mirror of
https://github.com/nspcc-dev/neo-go.git
synced 2024-12-18 15:44:44 +00:00
326 lines
8.9 KiB
Go
326 lines
8.9 KiB
Go
package native
|
|
|
|
import (
|
|
"errors"
|
|
"math/big"
|
|
|
|
"github.com/nspcc-dev/neo-go/pkg/core/interop"
|
|
"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/manifest"
|
|
"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
|
|
"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 account script hash.
|
|
func makeAccountKey(h util.Uint160) []byte {
|
|
k := make([]byte, util.Uint160Size+1)
|
|
k[0] = prefixAccount
|
|
copy(k[1:], h.BytesBE())
|
|
return k
|
|
}
|
|
|
|
// nep5TokenNative represents NEP-5 token contract.
|
|
type nep5TokenNative struct {
|
|
interop.ContractMD
|
|
name string
|
|
symbol string
|
|
decimals int64
|
|
factor int64
|
|
onPersist func(*interop.Context) error
|
|
incBalance func(*interop.Context, util.Uint160, *state.StorageItem, *big.Int) error
|
|
}
|
|
|
|
// totalSupplyKey is the key used to store totalSupply value.
|
|
var totalSupplyKey = []byte{11}
|
|
|
|
func (c *nep5TokenNative) Metadata() *interop.ContractMD {
|
|
return &c.ContractMD
|
|
}
|
|
|
|
var _ interop.Contract = (*nep5TokenNative)(nil)
|
|
|
|
func newNEP5Native(name string) *nep5TokenNative {
|
|
n := &nep5TokenNative{ContractMD: *interop.NewContractMD(name)}
|
|
|
|
desc := newDescriptor("name", smartcontract.StringType)
|
|
md := newMethodAndPrice(n.Name, 0, smartcontract.NoneFlag)
|
|
n.AddMethod(md, desc, true)
|
|
|
|
desc = newDescriptor("symbol", smartcontract.StringType)
|
|
md = newMethodAndPrice(n.Symbol, 0, smartcontract.NoneFlag)
|
|
n.AddMethod(md, desc, true)
|
|
|
|
desc = newDescriptor("decimals", smartcontract.IntegerType)
|
|
md = newMethodAndPrice(n.Decimals, 0, smartcontract.NoneFlag)
|
|
n.AddMethod(md, desc, true)
|
|
|
|
desc = newDescriptor("totalSupply", smartcontract.IntegerType)
|
|
md = newMethodAndPrice(n.TotalSupply, 1000000, smartcontract.AllowStates)
|
|
n.AddMethod(md, desc, true)
|
|
|
|
desc = newDescriptor("balanceOf", smartcontract.IntegerType,
|
|
manifest.NewParameter("account", smartcontract.Hash160Type))
|
|
md = newMethodAndPrice(n.balanceOf, 1000000, smartcontract.AllowStates)
|
|
n.AddMethod(md, desc, true)
|
|
|
|
desc = newDescriptor("transfer", smartcontract.BoolType,
|
|
manifest.NewParameter("from", smartcontract.Hash160Type),
|
|
manifest.NewParameter("to", smartcontract.Hash160Type),
|
|
manifest.NewParameter("amount", smartcontract.IntegerType),
|
|
)
|
|
md = newMethodAndPrice(n.Transfer, 8000000, smartcontract.AllowModifyStates)
|
|
n.AddMethod(md, desc, false)
|
|
|
|
desc = newDescriptor("onPersist", smartcontract.BoolType)
|
|
md = newMethodAndPrice(getOnPersistWrapper(n.OnPersist), 0, smartcontract.AllowModifyStates)
|
|
n.AddMethod(md, desc, false)
|
|
|
|
n.AddEvent("Transfer", desc.Parameters...)
