src.ctf.lttng-live: make `lttng_live_get_one_metadata_packet()` return status

[babeltrace.git] / src / plugins / ctf / lttng-live / lttng-live.h

diff --git a/src/plugins/ctf/lttng-live/lttng-live.h b/src/plugins/ctf/lttng-live/lttng-live.h
index 44c78e02be0fb5d7f917b80317a73b1f27c9318a..994563d0fc9afb4cb947350457f58258685555cb 100644 (file)
--- a/src/plugins/ctf/lttng-live/lttng-live.h
+++ b/src/plugins/ctf/lttng-live/lttng-live.h
@@ -133,8 +133,6 @@ struct lttng_live_metadata {
        uint64_t stream_id;
        /* Weak reference. */
        struct ctf_metadata_decoder *decoder;
-
-       bool closed;
 };
 
 struct lttng_live_trace {
@@ -296,8 +294,30 @@ int lttng_live_add_session(struct lttng_live_msg_iter *lttng_live_msg_iter,
                const char *hostname,
                const char *session_name);
 
-ssize_t lttng_live_get_one_metadata_packet(struct lttng_live_trace *trace,
-               FILE *fp);
+enum lttng_live_get_one_metadata_status {
+       /* The end of the metadata stream was reached. */
+       LTTNG_LIVE_GET_ONE_METADATA_STATUS_END      = 1,
+       /* One metadata packet was received and written to file. */
+       LTTNG_LIVE_GET_ONE_METADATA_STATUS_OK       = 0,
+       /* The metadata stream was not found on the relay. */
+       LTTNG_LIVE_GET_ONE_METADATA_STATUS_CLOSED   = -1,
+       /*
+        * A critical error occurred when contacting the relay or while
+        * handling its response.
+        */
+       LTTNG_LIVE_GET_ONE_METADATA_STATUS_ERROR    = -2,
+};
+
+/*
+ * lttng_live_get_one_metadata_packet() asks the Relay Daemon for new metadata.
+ * If new metadata is received, the function writes it to the provided file
+ * handle and updates the reply_len output parameter. This function should be
+ * called in loop until _END status is received to ensure all metadata is
+ * written to the file.
+ */
+enum lttng_live_get_one_metadata_status lttng_live_get_one_metadata_packet(
+               struct lttng_live_trace *trace, FILE *fp, size_t *reply_len);
+
 enum lttng_live_iterator_status lttng_live_get_next_index(
                struct lttng_live_msg_iter *lttng_live_msg_iter,
                struct lttng_live_stream_iterator *stream,