[#473] Implement EigenTrust calculations

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/services/reputation/eigentrust/calculator/deps.go

@@ -0,0 +1,47 @@
+package eigentrustcalc
+
+import (
+	"context"
+
+	"github.com/nspcc-dev/neofs-node/pkg/services/reputation"
+	"github.com/nspcc-dev/neofs-node/pkg/services/reputation/eigentrust"
+)
+
+type Context interface {
+	context.Context
+
+	// Must return epoch number to select the values
+	// for global trust calculation.
+	Epoch() uint64
+
+	// Must return the sequence number of the iteration.
+	I() uint32
+}
+
+type InitialTrustSource interface {
+	InitialTrust(reputation.PeerID) (reputation.TrustValue, error)
+}
+
+type TrustIterator interface {
+	Iterate(reputation.TrustHandler) error
+}
+
+type PeerTrustsHandler func(reputation.PeerID, TrustIterator) error
+
+type PeerTrustsIterator interface {
+	Iterate(PeerTrustsHandler) error
+}
+
+type DaughterTrustIteratorProvider interface {
+	InitDaughterIterator(Context, reputation.PeerID) (TrustIterator, error)
+	InitAllDaughtersIterator(Context) (PeerTrustsIterator, error)
+	InitConsumersIterator(Context) (PeerTrustsIterator, error)
+}
+
+type IntermediateWriter interface {
+	WriteIntermediateTrust(eigentrust.IterationTrust) error
+}
+
+type IntermediateWriterProvider interface {
+	InitIntermediateWriter(Context) (IntermediateWriter, error)
+}