handleProbes method

Future<ReconcilePlan> handleProbes(List<RangeProbe> probes)

Handles the peer's probes and produces this side's plan.

Implementation

Future<ReconcilePlan> handleProbes(List<RangeProbe> probes) async {
  final plan = ReconcilePlan();
  for (final probe in probes) {
    final local = await digest(probe.from, probe.to);
    if (local.matches(_asDigest(probe))) continue;

    final leaf = probe.count <= leafCount ||
        local.count <= leafCount ||
        probe.depth >= maxDepth ||
        plan.replyProbes.length + 2 > maxProbesPerReply;
    final mid = leaf ? null : _midpoint(probe, local);
    if (mid == null) {
      // A leaf: both sides exchange the range's records; the CRDT merge
      // dedups anything both already had.
      plan.shipRanges.add(RangeRequest(from: probe.from, to: probe.to));
      plan.requestRanges.add(RangeRequest(from: probe.from, to: probe.to));
      continue;
    }

    final low = await digest(probe.from, mid);
    final high = await digest(mid, probe.to);
    plan.replyProbes
      ..add(RangeProbe(
        from: probe.from,
        to: mid,
        depth: probe.depth + 1,
        count: low.count,
        fingerprint: low.fingerprint,
      ))
      ..add(RangeProbe(
        from: mid,
        to: probe.to,
        depth: probe.depth + 1,
        count: high.count,
        fingerprint: high.fingerprint,
      ));
  }
  return plan;
}