Function json_add_halfchan

plugins/topology.c:203–268

To avoid multiple fetches, we represent directions as a bitmap * so we can do two at once. */

/* To avoid multiple fetches, we represent directions as a bitmap
 * so we can do two at once. */
static void json_add_halfchan(struct json_stream *response,
			      struct gossmap *gossmap,
			      const struct gossmap_chan *c,
			      int dirbits)
{
	struct short_channel_id scid;
	struct node_id node_id[2];
	const u8 *chanfeatures;
	struct amount_msat capacity_msat;

	/* These are channel (not per-direction) properties */
	chanfeatures = gossmap_chan_get_features(tmpctx, gossmap, c);
	scid = gossmap_chan_scid(gossmap, c);
	for (size_t i = 0; i < 2; i++)
		gossmap_node_get_id(gossmap, gossmap_nth_node(gossmap, c, i),
				    &node_id[i]);

	capacity_msat = gossmap_chan_get_capacity(gossmap, c);

	for (int dir = 0; dir < 2; dir++) {
		u32 timestamp;
		u8 message_flags, channel_flags;
		u32 fee_base_msat, fee_proportional_millionths;
		struct amount_msat htlc_minimum_msat, htlc_maximum_msat;

		if (!((1 << dir) & dirbits))
			continue;

		if (!gossmap_chan_set(c, dir))
			continue;

		json_object_start(response, NULL);
		json_add_node_id(response, "source", &node_id[dir]);
		json_add_node_id(response, "destination", &node_id[!dir]);
		json_add_short_channel_id(response, "short_channel_id", scid);
		json_add_num(response, "direction", dir);
		json_add_bool(response, "public", !gossmap_chan_is_localmod(gossmap, c));

		gossmap_chan_get_update_details(gossmap, c, dir,
						&timestamp,
						&message_flags,
						&channel_flags,
						NULL,
						&fee_base_msat,
						&fee_proportional_millionths,
						&htlc_minimum_msat,
						&htlc_maximum_msat);

		json_add_amount_msat(response, "amount_msat", capacity_msat);
		json_add_num(response, "message_flags", message_flags);
		json_add_num(response, "channel_flags", channel_flags);

		json_add_bool(response, "active", c->half[dir].enabled);
		json_add_num(response, "last_update", timestamp);
		json_add_num(response, "base_fee_millisatoshi", fee_base_msat);
		json_add_num(response, "fee_per_millionth",
			     fee_proportional_millionths);
		json_add_num(response, "delay", c->half[dir].delay);