From 5ddc3ff312f3ca280f635234a7083bb6b2494af9 Mon Sep 17 00:00:00 2001
From: jochen <jschoubben@gmail.com>
Date: Thu, 22 Oct 2026 14:13:18 +0200
Subject: [PATCH] =?UTF-8?q?Measure=20a=20repository's=20last=20check=20tim?=
 =?UTF-8?q?e=20from=20its=20newest=20verdict=20(ADR=200505=20=C2=A74)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../cmd/mesh-delivery-gate/adr505_test.go     | 26 ++++++++++++++
 .../cmd/mesh-delivery-gate/checktime.go       | 34 +++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 modules/mesh-delivery-gate/cmd/mesh-delivery-gate/checktime.go

diff --git a/modules/mesh-delivery-gate/cmd/mesh-delivery-gate/adr505_test.go b/modules/mesh-delivery-gate/cmd/mesh-delivery-gate/adr505_test.go
index ee8bfdbf..ef3888ef 100644
--- a/modules/mesh-delivery-gate/cmd/mesh-delivery-gate/adr505_test.go
+++ b/modules/mesh-delivery-gate/cmd/mesh-delivery-gate/adr505_test.go
@@ -39,3 +39,29 @@ func TestTheBoundsAreSettingsWithTheirDefaults(t *testing.T) {
 		t.Fatalf("a bound of zero minutes was taken")
 	}
 }
+
+// ADR 0505 §4: a repository's last measured check time is its newest verdict's (`took`, as mesh-controller
+// cmd/mesh-builder main.go writes it: a duration rounded to the second); none, and the floor alone holds.
+func TestTheLastMeasuredCheckTimeIsTheNewestVerdictsOfItsRepository(t *testing.T) {
+	h := &Holder{}
+	h.init()
+	at := time.Date(2026, 10, 22, 10, 0, 0, 0, time.UTC)
+	h.deliveries["novox/mesh-catalog@a"] = &Delivery{ID: "novox/mesh-catalog@a", Repository: "novox/mesh-catalog",
+		Check: &Verdict{At: at, Took: "4m0s"}}
+	h.deliveries["novox/mesh-catalog@b"] = &Delivery{ID: "novox/mesh-catalog@b", Repository: "novox/mesh-catalog",
+		Check: &Verdict{At: at.Add(time.Hour), Took: "7m30s"}}
+	h.deliveries["novox/hq@c"] = &Delivery{ID: "novox/hq@c", Repository: "novox/hq",
+		Check: &Verdict{At: at.Add(2 * time.Hour), Took: "1m0s"}}
+	if got := h.lastCheckTime("novox/mesh-catalog"); got != 7*time.Minute+30*time.Second {
+		t.Fatalf("the newer of two: %s", got)
+	}
+	if got := h.answeredRefusalBound("novox/mesh-catalog"); got != 15*time.Minute {
+		t.Fatalf("twice 7m30s: %s", got)
+	}
+	if got := h.answeredRefusalBound("novox/hq"); got != 10*time.Minute {
+		t.Fatalf("twice one minute is under the floor: %s", got)
+	}
+	if got := h.answeredRefusalBound("novox/mesh-sdk"); got != 10*time.Minute {
+		t.Fatalf("no verdict: %s", got)
+	}
+}
diff --git a/modules/mesh-delivery-gate/cmd/mesh-delivery-gate/checktime.go b/modules/mesh-delivery-gate/cmd/mesh-delivery-gate/checktime.go
new file mode 100644
index 00000000..91bc0eec
--- /dev/null
+++ b/modules/mesh-delivery-gate/cmd/mesh-delivery-gate/checktime.go
@@ -0,0 +1,34 @@
+package main
+
+import "time"
+
+// lastCheckTime is how long the newest answered check of a repository ran, as its verdict says it (`took`): the
+// repository's last measured check time (novox/hq ADR 0505 §4). Zero when no verdict of the repository says it.
+// Under the lock.
+func (h *Holder) lastCheckTime(repository string) time.Duration {
+	var newest *Verdict
+	var took time.Duration
+	for _, d := range h.deliveries {
+		v := d.Check
+		if d.Repository != repository || v == nil || v.Took == "" {
+			continue
+		}
+		t, err := time.ParseDuration(v.Took)
+		if err != nil || t <= 0 {
+			continue
+		}
+		if newest == nil || v.At.After(newest.At) {
+			newest, took = v, t
+		}
+	}
+	return took
+}
+
+// answeredRefusalBound is how long a refusal the gate is already answering waits before it is said as stalled: twice
+// the repository's last measured check time, at least the floor (ADR 0505 §4). Under the lock.
+func (h *Holder) answeredRefusalBound(repository string) time.Duration {
+	if b := 2 * h.lastCheckTime(repository); b > h.refusalFloor() {
+		return b
+	}
+	return h.refusalFloor()
+}