[#460] reputation/local: Declare Managers

Declare interfaces for building list of
managers of certain peer in certain epoch.
Implement `Builder` struct that aggregates
fields that are necessary for building
list of managers.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/services/reputation/local/route/calls.go

@@ -65,11 +65,13 @@ func (r *Router) InitWriter(ctx reputationcontroller.Context) (reputationcontrol
 	}, nil
 }
 
-func (w *trustWriter) Write(a reputation.Trust) error {
+func (w *trustWriter) Write(t reputation.Trust) error {
 	w.routeMtx.Lock()
 	defer w.routeMtx.Unlock()
 
-	route, err := w.router.routeBuilder.NextStage(w.ctx.Epoch(), w.ctx.passedRoute)
+	localPeerID := reputation.PeerIDFromBytes(w.router.localSrvInfo.PublicKey())
+
+	route, err := w.router.routeBuilder.NextStage(w.ctx.Epoch(), localPeerID, w.ctx.passedRoute)
 	if err != nil {
 		return err
 	} else if len(route) == 0 {
@@ -106,7 +108,7 @@ func (w *trustWriter) Write(a reputation.Trust) error {
 			w.mServers[endpoint] = remoteWriter
 		}
 
-		err := remoteWriter.Write(a)
+		err := remoteWriter.Write(t)
 		if err != nil {
 			w.router.log.Debug("could not write the value",
 				zap.String("error", err.Error()),

pkg/services/reputation/local/route/deps.go

@@ -1,6 +1,7 @@
 package reputationroute
 
 import (
+	"github.com/nspcc-dev/neofs-node/pkg/services/reputation"
 	reputationcontroller "github.com/nspcc-dev/neofs-node/pkg/services/reputation/local/controller"
 )
 
@@ -18,6 +19,18 @@ type ServerInfo interface {
 	Address() string
 }
 
+// Builder groups methods to route values in the network.
+type Builder interface {
+	// NextStage must return next group of route points
+	// for passed epoch and PeerID of the current route point.
+	// Implementation must take into account already passed route points.
+	//
+	// Empty passed list means being at the starting point of the route.
+	//
+	// Must return empty list and no error if the endpoint of the route is reached.
+	NextStage(epoch uint64, p reputation.PeerID, passed []ServerInfo) ([]ServerInfo, error)
+}
+
 // RemoteWriterProvider describes the component
 // for sending values to a fixed route point.
 type RemoteWriterProvider interface {

pkg/services/reputation/local/route/managers/builder.go

@@ -0,0 +1,48 @@
+package managers
+
+import "fmt"
+
+// Prm groups the required parameters of the Builder's constructor.
+//
+// All values must comply with the requirements imposed on them.
+// Passing incorrect parameter values will result in constructor
+// failure (error or panic depending on the implementation).
+type Prm struct {
+	// Manager builder for current node.
+	//
+	// Must not be nil.
+	ManagerBuilder ManagerBuilder
+}
+
+// Builder represents component that routes node to its managers.
+//
+// For correct operation, Builder must be created using
+// the constructor (New) based on the required parameters
+// and optional components. After successful creation,
+// the Builder is immediately ready to work through API.
+type Builder struct {
+	managerBuilder ManagerBuilder
+}
+
+const invalidPrmValFmt = "invalid parameter %s (%T):%v"
+
+func panicOnPrmValue(n string, v interface{}) {
+	panic(fmt.Sprintf(invalidPrmValFmt, n, v, v))
+}
+
+// New creates a new instance of the Builder.
+//
+// Panics if at least one value of the parameters is invalid.
+//
+// The created Builder does not require additional
+// initialization and is completely ready for work.
+func New(prm Prm) *Builder {
+	switch {
+	case prm.ManagerBuilder == nil:
+		panicOnPrmValue("ManagerBuilder", prm.ManagerBuilder)
+	}
+
+	return &Builder{
+		managerBuilder: prm.ManagerBuilder,
+	}
+}

pkg/services/reputation/local/route/managers/calls.go

@@ -0,0 +1,23 @@
+package managers
+
+import (
+	"github.com/nspcc-dev/neofs-node/pkg/services/reputation"
+	reputationroute "github.com/nspcc-dev/neofs-node/pkg/services/reputation/local/route"
+	"github.com/pkg/errors"
+)
+
+// NextStage builds Manager list for node and returns it directly.
+//
+// If passed route has more than one point, then endpoint of the route is reached.
+func (b *Builder) NextStage(epoch uint64, p reputation.PeerID, passed []reputationroute.ServerInfo) ([]reputationroute.ServerInfo, error) {
+	if len(passed) > 1 {
+		return nil, nil
+	}
+
+	route, err := b.managerBuilder.BuildManagers(epoch, p)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not build managers for epoch: %d", epoch)
+	}
+
+	return route, nil
+}

pkg/services/reputation/local/route/managers/deps.go

@@ -0,0 +1,14 @@
+package managers
+
+import (
+	"github.com/nspcc-dev/neofs-node/pkg/services/reputation"
+	reputationroute "github.com/nspcc-dev/neofs-node/pkg/services/reputation/local/route"
+)
+
+// ManagerBuilder defines an interface for providing a list
+// of Managers for specific epoch. Implementation depends on trust value.
+type ManagerBuilder interface {
+	// BuildManagers must compose list of managers. It depends on
+	// particular epoch and PeerID of the current route point.
+	BuildManagers(epoch uint64, p reputation.PeerID) ([]reputationroute.ServerInfo, error)
+}