Function gather_range

gossipd/queries.c:422–500

This gets all the scids they asked for, and optionally the timestamps and checksums */

/* This gets all the scids they asked for, and optionally the timestamps and checksums */
static struct short_channel_id *gather_range(const tal_t *ctx,
					     struct routing_state *rstate,
					     u32 first_blocknum, u32 number_of_blocks,
					     enum query_option_flags query_option_flags,
					     struct channel_update_timestamps **tstamps,
					     struct channel_update_checksums **csums)
{
	struct short_channel_id scid, *scids;
	u32 end_block;
	bool scid_ok;

	scids = tal_arr(ctx, struct short_channel_id, 0);
	if (query_option_flags & QUERY_ADD_TIMESTAMPS)
		*tstamps = tal_arr(ctx, struct channel_update_timestamps, 0);
	else
		*tstamps = NULL;
	if (query_option_flags & QUERY_ADD_CHECKSUMS)
		*csums = tal_arr(ctx, struct channel_update_checksums, 0);
	else
		*csums = NULL;

	/* Avoid underflow: we don't use block 0 anyway */
	if (first_blocknum == 0)
		scid_ok = mk_short_channel_id(&scid, 1, 0, 0);
	else
		scid_ok = mk_short_channel_id(&scid, first_blocknum, 0, 0);
	scid.u64--;
	/* Out of range?  No blocks then. */
	if (!scid_ok)
		return NULL;

	if (number_of_blocks == 0)
		return NULL;

	/* Fix up number_of_blocks to avoid overflow. */
	end_block = first_blocknum + number_of_blocks - 1;
	if (end_block < first_blocknum)
		end_block = UINT_MAX;

	/* We keep a `uintmap` of `short_channel_id` to `struct chan *`.
	 * Unlike a htable, it's efficient to iterate through, but it only
	 * works because each short_channel_id is basically a 64-bit unsigned
	 * integer.
	 *
	 * First we iterate and gather all the short channel ids. */
	while (uintmap_after(&rstate->chanmap, &scid.u64)) {
		struct chan *chan;
		struct channel_update_timestamps ts;
		struct channel_update_checksums cs;

		if (short_channel_id_blocknum(&scid) > end_block)
			break;

		/* FIXME: Store csum in header. */
		chan = get_channel(rstate, &scid);
		if (!is_chan_public(chan))
			continue;