neo-go/pkg/core/native/native_gas.go
2020-10-02 15:45:49 +03:00

120 lines
2.9 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/state"
"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/util"
)
// GAS represents GAS native contract.
type GAS struct {
nep5TokenNative
NEO *NEO
}
const gasName = "GAS"
const gasContractID = -2
// GASFactor is a divisor for finding GAS integral value.
const GASFactor = NEOTotalSupply
const initialGAS = 30000000
// newGAS returns GAS native contract.
func newGAS() *GAS {
g := &GAS{}
nep5 := newNEP5Native(gasName)
nep5.symbol = "gas"
nep5.decimals = 8
nep5.factor = GASFactor
nep5.onPersist = chainOnPersist(nep5.OnPersist, g.OnPersist)
nep5.incBalance = g.increaseBalance
nep5.ContractID = gasContractID
g.nep5TokenNative = *nep5
onp := g.Methods["onPersist"]
onp.Func = getOnPersistWrapper(g.onPersist)
g.Methods["onPersist"] = onp
return g
}
func (g *GAS) increaseBalance(_ *interop.Context, _ util.Uint160, si *state.StorageItem, amount *big.Int) error {
acc, err := state.NEP5BalanceStateFromBytes(si.Value)
if err != nil {
return err
}
if sign := amount.Sign(); sign == 0 {
return nil
} else if sign == -1 && acc.Balance.Cmp(new(big.Int).Neg(amount)) == -1 {
return errors.New("insufficient funds")
}
acc.Balance.Add(&acc.Balance, amount)
if acc.Balance.Sign() != 0 {
si.Value = acc.Bytes()
} else {
si.Value = nil
}
return nil
}
// Initialize initializes GAS contract.
func (g *GAS) Initialize(ic *interop.Context) error {
if err := g.nep5TokenNative.Initialize(ic); err != nil {
return err
}
if g.nep5TokenNative.getTotalSupply(ic.DAO).Sign() != 0 {
return errors.New("already initialized")
}
h, err := getStandbyValidatorsHash(ic)
if err != nil {
return err
}
g.mint(ic, h, big.NewInt(initialGAS*GASFactor))
return nil
}
// OnPersist implements Contract interface.
func (g *GAS) OnPersist(ic *interop.Context) error {
if len(ic.Block.Transactions) == 0 {
return nil
}
for _, tx := range ic.Block.Transactions {
absAmount := big.NewInt(tx.SystemFee + tx.NetworkFee)
g.burn(ic, tx.Sender(), absAmount)
}
validators := g.NEO.GetNextBlockValidatorsInternal()
primary := validators[ic.Block.ConsensusData.PrimaryIndex].GetScriptHash()
var netFee int64
for _, tx := range ic.Block.Transactions {
netFee += tx.NetworkFee
}
g.mint(ic, primary, big.NewInt(int64(netFee)))
return nil
}
func getStandbyValidatorsHash(ic *interop.Context) (util.Uint160, error) {
s, err := smartcontract.CreateDefaultMultiSigRedeemScript(ic.Chain.GetStandByValidators())
if err != nil {
return util.Uint160{}, err
}
return hash.Hash160(s), nil
}
func chainOnPersist(fs ...func(*interop.Context) error) func(*interop.Context) error {
return func(ic *interop.Context) error {
for i := range fs {
if fs[i] != nil {
if err := fs[i](ic); err != nil {
return err
}
}
}
return nil
}
}