lib: notification iterator: transfer a batch of notifications

[babeltrace.git] / plugins / text / dmesg / dmesg.c

diff --git a/plugins/text/dmesg/dmesg.c b/plugins/text/dmesg/dmesg.c
index 9f0d9e1cbe8f6ca8b426e72ac5884bba445f9b9a..4a3aca8015f33f61e2738b5acff8e82ece0ef648 100644 (file)
--- a/plugins/text/dmesg/dmesg.c
+++ b/plugins/text/dmesg/dmesg.c
@@ -872,26 +872,22 @@ void dmesg_notif_iter_finalize(
                priv_notif_iter));
 }
 
-BT_HIDDEN
-struct bt_notification_iterator_next_method_return dmesg_notif_iter_next(
-               struct bt_private_connection_private_notification_iterator *priv_notif_iter)
+static
+enum bt_notification_iterator_status dmesg_notif_iter_next_one(
+               struct dmesg_notif_iter *dmesg_notif_iter,
+               struct bt_notification **notif)
 {
        ssize_t len;
-       struct dmesg_notif_iter *dmesg_notif_iter =
-               bt_private_connection_private_notification_iterator_get_user_data(
-                       priv_notif_iter);
        struct dmesg_component *dmesg_comp;
-       struct bt_notification_iterator_next_method_return next_ret = {
-               .status = BT_NOTIFICATION_ITERATOR_STATUS_OK,
-               .notification = NULL
-       };
+       enum bt_notification_iterator_status status =
+               BT_NOTIFICATION_ITERATOR_STATUS_OK;
 
        BT_ASSERT(dmesg_notif_iter);
        dmesg_comp = dmesg_notif_iter->dmesg_comp;
        BT_ASSERT(dmesg_comp);
 
        if (dmesg_notif_iter->state == STATE_DONE) {
-               next_ret.status = BT_NOTIFICATION_ITERATOR_STATUS_END;
+               status = BT_NOTIFICATION_ITERATOR_STATUS_END;
                goto end;
        }
 
@@ -909,16 +905,14 @@ struct bt_notification_iterator_next_method_return dmesg_notif_iter_next(
                        &dmesg_notif_iter->linebuf_len, dmesg_notif_iter->fp);
                if (len < 0) {
                        if (errno == EINVAL) {
-                               next_ret.status =
-                                       BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
+                               status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
                        } else if (errno == ENOMEM) {
-                               next_ret.status =
+                               status =
                                        BT_NOTIFICATION_ITERATOR_STATUS_NOMEM;
                        } else {
                                if (dmesg_notif_iter->state == STATE_EMIT_STREAM_BEGINNING) {
                                        /* Stream did not even begin */
-                                       next_ret.status =
-                                               BT_NOTIFICATION_ITERATOR_STATUS_END;
+                                       status = BT_NOTIFICATION_ITERATOR_STATUS_END;
                                        goto end;
                                } else {
                                        /* End current packet now */
@@ -961,28 +955,28 @@ handle_state:
        switch (dmesg_notif_iter->state) {
        case STATE_EMIT_STREAM_BEGINNING:
                BT_ASSERT(dmesg_notif_iter->tmp_event_notif);
-               next_ret.notification = bt_notification_stream_begin_create(
+               *notif = bt_notification_stream_begin_create(
                        dmesg_comp->graph, dmesg_comp->stream);
                dmesg_notif_iter->state = STATE_EMIT_PACKET_BEGINNING;
                break;
        case STATE_EMIT_PACKET_BEGINNING:
                BT_ASSERT(dmesg_notif_iter->tmp_event_notif);
-               next_ret.notification = bt_notification_packet_begin_create(
+               *notif = bt_notification_packet_begin_create(
                        dmesg_comp->graph, dmesg_comp->packet);
                dmesg_notif_iter->state = STATE_EMIT_EVENT;
                break;
        case STATE_EMIT_EVENT:
                BT_ASSERT(dmesg_notif_iter->tmp_event_notif);
-               BT_MOVE(next_ret.notification,
-                       dmesg_notif_iter->tmp_event_notif);
+               *notif = dmesg_notif_iter->tmp_event_notif;
+               dmesg_notif_iter->tmp_event_notif = NULL;
                break;
        case STATE_EMIT_PACKET_END:
-               next_ret.notification = bt_notification_packet_end_create(
+               *notif = bt_notification_packet_end_create(
                        dmesg_comp->graph, dmesg_comp->packet);
                dmesg_notif_iter->state = STATE_EMIT_STREAM_END;
                break;
        case STATE_EMIT_STREAM_END:
-               next_ret.notification = bt_notification_stream_end_create(
+               *notif = bt_notification_stream_end_create(
                        dmesg_comp->graph, dmesg_comp->stream);
                dmesg_notif_iter->state = STATE_DONE;
                break;
@@ -990,12 +984,52 @@ handle_state:
                break;
        }
 
-       if (!next_ret.notification) {
+       if (!*notif) {
                BT_LOGE("Cannot create notification: dmesg-comp-addr=%p",
                        dmesg_comp);
-               next_ret.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
+               status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
        }
 
 end:
-       return next_ret;
+       return status;
+}
+
+BT_HIDDEN
+enum bt_notification_iterator_status dmesg_notif_iter_next(
+               struct bt_private_connection_private_notification_iterator *priv_notif_iter,
+               bt_notification_array notifs, uint64_t capacity,
+               uint64_t *count)
+{
+       struct dmesg_notif_iter *dmesg_notif_iter =
+               bt_private_connection_private_notification_iterator_get_user_data(
+                       priv_notif_iter);
+       enum bt_notification_iterator_status status =
+               BT_NOTIFICATION_ITERATOR_STATUS_OK;
+       uint64_t i = 0;
+
+       while (i < capacity && status == BT_NOTIFICATION_ITERATOR_STATUS_OK) {
+               status = dmesg_notif_iter_next_one(dmesg_notif_iter, &notifs[i]);
+               if (status == BT_NOTIFICATION_ITERATOR_STATUS_OK) {
+                       i++;
+               }
+       }
+
+       if (i > 0) {
+               /*
+                * Even if dmesg_notif_iter_next_one() returned
+                * something else than
+                * BT_NOTIFICATION_ITERATOR_STATUS_OK, we accumulated
+                * notification objects in the output notification
+                * array, so we need to return
+                * BT_NOTIFICATION_ITERATOR_STATUS_OK so that they are
+                * transfered to downstream. This other status occurs
+                * again the next time muxer_notif_iter_do_next() is
+                * called, possibly without any accumulated
+                * notification, in which case we'll return it.
+                */
+               *count = i;
+               status = BT_NOTIFICATION_ITERATOR_STATUS_OK;
+       }
+
+       return status;
 }