From e7925fbc1c584a9886fc9a6685a5080f41e096d8 Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Thu, 17 Sep 2020 18:37:44 +0300
Subject: [PATCH] [#31] placement: Implement container placement traverser

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 go.mod                                        |   2 +-
 go.sum                                        | Bin 58116 -> 58361 bytes
 .../object_manager/placement/netmap.go        |  32 +++
 .../object_manager/placement/traverser.go     | 182 ++++++++++++++++++
 .../placement/traverser_test.go               | 120 ++++++++++++
 5 files changed, 335 insertions(+), 1 deletion(-)
 create mode 100644 pkg/services/object_manager/placement/netmap.go
 create mode 100644 pkg/services/object_manager/placement/traverser.go
 create mode 100644 pkg/services/object_manager/placement/traverser_test.go

diff --git a/go.mod b/go.mod
index a38a0750..91d8a572 100644
--- a/go.mod
+++ b/go.mod
@@ -13,7 +13,7 @@ require (
 	github.com/multiformats/go-multiaddr-net v0.1.2 // v0.1.1 => v0.1.2
 	github.com/multiformats/go-multihash v0.0.13 // indirect
 	github.com/nspcc-dev/neo-go v0.91.1-pre.0.20200827184617-7560aa345a78
-	github.com/nspcc-dev/neofs-api-go v1.3.1-0.20200916115135-ff325b877023
+	github.com/nspcc-dev/neofs-api-go v1.3.1-0.20200917104527-95ae0a649608
 	github.com/nspcc-dev/neofs-crypto v0.3.0
 	github.com/nspcc-dev/tzhash v1.4.0
 	github.com/panjf2000/ants/v2 v2.3.0
diff --git a/go.sum b/go.sum
index 339114a6840df098eb6b576d8a9ae9caea7be979..a05829f296f55a2e1a6b11d1fa21c3ded78c4ca1 100644
GIT binary patch
delta 115
zcmZoU#{Ba*^M+&TlReVKoy`pmOiYc;buCR3Qw<W$Of1a|EEF;ft%^d7eVxjDjY~~k
zEDH3)EOL@c3_`*J%uVwm0)w6PBc00&{DX?h%mQ5<Cm&3entU!zN(7r(n~T#YRs#Tc
CJtVdO

