[#1452] container: Add ListStream method

* Added new method for listing containers to container service.
  It opens stream and sends containers in batches.

* Added TransportSplitter wrapper around ExecutionService to
  split container ID list read from contract in parts that are
  smaller than grpc max message size. Batch size can be changed
  in node configuration file (as in example config file).

* Changed `container list` implementaion in cli: now ListStream
  is called by default. Old List is called only if ListStream
  is not implemented.

Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>

pkg/morph/client/balance/balanceOf.go

@@ -29,7 +29,7 @@ func (c *Client) BalanceOf(id user.ID) (*big.Int, error) {
 
 	amount, err := client.BigIntFromStackItem(prms[0])
 	if err != nil {
-		return nil, fmt.Errorf("get integer stack item from stack item (%s): %w", balanceOfMethod, err)
+		return nil, fmt.Errorf("could not get integer stack item from stack item (%s): %w", balanceOfMethod, err)
 	}
 	return amount, nil
 }

pkg/morph/client/balance/decimals.go

@@ -21,7 +21,7 @@ func (c *Client) Decimals() (uint32, error) {
 
 	decimals, err := client.IntFromStackItem(prms[0])
 	if err != nil {
-		return 0, fmt.Errorf("get integer stack item from stack item (%s): %w", decimalsMethod, err)
+		return 0, fmt.Errorf("could not get integer stack item from stack item (%s): %w", decimalsMethod, err)
 	}
 	return uint32(decimals), nil
 }

pkg/morph/client/balance/transfer.go

@@ -39,7 +39,7 @@ func (c *Client) TransferX(ctx context.Context, p TransferPrm) error {
 
 	_, err = c.client.Invoke(ctx, prm)
 	if err != nil {
-		return fmt.Errorf("invoke method (%s): %w", transferXMethod, err)
+		return fmt.Errorf("could not invoke method (%s): %w", transferXMethod, err)
 	}
 	return nil
 }

pkg/morph/client/client.go

@@ -196,7 +196,7 @@ func (c *Client) Invoke(ctx context.Context, contract util.Uint160, fee fixedn.F
 
 	txHash, vub, err := c.rpcActor.SendTunedCall(contract, method, nil, addFeeCheckerModifier(int64(fee)), args...)
 	if err != nil {
-		return InvokeRes{}, fmt.Errorf("invoke %s: %w", method, err)
+		return InvokeRes{}, fmt.Errorf("could not invoke %s: %w", method, err)
 	}
 
 	c.logger.Debug(ctx, logs.ClientNeoClientInvoke,
@@ -509,7 +509,7 @@ func (c *Client) NeoFSAlphabetList() (res keys.PublicKeys, err error) {
 
 	list, err := c.roleList(noderoles.NeoFSAlphabet)
 	if err != nil {
-		return nil, fmt.Errorf("get alphabet nodes role list: %w", err)
+		return nil, fmt.Errorf("can't get alphabet nodes role list: %w", err)
 	}
 
 	return list, nil
@@ -523,7 +523,7 @@ func (c *Client) GetDesignateHash() util.Uint160 {
 func (c *Client) roleList(r noderoles.Role) (keys.PublicKeys, error) {
 	height, err := c.rpcActor.GetBlockCount()
 	if err != nil {
-		return nil, fmt.Errorf("get chain height: %w", err)
+		return nil, fmt.Errorf("can't get chain height: %w", err)
 	}
 
 	return c.rolemgmt.GetDesignatedByRole(r, height)

pkg/morph/client/container/containers_of.go

@@ -26,7 +26,7 @@ func (c *Client) ContainersOf(idUser *user.ID) ([]cid.ID, error) {
 	cb := func(item stackitem.Item) error {
 		rawID, err := client.BytesFromStackItem(item)
 		if err != nil {
-			return fmt.Errorf("get byte array from stack item (%s): %w", containersOfMethod, err)
+			return fmt.Errorf("could not get byte array from stack item (%s): %w", containersOfMethod, err)
 		}
 
 		var id cid.ID

pkg/morph/client/container/delete.go

@@ -78,7 +78,7 @@ func (c *Client) Delete(ctx context.Context, p DeletePrm) (uint32, error) {
 
 	res, err := c.client.Invoke(ctx, prm)
 	if err != nil {
-		return 0, fmt.Errorf("invoke method (%s): %w", deleteMethod, err)
+		return 0, fmt.Errorf("could not invoke method (%s): %w", deleteMethod, err)
 	}
 	return res.VUB, nil
 }

pkg/morph/client/container/deletion_info.go

@@ -46,7 +46,7 @@ func (c *Client) DeletionInfo(cid []byte) (*containercore.DelInfo, error) {
 
