go-pulse/light/vm_env.go
Felix Lange c213fd1fd8 all: import "context" instead of "golang.org/x/net/context"
There is no need to depend on the old context package now that the
minimum Go version is 1.7. The move to "context" eliminates our weird
vendoring setup. Some vendored code still uses golang.org/x/net/context
and it is now vendored in the normal way.

This change triggered new vet checks around context.WithTimeout which
didn't fire with golang.org/x/net/context.
2017-03-22 20:49:15 +01:00

195 lines
6.0 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package light
import (
"context"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
)
// VMState is a wrapper for the light state that holds the actual context and
// passes it to any state operation that requires it.
type VMState struct {
ctx context.Context
state *LightState
snapshots []*LightState
err error
}
func NewVMState(ctx context.Context, state *LightState) *VMState {
return &VMState{ctx: ctx, state: state}
}
func (s *VMState) Error() error {
return s.err
}
func (s *VMState) AddLog(log *types.Log) {}
func (s *VMState) AddPreimage(hash common.Hash, preimage []byte) {}
// errHandler handles and stores any state error that happens during execution.
func (s *VMState) errHandler(err error) {
if err != nil && s.err == nil {
s.err = err
}
}
func (self *VMState) Snapshot() int {
self.snapshots = append(self.snapshots, self.state.Copy())
return len(self.snapshots) - 1
}
func (self *VMState) RevertToSnapshot(idx int) {
self.state.Set(self.snapshots[idx])
self.snapshots = self.snapshots[:idx]
}
// CreateAccount creates creates a new account object and takes ownership.
func (s *VMState) CreateAccount(addr common.Address) {
_, err := s.state.CreateStateObject(s.ctx, addr)
s.errHandler(err)
}
// AddBalance adds the given amount to the balance of the specified account
func (s *VMState) AddBalance(addr common.Address, amount *big.Int) {
err := s.state.AddBalance(s.ctx, addr, amount)
s.errHandler(err)
}
// SubBalance adds the given amount to the balance of the specified account
func (s *VMState) SubBalance(addr common.Address, amount *big.Int) {
err := s.state.SubBalance(s.ctx, addr, amount)
s.errHandler(err)
}
// ForEachStorage calls a callback function for every key/value pair found
// in the local storage cache. Note that unlike core/state.StateObject,
// light.StateObject only returns cached values and doesn't download the
// entire storage tree.
func (s *VMState) ForEachStorage(addr common.Address, cb func(key, value common.Hash) bool) {
err := s.state.ForEachStorage(s.ctx, addr, cb)
s.errHandler(err)
}
// GetBalance retrieves the balance from the given address or 0 if the account does
// not exist
func (s *VMState) GetBalance(addr common.Address) *big.Int {
res, err := s.state.GetBalance(s.ctx, addr)
s.errHandler(err)
return res
}
// GetNonce returns the nonce at the given address or 0 if the account does
// not exist
func (s *VMState) GetNonce(addr common.Address) uint64 {
res, err := s.state.GetNonce(s.ctx, addr)
s.errHandler(err)
return res
}
// SetNonce sets the nonce of the specified account
func (s *VMState) SetNonce(addr common.Address, nonce uint64) {
err := s.state.SetNonce(s.ctx, addr, nonce)
s.errHandler(err)
}
// GetCode returns the contract code at the given address or nil if the account
// does not exist
func (s *VMState) GetCode(addr common.Address) []byte {
res, err := s.state.GetCode(s.ctx, addr)
s.errHandler(err)
return res
}
// GetCodeHash returns the contract code hash at the given address
func (s *VMState) GetCodeHash(addr common.Address) common.Hash {
res, err := s.state.GetCode(s.ctx, addr)
s.errHandler(err)
return crypto.Keccak256Hash(res)
}
// GetCodeSize returns the contract code size at the given address
func (s *VMState) GetCodeSize(addr common.Address) int {
res, err := s.state.GetCode(s.ctx, addr)
s.errHandler(err)
return len(res)
}
// SetCode sets the contract code at the specified account
func (s *VMState) SetCode(addr common.Address, code []byte) {
err := s.state.SetCode(s.ctx, addr, code)
s.errHandler(err)
}
// AddRefund adds an amount to the refund value collected during a vm execution
func (s *VMState) AddRefund(gas *big.Int) {
s.state.AddRefund(gas)
}
// GetRefund returns the refund value collected during a vm execution
func (s *VMState) GetRefund() *big.Int {
return s.state.GetRefund()
}
// GetState returns the contract storage value at storage address b from the
// contract address a or common.Hash{} if the account does not exist
func (s *VMState) GetState(a common.Address, b common.Hash) common.Hash {
res, err := s.state.GetState(s.ctx, a, b)
s.errHandler(err)
return res
}
// SetState sets the storage value at storage address key of the account addr
func (s *VMState) SetState(addr common.Address, key common.Hash, value common.Hash) {
err := s.state.SetState(s.ctx, addr, key, value)
s.errHandler(err)
}
// Suicide marks an account to be removed and clears its balance
func (s *VMState) Suicide(addr common.Address) bool {
res, err := s.state.Suicide(s.ctx, addr)
s.errHandler(err)
return res
}
// Exist returns true if an account exists at the given address
func (s *VMState) Exist(addr common.Address) bool {
res, err := s.state.HasAccount(s.ctx, addr)
s.errHandler(err)
return res
}
// Empty returns true if the account at the given address is considered empty
func (s *VMState) Empty(addr common.Address) bool {
so, err := s.state.GetStateObject(s.ctx, addr)
s.errHandler(err)
return so == nil || so.empty()
}
// HasSuicided returns true if the given account has been marked for deletion
// or false if the account does not exist
func (s *VMState) HasSuicided(addr common.Address) bool {
res, err := s.state.HasSuicided(s.ctx, addr)
s.errHandler(err)
return res
}