go-pulse/params/config.go
Felix Lange 37dd9086ec core: refactor genesis handling
This commit solves several issues concerning the genesis block:

* Genesis/ChainConfig loading was handled by cmd/geth code. This left
  library users in the cold. They could specify a JSON-encoded
  string and overwrite the config, but didn't get any of the additional
  checks performed by geth.
* Decoding and writing of genesis JSON was conflated in
  WriteGenesisBlock. This made it a lot harder to embed the genesis
  block into the forthcoming config file loader. This commit changes
  things so there is a single Genesis type that represents genesis
  blocks. All uses of Write*Genesis* are changed to use the new type
  instead.
* If the chain config supplied by the user was incompatible with the
  current chain (i.e. the chain had already advanced beyond a scheduled
  fork), it got overwritten. This is not an issue in practice because
  previous forks have always had the highest total difficulty. It might
  matter in the future though. The new code reverts the local chain to
  the point of the fork when upgrading configuration.

The change to genesis block data removes compression library
dependencies from package core.
2017-03-23 15:58:43 +01:00

233 lines
8.2 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 params
import (
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/common"
)
var (
// MainnetChainConfig is the chain parameters to run a node on the main network.
MainnetChainConfig = &ChainConfig{
ChainId: MainNetChainID,
HomesteadBlock: MainNetHomesteadBlock,
DAOForkBlock: MainNetDAOForkBlock,
DAOForkSupport: true,
EIP150Block: MainNetHomesteadGasRepriceBlock,
EIP150Hash: MainNetHomesteadGasRepriceHash,
EIP155Block: MainNetSpuriousDragon,
EIP158Block: MainNetSpuriousDragon,
}
// TestnetChainConfig contains the chain parameters to run a node on the ropsten test network.
TestnetChainConfig = &ChainConfig{
ChainId: big.NewInt(3),
HomesteadBlock: big.NewInt(0),
DAOForkBlock: nil,
DAOForkSupport: true,
EIP150Block: big.NewInt(0),
EIP150Hash: common.HexToHash("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"),
EIP155Block: big.NewInt(10),
EIP158Block: big.NewInt(10),
}
// AllProtocolChanges contains every protocol change (EIPs)
// introduced and accepted by the Ethereum core developers.
// TestChainConfig is like AllProtocolChanges but has chain ID 1.
//
// This configuration is intentionally not using keyed fields.
// This configuration must *always* have all forks enabled, which
// means that all fields must be set at all times. This forces
// anyone adding flags to the config to also have to set these
// fields.
AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0)}
TestChainConfig = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0)}
)
// ChainConfig is the core config which determines the blockchain settings.
//
// ChainConfig is stored in the database on a per block basis. This means
// that any network, identified by its genesis block, can have its own
// set of configuration options.
type ChainConfig struct {
ChainId *big.Int `json:"chainId"` // Chain id identifies the current chain and is used for replay protection
HomesteadBlock *big.Int `json:"homesteadBlock"` // Homestead switch block (nil = no fork, 0 = already homestead)
DAOForkBlock *big.Int `json:"daoForkBlock"` // TheDAO hard-fork switch block (nil = no fork)
DAOForkSupport bool `json:"daoForkSupport"` // Whether the nodes supports or opposes the DAO hard-fork
// EIP150 implements the Gas price changes (https://github.com/ethereum/EIPs/issues/150)
EIP150Block *big.Int `json:"eip150Block"` // EIP150 HF block (nil = no fork)
EIP150Hash common.Hash `json:"eip150Hash"` // EIP150 HF hash (fast sync aid)
EIP155Block *big.Int `json:"eip155Block"` // EIP155 HF block
EIP158Block *big.Int `json:"eip158Block"` // EIP158 HF block
}
// String implements the fmt.Stringer interface.
func (c *ChainConfig) String() string {
return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v}",
c.ChainId,
c.HomesteadBlock,
c.DAOForkBlock,
c.DAOForkSupport,
c.EIP150Block,
c.EIP155Block,
c.EIP158Block,
)
}
// IsHomestead returns whether num is either equal to the homestead block or greater.
