G-delivery 6: the builder ends a remove on kept and records the version kept

A seat that cannot remove a tag alone (another tag names its digest) now answers and says kept. The builder ends
that remove there, with no retry, and marks the version kept on its store with the reason and the other tags;
builder_versions shows it, and a later branch end asks it no more. The four seats' kept are consumed.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

modules/mesh-delivery-builder/cmd/mesh-delivery-builder/seats.go

@@ -20,22 +20,26 @@ import (
 // seatEvent is one registry seat's event the builder hears: the seat and the event's name.
 type seatEvent struct{ seat, event string }
 
-// seatEvents are the four registry seats' published, refused and removed, by subject (design 51 *How a publish ends*,
+// seatEvents are the four registry seats' published, refused, removed and kept, by subject (design 51 *How a publish ends*,
 // DLV-B4): each a seat event `<seat>.<event>` on the shared events stream, heard on the builder's durable consumer of
 // it through the manifest's consumes. The subjects are the seats' contracts' (mesh-contracts).
 var seatEvents = map[string]seatEvent{
 	containerimageregistry.SubjectPublished: {containerimageregistry.Seat, containerimageregistry.EventPublished},
 	containerimageregistry.SubjectRefused:   {containerimageregistry.Seat, containerimageregistry.EventRefused},
 	containerimageregistry.SubjectRemoved:   {containerimageregistry.Seat, containerimageregistry.EventRemoved},
+	containerimageregistry.SubjectKept:      {containerimageregistry.Seat, containerimageregistry.EventKept},
 	ociartifactregistry.SubjectPublished:    {ociartifactregistry.Seat, ociartifactregistry.EventPublished},
 	ociartifactregistry.SubjectRefused:      {ociartifactregistry.Seat, ociartifactregistry.EventRefused},
 	ociartifactregistry.SubjectRemoved:      {ociartifactregistry.Seat, ociartifactregistry.EventRemoved},
+	ociartifactregistry.SubjectKept:         {ociartifactregistry.Seat, ociartifactregistry.EventKept},
 	gopackageregistry.SubjectPublished:      {gopackageregistry.Seat, gopackageregistry.EventPublished},
 	gopackageregistry.SubjectRefused:        {gopackageregistry.Seat, gopackageregistry.EventRefused},
 	gopackageregistry.SubjectRemoved:        {gopackageregistry.Seat, gopackageregistry.EventRemoved},
+	gopackageregistry.SubjectKept:           {gopackageregistry.Seat, gopackageregistry.EventKept},
 	npmpackageregistry.SubjectPublished:     {npmpackageregistry.Seat, npmpackageregistry.EventPublished},
 	npmpackageregistry.SubjectRefused:       {npmpackageregistry.Seat, npmpackageregistry.EventRefused},
 	npmpackageregistry.SubjectRemoved:       {npmpackageregistry.Seat, npmpackageregistry.EventRemoved},
+	npmpackageregistry.SubjectKept:          {npmpackageregistry.Seat, npmpackageregistry.EventKept},
 }
 
 // seatHearer takes the registry seats' outcomes in: each moves a numbered version (versions.Numberer.Heard), and a

modules/mesh-delivery-builder/cmd/mesh-delivery-builder/versions.go

@@ -11,6 +11,7 @@ import (
 	"github.com/nats-io/nats.go"
 	"github.com/nats-io/nats.go/jetstream"
 
+	"git.novox.be/novox/mesh-contracts/go/seats/ociartifactregistry"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/health"
 	"git.novox.be/novox/mesh-sdk/go/process"
@@ -310,11 +311,19 @@ func doneVia(b *build.Builder) func(ctx context.Context, module, fp string) (boo
 }
 