 	arr, err := client.ArrayFromStackItem(res[0])
 	if err != nil {
-		return nil, fmt.Errorf("get item array of container (%s): %w", deletionInfoMethod, err)
+		return nil, fmt.Errorf("could not get item array of container (%s): %w", deletionInfoMethod, err)
 	}
 
 	if len(arr) != 2 {
@@ -55,17 +55,17 @@ func (c *Client) DeletionInfo(cid []byte) (*containercore.DelInfo, error) {
 
 	rawOwner, err := client.BytesFromStackItem(arr[0])
 	if err != nil {
-		return nil, fmt.Errorf("get byte array of container (%s): %w", deletionInfoMethod, err)
+		return nil, fmt.Errorf("could not get byte array of container (%s): %w", deletionInfoMethod, err)
 	}
 
 	var owner user.ID
 	if err := owner.DecodeString(base58.Encode(rawOwner)); err != nil {
-		return nil, fmt.Errorf("decode container owner id (%s): %w", deletionInfoMethod, err)
+		return nil, fmt.Errorf("could not decode container owner id (%s): %w", deletionInfoMethod, err)
 	}
 
 	epoch, err := client.BigIntFromStackItem(arr[1])
 	if err != nil {
-		return nil, fmt.Errorf("get byte array of container signature (%s): %w", deletionInfoMethod, err)
+		return nil, fmt.Errorf("could not get byte array of container signature (%s): %w", deletionInfoMethod, err)
 	}
 
 	return &containercore.DelInfo{

pkg/morph/client/container/get.go

@@ -60,7 +60,7 @@ func (c *Client) Get(cid []byte) (*containercore.Container, error) {
 
 	arr, err := client.ArrayFromStackItem(res[0])
 	if err != nil {
-		return nil, fmt.Errorf("get item array of container (%s): %w", getMethod, err)
+		return nil, fmt.Errorf("could not get item array of container (%s): %w", getMethod, err)
 	}
 
 	if len(arr) != 4 {
@@ -69,29 +69,29 @@ func (c *Client) Get(cid []byte) (*containercore.Container, error) {
 
 	cnrBytes, err := client.BytesFromStackItem(arr[0])
 	if err != nil {
-		return nil, fmt.Errorf("get byte array of container (%s): %w", getMethod, err)
+		return nil, fmt.Errorf("could not get byte array of container (%s): %w", getMethod, err)
 	}
 
 	sigBytes, err := client.BytesFromStackItem(arr[1])
 	if err != nil {
-		return nil, fmt.Errorf("get byte array of container signature (%s): %w", getMethod, err)
+		return nil, fmt.Errorf("could not get byte array of container signature (%s): %w", getMethod, err)
 	}
 
 	pub, err := client.BytesFromStackItem(arr[2])
 	if err != nil {
-		return nil, fmt.Errorf("get byte array of public key (%s): %w", getMethod, err)
+		return nil, fmt.Errorf("could not get byte array of public key (%s): %w", getMethod, err)
 	}
 
 	tokBytes, err := client.BytesFromStackItem(arr[3])
 	if err != nil {
-		return nil, fmt.Errorf("get byte array of session token (%s): %w", getMethod, err)
+		return nil, fmt.Errorf("could not get byte array of session token (%s): %w", getMethod, err)
 	}
 
 	var cnr containercore.Container
 
 	if err := cnr.Value.Unmarshal(cnrBytes); err != nil {
 		// use other major version if there any
-		return nil, fmt.Errorf("unmarshal container: %w", err)
+		return nil, fmt.Errorf("can't unmarshal container: %w", err)
 	}
 
 	if len(tokBytes) > 0 {
@@ -99,7 +99,7 @@ func (c *Client) Get(cid []byte) (*containercore.Container, error) {
 
 		err = cnr.Session.Unmarshal(tokBytes)
 		if err != nil {
-			return nil, fmt.Errorf("unmarshal session token: %w", err)
+			return nil, fmt.Errorf("could not unmarshal session token: %w", err)
 		}
 	}
 

pkg/morph/client/container/list.go

@@ -34,14 +34,14 @@ func (c *Client) list(idUser *user.ID) ([]cid.ID, error) {
 
 	res, err = client.ArrayFromStackItem(res[0])
 	if err != nil {
-		return nil, fmt.Errorf("get stack item array from stack item (%s): %w", listMethod, err)
+		return nil, fmt.Errorf("could not get stack item array from stack item (%s): %w", listMethod, err)
 	}
 
 	cidList := make([]cid.ID, 0, len(res))
 	for i := range res {
 		rawID, err := client.BytesFromStackItem(res[i])
 		if err != nil {
-			return nil, fmt.Errorf("get byte array from stack item (%s): %w", listMethod, err)
+			return nil, fmt.Errorf("could not get byte array from stack item (%s): %w", listMethod, err)
 		}
 
