issue 974: the checks are queued by pull request on two work-queue streams, taken after a delivery build, dropped when judged, stopped when their key moves; the reordering and the forge-asking end are gone

internal/link/queue_kind.go

@@ -0,0 +1,50 @@
+package link
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"github.com/novox/mesh-controller/internal/broker"
+)
+
+// The kinds of ask, as the queue says them. **The kind decides the queue** (novox/hq ADR 0406 §3): a delivery build is on
+// the seat's own queue, taken before any check; a check of a pull request marked ready is on the second; every other
+// check on the third. Nothing orders the asks any more: a builder takes from the queues in that order, and the check
+// queues keep one request a pull request. The reordering of one queue by moving asks to its tail, with its pause of the
+// worker, its look every two seconds and its second copies, is gone (issue 558 is answered by the streams).
+const (
+	KindDelivery = "delivery"
+	KindCheck    = "check"
+)
+
+// KindOf is an ask's kind: a check for a pull request's check — a recheck the merge tool asks included —
+// a dry run, or an ask nothing could be read from; a delivery for any other build.
+func KindOf(r BuildRequest) string {
+	if r.ID == "" || r.Check != nil || r.DryRun {
+		return KindCheck
+	}
+	return KindDelivery
+}
+
+// DeleteAsk removes a waiting or dead ask from the queue it is in, at its sequence. Says the sequence it removed, 0 when
+// it was not there any more: taken and settled, or replaced by a newer request for its pull request.
+func DeleteAsk(_ context.Context, js *broker.JetStream, seat string, ask QueuedAsk) (uint64, error) {
+	stream := ask.Stream
+	if stream == "" {
+		worker, _ := broker.HolderConsumerFor("", "", broker.DeclaredSeat{Name: seat, Accepts: []string{"build"}})
+		stream = worker.Stream
+	}
+	err := js.Context().DeleteMsg(stream, ask.Seq)
+	switch {
+	case err == nil:
+		return ask.Seq, nil
+	case errors.Is(err, nats.ErrMsgNotFound) || errors.Is(err, jetstream.ErrMsgNotFound) ||
+		strings.Contains(err.Error(), "no message found"):
+		return 0, nil
+	}
+	return 0, err
+}