neo-go/pkg/core/native/contract.go
Evgenii Stratonikov bf01599430 vm: check return value on context unload
When calling external contracts we expect exactly 1 value to be on
stack. For methods returning nothing, `Null` value is pushed, otherwise
it is an error.`
2020-08-10 11:52:33 +03:00

68 lines
1.7 KiB
Go

package native
import (
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/io"
"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
Contracts []interop.Contract
// persistScript is vm script which executes "onPersist" method of every native contract.
persistScript []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
}
// 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)
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()
emit.Int(w.BinWriter, 0)
emit.Opcode(w.BinWriter, opcode.NEWARRAY)
emit.String(w.BinWriter, "onPersist")
emit.AppCall(w.BinWriter, md.Hash)
emit.Opcode(w.BinWriter, opcode.DROP)
}
cs.persistScript = w.Bytes()
return cs.persistScript
}