*: use slice.Concat where possible

Closes #2738.

Signed-off-by: Pavel Karpy <[email protected]>

pkg/morph/event/notary_preparator.go

@@ -5,6 +5,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"slices"
 	"sync"
 
 	lru "github.com/hashicorp/golang-lru/v2"
@@ -85,7 +86,7 @@ func notaryPreparator(localAcc util.Uint160, alphaKeys client.AlphabetKeys, bc B
 	contractSysCall := make([]byte, 4)
 	binary.LittleEndian.PutUint32(contractSysCall, interopnames.ToID([]byte(interopnames.SystemContractCall)))
 
-	dummyInvocationScript := append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...)
+	dummyInvocationScript := slices.Concat([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64))
 
 	const txCacheSize = 1000
 	cache, _ := lru.New[util.Uint256, struct{}](txCacheSize)

pkg/services/object/put/distributed.go

@@ -189,14 +189,7 @@ func (x placementIterator) iterateNodesForObject(obj oid.ID, f func(nodeDesc) er
 			return fmt.Errorf("sort container nodes for the object: %w", err)
 		}
 		if x.linearReplNum > 0 {
-			var n int
-			for i := range nodeLists {
-				n += len(nodeLists[i])
-			}
-			ns := make([]netmap.NodeInfo, 0, n)
-			for i := range nodeLists {
-				ns = append(ns, nodeLists[i]...)
-			}
+			ns := slices.Concat(nodeLists...)
 			nodeLists = [][]netmap.NodeInfo{ns}
 			replCounts = []uint{x.linearReplNum}
 		} else {

pkg/services/object_manager/placement/netmap.go

@@ -3,6 +3,7 @@ package placement
 import (
 	"crypto/sha256"
 	"fmt"
+	"slices"
 	"sync"
 
 	"github.com/hashicorp/golang-lru/v2/simplelru"
@@ -99,17 +100,5 @@ func BuildObjectPlacement(nm *netmapSDK.NetMap, cnrNodes [][]netmapSDK.NodeInfo,
 
 // FlattenNodes appends each row to the flat list.
 func FlattenNodes(ns [][]netmapSDK.NodeInfo) []netmapSDK.NodeInfo {
-	var sz int
-
-	for i := range ns {
-		sz += len(ns[i])
-	}
-
-	result := make([]netmapSDK.NodeInfo, 0, sz)
-
-	for i := range ns {
-		result = append(result, ns[i]...)
-	}
-
-	return result
+	return slices.Concat(ns...)
 }

pkg/services/object_manager/placement/traverser.go

@@ -3,6 +3,7 @@ package placement
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"sync"
 
 	"github.com/nspcc-dev/neofs-node/pkg/network"
@@ -119,17 +120,7 @@ func NewTraverser(opts ...Option) (*Traverser, error) {
 }
 
 func flatNodes(ns [][]netmap.NodeInfo) [][]netmap.NodeInfo {
-	sz := 0
-	for i := range ns {
-		sz += len(ns[i])
-	}
-
-	flat := make([]netmap.NodeInfo, 0, sz)
-	for i := range ns {
-		flat = append(flat, ns[i]...)
-	}
-
-	return [][]netmap.NodeInfo{flat}
+	return [][]netmap.NodeInfo{slices.Concat(ns...)}
 }
 
 // Node is a descriptor of storage node with information required for intra-container communication.

pkg/services/tree/sync.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"math"
 	"math/rand"
+	"slices"
 	"sync"
 
 	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/pilorama"
@@ -365,10 +366,7 @@ func randomizeNodeOrder(cnrNodes []netmap.NodeInfo, pos int) []netmap.NodeInfo {
 		return nil
 	}
 
-	nodes := make([]netmap.NodeInfo, len(cnrNodes)-1)
-	n := copy(nodes, cnrNodes[:pos])
-	copy(nodes[n:], cnrNodes[pos+1:])
-
+	nodes := slices.Concat(cnrNodes[:pos], cnrNodes[pos+1:])
 	rand.Shuffle(len(nodes), func(i, j int) {
 		nodes[i], nodes[j] = nodes[j], nodes[i]
 	})