 // removeVia calls a registry seat's remove for one tagged version, as the builder's own account (design 51 *Tagged
-// versions*): the reason tag-gone; the seat says removed on its events.
+// versions*): the reason tag-gone; the seat says removed on its events, or answers kept when another tag names the
-func removeVia(call toolCaller) func(ctx context.Context, seat string, e versions.Entry) error {
+// digest (the registry part's RemoveAnswer: kept, reason, tags), which ends the remove.
-	return func(_ context.Context, seat string, e versions.Entry) error {
+func removeVia(call toolCaller) func(ctx context.Context, seat string, e versions.Entry) (versions.RemoveOutcome, error) {
-		_, err := call("seat:"+seat+".remove", map[string]any{"name": e.Name, "version": e.Version, "tag": e.Tag, "reason": "tag-gone"})
+	return func(_ context.Context, seat string, e versions.Entry) (versions.RemoveOutcome, error) {
-		return err
+		raw, err := call("seat:"+seat+".remove", map[string]any{"name": e.Name, "version": e.Version, "tag": e.Tag, "reason": "tag-gone"})
+		if err != nil {
+			return versions.RemoveOutcome{}, err
+		}
+		var a ociartifactregistry.RemoveAnswer // the four registry seats share the part's answer
+		if len(raw) > 0 && json.Unmarshal(raw, &a) != nil {
+			return versions.RemoveOutcome{}, fmt.Errorf("%s's remove answered what is no answer of it: %s", seat, raw)
+		}
+		return versions.RemoveOutcome{Kept: a.Kept, Reason: a.Reason, Tags: a.Tags}, nil
 	}
 }
 

modules/mesh-delivery-builder/internal/versions/again.go

@@ -175,7 +175,7 @@ func Untagged(entries []Entry, repository, tag string) []Entry {
 	tag = CleanTag(tag)
 	var out []Entry
 	for _, e := range entries {
-		if e.Tag != "" && e.Repository == repository && CleanTag(e.Tag) == tag && e.State != Removed {
+		if e.Tag != "" && e.Repository == repository && CleanTag(e.Tag) == tag && e.State != Removed && e.State != Kept {
 			out = append(out, e)
 		}
 	}
@@ -213,8 +213,8 @@ type Acts struct {
 	BuildAgain func(ctx context.Context, module, fp, why, by string) (answer string, refused bool)
 	// Reconsider looks at every module again, so a claim asks a name's floor.
 	Reconsider func(ctx context.Context)
-	// Remove calls a seat's verb remove for one tagged version, reason tag-gone.
+	// Remove calls a seat's verb remove for one tagged version, reason tag-gone: what it answered, kept or asked.
-	Remove func(ctx context.Context, seat string, e Entry) error
+	Remove func(ctx context.Context, seat string, e Entry) (RemoveOutcome, error)
 	// DropOldForm drops a retired node from the old form's count by hand (builder_old_form): its answer, or why not.
 	DropOldForm func(ctx context.Context, node, by, why string, at time.Time) (string, error)
 }
@@ -240,8 +240,10 @@ func (a Acts) TagAsked(ctx context.Context, t TagAsk, now time.Time) TagAsk {
 		t.Versions[e.Name] = e.Version
 		at := e.Name + "@" + e.Version
 		t.Left[at] = e.Seat
-		if err := a.Remove(ctx, e.Seat, e); err != nil {
+		if left, ok := a.removeOne(ctx, e); ok {
-			t.Left[at] = e.Seat + ": " + err.Error()
+			delete(t.Left, at)
+		} else if left != "" {
+			t.Left[at] = left
 		}
 	}
 	if len(t.Left) == 0 {
@@ -253,6 +255,22 @@ func (a Acts) TagAsked(ctx context.Context, t TagAsk, now time.Time) TagAsk {
 	return t
 }
 
+// removeOne asks e's seat to remove it: done when the seat kept it whole (recorded Kept, no retry); otherwise left, with
+// the error of a call that failed.
+func (a Acts) removeOne(ctx context.Context, e Entry) (left string, done bool) {
+	got, err := a.Remove(ctx, e.Seat, e)
+	if err != nil {
+		return e.Seat + ": " + err.Error(), false
+	}
+	if !got.Kept {
+		return "", false
+	}
+	if err := a.Numberer.keep(ctx, e, got.Reason, got.Tags); err != nil {
+		return e.Seat + ": kept, and not recorded so: " + err.Error(), false
+	}
+	return "", true
+}
+
 // PublishAgain is builder_publish_again of name's fingerprint: what it did, the version, and its answer; an error refuses.
 func (a Acts) PublishAgain(ctx context.Context, name, fp, why, by string, at time.Time) (Again, string, error) {
 	module, _, _ := strings.Cut(name, "/")

