+/*
+ * Handle index for a data stream.
+ *
+ * RCU read side lock MUST be acquired.
+ *
+ * Return 0 on success else a negative value.
+ */
+static int handle_index_data(struct relay_stream *stream, uint64_t net_seq_num,
+ int rotate_index)
+{
+ int ret = 0, index_created = 0;
+ uint64_t stream_id, data_offset;
+ struct relay_index *index, *wr_index = NULL;
+
+ assert(stream);
+
+ stream_id = stream->stream_handle;
+ /* Get data offset because we are about to update the index. */
+ data_offset = htobe64(stream->tracefile_size_current);
+
+ /*
+ * Lookup for an existing index for that stream id/sequence number. If on
+ * exists, the control thread already received the data for it thus we need
+ * to write it on disk.
+ */
+ index = relay_index_find(stream_id, net_seq_num);
+ if (!index) {
+ /* A successful creation will add the object to the HT. */
+ index = relay_index_create(stream_id, net_seq_num);
+ if (!index) {
+ ret = -1;
+ goto error;
+ }
+ index_created = 1;
+ }
+
+ if (rotate_index || stream->index_fd < 0) {
+ index->to_close_fd = stream->index_fd;
+ ret = index_create_file(stream->path_name, stream->channel_name,
+ relayd_uid, relayd_gid, stream->tracefile_size,
+ stream->tracefile_count_current);
+ if (ret < 0) {
+ /* This will close the stream's index fd if one. */
+ relay_index_free_safe(index);
+ goto error;
+ }
+ stream->index_fd = ret;
+ }
+ index->fd = stream->index_fd;
+ index->index_data.offset = data_offset;
+
+ if (index_created) {
+ /*
+ * Try to add the relay index object to the hash table. If an object
+ * already exist, destroy back the index created and set the data.
+ */
+ relay_index_add(index, &wr_index);
+ if (wr_index) {
+ /* Copy back data from the created index. */
+ wr_index->fd = index->fd;
+ wr_index->to_close_fd = index->to_close_fd;
+ wr_index->index_data.offset = data_offset;
+ free(index);
+ }
+ } else {
+ /* The index already exists so write it on disk. */
+ wr_index = index;
+ }
+
+ /* Do we have a writable ready index to write on disk. */
+ if (wr_index) {
+ ret = relay_index_write(wr_index->fd, wr_index);
+ if (ret < 0) {
+ goto error;
+ }
+ stream->total_index_received++;
+ }
+
+error:
+ return ret;
+}
+