Continued scaffolding and interface definitions

services/data_service/internal/control/control.go

@@ -1,2 +1,25 @@
 // Package control
 package control
+
+import (
+	"github.com/google/uuid"
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/node"
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/node/processor"
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/router"
+)
+
+type nodeEntry struct {
+	Template            node.Template
+	TemplateFingerprint string
+}
+
+type Controller struct {
+	router            router.Router
+	sourceRegistry    any // source.Registry
+	processorRegistry processor.Registry
+	sinkRegistry      any // sink.Registry
+
+	sourceNodes    map[uuid.UUID]any
+	processorNodes map[uuid.UUID]processor.Processor
+	sinkNodes      map[uuid.UUID]any
+}

services/data_service/internal/control/fingerprint.go

@@ -0,0 +1,43 @@
+package control
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"sort"
+
+	"lukechampine.com/blake3"
+)
+
+func StreamFingerprint(templateFP, outPort string, inMap map[string]string) string {
+	// Sort input keys for determinism.
+	keys := make([]string, 0, len(inMap))
+	for k := range inMap {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	h := blake3.New(32, nil)
+
+	write := func(s string) {
+		var lenbuf [4]byte
+		binary.LittleEndian.PutUint32(lenbuf[:], uint32(len(s)))
+		_, _ = h.Write(lenbuf[:])
+		_, _ = h.Write([]byte(s))
+	}
+
+	// templateFP, outPort, input count, then pairs.
+	write(templateFP)
+	write(outPort)
+
+	var nbuf [4]byte
+	binary.LittleEndian.PutUint32(nbuf[:], uint32(len(keys)))
+	_, _ = h.Write(nbuf[:])
+
+	for _, k := range keys {
+		write(k)
+		write(inMap[k])
+	}
+
+	sum := h.Sum(nil)
+	return hex.EncodeToString(sum)
+}

services/data_service/internal/node/exit/session.go

@@ -1,2 +0,0 @@
-// Package exit
-package exit

services/data_service/internal/node/io.go

@@ -5,10 +5,10 @@ import (
 	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/domain"
 )
 
-type In interface {
+type Receiver interface {
 	Receive() (port string, message domain.Message, ok bool)
 }
 
-type Out interface {
+type Sender interface {
 	Send(port string, message domain.Message) error
 }

services/data_service/internal/node/node.go

@@ -0,0 +1,16 @@
+package node
+
+type Type string
+
+const (
+	Source    Type = "source"
+	Processor Type = "processor"
+	Sink      Type = "sink"
+)
+
+type Template struct {
+	Kind    Type
+	Type    string
+	Version string
+	Config  string
+}

services/data_service/internal/node/processor/processor.go

@@ -1,2 +1,18 @@
 // Package processor
 package processor
+
+import (
+	"context"
+
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/node"
+)
+
+type Processor interface {
+	Start(ctx context.Context, cfg string, io IO) error
+	Stop()
+}
+
+type IO interface {
+	node.Receiver
+	node.Sender
+}

services/data_service/internal/node/processor/registry.go

@@ -0,0 +1,11 @@
+package processor
+
+type Registry struct{}
+
+type Factory interface {
+	New() Processor
+	Type() string
+	Version() string
+
+	TemplateFingerprint(cfg string) (string, error)
+}

services/data_service/internal/node/sink/sink.go

@@ -0,0 +1,17 @@
+// Package sink
+package sink
+
+import (
+	"context"
+
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/node"
+)
+
+type Sink interface {
+	Start(ctx context.Context, io IO) error
+	Stop()
+}
+
+type IO interface {
+	node.Sender
+}

services/data_service/internal/node/source/registry.go

@@ -0,0 +1 @@
+package source

services/data_service/internal/node/source/source.go

@@ -1,2 +1,20 @@
 // Package source
 package source
+
+import (
+	"context"
+
+	"gitlab.michelsen.id/phillmichelsen/tessera/services/data_service/internal/node"
+)
+
+type Source interface {
+	Start(ctx context.Context, cfg string, io IO) error
+	Stop()
+
+	Serve(key string) error
+	Unserve(key string) error
+}
+
+type IO interface {
+	node.Sender
+}

services/data_service/internal/router/router.go

@@ -0,0 +1,9 @@
+// Package router
+package router
+
+import "github.com/google/uuid"
+
+type Router interface {
+	Route(fromNode uuid.UUID, fromOutPort string, toNode uuid.UUID, toInPort string)
+	Unroute(fromNode uuid.UUID, fromOutPort string, toNode uuid.UUID, toInPort string)
+}

services/data_service/internal/router/single/engine.go

@@ -0,0 +1,2 @@
+// Package single
+package single