[#31] placement: Fix incorrect selectors processing

In previous implementation traverser worked like all counts of all selectors
are equal to counts of corresponding replicas. Make traverser to take into
account select count of all replicas.

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

pkg/services/object_manager/placement/traverser.go

@@ -29,11 +29,9 @@ type Option func(*cfg)
 type Traverser struct {
 	mtx *sync.RWMutex
 
-	rem int
-
-	nextI, nextJ int
-
 	vectors []netmap.Nodes
+
+	rem []int
 }
 
 type cfg struct {
@@ -46,11 +44,14 @@ type cfg struct {
 	builder Builder
 }
 
+const invalidOptsMsg = "invalid traverser options"
+
 var errNilBuilder = errors.New("placement builder is nil")
 
+var errNilPolicy = errors.New("placement policy is nil")
+
 func defaultCfg() *cfg {
 	return &cfg{
-		rem:  1,
 		addr: object.NewAddress(),
 	}
 }
@@ -66,7 +67,9 @@ func NewTraverser(opts ...Option) (*Traverser, error) {
 	}
 
 	if cfg.builder == nil {
-		return nil, errors.Wrap(errNilBuilder, "incomplete traverser options")
+		return nil, errors.Wrap(errNilBuilder, invalidOptsMsg)
+	} else if cfg.policy == nil {
+		return nil, errors.Wrap(errNilPolicy, invalidOptsMsg)
 	}
 
 	ns, err := cfg.builder.BuildPlacement(cfg.addr, cfg.policy)
@@ -74,9 +77,22 @@ func NewTraverser(opts ...Option) (*Traverser, error) {
 		return nil, errors.Wrap(err, "could not build placement")
 	}
 
+	ss := cfg.policy.GetSelectors()
+	rem := make([]int, 0, len(ss))
+
+	for i := range ss {
+		cnt := cfg.rem
+
+		if cnt == 0 {
+			cnt = int(ss[i].GetCount())
+		}
+
+		rem = append(rem, cnt)
+	}
+
 	return &Traverser{
 		mtx:     new(sync.RWMutex),
-		rem:     cfg.rem,
+		rem:     rem,
 		vectors: ns,
 	}, nil
 }
@@ -84,41 +100,73 @@ func NewTraverser(opts ...Option) (*Traverser, error) {
 // Next returns next unprocessed address of the object placement.
 //
 // Returns nil if no nodes left or traversal operation succeeded.
-func (t *Traverser) Next() *network.Address {
+func (t *Traverser) Next() []*network.Address {
 	t.mtx.Lock()
 	defer t.mtx.Unlock()
 
-	if t.rem == 0 || t.nextI == len(t.vectors) {
+	t.skipEmptyVectors()
+
+	if len(t.vectors) == 0 {
+		return nil
+	} else if len(t.vectors[0]) < t.rem[0] {
 		return nil
 	}
 
-	addr, err := network.AddressFromString(t.vectors[t.nextI][t.nextJ].NetworkAddress())
-	if err != nil {
-		// TODO: log error
+	count := t.rem[0]
+	if count < 0 {
+		count = len(t.vectors[0])
 	}
 
-	if t.nextJ++; t.nextJ == len(t.vectors[t.nextI]) {
-		t.nextJ = 0
-		t.nextI++
+	addrs := make([]*network.Address, 0, count)
+
+	for i := 0; i < count; i++ {
+		addr, err := network.AddressFromString(t.vectors[0][i].NetworkAddress())
+		if err != nil {
+			// TODO: log error
+			return nil
+		}
+
+		addrs = append(addrs, addr)
 	}
 
-	return addr
+	t.vectors[0] = t.vectors[0][count:]
+
+	return addrs
+}
+
+func (t *Traverser) skipEmptyVectors() {
+	for i := 0; i < len(t.vectors); i++ { // don't use range, slice changes in body
+		if len(t.vectors[i]) == 0 && t.rem[i] <= 0 || t.rem[0] == 0 {
+			t.vectors = append(t.vectors[:i], t.vectors[i+1:]...)
+			t.rem = append(t.rem[:i], t.rem[i+1:]...)
+			i--
+		} else {
+			break
+		}
+	}
 }
 
