368 lines
9.8 KiB
Go
368 lines
9.8 KiB
Go
package native
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"math"
|
|
"math/big"
|
|
|
|
"github.com/nspcc-dev/neo-go/pkg/core/dao"
|
|
"github.com/nspcc-dev/neo-go/pkg/core/interop"
|
|
"github.com/nspcc-dev/neo-go/pkg/core/interop/contract"
|
|
"github.com/nspcc-dev/neo-go/pkg/core/interop/runtime"
|
|
"github.com/nspcc-dev/neo-go/pkg/core/state"
|
|
"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
|
|
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
|
|
"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
|
|
"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
|
|
"github.com/nspcc-dev/neo-go/pkg/util"
|
|
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
|
|
)
|
|
|
|
// prefixAccount is the standard prefix used to store account data.
|
|
const prefixAccount = 20
|
|
|
|
// makeAccountKey creates a key from the account script hash.
|
|
func makeAccountKey(h util.Uint160) []byte {
|
|
return makeUint160Key(prefixAccount, h)
|
|
}
|
|
|
|
// nep17TokenNative represents a NEP-17 token contract.
|
|
type nep17TokenNative struct {
|
|
interop.ContractMD
|
|
symbol string
|
|
decimals int64
|
|
factor int64
|
|
incBalance func(*interop.Context, util.Uint160, *state.StorageItem, *big.Int, *big.Int) (func(), error)
|
|
balFromBytes func(item *state.StorageItem) (*big.Int, error)
|
|
}
|
|
|
|
// totalSupplyKey is the key used to store totalSupply value.
|
|
var totalSupplyKey = []byte{11}
|
|
|
|
func (c *nep17TokenNative) Metadata() *interop.ContractMD {
|
|
return &c.ContractMD
|
|
}
|
|
|
|
func newNEP17Native(name string, id int32) *nep17TokenNative {
|
|
n := &nep17TokenNative{ContractMD: *interop.NewContractMD(name, id)}
|
|
n.Manifest.SupportedStandards = []string{manifest.NEP17StandardName}
|
|
|
|
desc := newDescriptor("symbol", smartcontract.StringType)
|
|
md := newMethodAndPrice(n.Symbol, 0, callflag.NoneFlag)
|
|
n.AddMethod(md, desc)
|
|
|
|
desc = newDescriptor("decimals", smartcontract.IntegerType)
|
|
md = newMethodAndPrice(n.Decimals, 0, callflag.NoneFlag)
|
|
n.AddMethod(md, desc)
|
|
|
|
desc = newDescriptor("totalSupply", smartcontract.IntegerType)
|
|
md = newMethodAndPrice(n.TotalSupply, 1<<15, callflag.ReadStates)
|
|
n.AddMethod(md, desc)
|
|
|
|
desc = newDescriptor("balanceOf", smartcontract.IntegerType,
|
|
manifest.NewParameter("account", smartcontract.Hash160Type))
|
|
md = newMethodAndPrice(n.balanceOf, 1<<15, callflag.ReadStates)
|
|
n.AddMethod(md, desc)
|
|
|
|
transferParams := []manifest.Parameter{
|
|
manifest.NewParameter("from", smartcontract.Hash160Type),
|
|
manifest.NewParameter("to", smartcontract.Hash160Type),
|
|
manifest.NewParameter("amount", smartcontract.IntegerType),
|
|
}
|
|
desc = newDescriptor("transfer", smartcontract.BoolType,
|
|
append(transferParams, manifest.NewParameter("data", smartcontract.AnyType))...,
|
|
)
|
|
md = newMethodAndPrice(n.Transfer, 1<<17, callflag.States|callflag.AllowCall|callflag.AllowNotify)
|
|
md.StorageFee = 50
|
|
n.AddMethod(md, desc)
|
|
|
|
n.AddEvent("Transfer", transferParams...)
