[#265] innerring: Select containers to audit

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

pkg/innerring/processors/audit/scheduler_test.go

@@ -0,0 +1,113 @@
+package audit_test
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/container"
+	"github.com/nspcc-dev/neofs-node/pkg/innerring/processors/audit"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSelect(t *testing.T) {
+	cids := generateContainers(10)
+
+	t.Run("invalid input", func(t *testing.T) {
+		require.Empty(t, audit.Select(cids, 0, 0, 0))
+	})
+
+	t.Run("even split", func(t *testing.T) {
+		const irSize = 5 // every node takes two audit nodes
+
+		m := hitMap(cids)
+
+		for i := 0; i < irSize; i++ {
+			s := audit.Select(cids, 0, uint64(i), irSize)
+			require.Equal(t, len(cids)/irSize, len(s))
+
+			for _, id := range s {
+				n, ok := m[id.String()]
+				require.True(t, ok)
+				require.Equal(t, 0, n)
+				m[id.String()] = 1
+			}
+		}
+
+		require.True(t, allHit(m))
+	})
+
+	t.Run("odd split", func(t *testing.T) {
+		const irSize = 3
+
+		m := hitMap(cids)
+
+		for i := 0; i < irSize; i++ {
+			s := audit.Select(cids, 0, uint64(i), irSize)
+
+			for _, id := range s {
+				n, ok := m[id.String()]
+				require.True(t, ok)
+				require.Equal(t, 0, n)
+				m[id.String()] = 1
+			}
+		}
+
+		require.True(t, allHit(m))
+	})
+
+	t.Run("epoch shift", func(t *testing.T) {
+		const irSize = 4
+
+		m := hitMap(cids)
+
+		for i := 0; i < irSize; i++ {
+			s := audit.Select(cids, uint64(i), 0, irSize)
+
+			for _, id := range s {
+				n, ok := m[id.String()]
+				require.True(t, ok)
+				require.Equal(t, 0, n)
+				m[id.String()] = 1
+			}
+		}
+
+		require.True(t, allHit(m))
+	})
+}
+
+func generateContainers(n int) []*container.ID {
+	var buf [sha256.Size]byte
+	result := make([]*container.ID, 0, n)
+
+	for i := 0; i < n; i++ {
+		_, _ = rand.Read(buf[:])
+
+		cid := container.NewID()
+		cid.SetSHA256(buf)
+
+		result = append(result, cid)
+	}
+
+	return result
+}
+
+func hitMap(ids []*container.ID) map[string]int {
+	result := make(map[string]int, len(ids))
+
+	for _, id := range ids {
+		result[id.String()] = 0
+	}
+
+	return result
+}
+
+func allHit(m map[string]int) bool {
+	for _, v := range m {
+		if v == 0 {
+			return false
+		}
+	}
+
+	return true
+}