go-ethereum/core/genesis.go
rjl493456442 743e404906
core, eth, les, tests, trie: abstract node scheme (#25532)
This PR introduces a node scheme abstraction. The interface is only implemented by `hashScheme` at the moment, but will be extended by `pathScheme` very soon.

Apart from that, a few changes are also included which is worth mentioning:

-  port the changes in the stacktrie, tracking the path prefix of nodes during commit
-  use ethdb.Database for constructing trie.Database. This is not necessary right now, but it is required for path-based used to open reverse diff freezer
2022-11-28 14:31:28 +01:00

641 lines
23 KiB
Go

// Copyright 2014 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 core
import (
"bytes"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"math/big"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
//go:generate go run github.com/fjl/gencodec -type Genesis -field-override genesisSpecMarshaling -out gen_genesis.go
//go:generate go run github.com/fjl/gencodec -type GenesisAccount -field-override genesisAccountMarshaling -out gen_genesis_account.go
var errGenesisNoConfig = errors.New("genesis has no chain configuration")
// Genesis specifies the header fields, state of a genesis block. It also defines hard
// fork switch-over blocks through the chain configuration.
type Genesis struct {
Config *params.ChainConfig `json:"config"`
Nonce uint64 `json:"nonce"`
Timestamp uint64 `json:"timestamp"`
ExtraData []byte `json:"extraData"`
GasLimit uint64 `json:"gasLimit" gencodec:"required"`
Difficulty *big.Int `json:"difficulty" gencodec:"required"`
Mixhash common.Hash `json:"mixHash"`
Coinbase common.Address `json:"coinbase"`
Alloc GenesisAlloc `json:"alloc" gencodec:"required"`
// These fields are used for consensus tests. Please don't use them
// in actual genesis blocks.
Number uint64 `json:"number"`
GasUsed uint64 `json:"gasUsed"`
ParentHash common.Hash `json:"parentHash"`
BaseFee *big.Int `json:"baseFeePerGas"`
}
func ReadGenesis(db ethdb.Database) (*Genesis, error) {
var genesis Genesis
stored := rawdb.ReadCanonicalHash(db, 0)
if (stored == common.Hash{}) {
return nil, fmt.Errorf("invalid genesis hash in database: %x", stored)
}
blob := rawdb.ReadGenesisStateSpec(db, stored)
if blob == nil {
return nil, fmt.Errorf("genesis state missing from db")
}
if len(blob) != 0 {
if err := genesis.Alloc.UnmarshalJSON(blob); err != nil {
return nil, fmt.Errorf("could not unmarshal genesis state json: %s", err)
}
}
genesis.Config = rawdb.ReadChainConfig(db, stored)
if genesis.Config == nil {
return nil, fmt.Errorf("genesis config missing from db")
}
genesisBlock := rawdb.ReadBlock(db, stored, 0)
if genesisBlock == nil {
return nil, fmt.Errorf("genesis block missing from db")
}
genesisHeader := genesisBlock.Header()
genesis.Nonce = genesisHeader.Nonce.Uint64()
genesis.Timestamp = genesisHeader.Time
genesis.ExtraData = genesisHeader.Extra
genesis.GasLimit = genesisHeader.GasLimit
genesis.Difficulty = genesisHeader.Difficulty
genesis.Mixhash = genesisHeader.MixDigest
genesis.Coinbase = genesisHeader.Coinbase
return &genesis, nil
}
// GenesisAlloc specifies the initial state that is part of the genesis block.
type GenesisAlloc map[common.Address]GenesisAccount
func (ga *GenesisAlloc) UnmarshalJSON(data []byte) error {
m := make(map[common.UnprefixedAddress]GenesisAccount)
if err := json.Unmarshal(data, &m); err != nil {
return err
}
*ga = make(GenesisAlloc)
for addr, a := range m {
(*ga)[common.Address(addr)] = a
}
return nil
}
// deriveHash computes the state root according to the genesis specification.
func (ga *GenesisAlloc) deriveHash() (common.Hash, error) {
// Create an ephemeral in-memory database for computing hash,
// all the derived states will be discarded to not pollute disk.