 		var id cid.ID

pkg/morph/client/container/put.go

@@ -117,7 +117,7 @@ func (c *Client) Put(ctx context.Context, p PutPrm) error {
 
 	_, err := c.client.Invoke(ctx, prm)
 	if err != nil {
-		return fmt.Errorf("invoke method (%s): %w", method, err)
+		return fmt.Errorf("could not invoke method (%s): %w", method, err)
 	}
 	return nil
 }

pkg/morph/client/frostfsid/subject.go

@@ -31,7 +31,7 @@ func (c *Client) GetSubject(addr util.Uint160) (*frostfsidclient.Subject, error)
 
 	subj, err := frostfsidclient.ParseSubject(structArr)
 	if err != nil {
-		return nil, fmt.Errorf("parse test invocation result (%s): %w", methodGetSubject, err)
+		return nil, fmt.Errorf("could not parse test invocation result (%s): %w", methodGetSubject, err)
 	}
 
 	return subj, nil
@@ -54,7 +54,7 @@ func (c *Client) GetSubjectExtended(addr util.Uint160) (*frostfsidclient.Subject
 
 	subj, err := frostfsidclient.ParseSubjectExtended(structArr)
 	if err != nil {
-		return nil, fmt.Errorf("parse test invocation result (%s): %w", methodGetSubject, err)
+		return nil, fmt.Errorf("could not parse test invocation result (%s): %w", methodGetSubject, err)
 	}
 
 	return subj, nil
@@ -67,7 +67,7 @@ func checkStackItem(res []stackitem.Item) (structArr []stackitem.Item, err error
 
 	structArr, err = client.ArrayFromStackItem(res[0])
 	if err != nil {
-		return nil, fmt.Errorf("get item array of container (%s): %w", methodGetSubject, err)
+		return nil, fmt.Errorf("could not get item array of container (%s): %w", methodGetSubject, err)
 	}
 	return
 }

pkg/morph/client/netmap/epoch.go

@@ -25,7 +25,7 @@ func (c *Client) Epoch() (uint64, error) {
 
 	num, err := client.IntFromStackItem(items[0])
 	if err != nil {
-		return 0, fmt.Errorf("get number from stack item (%s): %w", epochMethod, err)
+		return 0, fmt.Errorf("could not get number from stack item (%s): %w", epochMethod, err)
 	}
 	return uint64(num), nil
 }
@@ -49,7 +49,7 @@ func (c *Client) LastEpochBlock() (uint32, error) {
 
 	block, err := client.IntFromStackItem(items[0])
 	if err != nil {
-		return 0, fmt.Errorf("get number from stack item (%s): %w",
+		return 0, fmt.Errorf("could not get number from stack item (%s): %w",
 			lastEpochBlockMethod, err)
 	}
 	return uint32(block), nil

pkg/morph/client/netmap/innerring.go

@@ -59,7 +59,7 @@ func irKeysFromStackItem(stack []stackitem.Item, method string) (keys.PublicKeys
 
 	irs, err := client.ArrayFromStackItem(stack[0])
 	if err != nil {
-		return nil, fmt.Errorf("get stack item array from stack item (%s): %w", method, err)
+		return nil, fmt.Errorf("could not get stack item array from stack item (%s): %w", method, err)
 	}
 
 	irKeys := make(keys.PublicKeys, len(irs))
@@ -79,7 +79,7 @@ const irNodeFixedPrmNumber = 1
 func irKeyFromStackItem(prm stackitem.Item) (*keys.PublicKey, error) {
 	prms, err := client.ArrayFromStackItem(prm)
 	if err != nil {
-		return nil, fmt.Errorf("get stack item array (IRNode): %w", err)
+		return nil, fmt.Errorf("could not get stack item array (IRNode): %w", err)
 	} else if ln := len(prms); ln != irNodeFixedPrmNumber {
 		return nil, fmt.Errorf(
 			"unexpected stack item count (IRNode): expected %d, has %d",
@@ -90,7 +90,7 @@ func irKeyFromStackItem(prm stackitem.Item) (*keys.PublicKey, error) {
 
 	byteKey, err := client.BytesFromStackItem(prms[0])
 	if err != nil {
-		return nil, fmt.Errorf("parse bytes from stack item (IRNode): %w", err)
+		return nil, fmt.Errorf("could not parse bytes from stack item (IRNode): %w", err)
 	}
 
 	return keys.NewPublicKeyFromBytes(byteKey, elliptic.P256())

pkg/morph/client/netmap/new_epoch.go

@@ -16,7 +16,7 @@ func (c *Client) NewEpoch(ctx context.Context, epoch uint64) error {
 