|
|
|
|
return n
|
|
}
|
|
|
|
func (c *nep5TokenNative) Initialize(_ *interop.Context) error {
|
|
return nil
|
|
}
|
|
|
|
func (c *nep5TokenNative) Name(_ *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
return stackitem.NewByteArray([]byte(c.name))
|
|
}
|
|
|
|
func (c *nep5TokenNative) Symbol(_ *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
return stackitem.NewByteArray([]byte(c.symbol))
|
|
}
|
|
|
|
func (c *nep5TokenNative) Decimals(_ *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
return stackitem.NewBigInteger(big.NewInt(c.decimals))
|
|
}
|
|
|
|
func (c *nep5TokenNative) TotalSupply(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
return stackitem.NewBigInteger(c.getTotalSupply(ic))
|
|
}
|
|
|
|
func (c *nep5TokenNative) getTotalSupply(ic *interop.Context) *big.Int {
|
|
si := ic.DAO.GetStorageItem(c.ContractID, totalSupplyKey)
|
|
if si == nil {
|
|
return big.NewInt(0)
|
|
}
|
|
return bigint.FromBytes(si.Value)
|
|
}
|
|
|
|
func (c *nep5TokenNative) saveTotalSupply(ic *interop.Context, supply *big.Int) error {
|
|
si := &state.StorageItem{Value: bigint.ToBytes(supply)}
|
|
return ic.DAO.PutStorageItem(c.ContractID, totalSupplyKey, si)
|
|
}
|
|
|
|
func (c *nep5TokenNative) Transfer(ic *interop.Context, args []stackitem.Item) stackitem.Item {
|
|
from := toUint160(args[0])
|
|
to := toUint160(args[1])
|
|
amount := toBigInt(args[2])
|
|
err := c.transfer(ic, from, to, amount)
|
|
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 *nep5TokenNative) emitTransfer(ic *interop.Context, from, to *util.Uint160, amount *big.Int) {
|
|
ne := state.NotificationEvent{
|
|
ScriptHash: c.Hash,
|
|
Item: stackitem.NewArray([]stackitem.Item{
|
|
stackitem.NewByteArray([]byte("Transfer")),
|
|
addrToStackItem(from),
|
|
addrToStackItem(to),
|
|
stackitem.NewBigInteger(amount),
|
|
}),
|
|
}
|
|
ic.Notifications = append(ic.Notifications, ne)
|
|
}
|
|
|
|
func (c *nep5TokenNative) transfer(ic *interop.Context, from, to util.Uint160, amount *big.Int) error {
|
|
if amount.Sign() == -1 {
|
|
return errors.New("negative amount")
|
|
}
|
|
|
|
ok, err := runtime.CheckHashedWitness(ic, nep5ScriptHash{
|
|
callingScriptHash: c.Hash,
|
|
entryScriptHash: c.Hash,
|
|
currentScriptHash: c.Hash,
|
|
}, from)
|
|
if err != nil {
|
|
return err
|
|
} else if !ok {
|
|
return errors.New("invalid signature")
|
|
}
|
|
|
|
keyFrom := makeAccountKey(from)
|
|
siFrom := ic.DAO.GetStorageItem(c.ContractID, keyFrom)
|
|
if siFrom == nil {
|
|
return errors.New("insufficient funds")
|
|
}
|
|
|
|
isEmpty := from.Equals(to) || amount.Sign() == 0
|
|
inc := amount
|
|
if isEmpty {
|
|
inc = big.NewInt(0)
|
|
} else {
|
|
inc = new(big.Int).Neg(inc)
|
|
}
|
|
if err := c.incBalance(ic, from, siFrom, inc); err != nil {
|
|
return err
|
|
}
|
|
if err := ic.DAO.PutStorageItem(c.ContractID, keyFrom, siFrom); err != nil {
|
|
return err
|
|
}
|
|
|
|
if !isEmpty {
|
|
keyTo := makeAccountKey(to)
|
|
siTo := ic.DAO.GetStorageItem(c.ContractID, keyTo)
|
|
if siTo == nil {
|
|
siTo = new(state.StorageItem)
|
|
}
|
|
if err := c.incBalance(ic, to, siTo, amount); err != nil {
|
|
return err
|
|
}
|
|
if err := ic.DAO.PutStorageItem(c.ContractID, keyTo, siTo); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
