COND9: the keeper takes a part whose finding stream the bus module made as a source (the moved-stream half stops on a question)

Builds: design 47 G §515, §663

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

modules/mesh-conditions/cmd/mesh-conditions/bound.go

@@ -0,0 +1,73 @@
+package main
+
+// The keeper's sources are the parts whose finding stream the bus module made (design 47 G §515, §663): it takes a source
+// when it hears the seat mesh-broker's `created` of a part's `finding-events` entry, and at its start reads the entries
+// the bus module holds by `list`. No part is named here (§7).
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	broker "git.novox.be/novox/mesh-contracts/go/seats/meshbroker"
+)
+
+// FindingEventsTemplate is the template of a part's finding stream in its `requires` (design 47 G §529).
+const FindingEventsTemplate = "finding-events"
+
+// BrokerCreated takes one `created` of the bus module: a `finding-events` entry makes its module a source, asked once with
+// `findings-asked` naming it. An entry of another template, or a module already a source, changes nothing.
+func (k *Keeper) BrokerCreated(body []byte) error {
+	var said broker.Said
+	if err := json.Unmarshal(body, &said); err != nil || said.Module == "" {
+		k.Logf("a created of the bus module is not readable: %v", err)
+		return nil
+	}
+	if said.Template != FindingEventsTemplate {
+		return nil
+	}
+	return k.takeSource(said.Module)
+}
+
+// takeSource makes the module a source the bus module made a stream for, and asks it once.
+func (k *Keeper) takeSource(module string) error {
+	k.mu.Lock()
+	k.init()
+	if k.created == nil {
+		k.created = map[string]bool{}
+	}
+	if k.created[module] {
+		k.mu.Unlock()
+		return nil
+	}
+	k.created[module] = true
+	k.mu.Unlock()
+	if _, err := k.Ask(Module, module); err != nil {
+		return fmt.Errorf("asking %s for its findings: %w", module, err)
+	}
+	return nil
+}
+
+// ListBound reads the entries the bus module holds at the keeper's start: every module with a `finding-events` entry is a
+// source. A call that fails is asked again with a growing wait, the bus module being delivered after the keeper at times.
+func ListBound(k *Keeper, call func(key string, body any) (json.RawMessage, error)) {
+	for wait := 2 * time.Second; ; wait = min(wait*2, time.Minute) {
+		raw, err := call("seat:"+broker.Seat+"."+broker.VerbList, broker.ListInput{})
+		var answer broker.ListAnswer
+		if err == nil {
+			err = json.Unmarshal(raw, &answer)
+		}
+		if err == nil {
+			for _, e := range answer.Entries {
+				if e.Template == FindingEventsTemplate {
+					if err := k.takeSource(e.Module); err != nil {
+						k.Logf("%v", err)
+					}
+				}
+			}
+			return
+		}
+		k.Logf("the entries of the bus module are not read yet (%v); asked again in %s", err, wait)
+		time.Sleep(wait)
+	}
+}

modules/mesh-conditions/cmd/mesh-conditions/catalog.go

@@ -113,6 +113,10 @@ func (k *Keeper) isSource(observer string) bool {
 	k.mu.Lock()
 	defer k.mu.Unlock()
 	k.init()
+	// A part whose finding stream the bus module made is a source (design 47 G §663).
+	if k.created[observer] {
+		return true
+	}
 	// A source the keeper kept in `findings-views` is heard before its first view of the catalog half (design 47 G §388).
 	for _, v := range k.views {
 		if v.observer == observer && v.kept {

modules/mesh-conditions/cmd/mesh-conditions/events.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 	"time"
 
+	broker "git.novox.be/novox/mesh-contracts/go/seats/meshbroker"
 	engine "git.novox.be/novox/mesh-contracts/go/seats/nodeengine"
 	cc "git.novox.be/novox/mesh-contracts/health-and-repair/go/clients/meshconditionsclient"
 	seat "git.novox.be/novox/mesh-contracts/health-and-repair/go/seats/meshconditions"
@@ -51,6 +52,9 @@ func (k *Keeper) FindingEvent(e stdio.Envelope) error {
 	if e.Key == engine.Seat+"."+engine.EventRunning {
 		return k.EngineRunning(e.Node, e.Body)
 	}
+	if e.Key == broker.Seat+"."+broker.EventCreated {
+		return k.BrokerCreated(e.Body)
+	}
 	if observer, ok := emitterOf(e.Key, EventFindingsStated); ok {
 		return k.FindingsStated(observer, e.Node, e.Body)
 	}
@@ -202,7 +206,7 @@ func (k *Keeper) MachinePresence(body []byte, away bool) error {
 func hear(k *Keeper) {
 	patterns := []string{"*." + EventFindingWritten, "*." + EventFindingCleared, "*." + EventFindingsStated,
 		watchdogs.Seat + "." + watchdogs.EventMachineAway, watchdogs.Seat + "." + watchdogs.EventMachineBack,
-		engine.Seat + "." + engine.EventRunning}
+		engine.Seat + "." + engine.EventRunning, broker.Seat + "." + broker.EventCreated}
 	for _, pattern := range patterns {
 		go func() {
 			<-stdio.Served()

modules/mesh-conditions/cmd/mesh-conditions/keeper.go

@@ -147,6 +147,8 @@ type Keeper struct {
 	placed     map[string]bool
 	placedHeld bool
 	stopped    map[string]bool
+	// created are the modules whose `finding-events` entry the bus module made (bound.go).
+	created map[string]bool
 }
 