db := state.NewDatabase(rawdb.NewMemoryDatabase())
statedb, err := state.New(common.Hash{}, db, nil)
if err != nil {
return common.Hash{}, err
}
for addr, account := range *ga {
statedb.AddBalance(addr, account.Balance)
statedb.SetCode(addr, account.Code)
statedb.SetNonce(addr, account.Nonce)
for key, value := range account.Storage {
statedb.SetState(addr, key, value)
}
}
return statedb.Commit(false)
}
// flush is very similar with deriveHash, but the main difference is
// all the generated states will be persisted into the given database.
// Also, the genesis state specification will be flushed as well.
func (ga *GenesisAlloc) flush(db ethdb.Database, triedb *trie.Database) error {
statedb, err := state.New(common.Hash{}, state.NewDatabaseWithNodeDB(db, triedb), nil)
if err != nil {
return err
}
for addr, account := range *ga {
statedb.AddBalance(addr, account.Balance)
statedb.SetCode(addr, account.Code)
statedb.SetNonce(addr, account.Nonce)
for key, value := range account.Storage {
statedb.SetState(addr, key, value)
}
}
root, err := statedb.Commit(false)
if err != nil {
return err
}
// Commit newly generated states into disk if it's not empty.
if root != types.EmptyRootHash {
if err := triedb.Commit(root, true, nil); err != nil {
return err
}
}
// Marshal the genesis state specification and persist.
blob, err := json.Marshal(ga)
if err != nil {
return err
}
rawdb.WriteGenesisStateSpec(db, root, blob)
return nil
}
// CommitGenesisState loads the stored genesis state with the given block
// hash and commits it into the provided trie database.
func CommitGenesisState(db ethdb.Database, triedb *trie.Database, hash common.Hash) error {
var alloc GenesisAlloc
blob := rawdb.ReadGenesisStateSpec(db, hash)
if len(blob) != 0 {
if err := alloc.UnmarshalJSON(blob); err != nil {
return err
}
} else {
// Genesis allocation is missing and there are several possibilities:
// the node is legacy which doesn't persist the genesis allocation or
// the persisted allocation is just lost.
// - supported networks(mainnet, testnets), recover with defined allocations
// - private network, can't recover
var genesis *Genesis
switch hash {
case params.MainnetGenesisHash:
genesis = DefaultGenesisBlock()
case params.RopstenGenesisHash:
genesis = DefaultRopstenGenesisBlock()
case params.RinkebyGenesisHash:
genesis = DefaultRinkebyGenesisBlock()
case params.GoerliGenesisHash:
genesis = DefaultGoerliGenesisBlock()
case params.SepoliaGenesisHash:
genesis = DefaultSepoliaGenesisBlock()
}
if genesis != nil {
alloc = genesis.Alloc
} else {
return errors.New("not found")
}
}
return alloc.flush(db, triedb)
}
// GenesisAccount is an account in the state of the genesis block.
type GenesisAccount struct {
Code []byte `json:"code,omitempty"`
Storage map[common.Hash]common.Hash `json:"storage,omitempty"`
Balance *big.Int `json:"balance" gencodec:"required"`
Nonce uint64 `json:"nonce,omitempty"`
PrivateKey []byte `json:"secretKey,omitempty"` // for tests
}
// field type overrides for gencodec
type genesisSpecMarshaling struct {
Nonce math.HexOrDecimal64
Timestamp math.HexOrDecimal64
ExtraData hexutil.Bytes
GasLimit math.HexOrDecimal64
GasUsed math.HexOrDecimal64
Number math.HexOrDecimal64
Difficulty *math.HexOrDecimal256
BaseFee *math.HexOrDecimal256
Alloc map[common.UnprefixedAddress]GenesisAccount
}
type genesisAccountMarshaling struct {
Code hexutil.Bytes
Balance *math.HexOrDecimal256
Nonce math.HexOrDecimal64
Storage map[storageJSON]storageJSON
PrivateKey hexutil.Bytes
}
// storageJSON represents a 256 bit byte array, but allows less than 256 bits when
// unmarshaling from hex.
