[#86] node: Move testing utils to one package

Move testing utils from tests in local_object_storage package to
unified testutil package

Signed-off-by: Airat Arifullin <aarifullin@yadro.com>

pkg/local_object_storage/internal/testutil/generators.go

@@ -0,0 +1,110 @@
+package testutil
+
+import (
+	"encoding/binary"
+
+	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"go.uber.org/atomic"
+	"golang.org/x/exp/rand"
+)
+
+// AddressGenerator is the interface of types that generate object addresses.
+type AddressGenerator interface {
+	Next() oid.Address
+}
+
+// SeqAddrGenerator is an AddressGenerator that generates addresses sequentially and wraps around the given max ID.
+type SeqAddrGenerator struct {
+	cnt   atomic.Uint64
+	MaxID uint64
+}
+
+var _ AddressGenerator = &SeqAddrGenerator{}
+
+func (g *SeqAddrGenerator) Next() oid.Address {
+	var id oid.ID
+	binary.LittleEndian.PutUint64(id[:], ((g.cnt.Inc()-1)%g.MaxID)+1)
+	var addr oid.Address
+	addr.SetContainer(cid.ID{})
+	addr.SetObject(id)
+	return addr
+}
+
+// RandAddrGenerator is an addressGenerator that generates random addresses in the given range.
+type RandAddrGenerator uint64
+
+func (g RandAddrGenerator) Next() oid.Address {
+	var id oid.ID
+	binary.LittleEndian.PutUint64(id[:], uint64(1+int(rand.Int63n(int64(g)))))
+	var addr oid.Address
+	addr.SetContainer(cid.ID{})
+	addr.SetObject(id)
+	return addr
+}
+
+// ObjectGenerator is the interface of types that generate object entries.
+type ObjectGenerator interface {
+	Next() *object.Object
+}
+
+// SeqObjGenerator is an ObjectGenerator that generates entries with random payloads of size objSize and sequential IDs.
+type SeqObjGenerator struct {
+	cnt     atomic.Uint64
+	ObjSize uint64
+}
+
+var _ ObjectGenerator = &SeqObjGenerator{}
+
+func generateObjectWithOIDWithCIDWithSize(oid oid.ID, cid cid.ID, sz uint64) *object.Object {
+	data := make([]byte, sz)
+	rand.Read(data)
+	obj := GenerateObjectWithCIDWithPayload(cid, data)
+	obj.SetID(oid)
+	return obj
+}
+
+func (g *SeqObjGenerator) Next() *object.Object {
+	var id oid.ID
+	binary.LittleEndian.PutUint64(id[:], g.cnt.Inc())
+	return generateObjectWithOIDWithCIDWithSize(id, cid.ID{}, g.ObjSize)
+}
+
+// RandObjGenerator is an ObjectGenerator that generates entries with random IDs and payloads of size objSize.
+type RandObjGenerator struct {
+	ObjSize uint64
+}
+
+var _ ObjectGenerator = &RandObjGenerator{}
+
+func (g *RandObjGenerator) Next() *object.Object {
+	return generateObjectWithOIDWithCIDWithSize(oid.ID{}, cid.ID{}, g.ObjSize)
+}
+
+// OverwriteObjGenerator is an ObjectGenerator that generates entries with random payloads of size objSize and at most maxObjects distinct IDs.
+type OverwriteObjGenerator struct {
+	ObjSize    uint64
+	MaxObjects uint64
+}
+
+func (g *OverwriteObjGenerator) Next() *object.Object {
+	var id oid.ID
+	binary.LittleEndian.PutUint64(id[:], uint64(1+rand.Int63n(int64(g.MaxObjects))))
+	return generateObjectWithOIDWithCIDWithSize(id, cid.ID{}, g.ObjSize)
+}
+
+func AddressFromObject(obj *object.Object) oid.Address {
+	var addr oid.Address
+	if id, isSet := obj.ID(); isSet {
+		addr.SetObject(id)
+	} else {
+		panic("object ID is not set")
+	}
+	if cid, isSet := obj.ContainerID(); isSet {
+		addr.SetContainer(cid)
+	} else {
+		panic("container ID is not set")
+	}
+	return addr
+}