Fold a pending assignment into the value of its assignment key (issue 1094)

A wait for a build is the value of <node>.<module> with state pending and a pending object (id p-<unix nanoseconds>, a string), so every reader that skips a value with a state skips it, and the controller's own lists skip it through Stands. The transitions are compare-and-set on the key's revision (claim, release, settle, repoint, mark); assigning over a wait carries it into the value that stands, applied when it was waiting; a plan pass never overwrites it; one open wait per machine and module, and a key that holds the module refuses a new one. The table is no longer read or written, ForgetEndedPending is gone (no key is removed), and a wait of a machine the store dropped is none. Callers change type only; their conditions are the next issue.

cmd/mesh-controller/pending.go

@@ -491,8 +491,7 @@ func settlingPending(ctx context.Context, open *stores) {
 
 // settlePending is one tick: claims left by a controller that stopped are settled from what the mesh holds;
 // a module registered meanwhile is assigned; a build heard and not registered, or silent past its bound,
-// ends its assignment; ended ones are raised as conditions and cleared once answered; ended rows older than
-// KeptFor are deleted. Returns what it did.
+// ends its assignment; ended ones are raised as conditions and cleared once answered. Returns what it did.
 func settlePending(ctx context.Context, open *stores, now time.Time) []string {
 	inv := open.inventory
 	var said []string
@@ -565,11 +564,6 @@ func settlePending(ctx context.Context, open *stores, now time.Time) []string {
 	}
 
 	said = append(said, raisePendingEnded(ctx, inv)...)
-	if n, err := inv.ForgetEndedPending(ctx, now); err != nil {
-		say("ended pending assignments could not be deleted: %v", err)
-	} else if n > 0 {
-		say("deleted %d pending assignment(s) ended more than %s ago", n, inventory.KeptFor)
-	}
 	return said
 }
 
@@ -585,7 +579,7 @@ func containsString(xs []string, x string) bool {
 // pendingObservation is the condition for a pending assignment that was not made: one per pending
 // assignment, its row's id the last part of its id, so one row's condition is never another's.
 func pendingObservation(p inventory.PendingAssignment) conditions.Observation {
-	return conditions.Observation{Scope: conditions.ScopeMachine, ID: fmt.Sprintf("%s.%s.%d", p.Node, p.Module, p.ID),
+	return conditions.Observation{Scope: conditions.ScopeMachine, ID: fmt.Sprintf("%s.%s.%s", p.Node, p.Module, p.ID),
 		Token: kindPendingEnded, Kind: kindPendingEnded, Machine: p.Node, Severity: conditions.Warning,
 		Resolver: conditions.ResolverOperator, Source: "pending assignments",
 		Summary: p.Note}
@@ -671,8 +665,8 @@ func clearOrphaned(ctx context.Context, keeper *conditions.Keeper, inv *inventor
 	if err != nil {
 		return []string{fmt.Sprintf("the open conditions could not be read to clear orphaned ones: %v", err)}
 	}
-	byID := map[int64]string{}
-	var ids []int64
+	byID := map[string]string{}
+	var ids []string
 	for _, c := range open {
 		if c.Kind != kindPendingEnded {
 			continue
@@ -682,8 +676,8 @@ func clearOrphaned(ctx context.Context, keeper *conditions.Keeper, inv *inventor
 		if len(parts) < 2 {
 			continue
 		}
-		var id int64
-		if _, err := fmt.Sscan(parts[len(parts)-2], &id); err != nil {
+		id := parts[len(parts)-2]
+		if !strings.HasPrefix(id, "p-") {
 			continue
 		}
 		byID[id] = c.Key

cmd/mesh-controller/pending_integration_test.go

@@ -637,8 +637,9 @@ func TestARaisedRowIsKeptUntilItsConditionClears(t *testing.T) {
 	}
 	settlePending(ctx, open, time.Now())
 	settlePending(ctx, open, time.Now().Add(inventory.KeptFor+time.Hour))
-	if known, err := inv.PendingKnown(ctx, []int64{row.ID}); err != nil || known[row.ID] {
-		t.Fatalf("a cleared row outlived %s: %v", inventory.KeptFor, err)
+	// No key of the chain is removed (ADR 0408 §4): a cleared wait stays in the value of its key, saying it was cleared.
+	if known, err := inv.PendingKnown(ctx, []string{row.ID}); err != nil || !known[row.ID] || rowOf(t, open, row.ID).Cleared == nil {
+		t.Fatalf("a cleared row is not kept, saying so: %v", err)
 	}
 
 	// On anchor, then anchor removed: the row goes, and its condition with it at the next tick.

cmd/mesh-controller/pending_test.go

@@ -23,7 +23,7 @@ func conditionOpen(t *testing.T, p inventory.PendingAssignment) bool {
 	return found
 }
 
-func rowOf(t *testing.T, open *stores, id int64) inventory.PendingAssignment {
+func rowOf(t *testing.T, open *stores, id string) inventory.PendingAssignment {
 	t.Helper()
 	rows, err := open.inventory.Pending(t.Context(), time.Unix(0, 0))
 	if err != nil {
@@ -34,7 +34,7 @@ func rowOf(t *testing.T, open *stores, id int64) inventory.PendingAssignment {
 			return r
 		}
 	}
-	t.Fatalf("pending assignment %d is not on record", id)
+	t.Fatalf("pending assignment %s is not on record", id)
 	return inventory.PendingAssignment{}
 }