type storageJSON common.Hash
func (h *storageJSON) UnmarshalText(text []byte) error {
text = bytes.TrimPrefix(text, []byte("0x"))
if len(text) > 64 {
return fmt.Errorf("too many hex characters in storage key/value %q", text)
}
offset := len(h) - len(text)/2 // pad on the left
if _, err := hex.Decode(h[offset:], text); err != nil {
return fmt.Errorf("invalid hex storage key/value %q", text)
}
return nil
}
func (h storageJSON) MarshalText() ([]byte, error) {
return hexutil.Bytes(h[:]).MarshalText()
}
// GenesisMismatchError is raised when trying to overwrite an existing
// genesis block with an incompatible one.
type GenesisMismatchError struct {
Stored, New common.Hash
}
func (e *GenesisMismatchError) Error() string {
return fmt.Sprintf("database contains incompatible genesis (have %x, new %x)", e.Stored, e.New)
}
// ChainOverrides contains the changes to chain config.
type ChainOverrides struct {
OverrideTerminalTotalDifficulty *big.Int
OverrideTerminalTotalDifficultyPassed *bool
}
// SetupGenesisBlock writes or updates the genesis block in db.
// The block that will be used is:
//
// genesis == nil genesis != nil
// +------------------------------------------
// db has no genesis | main-net default | genesis
// db has genesis | from DB | genesis (if compatible)
//
// The stored chain configuration will be updated if it is compatible (i.e. does not
// specify a fork block below the local head block). In case of a conflict, the
// error is a *params.ConfigCompatError and the new, unwritten config is returned.
//
// The returned chain configuration is never nil.
func SetupGenesisBlock(db ethdb.Database, triedb *trie.Database, genesis *Genesis) (*params.ChainConfig, common.Hash, error) {
return SetupGenesisBlockWithOverride(db, triedb, genesis, nil)
}
func SetupGenesisBlockWithOverride(db ethdb.Database, triedb *trie.Database, genesis *Genesis, overrides *ChainOverrides) (*params.ChainConfig, common.Hash, error) {
if genesis != nil && genesis.Config == nil {
return params.AllEthashProtocolChanges, common.Hash{}, errGenesisNoConfig
}
applyOverrides := func(config *params.ChainConfig) {
if config != nil {
if overrides != nil && overrides.OverrideTerminalTotalDifficulty != nil {
config.TerminalTotalDifficulty = overrides.OverrideTerminalTotalDifficulty
}
if overrides != nil && overrides.OverrideTerminalTotalDifficultyPassed != nil {
config.TerminalTotalDifficultyPassed = *overrides.OverrideTerminalTotalDifficultyPassed
}
}
}
// Just commit the new block if there is no stored genesis block.
stored := rawdb.ReadCanonicalHash(db, 0)
if (stored == common.Hash{}) {
if genesis == nil {
log.Info("Writing default main-net genesis block")
genesis = DefaultGenesisBlock()
} else {
log.Info("Writing custom genesis block")
}
block, err := genesis.Commit(db, triedb)
if err != nil {
return genesis.Config, common.Hash{}, err
}
applyOverrides(genesis.Config)
return genesis.Config, block.Hash(), nil
}
// We have the genesis block in database(perhaps in ancient database)
// but the corresponding state is missing.
header := rawdb.ReadHeader(db, stored, 0)
if _, err := state.New(header.Root, state.NewDatabaseWithNodeDB(db, triedb), nil); err != nil {
if genesis == nil {
genesis = DefaultGenesisBlock()
}
// Ensure the stored genesis matches with the given one.
hash := genesis.ToBlock().Hash()
if hash != stored {
return genesis.Config, hash, &GenesisMismatchError{stored, hash}
}
block, err := genesis.Commit(db, triedb)
if err != nil {
return genesis.Config, hash, err
}
applyOverrides(genesis.Config)
return genesis.Config, block.Hash(), nil
}
// Check whether the genesis block is already written.