 	_, err := c.client.Invoke(ctx, prm)
 	if err != nil {
-		return fmt.Errorf("invoke method (%s): %w", newEpochMethod, err)
+		return fmt.Errorf("could not invoke method (%s): %w", newEpochMethod, err)
 	}
 	return nil
 }
@@ -34,7 +34,7 @@ func (c *Client) NewEpochControl(ctx context.Context, epoch uint64, vub uint32)
 
 	res, err := c.client.Invoke(ctx, prm)
 	if err != nil {
-		return 0, fmt.Errorf("invoke method (%s): %w", newEpochMethod, err)
+		return 0, fmt.Errorf("could not invoke method (%s): %w", newEpochMethod, err)
 	}
 	return res.VUB, nil
 }

pkg/morph/client/netmap/peer.go

@@ -41,7 +41,7 @@ func (c *Client) AddPeer(ctx context.Context, p AddPeerPrm) error {
 	prm.InvokePrmOptional = p.InvokePrmOptional
 
 	if _, err := c.client.Invoke(ctx, prm); err != nil {
-		return fmt.Errorf("invoke method (%s): %w", method, err)
+		return fmt.Errorf("could not invoke method (%s): %w", method, err)
 	}
 	return nil
 }

pkg/morph/client/nns.go

@@ -107,7 +107,7 @@ func (c *Client) NNSHash() (util.Uint160, error) {
 func nnsResolveItem(c *rpcclient.WSClient, nnsHash util.Uint160, domain string) (stackitem.Item, error) {
 	found, err := exists(c, nnsHash, domain)
 	if err != nil {
-		return nil, fmt.Errorf("check presence in NNS contract for %s: %w", domain, err)
+		return nil, fmt.Errorf("could not check presence in NNS contract for %s: %w", domain, err)
 	}
 
 	if !found {

pkg/morph/client/notary.go

@@ -58,11 +58,16 @@ const (
 	defaultNotaryValidTime = 50
 	defaultNotaryRoundTime = 100
 
-	setDesignateMethod = "designateAsRole"
+	notaryBalanceOfMethod    = "balanceOf"
+	notaryExpirationOfMethod = "expirationOf"
+	setDesignateMethod       = "designateAsRole"
 
+	notaryBalanceErrMsg      = "can't fetch notary balance"
 	notaryNotEnabledPanicMsg = "notary support was not enabled on this client"
 )
 
+var errUnexpectedItems = errors.New("invalid number of NEO VM arguments on stack")
+
 func defaultNotaryConfig(c *Client) *notaryCfg {
 	return &notaryCfg{
 		txValidTime:    defaultNotaryValidTime,
@@ -150,16 +155,15 @@ func (c *Client) DepositNotary(ctx context.Context, amount fixedn.Fixed8, delta
 
 	bc, err := c.rpcActor.GetBlockCount()
 	if err != nil {
-		return util.Uint256{}, fmt.Errorf("get blockchain height: %w", err)
+		return util.Uint256{}, fmt.Errorf("can't get blockchain height: %w", err)
 	}
 
-	r := notary.NewReader(c.rpcActor)
+	currentTill, err := c.depositExpirationOf()
-	currentTill, err := r.ExpirationOf(c.acc.PrivateKey().GetScriptHash())
 	if err != nil {
-		return util.Uint256{}, fmt.Errorf("get previous expiration value: %w", err)
+		return util.Uint256{}, fmt.Errorf("can't get previous expiration value: %w", err)
 	}
 
-	till := max(int64(bc+delta), int64(currentTill))
+	till := max(int64(bc+delta), currentTill)
 	res, _, err := c.depositNotary(ctx, amount, till)
 	return res, err
 }
@@ -193,7 +197,7 @@ func (c *Client) depositNotary(ctx context.Context, amount fixedn.Fixed8, till i
 		[]any{c.acc.PrivateKey().GetScriptHash(), till})
 	if err != nil {
 		if !errors.Is(err, neorpc.ErrAlreadyExists) {
-			return util.Uint256{}, 0, fmt.Errorf("make notary deposit: %w", err)
+			return util.Uint256{}, 0, fmt.Errorf("can't make notary deposit: %w", err)
 		}
 
 		// Transaction is already in mempool waiting to be processed.
@@ -233,10 +237,18 @@ func (c *Client) GetNotaryDeposit() (res int64, err error) {
 
 	sh := c.acc.PrivateKey().PublicKey().GetScriptHash()
 
