consensus, core/*, params: metropolis preparation refactor

This commit is a preparation for the upcoming metropolis hardfork. It
prepares the state, core and vm packages such that integration with
metropolis becomes less of a hassle.

* Difficulty calculation requires header instead of individual
  parameters
* statedb.StartRecord renamed to statedb.Prepare and added Finalise
  method required by metropolis, which removes unwanted accounts from
  the state (i.e. selfdestruct)
* State keeps record of destructed objects (in addition to dirty
  objects)
* core/vm pre-compiles may now return errors
* core/vm pre-compiles gas check now take the full byte slice as argument
  instead of just the size
* core/vm now keeps several hard-fork instruction tables instead of a
  single instruction table and removes the need for hard-fork checks in
  the instructions
* core/vm contains a empty restruction function which is added in
  preparation of metropolis write-only mode operations
* Adds the bn256 curve
* Adds and sets the metropolis chain config block parameters (2^64-1)
This commit is contained in:
Jeffrey Wilcke
2017-02-01 22:36:51 +01:00
parent a2f23ca9b1
commit 10a57fc3d4
28 changed files with 2865 additions and 183 deletions

View File

@ -33,7 +33,20 @@ type (
GetHashFunc func(uint64) common.Hash
)
// Context provides the EVM with auxiliary information. Once provided it shouldn't be modified.
// run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter.
func run(evm *EVM, snapshot int, contract *Contract, input []byte) ([]byte, error) {
if contract.CodeAddr != nil {
precompiledContracts := PrecompiledContracts
if p := precompiledContracts[*contract.CodeAddr]; p != nil {
return RunPrecompiledContract(p, input, contract)
}
}
return evm.interpreter.Run(snapshot, contract, input)
}
// Context provides the EVM with auxiliary information. Once provided
// it shouldn't be modified.
type Context struct {
// CanTransfer returns whether the account contains
// sufficient ether to transfer the value
@ -55,7 +68,13 @@ type Context struct {
Difficulty *big.Int // Provides information for DIFFICULTY
}
// EVM provides information about external sources for the EVM
// EVM is the Ethereum Virtual Machine base object and provides
// the necessary tools to run a contract on the given state with
// the provided context. It should be noted that any error
// generated through any of the calls should be considered a
// revert-state-and-consume-all-gas operation, no checks on
// specific errors should ever be performed. The interpreter makes
// sure that any errors generated are to be considered faulty code.
//
// The EVM should never be reused and is not thread safe.
type EVM struct {
@ -68,6 +87,8 @@ type EVM struct {
// chainConfig contains information about the current chain
chainConfig *params.ChainConfig
// chain rules contains the chain rules for the current epoch
chainRules params.Rules
// virtual machine configuration options used to initialise the
// evm.
vmConfig Config
@ -79,21 +100,23 @@ type EVM struct {
abort int32
}
// NewEVM retutrns a new EVM evmironment.
// NewEVM retutrns a new EVM evmironment. The returned EVM is not thread safe
// and should only ever be used *once*.
func NewEVM(ctx Context, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *EVM {
evm := &EVM{
Context: ctx,
StateDB: statedb,
vmConfig: vmConfig,
chainConfig: chainConfig,
chainRules: chainConfig.Rules(ctx.BlockNumber),
}
evm.interpreter = NewInterpreter(evm, vmConfig)
return evm
}
// Cancel cancels any running EVM operation. This may be called concurrently and it's safe to be
// called multiple times.
// Cancel cancels any running EVM operation. This may be called concurrently and
// it's safe to be called multiple times.
func (evm *EVM) Cancel() {
atomic.StoreInt32(&evm.abort, 1)
}
@ -134,13 +157,12 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
contract := NewContract(caller, to, value, gas)
contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
ret, err = evm.interpreter.Run(contract, input)
ret, err = run(evm, snapshot, contract, input)
// When an error was returned by the EVM or when setting the creation code
// above we revert to the snapshot and consume any gas remaining. Additionally
// when we're in homestead this also counts for code storage gas errors.
if err != nil {
contract.UseGas(contract.Gas)
evm.StateDB.RevertToSnapshot(snapshot)
}
return ret, contract.Gas, err
@ -175,10 +197,9 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
contract := NewContract(caller, to, value, gas)
contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
ret, err = evm.interpreter.Run(contract, input)
ret, err = run(evm, snapshot, contract, input)
if err != nil {
contract.UseGas(contract.Gas)
evm.StateDB.RevertToSnapshot(snapshot)
}
@ -210,10 +231,9 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
contract := NewContract(caller, to, nil, gas).AsDelegate()
contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
ret, err = evm.interpreter.Run(contract, input)
ret, err = run(evm, snapshot, contract, input)
if err != nil {
contract.UseGas(contract.Gas)
evm.StateDB.RevertToSnapshot(snapshot)
}
@ -253,8 +273,7 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
contract := NewContract(caller, AccountRef(contractAddr), value, gas)
contract.SetCallCode(&contractAddr, crypto.Keccak256Hash(code), code)
ret, err = evm.interpreter.Run(contract, nil)
ret, err = run(evm, snapshot, contract, nil)
// check whether the max code size has been exceeded
maxCodeSizeExceeded := len(ret) > params.MaxCodeSize
// if the contract creation ran successfully and no errors were returned
@ -275,10 +294,8 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
// when we're in homestead this also counts for code storage gas errors.
if maxCodeSizeExceeded ||
(err != nil && (evm.ChainConfig().IsHomestead(evm.BlockNumber) || err != ErrCodeStoreOutOfGas)) {
contract.UseGas(contract.Gas)
evm.StateDB.RevertToSnapshot(snapshot)
// Nothing should be returned when an error is thrown.
return nil, contractAddr, 0, err
}
// If the vm returned with an error the return value should be set to nil.
// This isn't consensus critical but merely to for behaviour reasons such as