if genesis != nil {
hash := genesis.ToBlock().Hash()
if hash != stored {
return genesis.Config, hash, &GenesisMismatchError{stored, hash}
}
}
// Get the existing chain configuration.
newcfg := genesis.configOrDefault(stored)
applyOverrides(newcfg)
if err := newcfg.CheckConfigForkOrder(); err != nil {
return newcfg, common.Hash{}, err
}
storedcfg := rawdb.ReadChainConfig(db, stored)
if storedcfg == nil {
log.Warn("Found genesis block without chain config")
rawdb.WriteChainConfig(db, stored, newcfg)
return newcfg, stored, nil
}
storedData, _ := json.Marshal(storedcfg)
// Special case: if a private network is being used (no genesis and also no
// mainnet hash in the database), we must not apply the `configOrDefault`
// chain config as that would be AllProtocolChanges (applying any new fork
// on top of an existing private network genesis block). In that case, only
// apply the overrides.
if genesis == nil && stored != params.MainnetGenesisHash {
newcfg = storedcfg
applyOverrides(newcfg)
}
// Check config compatibility and write the config. Compatibility errors
// are returned to the caller unless we're already at block zero.
height := rawdb.ReadHeaderNumber(db, rawdb.ReadHeadHeaderHash(db))
if height == nil {
return newcfg, stored, fmt.Errorf("missing block number for head header hash")
}
compatErr := storedcfg.CheckCompatible(newcfg, *height)
if compatErr != nil && *height != 0 && compatErr.RewindTo != 0 {
return newcfg, stored, compatErr
}
// Don't overwrite if the old is identical to the new
if newData, _ := json.Marshal(newcfg); !bytes.Equal(storedData, newData) {
rawdb.WriteChainConfig(db, stored, newcfg)
}
return newcfg, stored, nil
}
// LoadCliqueConfig loads the stored clique config if the chain config
// is already present in database, otherwise, return the config in the
// provided genesis specification. Note the returned clique config can
// be nil if we are not in the clique network.
func LoadCliqueConfig(db ethdb.Database, genesis *Genesis) (*params.CliqueConfig, error) {
// Load the stored chain config from the database. It can be nil
// in case the database is empty. Notably, we only care about the
// chain config corresponds to the canonical chain.
stored := rawdb.ReadCanonicalHash(db, 0)
if stored != (common.Hash{}) {
storedcfg := rawdb.ReadChainConfig(db, stored)
if storedcfg != nil {
return storedcfg.Clique, nil
}
}
// Load the clique config from the provided genesis specification.
if genesis != nil {
// Reject invalid genesis spec without valid chain config
if genesis.Config == nil {
return nil, errGenesisNoConfig
}
// If the canonical genesis header is present, but the chain
// config is missing(initialize the empty leveldb with an
// external ancient chain segment), ensure the provided genesis
// is matched.
if stored != (common.Hash{}) && genesis.ToBlock().Hash() != stored {
return nil, &GenesisMismatchError{stored, genesis.ToBlock().Hash()}
}
return genesis.Config.Clique, nil
}
// There is no stored chain config and no new config provided,
// In this case the default chain config(mainnet) will be used,
// namely ethash is the specified consensus engine, return nil.
return nil, nil
}
func (g *Genesis) configOrDefault(ghash common.Hash) *params.ChainConfig {
switch {
case g != nil:
return g.Config
case ghash == params.MainnetGenesisHash:
return params.MainnetChainConfig
case ghash == params.RopstenGenesisHash:
return params.RopstenChainConfig
case ghash == params.SepoliaGenesisHash:
return params.SepoliaChainConfig
case ghash == params.RinkebyGenesisHash:
return params.RinkebyChainConfig
case ghash == params.GoerliGenesisHash:
return params.GoerliChainConfig
case ghash == params.KilnGenesisHash:
return DefaultKilnGenesisBlock().Config
default:
return params.AllEthashProtocolChanges
}
}
// ToBlock returns the genesis block according to genesis specification.