modules/mesh-delivery-builder/internal/versions/branchend.go

@@ -67,8 +67,11 @@ func (a Acts) BranchEnded(ctx context.Context, repository, branch string) (Branc
 		if a.Remove == nil {
 			continue
 		}
-		if err := a.Remove(ctx, e.Seat, e); err != nil {
+		// A seat that kept it whole (another tag names its digest) ends it here: recorded kept, never asked again.
-			left[at] = e.Seat + ": " + err.Error()
+		if l, done := a.removeOne(ctx, e); done {
+			delete(left, at)
+		} else if l != "" {
+			left[at] = l
 		}
 	}
 	return BranchEnd{Left: left, Done: len(left) == 0}, nil

modules/mesh-delivery-builder/internal/versions/heard.go

@@ -11,6 +11,7 @@ const (
 	HeardPublished = "published"
 	HeardRefused   = "refused"
 	HeardRemoved   = "removed"
+	HeardKept      = "kept"
 )
 
 // Outcome is the body of a registry seat's published, refused and removed (mesh-contracts parts/registry Outcome), the
@@ -22,10 +23,32 @@ type Outcome struct {
 	Kind    string `json:"kind"`
 	Holder  string `json:"holder"`
 	Reason  string `json:"reason,omitempty"`
+	// Tags are, on kept, the other tags still naming its digest.
+	Tags []string `json:"tags,omitempty"`
+}
+
+// RemoveOutcome is what a seat's remove answered: kept whole (another tag names its digest), with why and those tags; or
+// asked, the seat saying removed on its events.
+type RemoveOutcome struct {
+	Kept   bool
+	Reason string
+	Tags   []string
+}
+
+// keep marks a tagged version kept by its seat, so it is asked no more.
+func (n *Numberer) keep(ctx context.Context, e Entry, reason string, tags []string) error {
+	if reason == "" {
+		reason = "shared-digest"
+	}
+	_, err := n.Versions.Mark(ctx, e.Name, e.Version, func(x *Entry) {
+		x.State, x.Reason, x.KeptWith = Kept, reason, append([]string(nil), tags...)
+	})
+	return err
 }
 
 // Heard takes one seat event in: a numbered version's entry turns published (with its digest when it held none),
-// refused with the holder's reason, or removed with its reason and the event's id; a by-digest publish (no version)
+// refused with the holder's reason, removed with its reason and the event's id, or kept (another tag names its digest)
+// with the other tags; a by-digest publish (no version)
 // marks nothing. It answers the names waiting on their floor that the event wakes: a `published` says the seat
 // answers (design 51 *The floor*).
 func (n *Numberer) Heard(ctx context.Context, seat, event, id string, o Outcome) ([]string, error) {
@@ -53,6 +76,15 @@ func (n *Numberer) Heard(ctx context.Context, seat, event, id string, o Outcome)
 		}
 	case HeardRemoved:
 		change = func(e *Entry) { e.State, e.Reason, e.RemovedBy = Removed, o.Reason, id }
+	case HeardKept:
+		change = func(e *Entry) {
+			if e.State != Removed {
+				e.State, e.Reason, e.KeptWith = Kept, o.Reason, append([]string(nil), o.Tags...)
+				if e.Reason == "" {
+					e.Reason = "shared-digest"
+				}
+			}
+		}
 	default:
 		return wake, fmt.Errorf("%s says %q, which the builder does not hear", seat, event)
 	}

modules/mesh-delivery-builder/internal/versions/tools.go

@@ -106,6 +106,6 @@ func AnswerVersions(ctx context.Context, r Reader, name, version, digest string)
 // VersionsDescription is builder_versions' description.
 const VersionsDescription = "A name's versions as the builder numbered them (its state versions, design 51): every trunk and tagged " +
 	"version of a package, image, bundle or archive in order, each with its kind, series, fingerprint, commit, source revision, digest, " +
-	"seat, state (numbered, published, refused with its reason, removed with its time, reason and the event that removed it) and when. " +
+	"seat, state (numbered, published, refused with its reason, removed with its time, reason and the event that removed it, or kept: its seat kept it whole on remove, its digest shared, with the reason and the other tags naming it, kept_with) and when. " +
 	"With version, and digest, it also answers recorded: whether the builder numbered that version with that digest, and why not: the " +
 	"question a registry seat's holder asks before it stores a publish (ADR 0605 §4). Read-only."

