neo-go/pkg/core/native/native_gas.go
Anna Shaleva 58ab3b5ad1 core: get native nep17 balance from contract storage
Not from DAO's items with storage.STNEP17Balances prefix, because
changes are reflected there only after notifications processing. And
this happens only after the transaction script is executed, but there
might be cases when we need to get the balance that was updated
earlier during the same transaction processing.

Affects storage dumps.
2021-04-01 18:37:44 +03:00

117 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/native/nativenames"
"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 {
nep17TokenNative
NEO *NEO
}
const gasContractID = -6
// 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{}
defer g.UpdateHash()
nep17 := newNEP17Native(nativenames.Gas, gasContractID)
nep17.symbol = "GAS"
nep17.decimals = 8
nep17.factor = GASFactor
nep17.incBalance = g.increaseBalance
nep17.balFromBytes = g.balanceFromBytes
g.nep17TokenNative = *nep17
return g
}
func (g *GAS) increaseBalance(_ *interop.Context, _ util.Uint160, si *state.StorageItem, amount *big.Int) error {
acc, err := state.NEP17BalanceStateFromBytes(*si)
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 = acc.Bytes()
} else {
*si = nil
}
return nil
}
func (g *GAS) balanceFromBytes(si *state.StorageItem) (*big.Int, error) {
acc, err := state.NEP17BalanceStateFromBytes(*si)
if err != nil {
return nil, err
}
return &acc.Balance, err
}
// Initialize initializes GAS contract.
func (g *GAS) Initialize(ic *interop.Context) error {
if err := g.nep17TokenNative.Initialize(ic); err != nil {
return err
}
if g.nep17TokenNative.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), false)
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.PrimaryIndex].GetScriptHash()
var netFee int64
for _, tx := range ic.Block.Transactions {
netFee += tx.NetworkFee
}
g.mint(ic, primary, big.NewInt(int64(netFee)), false)
return nil
}
// PostPersist implements Contract interface.
func (g *GAS) PostPersist(ic *interop.Context) error {
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
}