func (g *Genesis) ToBlock() *types.Block {
root, err := g.Alloc.deriveHash()
if err != nil {
panic(err)
}
head := &types.Header{
Number: new(big.Int).SetUint64(g.Number),
Nonce: types.EncodeNonce(g.Nonce),
Time: g.Timestamp,
ParentHash: g.ParentHash,
Extra: g.ExtraData,
GasLimit: g.GasLimit,
GasUsed: g.GasUsed,
BaseFee: g.BaseFee,
Difficulty: g.Difficulty,
MixDigest: g.Mixhash,
Coinbase: g.Coinbase,
Root: root,
}
if g.GasLimit == 0 {
head.GasLimit = params.GenesisGasLimit
}
if g.Difficulty == nil && g.Mixhash == (common.Hash{}) {
head.Difficulty = params.GenesisDifficulty
}
if g.Config != nil && g.Config.IsLondon(common.Big0) {
if g.BaseFee != nil {
head.BaseFee = g.BaseFee
} else {
head.BaseFee = new(big.Int).SetUint64(params.InitialBaseFee)
}
}
return types.NewBlock(head, nil, nil, nil, trie.NewStackTrie(nil))
}
// Commit writes the block and state of a genesis specification to the database.
// The block is committed as the canonical head block.
func (g *Genesis) Commit(db ethdb.Database, triedb *trie.Database) (*types.Block, error) {
block := g.ToBlock()
if block.Number().Sign() != 0 {
return nil, errors.New("can't commit genesis block with number > 0")
}
config := g.Config
if config == nil {
config = params.AllEthashProtocolChanges
}
if err := config.CheckConfigForkOrder(); err != nil {
return nil, err
}
if config.Clique != nil && len(block.Extra()) < 32+crypto.SignatureLength {
return nil, errors.New("can't start clique chain without signers")
}
// All the checks has passed, flush the states derived from the genesis
// specification as well as the specification itself into the provided
// database.
if err := g.Alloc.flush(db, triedb); err != nil {
return nil, err
}
rawdb.WriteTd(db, block.Hash(), block.NumberU64(), block.Difficulty())
rawdb.WriteBlock(db, block)
rawdb.WriteReceipts(db, block.Hash(), block.NumberU64(), nil)
rawdb.WriteCanonicalHash(db, block.Hash(), block.NumberU64())
rawdb.WriteHeadBlockHash(db, block.Hash())
rawdb.WriteHeadFastBlockHash(db, block.Hash())
rawdb.WriteHeadHeaderHash(db, block.Hash())
rawdb.WriteChainConfig(db, block.Hash(), config)
return block, nil
}
// MustCommit writes the genesis block and state to db, panicking on error.
// The block is committed as the canonical head block.
// Note the state changes will be committed in hash-based scheme, use Commit
// if path-scheme is preferred.
func (g *Genesis) MustCommit(db ethdb.Database) *types.Block {
block, err := g.Commit(db, trie.NewDatabase(db))
if err != nil {
panic(err)
}
return block
}
// DefaultGenesisBlock returns the Ethereum main net genesis block.
func DefaultGenesisBlock() *Genesis {
return &Genesis{
Config: params.MainnetChainConfig,
Nonce: 66,
ExtraData: hexutil.MustDecode("0x11bbe8db4e347b4e8c937c1c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa"),
GasLimit: 5000,
Difficulty: big.NewInt(17179869184),
Alloc: decodePrealloc(mainnetAllocData),
}
}
// DefaultRopstenGenesisBlock returns the Ropsten network genesis block.
func DefaultRopstenGenesisBlock() *Genesis {
return &Genesis{
Config: params.RopstenChainConfig,
Nonce: 66,
ExtraData: hexutil.MustDecode("0x3535353535353535353535353535353535353535353535353535353535353535"),
GasLimit: 16777216,
Difficulty: big.NewInt(1048576),
Alloc: decodePrealloc(ropstenAllocData),
}
}
// DefaultRinkebyGenesisBlock returns the Rinkeby network genesis block.