modules/mesh-delivery-builder/internal/versions/versions.go

@@ -36,6 +36,10 @@ const (
 	Published = "published"
 	Refused   = "refused"
 	Removed   = "removed"
+	// Kept is a tagged version its seat kept whole on remove: another tag names its digest, so the store cannot remove the
+	// tag alone (review round 2; the registry seats' `kept`). Its Reason is the seat's (shared-digest), KeptWith the
+	// other tags; it is asked no more.
+	Kept = "kept"
 )
 
 // The kinds the builder numbers: a package per source revision, the rest per fingerprint (design 51).
@@ -69,6 +73,8 @@ type Entry struct {
 	Reason string `json:"reason,omitempty"`
 	// Repository is a tagged version's repository: its branch's end removes it (Untagged).
 	Repository string `json:"repository,omitempty"`
+	// KeptWith are the other tags naming its digest, when its seat kept it (Kept).
+	KeptWith []string `json:"kept_with,omitempty"`
 	// RemovedBy is the id of the event that removed it.
 	RemovedBy string `json:"removed_by,omitempty"`
 	// RefusedDigest is the digest the holder refused: one other than Digest means the seat was offered other bytes under
@@ -87,7 +93,7 @@ func (e Entry) Valid() error {
 		return fmt.Errorf("%s: a version with no version", e.Name)
 	}
 	switch e.State {
-	case Numbered, Published, Refused, Removed:
+	case Numbered, Published, Refused, Removed, Kept:
 	default:
 		return fmt.Errorf("%s@%s: unknown state %q", e.Name, e.Version, e.State)
 	}

modules/mesh-delivery-builder/internal/versions/versions_test.go

@@ -727,12 +727,16 @@ func TestTheBuildersVersions(t *testing.T) {
 			_, _ = st.Create(context.Background(), Key(e.Name, e.Version), raw)
 		}
 		var removed []string
-		acts := Acts{Numberer: &Numberer{Versions: Versions{Store: st}}, Remove: func(_ context.Context, seat string, e Entry) error {
+		var kept map[string]bool // review round 2: the names whose seat keeps them whole (a shared digest)
+		acts := Acts{Numberer: &Numberer{Versions: Versions{Store: st}}, Remove: func(_ context.Context, seat string, e Entry) (RemoveOutcome, error) {
 			removed = append(removed, e.Name+"@"+e.Version)
-			if seat == SeatNPM {
+			if kept[e.Name] {
-				return errors.New("down")
+				return RemoveOutcome{Kept: true, Reason: "shared-digest", Tags: []string{"0.1.2"}}, nil
 			}
-			return nil
+			if seat == SeatNPM {
+				return RemoveOutcome{}, errors.New("down")
+			}
+			return RemoveOutcome{}, nil
 		}}
 		u, _ := DecodeTagAsk(uraw)
 		got := acts.TagAsked(context.Background(), u, at)
@@ -756,6 +760,26 @@ func TestTheBuildersVersions(t *testing.T) {
 		if end, _ := acts.BranchEnded(context.Background(), "o/r", "feat/x"); !end.Done {
 			t.Errorf("every seat said removed, and the branch's end is not done: %+v", end)
 		}
+		// Review round 2: a remove its seat answers kept (another tag names the digest) ends there, with no retry: the
+		// version is recorded kept on the store with the reason and the other tags, which builder_versions shows.
+		raw, _ = Encode(Entry{Name: "n4", Kind: KindPackage, Series: "0.1", Version: "0.1.2-feat-x.1", Tag: "feat-x", Repository: "o/r", Seat: SeatNPM, State: Numbered})
+		_, _ = st.Create(context.Background(), Key("n4", "0.1.2-feat-x.1"), raw)
+		kept, removed = map[string]bool{"n4": true}, nil
+		if end, err := acts.BranchEnded(context.Background(), "o/r", "feat/x"); err != nil || !end.Done || len(removed) != 1 {
+			t.Fatalf("a kept remove: %+v %v, removed %v; want done at once", end, err, removed)
+		}
+		if es, _ := acts.Numberer.Versions.Of(context.Background(), "n4"); len(es) != 1 || es[0].State != Kept || es[0].Reason != "shared-digest" || !reflect.DeepEqual(es[0].KeptWith, []string{"0.1.2"}) {
+			t.Errorf("the kept version = %+v, want kept, shared-digest, with 0.1.2", es)
+		}
+		if removed = nil; func() bool { end, _ := acts.BranchEnded(context.Background(), "o/r", "feat/x"); return !end.Done || len(removed) != 0 }() {
+			t.Errorf("a kept version is asked again: removed %v", removed)
+		}
+		if _, err := acts.Numberer.Heard(context.Background(), SeatNPM, HeardKept, "k", Outcome{Name: "n", Version: "0.1.2-feat-x.1", Tags: []string{"0.1.2"}}); err != nil {
+			t.Fatal(err)
+		}
+		if es, _ := acts.Numberer.Versions.Of(context.Background(), "n"); slices.ContainsFunc(es, func(e Entry) bool { return e.Version == "0.1.2-feat-x.1" && e.State == Kept }) {
+			t.Error("a seat's kept turned a removed version back to kept")
+		}
 		// B6: a check's build of the ask's head marks it numbered with its versions; another head, or an untag, is left.
 		if !a.Unanswered() {
 			t.Errorf("a kept ask with no version is answered: %+v", a)