-	r := notary.NewReader(c.rpcActor)
+	items, err := c.TestInvoke(c.notary.notary, notaryBalanceOfMethod, sh)
-	bigIntDeposit, err := r.BalanceOf(sh)
 	if err != nil {
-		return 0, fmt.Errorf("get notary deposit: %w", err)
+		return 0, fmt.Errorf("test invoke (%s): %w", notaryBalanceOfMethod, err)
+	}
+
+	if len(items) != 1 {
+		return 0, wrapFrostFSError(fmt.Errorf("%v: %w", notaryBalanceErrMsg, errUnexpectedItems))
+	}
+
+	bigIntDeposit, err := items[0].TryInteger()
+	if err != nil {
+		return 0, wrapFrostFSError(fmt.Errorf("%v: %w", notaryBalanceErrMsg, err))
 	}
 
 	return bigIntDeposit.Int64(), nil
@@ -277,7 +289,7 @@ func (c *Client) UpdateNotaryList(ctx context.Context, prm UpdateNotaryListPrm)
 
 	nonce, vub, err := c.CalculateNonceAndVUB(&prm.hash)
 	if err != nil {
-		return fmt.Errorf("calculate nonce and `valicUntilBlock` values: %w", err)
+		return fmt.Errorf("could not calculate nonce and `valicUntilBlock` values: %w", err)
 	}
 
 	return c.notaryInvokeAsCommittee(
@@ -326,7 +338,7 @@ func (c *Client) UpdateNeoFSAlphabetList(ctx context.Context, prm UpdateAlphabet
 
 	nonce, vub, err := c.CalculateNonceAndVUB(&prm.hash)
 	if err != nil {
-		return fmt.Errorf("calculate nonce and `valicUntilBlock` values: %w", err)
+		return fmt.Errorf("could not calculate nonce and `valicUntilBlock` values: %w", err)
 	}
 
 	return c.notaryInvokeAsCommittee(
@@ -395,7 +407,7 @@ func (c *Client) NotarySignAndInvokeTX(mainTx *transaction.Transaction) error {
 
 	alphabetList, err := c.notary.alphabetSource()
 	if err != nil {
-		return fmt.Errorf("fetch current alphabet keys: %w", err)
+		return fmt.Errorf("could not fetch current alphabet keys: %w", err)
 	}
 
 	cosigners, err := c.notaryCosignersFromTx(mainTx, alphabetList)
@@ -517,24 +529,24 @@ func (c *Client) notaryCosignersFromTx(mainTx *transaction.Transaction, alphabet
 			if ok {
 				pub, err := keys.NewPublicKeyFromBytes(pubBytes, elliptic.P256())
 				if err != nil {
-					return nil, fmt.Errorf("parse verification script of signer #2: invalid public key: %w", err)
+					return nil, fmt.Errorf("failed to parse verification script of signer #2: invalid public key: %w", err)
 				}
 				acc = notary.FakeSimpleAccount(pub)
 			} else {
 				m, pubsBytes, ok := vm.ParseMultiSigContract(script)
 				if !ok {
-					return nil, errors.New("parse verification script of signer #2: unknown witness type")
+					return nil, errors.New("failed to parse verification script of signer #2: unknown witness type")
 				}
 				pubs := make(keys.PublicKeys, len(pubsBytes))
 				for i := range pubs {
 					pubs[i], err = keys.NewPublicKeyFromBytes(pubsBytes[i], elliptic.P256())
 					if err != nil {
-						return nil, fmt.Errorf("parse verification script of signer #2: invalid public key #%d: %w", i, err)
+						return nil, fmt.Errorf("failed to parse verification script of signer #2: invalid public key #%d: %w", i, err)
 					}
 				}
 				acc, err = notary.FakeMultisigAccount(m, pubs)
 				if err != nil {
-					return nil, fmt.Errorf("create fake account for signer #2: %w", err)
+					return nil, fmt.Errorf("failed to create fake account for signer #2: %w", err)
 				}
 			}
 		}
@@ -611,7 +623,7 @@ func (c *Client) notaryMultisigAccount(ir []*keys.PublicKey, committee, invokedB
 		err := multisigAccount.ConvertMultisig(m, ir)
 		if err != nil {
 			// wrap error as FrostFS-specific since the call is not related to any client
-			return nil, wrapFrostFSError(fmt.Errorf("convert account to inner ring multisig wallet: %w", err))
+			return nil, wrapFrostFSError(fmt.Errorf("can't convert account to inner ring multisig wallet: %w", err))
 		}
 	} else {
 		// alphabet multisig redeem script is
@@ -620,7 +632,7 @@ func (c *Client) notaryMultisigAccount(ir []*keys.PublicKey, committee, invokedB
 		multisigAccount, err = notary.FakeMultisigAccount(m, ir)
 		if err != nil {
 			// wrap error as FrostFS-specific since the call is not related to any client
-			return nil, wrapFrostFSError(fmt.Errorf("make inner ring multisig wallet: %w", err))
+			return nil, wrapFrostFSError(fmt.Errorf("can't make inner ring multisig wallet: %w", err))
 		}
 	}
 