func (c *ChainConfig) IsHomestead(num *big.Int) bool {
return isForked(c.HomesteadBlock, num)
}
// IsDAO returns whether num is either equal to the DAO fork block or greater.
func (c *ChainConfig) IsDAOFork(num *big.Int) bool {
return isForked(c.DAOForkBlock, num)
}
func (c *ChainConfig) IsEIP150(num *big.Int) bool {
return isForked(c.EIP150Block, num)
}
func (c *ChainConfig) IsEIP155(num *big.Int) bool {
return isForked(c.EIP155Block, num)
}
func (c *ChainConfig) IsEIP158(num *big.Int) bool {
return isForked(c.EIP158Block, num)
}
// GasTable returns the gas table corresponding to the current phase (homestead or homestead reprice).
//
// The returned GasTable's fields shouldn't, under any circumstances, be changed.
func (c *ChainConfig) GasTable(num *big.Int) GasTable {
if num == nil {
return GasTableHomestead
}
switch {
case c.IsEIP158(num):
return GasTableEIP158
case c.IsEIP150(num):
return GasTableHomesteadGasRepriceFork
default:
return GasTableHomestead
}
}
// CheckCompatible checks whether scheduled fork transitions have been imported
// with a mismatching chain configuration.
func (c *ChainConfig) CheckCompatible(newcfg *ChainConfig, height uint64) *ConfigCompatError {
bhead := new(big.Int).SetUint64(height)
// Iterate checkCompatible to find the lowest conflict.
var lasterr *ConfigCompatError
for {
err := c.checkCompatible(newcfg, bhead)
if err == nil || (lasterr != nil && err.RewindTo == lasterr.RewindTo) {
break
}
lasterr = err
bhead.SetUint64(err.RewindTo)
}
return lasterr
}
func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, head *big.Int) *ConfigCompatError {
if isForkIncompatible(c.HomesteadBlock, newcfg.HomesteadBlock, head) {
return newCompatError("Homestead fork block", c.HomesteadBlock, newcfg.HomesteadBlock)
}
if isForkIncompatible(c.DAOForkBlock, newcfg.DAOForkBlock, head) {
return newCompatError("DAO fork block", c.DAOForkBlock, newcfg.DAOForkBlock)
}
if c.IsDAOFork(head) && c.DAOForkSupport != newcfg.DAOForkSupport {
return newCompatError("DAO fork support flag", c.DAOForkBlock, newcfg.DAOForkBlock)
}
if isForkIncompatible(c.EIP150Block, newcfg.EIP150Block, head) {
return newCompatError("EIP150 fork block", c.EIP150Block, newcfg.EIP150Block)
}
if isForkIncompatible(c.EIP155Block, newcfg.EIP155Block, head) {
return newCompatError("EIP155 fork block", c.EIP155Block, newcfg.EIP155Block)
}
if isForkIncompatible(c.EIP158Block, newcfg.EIP158Block, head) {
return newCompatError("EIP158 fork block", c.EIP158Block, newcfg.EIP158Block)
}
if c.IsEIP158(head) && !configNumEqual(c.ChainId, newcfg.ChainId) {
return newCompatError("EIP158 chain ID", c.EIP158Block, newcfg.EIP158Block)
}
return nil
}
// isForkIncompatible returns true if a fork scheduled at s1 cannot be rescheduled to
// block s2 because head is already past the fork.
func isForkIncompatible(s1, s2, head *big.Int) bool {
return (isForked(s1, head) || isForked(s2, head)) && !configNumEqual(s1, s2)
}
// isForked returns whether a fork scheduled at block s is active at the given head block.
func isForked(s, head *big.Int) bool {
if s == nil || head == nil {
return false
}
return s.Cmp(head) <= 0
}
func configNumEqual(x, y *big.Int) bool {
if x == nil {
return y == nil
}
if y == nil {
return x == nil
}
return x.Cmp(y) == 0
}
// ConfigCompatError is raised if the locally-stored blockchain is initialised with a
// ChainConfig that would alter the past.
type ConfigCompatError struct {
What string
// block numbers of the stored and new configurations
StoredConfig, NewConfig *big.Int
// the block number to which the local chain must be rewound to correct the error
RewindTo uint64
}
func newCompatError(what string, storedblock, newblock *big.Int) *ConfigCompatError {
var rew *big.Int
switch {
case storedblock == nil:
rew = newblock
case newblock == nil || storedblock.Cmp(newblock) < 0:
rew = storedblock
default:
rew = newblock
}
err := &ConfigCompatError{what, storedblock, newblock, 0}
if rew != nil && rew.Sign() > 0 {
err.RewindTo = rew.Uint64() - 1
}
return err
}
func (err *ConfigCompatError) Error() string {
return fmt.Sprintf("mismatching %s in database (have %d, want %d, rewindto %d)", err.What, err.StoredConfig, err.NewConfig, err.RewindTo)
}