 // SubmitSuccess writes single succeeded node operation.
 func (t *Traverser) SubmitSuccess() {
 	t.mtx.Lock()
-	t.rem--
+	if len(t.rem) > 0 {
+		t.rem[0]--
+	}
 	t.mtx.Unlock()
 }
 
 // Success returns true if traversal operation succeeded.
 func (t *Traverser) Success() bool {
 	t.mtx.RLock()
-	s := t.rem <= 0
-	t.mtx.RUnlock()
+	defer t.mtx.RUnlock()
 
-	return s
+	for i := range t.rem {
+		if t.rem[i] > 0 {
+			return false
+		}
+	}
+
+	return true
 }
 
 // UseBuilder is a placement builder setting option.
@@ -146,12 +194,6 @@ func UseNetworkMap(nm *netmap.Netmap) Option {
 func ForContainer(cnr *container.Container) Option {
 	return func(c *cfg) {
 		c.policy = cnr.GetPlacementPolicy()
-
-		c.rem = 0
-		for _, r := range c.policy.GetReplicas() {
-			c.rem += int(r.GetCount())
-		}
-
 		c.addr.SetContainerID(container.CalculateID(cnr))
 	}
 }

pkg/services/object_manager/placement/traverser_test.go

@@ -4,6 +4,7 @@ import (
 	"strconv"
 	"testing"
 
+	"github.com/nspcc-dev/neofs-api-go/pkg/container"
 	"github.com/nspcc-dev/neofs-api-go/pkg/netmap"
 	"github.com/nspcc-dev/neofs-api-go/pkg/object"
 	netmapV2 "github.com/nspcc-dev/neofs-node/pkg/morph/client/netmap"
@@ -35,86 +36,156 @@ func flattenVectors(vs []netmap.Nodes) netmap.Nodes {
 	return v
 }
 
-func testPlacement(t *testing.T, sz []int) []netmap.Nodes {
-	res := make([]netmap.Nodes, 0, len(sz))
+func copyVectors(v []netmap.Nodes) []netmap.Nodes {
+	vc := make([]netmap.Nodes, 0, len(v))
+
+	for i := range v {
+		ns := make(netmap.Nodes, len(v[i]))
+		copy(ns, v[i])
+
+		vc = append(vc, ns)
+	}
+
+	return vc
+}
+
+func testPlacement(t *testing.T, rs, ss []int) ([]netmap.Nodes, *container.Container) {
+	nodes := make([]netmap.Nodes, 0, len(rs))
+	selectors := make([]*netmap.Selector, 0, len(rs))
 	num := uint32(0)
 
-	for i := range sz {
-		ns := make([]netmapV2.NodeInfo, 0, sz[i])
+	for i := range rs {
+		ns := make([]netmapV2.NodeInfo, 0, rs[i])
 
-		for j := 0; j < sz[i]; j++ {
+		for j := 0; j < rs[i]; j++ {
 			ns = append(ns, testNode(num))
 			num++
 		}
 
-		res = append(res, netmap.NodesFromV2(ns))
+		nodes = append(nodes, netmap.NodesFromV2(ns))
+
+		s := new(netmap.Selector)
+		s.SetCount(uint32(ss[i]))
+
+		selectors = append(selectors, s)
 	}
 
-	return res
+	policy := new(netmap.PlacementPolicy)
+	policy.SetSelectors(selectors)
+
+	return nodes, container.New(container.WithPolicy(policy))
 }
 
 func TestTraverserObjectScenarios(t *testing.T) {
 	t.Run("search scenario", func(t *testing.T) {
-		nodes := testPlacement(t, []int{2, 3})
+		replicas := []int{2, 3}
+		selectors := []int{1, 2}
 
-		allNodes := flattenVectors(nodes)
+		nodes, cnr := testPlacement(t, replicas, selectors)
+
+		nodesCopy := copyVectors(nodes)
 
 		tr, err := NewTraverser(
-			UseBuilder(&testBuilder{vectors: nodes}),
+			ForContainer(cnr),
+			UseBuilder(&testBuilder{vectors: nodesCopy}),
 			WithoutSuccessTracking(),
 		)
 		require.NoError(t, err)
 