delta 14
Wcmex)oVn!~^M+&Tn|Ei}RRaJ!TnBvs

diff --git a/pkg/services/object_manager/placement/netmap.go b/pkg/services/object_manager/placement/netmap.go
new file mode 100644
index 00000000..e82ca0d1
--- /dev/null
+++ b/pkg/services/object_manager/placement/netmap.go
@@ -0,0 +1,32 @@
+package placement
+
+import (
+	"github.com/nspcc-dev/neofs-api-go/pkg/netmap"
+	"github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/pkg/errors"
+)
+
+type netMapBuilder struct {
+	nm *netmap.Netmap
+}
+
+func (b *netMapBuilder) BuildPlacement(a *object.Address, p *netmap.PlacementPolicy) ([]netmap.Nodes, error) {
+	aV2 := a.ToV2()
+
+	cn, err := b.nm.GetContainerNodes(p, aV2.GetContainerID().GetValue())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get container nodes")
+	}
+
+	oid := aV2.GetObjectID()
+	if oid == nil {
+		return cn.Replicas(), nil
+	}
+
+	on, err := b.nm.GetPlacementVectors(cn, oid.GetValue())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get placement vectors for object")
+	}
+
+	return on, nil
+}
diff --git a/pkg/services/object_manager/placement/traverser.go b/pkg/services/object_manager/placement/traverser.go
new file mode 100644
index 00000000..94fb47b7
--- /dev/null
+++ b/pkg/services/object_manager/placement/traverser.go
@@ -0,0 +1,182 @@
+package placement
+
+import (
+	"sync"
+
+	"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"
+	"github.com/nspcc-dev/neofs-node/pkg/network"
+	"github.com/pkg/errors"
+)
+
+// Builder is an interface of the
+// object placement vector builder.
+type Builder interface {
+	// BuildPlacement returns the list of placement vectors
+	// for object according to the placement policy.
+	//
+	// Must return all container nodes if object identifier
+	// is nil.
+	BuildPlacement(*object.Address, *netmap.PlacementPolicy) ([]netmap.Nodes, error)
+}
+
+// Option represents placement traverser option.
+type Option func(*cfg)
+
+// Traverser represents utility for controlling
+// traversal of object placement vectors.
+type Traverser struct {
+	mtx *sync.RWMutex
+
+	rem int
+
+	nextI, nextJ int
+
+	vectors []netmap.Nodes
+}
+
+type cfg struct {
+	rem int
+
+	addr *object.Address
+
+	policy *netmap.PlacementPolicy
+
+	builder Builder
+}
+
+var errNilBuilder = errors.New("placement builder is nil")
+
+func defaultCfg() *cfg {
+	return &cfg{
+		rem:  1,
+		addr: object.NewAddress(),
+	}
+}
+
+// NewTraverser creates, initializes with options and returns Traverser instance.
+func NewTraverser(opts ...Option) (*Traverser, error) {
+	cfg := defaultCfg()
+
+	for i := range opts {
+		if opts[i] != nil {
+			opts[i](cfg)
+		}
+	}
+
+	if cfg.builder == nil {
+		return nil, errors.Wrap(errNilBuilder, "incomplete traverser options")
+	}
+
+	ns, err := cfg.builder.BuildPlacement(cfg.addr, cfg.policy)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not build placement")
+	}
+
+	return &Traverser{
+		mtx:     new(sync.RWMutex),
+		rem:     cfg.rem,
+		vectors: ns,
+	}, nil
+}
+
+// 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 {
+	t.mtx.Lock()
+	defer t.mtx.Unlock()
+
+	if t.rem == 0 || t.nextI == len(t.vectors) {
+		return nil
+	}
+
+	addr, err := network.AddressFromString(t.vectors[t.nextI][t.nextJ].NetworkAddress())
+	if err != nil {
+		// TODO: log error
+	}
+
+	if t.nextJ++; t.nextJ == len(t.vectors[t.nextI]) {
+		t.nextJ = 0
+		t.nextI++
+	}
+
+	return addr
+}
+
+// SubmitSuccess writes single succeeded node operation.
+func (t *Traverser) SubmitSuccess() {
+	t.mtx.Lock()
+	t.rem--
+	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()
+
+	return s
+}
+
+// UseBuilder is a placement builder setting option.
+//
+// Overlaps UseNetworkMap option.
+func UseBuilder(b Builder) Option {
+	return func(c *cfg) {
+		c.builder = b
+	}
+}
+
+// UseNetworkMap is a placement builder based on network
+// map setting option.
+//
+// Overlaps UseBuilder option.
+func UseNetworkMap(nm *netmap.Netmap) Option {
+	return func(c *cfg) {
+		c.builder = &netMapBuilder{
+			nm: nm,
+		}
+	}
+}
+
+// ForContainer is a traversal container setting 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))
+	}
+}
+
+// ForObject is a processing object setting option.
+func ForObject(id *object.ID) Option {
+	return func(c *cfg) {
+		c.addr.SetObjectID(id)
+	}
+}
+
+// SuccessAfter is a success number setting option.
+//
+// Option has no effect if the number is not positive.
+func SuccessAfter(v int) Option {
+	return func(c *cfg) {
+		if v > 0 {
+			c.rem = v
+		}
+	}
+}
+
+// WithoutSuccessTracking disables success tracking in traversal.
+func WithoutSuccessTracking() Option {
+	return func(c *cfg) {
+		c.rem = -1
+	}
+}
diff --git a/pkg/services/object_manager/placement/traverser_test.go b/pkg/services/object_manager/placement/traverser_test.go
new file mode 100644
index 00000000..291ec070
--- /dev/null
+++ b/pkg/services/object_manager/placement/traverser_test.go
@@ -0,0 +1,120 @@
+package placement
+
+import (
+	"strconv"
+	"testing"
+
+	"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"
+	"github.com/stretchr/testify/require"
+)
+
+type testBuilder struct {
+	vectors []netmap.Nodes
+}
+
+func (b testBuilder) BuildPlacement(*object.Address, *netmap.PlacementPolicy) ([]netmap.Nodes, error) {
+	return b.vectors, nil
+}
+
+func testNode(v uint32) netmapV2.NodeInfo {
+	n := netmapV2.NodeInfo{}
+	n.SetAddress("/ip4/0.0.0.0/tcp/" + strconv.Itoa(int(v)))
+
+	return n
+}
+
+func flattenVectors(vs []netmap.Nodes) netmap.Nodes {
+	v := make(netmap.Nodes, 0)
+
+	for i := range vs {
+		v = append(v, vs[i]...)
+	}
+
+	return v
+}
+
+func testPlacement(t *testing.T, sz []int) []netmap.Nodes {
+	res := make([]netmap.Nodes, 0, len(sz))
+	num := uint32(0)
+
+	for i := range sz {
+		ns := make([]netmapV2.NodeInfo, 0, sz[i])
+
+		for j := 0; j < sz[i]; j++ {
+			ns = append(ns, testNode(num))
+			num++
+		}
+
+		res = append(res, netmap.NodesFromV2(ns))
+	}
+
+	return res
+}
+
+func TestTraverserObjectScenarios(t *testing.T) {
+	t.Run("search scenario", func(t *testing.T) {
+		nodes := testPlacement(t, []int{2, 3})
+
+		allNodes := flattenVectors(nodes)
+
+		tr, err := NewTraverser(
+			UseBuilder(&testBuilder{vectors: nodes}),
+			WithoutSuccessTracking(),
+		)
+		require.NoError(t, err)
+
+		require.True(t, tr.Success())
+
+		for i := range allNodes {
+			require.Equal(t, allNodes[i].NetworkAddress(), tr.Next().String())
+		}
+
+		require.Nil(t, tr.Next())
+		require.True(t, tr.Success())
+	})
+
+	t.Run("read scenario", func(t *testing.T) {
+		nodes := testPlacement(t, []int{5, 3, 4})
+
+		allNodes := flattenVectors(nodes)
+
+		tr, err := NewTraverser(
+			UseBuilder(&testBuilder{vectors: nodes}),
+		)
+		require.NoError(t, err)
+
+		for i := range allNodes[:len(allNodes)-3] {
+			require.Equal(t, allNodes[i].NetworkAddress(), tr.Next().String())
+		}
+
+		require.False(t, tr.Success())
+
+		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.False(t, tr.Success())
+			tr.SubmitSuccess()
+		}
+
+		require.Nil(t, tr.Next())
+		require.True(t, tr.Success())
+	})
+}