[#233] services/object: Implement new Get algorithm

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

pkg/services/object/util/placement.go

@@ -0,0 +1,155 @@
+package util
+
+import (
+	netmapSDK "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/core/container"
+	"github.com/nspcc-dev/neofs-node/pkg/core/netmap"
+	"github.com/nspcc-dev/neofs-node/pkg/network"
+	"github.com/nspcc-dev/neofs-node/pkg/services/object_manager/placement"
+	"github.com/pkg/errors"
+)
+
+type localPlacement struct {
+	builder placement.Builder
+
+	localAddrSrc network.LocalAddressSource
+}
+
+type remotePlacement struct {
+	builder placement.Builder
+
+	localAddrSrc network.LocalAddressSource
+}
+
+// TraverserGenerator represents tool that generates
+// container traverser for the particular need.
+type TraverserGenerator struct {
+	netMapSrc netmap.Source
+
+	cnrSrc container.Source
+
+	localAddrSrc network.LocalAddressSource
+
+	customOpts []placement.Option
+}
+
+func NewLocalPlacement(b placement.Builder, s network.LocalAddressSource) placement.Builder {
+	return &localPlacement{
+		builder:      b,
+		localAddrSrc: s,
+	}
+}
+
+func (p *localPlacement) BuildPlacement(addr *object.Address, policy *netmapSDK.PlacementPolicy) ([]netmapSDK.Nodes, error) {
+	vs, err := p.builder.BuildPlacement(addr, policy)
+	if err != nil {
+		return nil, errors.Wrapf(err, "(%T) could not build object placement", p)
+	}
+
+	for i := range vs {
+		for j := range vs[i] {
+			addr, err := network.AddressFromString(vs[i][j].Address())
+			if err != nil {
+				// TODO: log error
+				continue
+			}
+
+			if network.IsLocalAddress(p.localAddrSrc, addr) {
+				return []netmapSDK.Nodes{{vs[i][j]}}, nil
+			}
+		}
+	}
+
+	return nil, errors.Errorf("(%T) local node is outside of object placement", p)
+}
+
+// NewRemotePlacementBuilder creates, initializes and returns placement builder that
+// excludes local node from any placement vector.
+func NewRemotePlacementBuilder(b placement.Builder, s network.LocalAddressSource) placement.Builder {
+	return &remotePlacement{
+		builder:      b,
+		localAddrSrc: s,
+	}
+}
+
+func (p *remotePlacement) BuildPlacement(addr *object.Address, policy *netmapSDK.PlacementPolicy) ([]netmapSDK.Nodes, error) {
+	vs, err := p.builder.BuildPlacement(addr, policy)
+	if err != nil {
+		return nil, errors.Wrapf(err, "(%T) could not build object placement", p)
+	}
+
+	for i := range vs {
+		for j := 0; j < len(vs[i]); j++ {
+			addr, err := network.AddressFromString(vs[i][j].Address())
+			if err != nil {
+				// TODO: log error
+				continue
+			}
+
+			if network.IsLocalAddress(p.localAddrSrc, addr) {
+				vs[i] = append(vs[i][:j], vs[i][j+1:]...)
+				j--
+			}
+		}
+	}
+
+	return vs, nil
+}
+
+// NewTraverserGenerator creates, initializes and returns new TraverserGenerator instance.
+func NewTraverserGenerator(nmSrc netmap.Source, cnrSrc container.Source, localAddrSrc network.LocalAddressSource) *TraverserGenerator {
+	return &TraverserGenerator{
+		netMapSrc:    nmSrc,
+		cnrSrc:       cnrSrc,
+		localAddrSrc: localAddrSrc,
+	}
+}
+
+// WithTraverseOptions returns TraverseGenerator that additionally applies provided options.
+func (g *TraverserGenerator) WithTraverseOptions(opts ...placement.Option) *TraverserGenerator {
+	return &TraverserGenerator{
+		netMapSrc:    g.netMapSrc,
+		cnrSrc:       g.cnrSrc,
+		localAddrSrc: g.localAddrSrc,
+		customOpts:   opts,
+	}
+}
+
+// GenerateTraverser generates placement Traverser for provided object address.
+func (g *TraverserGenerator) GenerateTraverser(addr *object.Address) (*placement.Traverser, error) {
+	// get latest network map
+	nm, err := netmap.GetLatestNetworkMap(g.netMapSrc)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not get latest network map")
+	}
+
+	// get container related container
+	cnr, err := g.cnrSrc.Get(addr.ContainerID())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get container")
+	}
+
+	// allocate placement traverser options
+	traverseOpts := make([]placement.Option, 0, 3+len(g.customOpts))
+	traverseOpts = append(traverseOpts, g.customOpts...)
+
+	// create builder of the remote nodes from network map
+	builder := NewRemotePlacementBuilder(
+		placement.NewNetworkMapBuilder(nm),
+		g.localAddrSrc,
+	)
+
+	traverseOpts = append(traverseOpts,
+		// set processing container
+		placement.ForContainer(cnr),
+
+		// set identifier of the processing object
+		placement.ForObject(addr.ObjectID()),
+
+		// set placement builder
+		placement.UseBuilder(builder),
+	)
+
+	return placement.NewTraverser(traverseOpts...)
+}