func DefaultRinkebyGenesisBlock() *Genesis {
return &Genesis{
Config: params.RinkebyChainConfig,
Timestamp: 1492009146,
ExtraData: hexutil.MustDecode("0x52657370656374206d7920617574686f7269746168207e452e436172746d616e42eb768f2244c8811c63729a21a3569731535f067ffc57839b00206d1ad20c69a1981b489f772031b279182d99e65703f0076e4812653aab85fca0f00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
GasLimit: 4700000,
Difficulty: big.NewInt(1),
Alloc: decodePrealloc(rinkebyAllocData),
}
}
// DefaultGoerliGenesisBlock returns the Görli network genesis block.
func DefaultGoerliGenesisBlock() *Genesis {
return &Genesis{
Config: params.GoerliChainConfig,
Timestamp: 1548854791,
ExtraData: hexutil.MustDecode("0x22466c6578692069732061207468696e6722202d204166726900000000000000e0a2bd4258d2768837baa26a28fe71dc079f84c70000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
GasLimit: 10485760,
Difficulty: big.NewInt(1),
Alloc: decodePrealloc(goerliAllocData),
}
}
// DefaultSepoliaGenesisBlock returns the Sepolia network genesis block.
func DefaultSepoliaGenesisBlock() *Genesis {
return &Genesis{
Config: params.SepoliaChainConfig,
Nonce: 0,
ExtraData: []byte("Sepolia, Athens, Attica, Greece!"),
GasLimit: 0x1c9c380,
Difficulty: big.NewInt(0x20000),
Timestamp: 1633267481,
Alloc: decodePrealloc(sepoliaAllocData),
}
}
// DefaultKilnGenesisBlock returns the kiln network genesis block.
func DefaultKilnGenesisBlock() *Genesis {
g := new(Genesis)
reader := strings.NewReader(KilnAllocData)
if err := json.NewDecoder(reader).Decode(g); err != nil {
panic(err)
}
return g
}
// DeveloperGenesisBlock returns the 'geth --dev' genesis block.
func DeveloperGenesisBlock(period uint64, gasLimit uint64, faucet common.Address) *Genesis {
// Override the default period to the user requested one
config := *params.AllCliqueProtocolChanges
config.Clique = &params.CliqueConfig{
Period: period,
Epoch: config.Clique.Epoch,
}
// Assemble and return the genesis with the precompiles and faucet pre-funded
return &Genesis{
Config: &config,
ExtraData: append(append(make([]byte, 32), faucet[:]...), make([]byte, crypto.SignatureLength)...),
GasLimit: gasLimit,
BaseFee: big.NewInt(params.InitialBaseFee),
Difficulty: big.NewInt(1),
Alloc: map[common.Address]GenesisAccount{
common.BytesToAddress([]byte{1}): {Balance: big.NewInt(1)}, // ECRecover
common.BytesToAddress([]byte{2}): {Balance: big.NewInt(1)}, // SHA256
common.BytesToAddress([]byte{3}): {Balance: big.NewInt(1)}, // RIPEMD
common.BytesToAddress([]byte{4}): {Balance: big.NewInt(1)}, // Identity
common.BytesToAddress([]byte{5}): {Balance: big.NewInt(1)}, // ModExp
common.BytesToAddress([]byte{6}): {Balance: big.NewInt(1)}, // ECAdd
common.BytesToAddress([]byte{7}): {Balance: big.NewInt(1)}, // ECScalarMul
common.BytesToAddress([]byte{8}): {Balance: big.NewInt(1)}, // ECPairing
common.BytesToAddress([]byte{9}): {Balance: big.NewInt(1)}, // BLAKE2b
faucet: {Balance: new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(9))},
},
}
}
func decodePrealloc(data string) GenesisAlloc {
var p []struct{ Addr, Balance *big.Int }
if err := rlp.NewStream(strings.NewReader(data), 0).Decode(&p); err != nil {
panic(err)
}
ga := make(GenesisAlloc, len(p))
for _, account := range p {
ga[common.BigToAddress(account.Addr)] = GenesisAccount{Balance: account.Balance}
}
return ga
}