[#473] Implement EigenTrust calculations

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

pkg/services/reputation/eigentrust/controller/calls.go

@@ -0,0 +1,69 @@
+package eigentrustctrl
+
+import (
+	"context"
+
+	"github.com/nspcc-dev/neofs-node/pkg/services/reputation/eigentrust"
+	"go.uber.org/zap"
+)
+
+// ContinuePrm groups the required parameters of Continue operation.
+type ContinuePrm struct {
+	epoch uint64
+}
+
+type iterContext struct {
+	context.Context
+
+	eigentrust.EpochIteration
+
+	last bool
+}
+
+func (x iterContext) Last() bool {
+	return x.last
+}
+
+type iterContextCancel struct {
+	iterContext
+
+	cancel context.CancelFunc
+}
+
+// Continue moves the global reputation calculator to the next iteration.
+func (c *Controller) Continue(prm ContinuePrm) {
+	c.mtx.Lock()
+
+	{
+		iterCtx, ok := c.mCtx[prm.epoch]
+		if !ok {
+			iterCtx := new(iterContextCancel)
+			c.mCtx[prm.epoch] = iterCtx
+
+			iterCtx.Context, iterCtx.cancel = context.WithCancel(context.Background())
+		} else {
+			iterCtx.cancel()
+		}
+
+		iterCtx.last = iterCtx.I() == c.prm.IterationNumber
+
+		err := c.prm.WorkerPool.Submit(func() {
+			c.prm.DaughtersTrustCalculator.Calculate(iterCtx.iterContext)
+		})
+		if err != nil {
+			c.opts.log.Debug("iteration submit failure",
+				zap.String("error", err.Error()),
+			)
+		}
+
+		if iterCtx.last {
+			delete(c.mCtx, prm.epoch)
+			// In this case and worker pool failure we can mark epoch
+			// number as already processed, but in any case it grows up
+			// during normal operation of the system. Also, such information
+			// will only live while the application is alive.
+		}
+	}
+
+	c.mtx.Unlock()
+}