 func (k *Keeper) init() {

modules/mesh-conditions/cmd/mesh-conditions/keeper_test.go

@@ -617,6 +617,24 @@ func TestTheKeeperSetsItsViewFromWhatAnObserverStates(t *testing.T) {
 		{"the second branch dropped takes its source away", func() error {
 			return r.k.CatalogDropped("feature")
 		}, []string{"machine.d.silent", "machine.g.silent"}, whyLeftCatalog},
+		// Design 47 G §663: a part whose finding-events entry the bus module made is a source, asked once.
+		{"a created finding-events entry makes its part a source, asked once", func() error {
+			before := len(asked)
+			created := mustJSON(t, map[string]any{"module": "newpart", "template": FindingEventsTemplate, "bus-name": "newpart_finding-events", "local-name": "finding-events"})
+			other := mustJSON(t, map[string]any{"module": "otherpart", "template": "state", "bus-name": "otherpart_x", "local-name": "x"})
+			for _, body := range [][]byte{created, other, created} {
+				if err := r.k.FindingEvent(stdio.Envelope{Key: "mesh-broker.created", Body: body}); err != nil {
+					return err
+				}
+			}
+			if len(asked) != before+1 || asked[before]["module"] != "newpart" {
+				t.Errorf("asked %v, want newpart once", asked[before:])
+			}
+			if err := r.k.FindingWritten("otherpart", "ace", mustJSON(t, f("otherpart", "o"))); err != nil {
+				return err
+			}
+			return r.k.FindingWritten("newpart", "ace", mustJSON(t, f("newpart", "w")))
+		}, []string{"machine.d.silent", "machine.g.silent", "machine.w.silent"}, ""},
 	}
 	for _, s := range steps {
 		if err := s.do(); err != nil {

modules/mesh-conditions/cmd/mesh-conditions/main.go

@@ -130,6 +130,7 @@ func Keep(k *Keeper, v *views.Reader) {
 		return said(k.Attempt(c.Key, c.Value, c.Op != "put"))
 	})
 	hear(k)
+	go func() { <-stdio.Served(); ListBound(k, stdio.Ask) }()
 	watch(k, v, BoundsState, "", func(c stdio.StateChange) error {
 		if c.Op == stdio.OpExpire {
 			return said(k.BoundPassed(c.Key))

modules/mesh-conditions/cmd/mesh-conditions/manifest_test.go

@@ -37,9 +37,9 @@ func TestTheManifestSaysWhatTheCodeDoes(t *testing.T) {
 	// the observers' findings are heard as events and no `findings` is read (design 47 G §383).
 	reads := []string{HavesRead, AttemptsRead}
 	if !slices.Equal(m.Invokes, []string{WantsTool, AssignmentsTool, "seat:mesh-hand-acts.hand-act", "seat:mesh-wants.revision",
-		"seat:mesh-catalog.registrations", "seat:mesh-catalog.revision"}) ||
+		"seat:mesh-catalog.registrations", "seat:mesh-catalog.revision", "seat:mesh-broker.list"}) ||
 		!slices.Equal(m.Consumes, []string{"mesh-delivery-assigner.views.wants", "mesh-delivery-assigner.views.assignments",
-			"*.finding-written", "*.finding-cleared", "*.findings-stated", "mesh-watchdogs.machine-away", "mesh-watchdogs.machine-back", "mesh-wants.assignment-revision", "mesh-catalog.registration-changed", "mesh-catalog.catalog-revision", "node-engine.running"}) {
+			"*.finding-written", "*.finding-cleared", "*.findings-stated", "mesh-watchdogs.machine-away", "mesh-watchdogs.machine-back", "mesh-wants.assignment-revision", "mesh-catalog.registration-changed", "mesh-catalog.catalog-revision", "mesh-broker.created", "node-engine.running"}) {
 		t.Errorf("invokes %v, consumes %v", m.Invokes, m.Consumes)
 	}
 	for _, r := range m.Reads {

modules/mesh-conditions/go.mod

@@ -5,6 +5,7 @@ go 1.26.0
 require (
 	git.novox.be/novox/mesh-contracts/go/clients/meshmoduleassignerclient v0.0.0-00010101000000-000000000000
 	git.novox.be/novox/mesh-contracts/go/clients/nodeengineclient v0.0.0-00010101000000-000000000000
+	git.novox.be/novox/mesh-contracts/go/seats/meshbroker v0.0.0-00010101000000-000000000000
 	git.novox.be/novox/mesh-contracts/go/seats/meshmoduleassigner v0.0.0-00010101000000-000000000000
 	git.novox.be/novox/mesh-contracts/go/seats/nodeengine v0.0.0-00010101000000-000000000000
 	git.novox.be/novox/mesh-contracts/health-and-repair/go/clients/meshconditionsclient v0.0.0-00010101000000-000000000000

modules/mesh-conditions/module.json

@@ -23,7 +23,8 @@
     "seat:mesh-hand-acts.hand-act",
     "seat:mesh-wants.revision",
     "seat:mesh-catalog.registrations",
-    "seat:mesh-catalog.revision"
+    "seat:mesh-catalog.revision",
+    "seat:mesh-broker.list"
   ],
   "consumes": [
     "mesh-delivery-assigner.views.wants",
@@ -36,6 +37,7 @@
     "mesh-wants.assignment-revision",
     "mesh-catalog.registration-changed",
     "mesh-catalog.catalog-revision",
+    "mesh-broker.created",
     "node-engine.running"
   ],
   "state": [