package client import ( "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/rpc/client" sc "github.com/nspcc-dev/neo-go/pkg/smartcontract" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" "github.com/nspcc-dev/neo-go/pkg/wallet" "github.com/nspcc-dev/neofs-node/pkg/util/logger" "github.com/pkg/errors" "go.uber.org/zap" ) // Client is a neo-go wrapper that provides // smart-contract invocation interface. // // Working client must be created via constructor New. // Using the Client that has been created with new(Client) // expression (or just declaring a Client variable) is unsafe // and can lead to panic. type Client struct { logger *logger.Logger // logging component client *client.Client // neo-go client acc *wallet.Account // neo account gas util.Uint160 // native gas script-hash } // ErrNilClient is returned by functions that expect // a non-nil Client pointer, but received nil. var ErrNilClient = errors.New("client is nil") // HaltState returned if TestInvoke function processed without panic. const HaltState = "HALT" var errEmptyInvocationScript = errors.New("got empty invocation script from neo node") var errScriptDecode = errors.New("could not decode invocation script from neo node") // Invoke invokes contract method by sending transaction into blockchain. // Supported args types: int64, string, util.Uint160, []byte and bool. func (c *Client) Invoke(contract util.Uint160, fee util.Fixed8, method string, args ...interface{}) error { params := make([]sc.Parameter, 0, len(args)) for i := range args { param, err := toStackParameter(args[i]) if err != nil { return err } params = append(params, param) } cosigner := []transaction.Signer{ { Account: c.acc.PrivateKey().PublicKey().GetScriptHash(), Scopes: transaction.Global, }, } resp, err := c.client.InvokeFunction(contract, method, params, cosigner) if err != nil { return err } if len(resp.Script) == 0 { return errEmptyInvocationScript } script := resp.Script sysFee := resp.GasConsumed + int64(fee) // consumed gas + extra fee txHash, err := c.client.SignAndPushInvocationTx(script, c.acc, sysFee, 0, cosigner) if err != nil { return err } c.logger.Debug("neo client invoke", zap.String("method", method), zap.Stringer("tx_hash", txHash)) return nil } // TestInvoke invokes contract method locally in neo-go node. This method should // be used to read data from smart-contract. func (c *Client) TestInvoke(contract util.Uint160, method string, args ...interface{}) ([]stackitem.Item, error) { var params = make([]sc.Parameter, 0, len(args)) for i := range args { p, err := toStackParameter(args[i]) if err != nil { return nil, err } params = append(params, p) } cosigner := []transaction.Signer{ { Account: c.acc.PrivateKey().PublicKey().GetScriptHash(), Scopes: transaction.Global, }, } val, err := c.client.InvokeFunction(contract, method, params, cosigner) if err != nil { return nil, err } if val.State != HaltState { return nil, errors.Errorf("chain/client: contract execution finished with state %s", val.State) } return val.Stack, nil } // TransferGas to the receiver from local wallet func (c *Client) TransferGas(receiver util.Uint160, amount util.Fixed8) error { txHash, err := c.client.TransferNEP5(c.acc, receiver, c.gas, int64(amount), 0) if err != nil { return err } c.logger.Debug("native gas transfer invoke", zap.String("to", receiver.StringLE()), zap.Stringer("tx_hash", txHash)) return nil } func toStackParameter(value interface{}) (sc.Parameter, error) { var result = sc.Parameter{ Value: value, } // todo: add more types switch v := value.(type) { case []byte: result.Type = sc.ByteArrayType case int64: // TODO: add other numerical types result.Type = sc.IntegerType case [][]byte: arr := make([]sc.Parameter, 0, len(v)) for i := range v { elem, err := toStackParameter(v[i]) if err != nil { return result, err } arr = append(arr, elem) } result.Type = sc.ArrayType result.Value = arr case string: result.Type = sc.StringType default: return result, errors.Errorf("chain/client: unsupported parameter %v", value) } return result, nil }