@@ -630,7 +642,7 @@ func (c *Client) notaryMultisigAccount(ir []*keys.PublicKey, committee, invokedB
 func (c *Client) notaryTxValidationLimit() (uint32, error) {
 	bc, err := c.rpcActor.GetBlockCount()
 	if err != nil {
-		return 0, fmt.Errorf("get current blockchain height: %w", err)
+		return 0, fmt.Errorf("can't get current blockchain height: %w", err)
 	}
 
 	minTime := bc + c.notary.txValidTime
@@ -639,6 +651,24 @@ func (c *Client) notaryTxValidationLimit() (uint32, error) {
 	return rounded, nil
 }
 
+func (c *Client) depositExpirationOf() (int64, error) {
+	expirationRes, err := c.TestInvoke(c.notary.notary, notaryExpirationOfMethod, c.acc.PrivateKey().GetScriptHash())
+	if err != nil {
+		return 0, fmt.Errorf("test invoke (%s): %w", notaryExpirationOfMethod, err)
+	}
+
+	if len(expirationRes) != 1 {
+		return 0, fmt.Errorf("method returned unexpected item count: %d", len(expirationRes))
+	}
+
+	currentTillBig, err := expirationRes[0].TryInteger()
+	if err != nil {
+		return 0, fmt.Errorf("can't parse deposit till value: %w", err)
+	}
+
+	return currentTillBig.Int64(), nil
+}
+
 // sigCount returns the number of required signature.
 // For FrostFS Alphabet M is a 2/3+1 of it (like in dBFT).
 // If committee is true, returns M as N/2+1.
@@ -712,12 +742,12 @@ func alreadyOnChainError(err error) bool {
 func CalculateNotaryDepositAmount(c *Client, gasMul, gasDiv int64) (fixedn.Fixed8, error) {
 	notaryBalance, err := c.GetNotaryDeposit()
 	if err != nil {
-		return 0, fmt.Errorf("get notary balance: %w", err)
+		return 0, fmt.Errorf("could not get notary balance: %w", err)
 	}
 
 	gasBalance, err := c.GasBalance()
 	if err != nil {
-		return 0, fmt.Errorf("get GAS balance: %w", err)
+		return 0, fmt.Errorf("could not get GAS balance: %w", err)
 	}
 
 	if gasBalance == 0 {
@@ -766,12 +796,12 @@ func (c *Client) calculateNonceAndVUB(hash *util.Uint256, roundBlockHeight bool)
 	if hash != nil {
 		height, err = c.getTransactionHeight(*hash)
 		if err != nil {
-			return 0, 0, fmt.Errorf("get transaction height: %w", err)
+			return 0, 0, fmt.Errorf("could not get transaction height: %w", err)
 		}
 	} else {
 		height, err = c.rpcActor.GetBlockCount()
 		if err != nil {
-			return 0, 0, fmt.Errorf("get chain height: %w", err)
+			return 0, 0, fmt.Errorf("could not get chain height: %w", err)
 		}
 	}
 

pkg/morph/client/static.go

@@ -159,7 +159,7 @@ func (s StaticClient) Invoke(ctx context.Context, prm InvokePrm) (InvokeRes, err
 					nonce, vub, err = s.client.CalculateNonceAndVUB(prm.hash)
 				}
 				if err != nil {
-					return InvokeRes{}, fmt.Errorf("calculate nonce and VUB for notary alphabet invoke: %w", err)
+					return InvokeRes{}, fmt.Errorf("could not calculate nonce and VUB for notary alphabet invoke: %w", err)
 				}
 
 				vubP = &vub

pkg/morph/client/util.go

@@ -53,7 +53,7 @@ func BytesFromStackItem(param stackitem.Item) ([]byte, error) {
 	case stackitem.IntegerT:
 		n, err := param.TryInteger()
 		if err != nil {
-			return nil, fmt.Errorf("parse integer bytes: %w", err)
+			return nil, fmt.Errorf("can't parse integer bytes: %w", err)
 		}
 
 		return n.Bytes(), nil

pkg/morph/event/listener.go

@@ -111,7 +111,7 @@ type listener struct {
 	pool *ants.Pool
 }
 
-const newListenerFailMsg = "instantiate Listener"
+const newListenerFailMsg = "could not instantiate Listener"
 
 var (
 	errNilLogger = errors.New("nil logger")
@@ -180,7 +180,7 @@ func (l *listener) subscribe(errCh chan error) {
 	// fill the list with the contracts with set event parsers.
 	l.mtx.RLock()
 	for hashType := range l.notificationParsers {
-		scHash := hashType.Hash
+		scHash := hashType.ScriptHash()
 