-		require.True(t, tr.Success())
+		for i := range replicas {
+			addrs := tr.Next()
 
-		for i := range allNodes {
-			require.Equal(t, allNodes[i].NetworkAddress(), tr.Next().String())
+			require.Len(t, addrs, len(nodes[i]))
+
+			for j, n := range nodes[i] {
+				require.Equal(t, n.NetworkAddress(), addrs[j].String())
+			}
 		}
 
-		require.Nil(t, tr.Next())
+		require.Empty(t, tr.Next())
 		require.True(t, tr.Success())
 	})
 
 	t.Run("read scenario", func(t *testing.T) {
-		nodes := testPlacement(t, []int{5, 3, 4})
+		replicas := []int{5, 3}
+		selectors := []int{2, 2}
 
-		allNodes := flattenVectors(nodes)
+		nodes, cnr := testPlacement(t, replicas, selectors)
+
+		nodesCopy := copyVectors(nodes)
 
 		tr, err := NewTraverser(
-			UseBuilder(&testBuilder{vectors: nodes}),
+			ForContainer(cnr),
+			UseBuilder(&testBuilder{vectors: nodesCopy}),
+			SuccessAfter(1),
 		)
 		require.NoError(t, err)
 
-		for i := range allNodes[:len(allNodes)-3] {
-			require.Equal(t, allNodes[i].NetworkAddress(), tr.Next().String())
-		}
+		fn := func(curVector int) {
+			for i := 0; i < replicas[curVector]; i++ {
+				addrs := tr.Next()
+				require.Len(t, addrs, 1)
 
-		require.False(t, tr.Success())
+				require.Equal(t, nodes[curVector][i].NetworkAddress(), addrs[0].String())
+			}
 
-		tr.SubmitSuccess()
-
-		require.True(t, tr.Success())
-
-		require.Nil(t, tr.Next())
-	})
-
-	t.Run("put scenario", func(t *testing.T) {
-		nodes := testPlacement(t, []int{3, 3, 3})
-		sucCount := 3
-
-		tr, err := NewTraverser(
-			UseBuilder(&testBuilder{vectors: nodes}),
-			SuccessAfter(sucCount),
-		)
-		require.NoError(t, err)
-
-		for i := 0; i < sucCount; i++ {
-			require.NotNil(t, tr.Next())
+			require.Empty(t, tr.Next())
 			require.False(t, tr.Success())
+
 			tr.SubmitSuccess()
 		}
 
-		require.Nil(t, tr.Next())
-		require.True(t, tr.Success())
+		for i := range replicas {
+			fn(i)
+
+			if i < len(replicas)-1 {
+				require.False(t, tr.Success())
+			} else {
+				require.True(t, tr.Success())
+			}
+		}
+	})
+
+	t.Run("put scenario", func(t *testing.T) {
+		replicas := []int{5, 3}
+		selectors := []int{2, 2}
+
+		nodes, cnr := testPlacement(t, replicas, selectors)
+
+		nodesCopy := copyVectors(nodes)
+
+		tr, err := NewTraverser(
+			ForContainer(cnr),
+			UseBuilder(&testBuilder{vectors: nodesCopy}),
+		)
+		require.NoError(t, err)
+
+		fn := func(curVector int) {
+			for i := 0; i+selectors[curVector] < replicas[curVector]; i += selectors[curVector] {
+				addrs := tr.Next()
+				require.Len(t, addrs, selectors[curVector])
+
+				for j := range addrs {
+					require.Equal(t, nodes[curVector][i+j].NetworkAddress(), addrs[j].String())
+				}
+			}
+
+			require.Empty(t, tr.Next())
+			require.False(t, tr.Success())
+
+			for i := 0; i < selectors[curVector]; i++ {
+				tr.SubmitSuccess()
+			}
+		}
+
+		for i := range replicas {
+			fn(i)
+
+			if i < len(replicas)-1 {
+				require.False(t, tr.Success())
+			} else {
+				require.True(t, tr.Success())
+			}
+		}
 	})
 }