neo-go/pkg/core/native/contract.go
2020-11-03 17:23:49 +03:00

135 lines
3.7 KiB
Go

package native
import (
"errors"
"strings"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/io"
"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/emit"
"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
)
// Contracts is a set of registered native contracts.
type Contracts struct {
NEO *NEO
GAS *GAS
Policy *Policy
Oracle *Oracle
Designate *Designate
Contracts []interop.Contract
// persistScript is vm script which executes "onPersist" method of every native contract.
persistScript []byte
// postPersistScript is vm script which executes "postPersist" method of every native contract.
postPersistScript []byte
}
// ByHash returns native contract with the specified hash.
func (cs *Contracts) ByHash(h util.Uint160) interop.Contract {
for _, ctr := range cs.Contracts {
if ctr.Metadata().Hash.Equals(h) {
return ctr
}
}
return nil
}
// ByName returns native contract with the specified name.
func (cs *Contracts) ByName(name string) interop.Contract {
name = strings.ToLower(name)
for _, ctr := range cs.Contracts {
if strings.ToLower(ctr.Metadata().Name) == name {
return ctr
}
}
return nil
}
// NewContracts returns new set of native contracts with new GAS, NEO and Policy
// contracts.
func NewContracts() *Contracts {
cs := new(Contracts)
gas := newGAS()
neo := newNEO()
neo.GAS = gas
gas.NEO = neo
cs.GAS = gas
cs.Contracts = append(cs.Contracts, gas)
cs.NEO = neo
cs.Contracts = append(cs.Contracts, neo)
policy := newPolicy()
cs.Policy = policy
cs.Contracts = append(cs.Contracts, policy)
oracle := newOracle()
oracle.GAS = gas
oracle.NEO = neo
cs.Oracle = oracle
cs.Contracts = append(cs.Contracts, oracle)
desig := newDesignate()
desig.NEO = neo
cs.Designate = desig
cs.Oracle.Desig = desig
cs.Contracts = append(cs.Contracts, desig)
return cs
}
// GetPersistScript returns VM script calling "onPersist" method of every native contract.
func (cs *Contracts) GetPersistScript() []byte {
if cs.persistScript != nil {
return cs.persistScript
}
w := io.NewBufBinWriter()
for i := range cs.Contracts {
md := cs.Contracts[i].Metadata()
// Not every contract is persisted:
// https://github.com/neo-project/neo/blob/master/src/neo/Ledger/Blockchain.cs#L90
if md.ContractID == policyContractID || md.ContractID == oracleContractID || md.ContractID == designateContractID {
continue
}
emit.Int(w.BinWriter, 0)
emit.Opcodes(w.BinWriter, opcode.NEWARRAY)
emit.String(w.BinWriter, "onPersist")
emit.AppCall(w.BinWriter, md.Hash)
emit.Opcodes(w.BinWriter, opcode.DROP)
}
cs.persistScript = w.Bytes()
return cs.persistScript
}
// GetPostPersistScript returns VM script calling "postPersist" method of some native contracts.
func (cs *Contracts) GetPostPersistScript() []byte {
if cs.postPersistScript != nil {
return cs.postPersistScript
}
w := io.NewBufBinWriter()
for i := range cs.Contracts {
md := cs.Contracts[i].Metadata()
// Not every contract is persisted:
// https://github.com/neo-project/neo/blob/master/src/neo/Ledger/Blockchain.cs#L103
if md.ContractID == policyContractID || md.ContractID == gasContractID || md.ContractID == designateContractID {
continue
}
emit.Int(w.BinWriter, 0)
emit.Opcodes(w.BinWriter, opcode.NEWARRAY)
emit.String(w.BinWriter, "postPersist")
emit.AppCall(w.BinWriter, md.Hash)
emit.Opcodes(w.BinWriter, opcode.DROP)
}
cs.postPersistScript = w.Bytes()
return cs.postPersistScript
}
func postPersistBase(ic *interop.Context) error {
if ic.Trigger != trigger.PostPersist {
return errors.New("postPersist must be trigered by system")
}
return nil
}