 		// prevent repetitions
 		for _, hash := range hashes {
@@ -189,26 +189,26 @@ func (l *listener) subscribe(errCh chan error) {
 			}
 		}
 
-		hashes = append(hashes, hashType.Hash)
+		hashes = append(hashes, hashType.ScriptHash())
 	}
 	l.mtx.RUnlock()
 
 	err := l.subscriber.SubscribeForNotification(hashes...)
 	if err != nil {
-		errCh <- fmt.Errorf("subscribe for notifications: %w", err)
+		errCh <- fmt.Errorf("could not subscribe for notifications: %w", err)
 		return
 	}
 
 	if len(l.blockHandlers) > 0 {
 		if err = l.subscriber.BlockNotifications(); err != nil {
-			errCh <- fmt.Errorf("subscribe for blocks: %w", err)
+			errCh <- fmt.Errorf("could not subscribe for blocks: %w", err)
 			return
 		}
 	}
 
 	if l.listenNotary {
 		if err = l.subscriber.SubscribeForNotaryRequests(l.notaryMainTXSigner); err != nil {
-			errCh <- fmt.Errorf("subscribe for notary requests: %w", err)
+			errCh <- fmt.Errorf("could not subscribe for notary requests: %w", err)
 			return
 		}
 	}
@@ -326,7 +326,9 @@ func (l *listener) parseAndHandleNotification(ctx context.Context, notifyEvent *
 	)
 
 	// get the event parser
-	keyEvent := scriptHashWithType{Hash: notifyEvent.ScriptHash, Type: typEvent}
+	keyEvent := scriptHashWithType{}
+	keyEvent.SetScriptHash(notifyEvent.ScriptHash)
+	keyEvent.SetType(typEvent)
 
 	l.mtx.RLock()
 	parser, ok := l.notificationParsers[keyEvent]
@@ -449,7 +451,9 @@ func (l *listener) RegisterNotificationHandler(hi NotificationHandlerInfo) {
 	l.mtx.Lock()
 	defer l.mtx.Unlock()
 
-	k := scriptHashWithType{Hash: hi.Contract, Type: hi.Type}
+	var k scriptHashWithType
+	k.hash = hi.Contract
+	k.typ = hi.Type
 
 	l.notificationParsers[k] = hi.Parser
 	l.notificationHandlers[k] = append(
@@ -566,7 +570,7 @@ func NewListener(p ListenerParams) (Listener, error) {
 	// The default capacity is 0, which means "infinite".
 	pool, err := ants.NewPool(p.WorkerPoolCapacity)
 	if err != nil {
-		return nil, fmt.Errorf("init worker pool: %w", err)
+		return nil, fmt.Errorf("could not init worker pool: %w", err)
 	}
 
 	return &listener{

pkg/morph/event/netmap/update_peer_notary.go

@@ -10,7 +10,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 )
 
-var errNilPubKey = errors.New("public key is nil")
+var errNilPubKey = errors.New("could not parse public key: public key is nil")
 
 func (s *UpdatePeer) setPublicKey(v []byte) (err error) {
 	if v == nil {
@@ -19,7 +19,7 @@ func (s *UpdatePeer) setPublicKey(v []byte) (err error) {
 
 	s.PubKey, err = keys.NewPublicKeyFromBytes(v, elliptic.P256())
 	if err != nil {
-		return fmt.Errorf("parse public key: %w", err)
+		return fmt.Errorf("could not parse public key: %w", err)
 	}
 
 	return

pkg/morph/event/notary_preparator.go

@@ -127,7 +127,7 @@ func (p Preparator) Prepare(nr *payload.P2PNotaryRequest) (NotaryEvent, error) {
 	for {
 		opCode, param, err = ctx.Next()
 		if err != nil {
-			return nil, fmt.Errorf("get next opcode in script: %w", err)
+			return nil, fmt.Errorf("could not get next opcode in script: %w", err)
 		}
 
 		if opCode == opcode.RET {
@@ -147,7 +147,7 @@ func (p Preparator) Prepare(nr *payload.P2PNotaryRequest) (NotaryEvent, error) {
 	// retrieve contract's script hash
 	contractHash, err := util.Uint160DecodeBytesBE(ops[opsLen-2].param)
 	if err != nil {
-		return nil, fmt.Errorf("decode contract hash: %w", err)
+		return nil, fmt.Errorf("could not decode contract hash: %w", err)
 	}
 