|
|
|
|
return n
|
|
}
|
|
|
|
func (c *nep17TokenNative) Initialize(_ *interop.Context) error {
|
|
return nil
|
|
}
|
|
|
|
func (c *nep17TokenNative) Symbol(_ *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
return stackitem.NewByteArray([]byte(c.symbol))
|
|
}
|
|
|
|
func (c *nep17TokenNative) Decimals(_ *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
return stackitem.NewBigInteger(big.NewInt(c.decimals))
|
|
}
|
|
|
|
func (c *nep17TokenNative) TotalSupply(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
_, supply := c.getTotalSupply(ic.DAO)
|
|
return stackitem.NewBigInteger(supply)
|
|
}
|
|
|
|
func (c *nep17TokenNative) getTotalSupply(d *dao.Simple) (state.StorageItem, *big.Int) {
|
|
si := d.GetStorageItem(c.ID, totalSupplyKey)
|
|
if si == nil {
|
|
si = []byte{}
|
|
}
|
|
return si, bigint.FromBytes(si)
|
|
}
|
|
|
|
func (c *nep17TokenNative) saveTotalSupply(d *dao.Simple, si state.StorageItem, supply *big.Int) {
|
|
d.PutBigInt(c.ID, totalSupplyKey, supply)
|
|
}
|
|
|
|
func (c *nep17TokenNative) Transfer(ic *interop.Context, args []stackitem.Item) stackitem.Item {
|
|
from := toUint160(args[0])
|
|
to := toUint160(args[1])
|
|
amount := toBigInt(args[2])
|
|
err := c.TransferInternal(ic, from, to, amount, args[3])
|
|
return stackitem.NewBool(err == nil)
|
|
}
|
|
|
|
func addrToStackItem(u *util.Uint160) stackitem.Item {
|
|
if u == nil {
|
|
return stackitem.Null{}
|
|
}
|
|
return stackitem.NewByteArray(u.BytesBE())
|
|
}
|
|
|
|
func (c *nep17TokenNative) postTransfer(ic *interop.Context, from, to *util.Uint160, amount *big.Int,
|
|
data stackitem.Item, callOnPayment bool, postCalls ...func()) {
|
|
var skipPostCalls bool
|
|
defer func() {
|
|
if skipPostCalls {
|
|
return
|
|
}
|
|
for _, f := range postCalls {
|
|
if f != nil {
|
|
f()
|
|
}
|
|
}
|
|
}()
|
|
c.emitTransfer(ic, from, to, amount)
|
|
if to == nil || !callOnPayment {
|
|
return
|
|
}
|
|
cs, err := ic.GetContract(*to)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
fromArg := stackitem.Item(stackitem.Null{})
|
|
if from != nil {
|
|
fromArg = stackitem.NewByteArray((*from).BytesBE())
|
|
}
|
|
args := []stackitem.Item{
|
|
fromArg,
|
|
stackitem.NewBigInteger(amount),
|
|
data,
|
|
}
|
|
if err := contract.CallFromNative(ic, c.Hash, cs, manifest.MethodOnNEP17Payment, args, false); err != nil {
|
|
skipPostCalls = true
|
|
panic(err)
|
|
}
|
|
}
|
|
|
|
func (c *nep17TokenNative) emitTransfer(ic *interop.Context, from, to *util.Uint160, amount *big.Int) {
|
|
ic.AddNotification(c.Hash, "Transfer", stackitem.NewArray([]stackitem.Item{
|
|
addrToStackItem(from),
|
|
addrToStackItem(to),
|
|
stackitem.NewBigInteger(amount),
|
|
}))
|
|
}
|
|
|
|
// updateAccBalance adds the specified amount to the acc's balance. If requiredBalance
|
|
// is set and amount is 0, the acc's balance is checked against requiredBalance.
|
|
func (c *nep17TokenNative) updateAccBalance(ic *interop.Context, acc util.Uint160, amount *big.Int, requiredBalance *big.Int) (func(), error) {
|
|
key := makeAccountKey(acc)
|
|
si := ic.DAO.GetStorageItem(c.ID, key)
|
|
if si == nil {
|
|
if amount.Sign() < 0 {
|
|
return nil, errors.New("insufficient funds")
|
|
}
|
|
if requiredBalance != nil && requiredBalance.Sign() > 0 {
|
|
return nil, errors.New("insufficient funds")
|
|
}
|
|
if amount.Sign() == 0 {
|
|
// it's OK to transfer 0 if the balance is 0, no need to put si to the storage
|
|
return nil, nil
|
|
}
|
|
si = state.StorageItem{}
|
|
}
|
|
|
|
postF, err := c.incBalance(ic, acc, &si, amount, requiredBalance)
|
|
if err != nil {
|
|
if si != nil && amount.Sign() <= 0 {
|
|
ic.DAO.PutStorageItem(c.ID, key, si)
|
|
}
|
|
return nil, err
|
|
}
|
|
if si == nil {
|
|
ic.DAO.DeleteStorageItem(c.ID, key)
|
|
} else {
|
|
ic.DAO.PutStorageItem(c.ID, key, si)
|
|
}
|
|
return postF, nil
|
|
}
|
|
|
|
// TransferInternal transfers NEO across accounts.