modules/mesh-delivery-builder/manifest_test.go

@@ -130,14 +130,14 @@ func TestManifestDeclarations(t *testing.T) { // 1607/AC1
 	// Design 51 *The floor*: the indexer's manifest-accepted and the condition keeper's condition-cleared wake a silent floor.
 	// DLV-B4: the four registry seats' outcomes, each a seat event `<seat>.<event>` on the shared events stream.
 	// DLV-M1: the indexer's and the assigner's views families of the states it follows.
-	if want := []string{"container-image-registry.published", "container-image-registry.refused", "container-image-registry.removed",
+	if want := []string{"container-image-registry.kept", "container-image-registry.published", "container-image-registry.refused", "container-image-registry.removed",
-		"go-package-registry.published", "go-package-registry.refused", "go-package-registry.removed",
+		"go-package-registry.kept", "go-package-registry.published", "go-package-registry.refused", "go-package-registry.removed",
 		"mesh-artifact-sweep.artifacts-gone", "mesh-build-go.toolchain.reported", "mesh-build-node.toolchain.reported",
 		"mesh-conditions.condition-cleared", "mesh-delivery-assigner.views.placement", "mesh-delivery-checker.tag-wanted", "mesh-delivery-forge-bridge.forge.**",
 		"mesh-delivery-indexer.manifest-accepted", "mesh-delivery-indexer.views.candidates", "mesh-delivery-indexer.views.manifests", "mesh-delivery-indexer.views.modules",
 		"mesh-delivery-indexer.views.packages", "node-engine.manifest-reads-changed",
-		"npm-package-registry.published", "npm-package-registry.refused", "npm-package-registry.removed",
+		"npm-package-registry.kept", "npm-package-registry.published", "npm-package-registry.refused", "npm-package-registry.removed",
-		"oci-artifact-registry.published", "oci-artifact-registry.refused", "oci-artifact-registry.removed"}; !reflect.DeepEqual(sorted(m.Consumes), want) {
+		"oci-artifact-registry.kept", "oci-artifact-registry.published", "oci-artifact-registry.refused", "oci-artifact-registry.removed"}; !reflect.DeepEqual(sorted(m.Consumes), want) {
 		t.Errorf("consumes = %v, want %v", m.Consumes, want)
 	}
 	if b, ok := m.OwnSecrets["broker"]; !ok || len(m.OwnSecrets) != 1 || b != "${dir:state}/broker" {

modules/mesh-delivery-builder/module.json

@@ -28,9 +28,11 @@
     "version.old-form-closed"
   ],
   "consumes": [
+    "container-image-registry.kept",
     "container-image-registry.published",
     "container-image-registry.refused",
     "container-image-registry.removed",
+    "go-package-registry.kept",
     "go-package-registry.published",
     "go-package-registry.refused",
     "go-package-registry.removed",
@@ -42,9 +44,11 @@
     "mesh-delivery-forge-bridge.forge.**",
     "mesh-delivery-indexer.manifest-accepted",
     "node-engine.manifest-reads-changed",
+    "npm-package-registry.kept",
     "npm-package-registry.published",
     "npm-package-registry.refused",
     "npm-package-registry.removed",
+    "oci-artifact-registry.kept",
     "oci-artifact-registry.published",
     "oci-artifact-registry.refused",
     "oci-artifact-registry.removed",