageHeader);
+ return copy;
+}
+
+
+/**
+ * Count the handlers in a handler array.
+ *
+ * @param handlers Array of handlers to be counted.
+ * @return The number of handlers in the array.
+ */
+unsigned int
+GNUNET_MQ_count_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
+{
+ unsigned int i;
+
+ if (NULL == handlers)
+ return 0;
+
+ for (i=0; NULL != handlers[i].cb; i++) ;
+
+ return i;
+}
+
+
+