c.emitTransfer(ic, &from, &to, amount)
|
|
return nil
|
|
}
|
|
|
|
func (c *nep5TokenNative) balanceOf(ic *interop.Context, args []stackitem.Item) stackitem.Item {
|
|
h := toUint160(args[0])
|
|
bs, err := ic.DAO.GetNEP5Balances(h)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
balance := bs.Trackers[c.Hash].Balance
|
|
return stackitem.NewBigInteger(big.NewInt(balance))
|
|
}
|
|
|
|
func (c *nep5TokenNative) mint(ic *interop.Context, h util.Uint160, amount *big.Int) {
|
|
if amount.Sign() == 0 {
|
|
return
|
|
}
|
|
c.addTokens(ic, h, amount)
|
|
c.emitTransfer(ic, nil, &h, amount)
|
|
}
|
|
|
|
func (c *nep5TokenNative) burn(ic *interop.Context, h util.Uint160, amount *big.Int) {
|
|
if amount.Sign() == 0 {
|
|
return
|
|
}
|
|
c.addTokens(ic, h, new(big.Int).Neg(amount))
|
|
c.emitTransfer(ic, &h, nil, amount)
|
|
}
|
|
|
|
func (c *nep5TokenNative) addTokens(ic *interop.Context, h util.Uint160, amount *big.Int) {
|
|
if amount.Sign() == 0 {
|
|
return
|
|
}
|
|
|
|
key := makeAccountKey(h)
|
|
si := ic.DAO.GetStorageItem(c.ContractID, key)
|
|
if si == nil {
|
|
si = new(state.StorageItem)
|
|
}
|
|
if err := c.incBalance(ic, h, si, amount); err != nil {
|
|
panic(err)
|
|
}
|
|
if err := ic.DAO.PutStorageItem(c.ContractID, key, si); err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
supply := c.getTotalSupply(ic)
|
|
supply.Add(supply, amount)
|
|
err := c.saveTotalSupply(ic, supply)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
}
|
|
|
|
func (c *nep5TokenNative) OnPersist(ic *interop.Context) error {
|
|
if ic.Trigger != trigger.System {
|
|
return errors.New("onPersist should be triggerred by system")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func newDescriptor(name string, ret smartcontract.ParamType, ps ...manifest.Parameter) *manifest.Method {
|
|
return &manifest.Method{
|
|
Name: name,
|
|
Parameters: ps,
|
|
ReturnType: ret,
|
|
}
|
|
}
|
|
|
|
func newMethodAndPrice(f interop.Method, price int64, flags smartcontract.CallFlag) *interop.MethodAndPrice {
|
|
return &interop.MethodAndPrice{
|
|
Func: f,
|
|
Price: price,
|
|
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
|
|
}
|
|
|
|
// scriptHash is an auxiliary structure which implements ScriptHashGetter
|
|
// interface over NEP5 native contract and is used for runtime.CheckHashedWitness
|
|
type nep5ScriptHash struct {
|
|
callingScriptHash util.Uint160
|
|
entryScriptHash util.Uint160
|
|
currentScriptHash util.Uint160
|
|
}
|
|
|
|
// GetCallingScriptHash implements ScriptHashGetter interface
|
|
func (s nep5ScriptHash) GetCallingScriptHash() util.Uint160 {
|
|
return s.callingScriptHash
|
|
}
|
|
|
|
// GetEntryScriptHash implements ScriptHashGetter interface
|
|
func (s nep5ScriptHash) GetEntryScriptHash() util.Uint160 {
|
|
return s.entryScriptHash
|
|
}
|
|
|
|
// GetCurrentScriptHash implements ScriptHashGetter interface
|
|
func (s nep5ScriptHash) GetCurrentScriptHash() util.Uint160 {
|
|
return s.currentScriptHash
|
|
}
|
|
|
|
func getOnPersistWrapper(f func(ic *interop.Context) error) interop.Method {
|
|
return func(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
|
|
return stackitem.NewBool(f(ic) == nil)
|
|
}
|
|
}
|