[#2139] object/put: Use sync.Pool for temporary payloads

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

CHANGELOG.md

@@ -26,6 +26,7 @@ Changelog for NeoFS Node
 - Policer cache size is now 1024 (#2158)
 - Tree service now synchronizes with container nodes in a random order (#2127)
 - Pilorama no longer tries to apply already applied operations (#2161)
+- Use `sync.Pool` in Object.PUT service (#2139)
 
 ### Fixed
 - Open FSTree in sync mode by default (#1992)

pkg/services/object/put/distributed.go

@@ -128,6 +128,11 @@ func (t *distributedTarget) Write(p []byte) (n int, err error) {
 }
 
 func (t *distributedTarget) Close() (*transformer.AccessIdentifiers, error) {
+	defer func() {
+		putPayload(t.payload)
+		t.payload = nil
+	}()
+
 	t.obj.SetPayload(t.payload)
 
 	var err error

pkg/services/object/put/pool.go

@@ -0,0 +1,20 @@
+package putsvc
+
+import (
+	"sync"
+)
+
+const defaultAllocSize = 1024
+
+var putBytesPool = &sync.Pool{
+	New: func() interface{} { return make([]byte, 0, defaultAllocSize) },
+}
+
+func getPayload() []byte {
+	return putBytesPool.Get().([]byte)
+}
+
+func putPayload(p []byte) {
+	//nolint:staticcheck
+	putBytesPool.Put(p[:0])
+}

pkg/services/object/put/streamer.go

@@ -215,6 +215,7 @@ func (p *Streamer) newCommonTarget(prm *PutInitPrm) transformer.ObjectTarget {
 
 			extraBroadcastEnabled: withBroadcast,
 		},
+		payload:    getPayload(),
 		remotePool: p.remotePool,
 		localPool:  p.localPool,
 		nodeTargetInitializer: func(node nodeDesc) preparedObjectTarget {