 	// retrieve contract's method
@@ -164,7 +164,7 @@ func (p Preparator) Prepare(nr *payload.P2PNotaryRequest) (NotaryEvent, error) {
 	if len(args) != 0 {
 		err = p.validateParameterOpcodes(args)
 		if err != nil {
-			return nil, fmt.Errorf("validate arguments: %w", err)
+			return nil, fmt.Errorf("could not validate arguments: %w", err)
 		}
 
 		// without args packing opcodes
@@ -206,7 +206,7 @@ func (p Preparator) validateNotaryRequest(nr *payload.P2PNotaryRequest) error {
 
 	currentAlphabet, err := p.alphaKeys()
 	if err != nil {
-		return fmt.Errorf("fetch Alphabet public keys: %w", err)
+		return fmt.Errorf("could not fetch Alphabet public keys: %w", err)
 	}
 
 	err = p.validateCosigners(ln, nr.MainTransaction.Signers, currentAlphabet)
@@ -239,7 +239,7 @@ func (p Preparator) validateParameterOpcodes(ops []Op) error {
 
 	argsLen, err := IntFromOpcode(ops[l-2])
 	if err != nil {
-		return fmt.Errorf("parse argument len: %w", err)
+		return fmt.Errorf("could not parse argument len: %w", err)
 	}
 
 	err = validateNestedArgs(argsLen, ops[:l-2])
@@ -273,7 +273,7 @@ func validateNestedArgs(expArgLen int64, ops []Op) error {
 
 			argsLen, err := IntFromOpcode(ops[i-1])
 			if err != nil {
-				return fmt.Errorf("parse argument len: %w", err)
+				return fmt.Errorf("could not parse argument len: %w", err)
 			}
 
 			expArgLen += argsLen + 1
@@ -307,7 +307,7 @@ func (p Preparator) validateExpiration(fbTX *transaction.Transaction) error {
 
 	currBlock, err := p.blockCounter.BlockCount()
 	if err != nil {
-		return fmt.Errorf("fetch current chain height: %w", err)
+		return fmt.Errorf("could not fetch current chain height: %w", err)
 	}
 
 	if currBlock >= nvb.Height {
@@ -327,7 +327,7 @@ func (p Preparator) validateCosigners(expected int, s []transaction.Signer, alph
 
 	alphaVerificationScript, err := smartcontract.CreateMultiSigRedeemScript(len(alphaKeys)*2/3+1, alphaKeys)
 	if err != nil {
-		return fmt.Errorf("get Alphabet verification script: %w", err)
+		return fmt.Errorf("could not get Alphabet verification script: %w", err)
 	}
 
 	if !s[1].Account.Equals(hash.Hash160(alphaVerificationScript)) {
@@ -346,7 +346,7 @@ func (p Preparator) validateWitnesses(w []transaction.Witness, alphaKeys keys.Pu
 
 	alphaVerificationScript, err := smartcontract.CreateMultiSigRedeemScript(len(alphaKeys)*2/3+1, alphaKeys)
 	if err != nil {
-		return fmt.Errorf("get Alphabet verification script: %w", err)
+		return fmt.Errorf("could not get Alphabet verification script: %w", err)
 	}
 
 	// the second one must be witness of the current

pkg/morph/event/rolemanagement/designate.go

@@ -26,7 +26,7 @@ func (Designate) MorphEvent() {}
 func ParseDesignate(e *state.ContainedNotificationEvent) (event.Event, error) {
 	params, err := event.ParseStackArray(e)
 	if err != nil {
-		return nil, fmt.Errorf("parse stack items from notify event: %w", err)
+		return nil, fmt.Errorf("could not parse stack items from notify event: %w", err)
 	}
 
 	if len(params) != 2 {

pkg/morph/event/utils.go

@@ -20,9 +20,13 @@ type scriptHashValue struct {
 	hash util.Uint160
 }
 
+type typeValue struct {
+	typ Type
+}
+
 type scriptHashWithType struct {
-	Hash util.Uint160
+	scriptHashValue
-	Type Type
+	typeValue
 }
 
 type notaryRequestTypes struct {
@@ -69,6 +73,16 @@ func (s scriptHashValue) ScriptHash() util.Uint160 {
 	return s.hash
 }
 
+// SetType is an event type setter.
+func (s *typeValue) SetType(v Type) {
+	s.typ = v
+}
+
+// GetType is an event type getter.
+func (s typeValue) GetType() Type {
+	return s.typ
+}
+
 // WorkerPoolHandler sets closure over worker pool w with passed handler h.
 func WorkerPoolHandler(w util2.WorkerPool, h Handler, log *logger.Logger) Handler {
 	return func(ctx context.Context, e Event) {