|
|
func (c *nep17TokenNative) TransferInternal(ic *interop.Context, from, to util.Uint160, amount *big.Int, data stackitem.Item) error {
|
|
var postF1, postF2 func()
|
|
|
|
if amount.Sign() == -1 {
|
|
return errors.New("negative amount")
|
|
}
|
|
|
|
caller := ic.VM.GetCallingScriptHash()
|
|
if caller.Equals(util.Uint160{}) || !from.Equals(caller) {
|
|
ok, err := runtime.CheckHashedWitness(ic, from)
|
|
if err != nil {
|
|
return err
|
|
} else if !ok {
|
|
return errors.New("invalid signature")
|
|
}
|
|
}
|
|
isEmpty := from.Equals(to) || amount.Sign() == 0
|
|
inc := amount
|
|
if isEmpty {
|
|
inc = big.NewInt(0)
|
|
} else {
|
|
inc = new(big.Int).Neg(inc)
|
|
}
|
|
|
|
postF1, err := c.updateAccBalance(ic, from, inc, amount)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if !isEmpty {
|
|
postF2, err = c.updateAccBalance(ic, to, amount, nil)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
c.postTransfer(ic, &from, &to, amount, data, true, postF1, postF2)
|
|
return nil
|
|
}
|
|
|
|
func (c *nep17TokenNative) balanceOf(ic *interop.Context, args []stackitem.Item) stackitem.Item {
|
|
h := toUint160(args[0])
|
|
return stackitem.NewBigInteger(c.balanceOfInternal(ic.DAO, h))
|
|
}
|
|
|
|
func (c *nep17TokenNative) balanceOfInternal(d *dao.Simple, h util.Uint160) *big.Int {
|
|
key := makeAccountKey(h)
|
|
si := d.GetStorageItem(c.ID, key)
|
|
if si == nil {
|
|
return big.NewInt(0)
|
|
}
|
|
balance, err := c.balFromBytes(&si)
|
|
if err != nil {
|
|
panic(fmt.Errorf("can not deserialize balance state: %w", err))
|
|
}
|
|
return balance
|
|
}
|
|
|
|
func (c *nep17TokenNative) mint(ic *interop.Context, h util.Uint160, amount *big.Int, callOnPayment bool) {
|
|
if amount.Sign() == 0 {
|
|
return
|
|
}
|
|
postF := c.addTokens(ic, h, amount)
|
|
c.postTransfer(ic, nil, &h, amount, stackitem.Null{}, callOnPayment, postF)
|
|
}
|
|
|
|
func (c *nep17TokenNative) burn(ic *interop.Context, h util.Uint160, amount *big.Int) {
|
|
if amount.Sign() == 0 {
|
|
return
|
|
}
|
|
amount.Neg(amount)
|
|
postF := c.addTokens(ic, h, amount)
|
|
amount.Neg(amount)
|
|
c.postTransfer(ic, &h, nil, amount, stackitem.Null{}, false, postF)
|
|
}
|
|
|
|
func (c *nep17TokenNative) addTokens(ic *interop.Context, h util.Uint160, amount *big.Int) func() {
|
|
if amount.Sign() == 0 {
|
|
return nil
|
|
}
|
|
|
|
key := makeAccountKey(h)
|
|
si := ic.DAO.GetStorageItem(c.ID, key)
|
|
if si == nil {
|
|
si = state.StorageItem{}
|
|
}
|
|
postF, err := c.incBalance(ic, h, &si, amount, nil)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
if si == nil {
|
|
ic.DAO.DeleteStorageItem(c.ID, key)
|
|
} else {
|
|
ic.DAO.PutStorageItem(c.ID, key, si)
|
|
}
|
|
|
|
buf, supply := c.getTotalSupply(ic.DAO)
|
|
supply.Add(supply, amount)
|
|
c.saveTotalSupply(ic.DAO, buf, supply)
|
|
return postF
|
|
}
|
|
|
|
func newDescriptor(name string, ret smartcontract.ParamType, ps ...manifest.Parameter) *manifest.Method {
|
|
if len(ps) == 0 {
|
|
ps = []manifest.Parameter{}
|
|
}
|
|
return &manifest.Method{
|
|
Name: name,
|
|
Parameters: ps,
|
|
ReturnType: ret,
|
|
}
|
|
}
|
|
|
|
func newMethodAndPrice(f interop.Method, cpuFee int64, flags callflag.CallFlag) *interop.MethodAndPrice {
|
|
return &interop.MethodAndPrice{
|
|
Func: f,
|
|
CPUFee: cpuFee,
|
|
RequiredFlags: flags,
|
|
}
|
|
}
|
|
|
|
func toBigInt(s stackitem.Item) *big.Int {
|
|
bi, err := s.TryInteger()
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return bi
|
|
}
|
|
|
|
func toUint160(s stackitem.Item) util.Uint160 {
|
|
buf, err := s.TryBytes()
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
u, err := util.Uint160DecodeBytesBE(buf)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return u
|
|
}
|
|
|
|
func toUint32(s stackitem.Item) uint32 {
|
|
bigInt := toBigInt(s)
|
|
if !bigInt.IsUint64() {
|
|
panic("bigint is not an uint64")
|
|
}
|
|
uint64Value := bigInt.Uint64()
|
|
if uint64Value > math.MaxUint32 {
|
|
panic("bigint does not fit into uint32")
|
|
}
|
|
return uint32(uint64Value)
|
|
}
|
|
|
|
func toInt64(s stackitem.Item) int64 {
|
|
bigInt := toBigInt(s)
|
|
if !bigInt.IsInt64() {
|
|
panic("bigint is not an uint64")
|
|
}
|
|
return bigInt.Int64()
|
|
}
|