564 lines
18 KiB
Go
564 lines
18 KiB
Go
// Copyright 2015 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/binary"
|
|
"encoding/json"
|
|
"fmt"
|
|
"math/big"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/core/types"
|
|
"github.com/ethereum/go-ethereum/ethdb"
|
|
"github.com/ethereum/go-ethereum/logger"
|
|
"github.com/ethereum/go-ethereum/logger/glog"
|
|
"github.com/ethereum/go-ethereum/rlp"
|
|
)
|
|
|
|
var (
|
|
headHeaderKey = []byte("LastHeader")
|
|
headBlockKey = []byte("LastBlock")
|
|
headFastKey = []byte("LastFast")
|
|
|
|
blockPrefix = []byte("block-")
|
|
blockNumPrefix = []byte("block-num-")
|
|
|
|
headerSuffix = []byte("-header")
|
|
bodySuffix = []byte("-body")
|
|
tdSuffix = []byte("-td")
|
|
|
|
txMetaSuffix = []byte{0x01}
|
|
receiptsPrefix = []byte("receipts-")
|
|
blockReceiptsPrefix = []byte("receipts-block-")
|
|
|
|
mipmapPre = []byte("mipmap-log-bloom-")
|
|
MIPMapLevels = []uint64{1000000, 500000, 100000, 50000, 1000}
|
|
|
|
blockHashPrefix = []byte("block-hash-") // [deprecated by the header/block split, remove eventually]
|
|
|
|
configPrefix = []byte("ethereum-config-") // config prefix for the db
|
|
)
|
|
|
|
// GetCanonicalHash retrieves a hash assigned to a canonical block number.
|
|
func GetCanonicalHash(db ethdb.Database, number uint64) common.Hash {
|
|
data, _ := db.Get(append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...))
|
|
if len(data) == 0 {
|
|
return common.Hash{}
|
|
}
|
|
return common.BytesToHash(data)
|
|
}
|
|
|
|
// GetHeadHeaderHash retrieves the hash of the current canonical head block's
|
|
// header. The difference between this and GetHeadBlockHash is that whereas the
|
|
// last block hash is only updated upon a full block import, the last header
|
|
// hash is updated already at header import, allowing head tracking for the
|
|
// light synchronization mechanism.
|
|
func GetHeadHeaderHash(db ethdb.Database) common.Hash {
|
|
data, _ := db.Get(headHeaderKey)
|
|
if len(data) == 0 {
|
|
return common.Hash{}
|
|
}
|
|
return common.BytesToHash(data)
|
|
}
|
|
|
|
// GetHeadBlockHash retrieves the hash of the current canonical head block.
|
|
func GetHeadBlockHash(db ethdb.Database) common.Hash {
|
|
data, _ := db.Get(headBlockKey)
|
|
if len(data) == 0 {
|
|
return common.Hash{}
|
|
}
|
|
return common.BytesToHash(data)
|
|
}
|
|
|
|
// GetHeadFastBlockHash retrieves the hash of the current canonical head block during
|
|
// fast synchronization. The difference between this and GetHeadBlockHash is that
|
|
// whereas the last block hash is only updated upon a full block import, the last
|
|
// fast hash is updated when importing pre-processed blocks.
|
|
func GetHeadFastBlockHash(db ethdb.Database) common.Hash {
|
|
data, _ := db.Get(headFastKey)
|
|
if len(data) == 0 {
|
|
return common.Hash{}
|
|
}
|
|
return common.BytesToHash(data)
|
|
}
|
|
|
|
// GetHeaderRLP retrieves a block header in its raw RLP database encoding, or nil
|
|
// if the header's not found.
|
|
func GetHeaderRLP(db ethdb.Database, hash common.Hash) rlp.RawValue {
|
|
data, _ := db.Get(append(append(blockPrefix, hash[:]...), headerSuffix...))
|
|
return data
|
|
}
|
|
|
|
// GetHeader retrieves the block header corresponding to the hash, nil if none
|
|
// found.
|
|
func GetHeader(db ethdb.Database, hash common.Hash) *types.Header {
|
|
data := GetHeaderRLP(db, hash)
|
|
if len(data) == 0 {
|
|
return nil
|
|
}
|
|
header := new(types.Header)
|
|
if err := rlp.Decode(bytes.NewReader(data), header); err != nil {
|
|
glog.V(logger.Error).Infof("invalid block header RLP for hash %x: %v", hash, err)
|
|
return nil
|
|
}
|
|
return header
|
|
}
|
|
|
|
// GetBodyRLP retrieves the block body (transactions and uncles) in RLP encoding.
|
|
func GetBodyRLP(db ethdb.Database, hash common.Hash) rlp.RawValue {
|
|
data, _ := db.Get(append(append(blockPrefix, hash[:]...), bodySuffix...))
|
|
return data
|
|
}
|
|
|
|
// GetBody retrieves the block body (transactons, uncles) corresponding to the
|
|
// hash, nil if none found.
|
|
func GetBody(db ethdb.Database, hash common.Hash) *types.Body {
|
|
data := GetBodyRLP(db, hash)
|
|
if len(data) == 0 {
|
|
return nil
|
|
}
|
|
body := new(types.Body)
|
|
if err := rlp.Decode(bytes.NewReader(data), body); err != nil {
|
|
glog.V(logger.Error).Infof("invalid block body RLP for hash %x: %v", hash, err)
|
|
return nil
|
|
}
|
|
return body
|
|
}
|
|
|
|
// GetTd retrieves a block's total difficulty corresponding to the hash, nil if
|
|
// none found.
|
|
func GetTd(db ethdb.Database, hash common.Hash) *big.Int {
|
|
data, _ := db.Get(append(append(blockPrefix, hash.Bytes()...), tdSuffix...))
|
|
if len(data) == 0 {
|
|
return nil
|
|
}
|
|
td := new(big.Int)
|
|
if err := rlp.Decode(bytes.NewReader(data), td); err != nil {
|
|
glog.V(logger.Error).Infof("invalid block total difficulty RLP for hash %x: %v", hash, err)
|
|
return nil
|
|
}
|
|
return td
|
|
}
|
|
|
|
// GetBlock retrieves an entire block corresponding to the hash, assembling it
|
|
// back from the stored header and body.
|
|
func GetBlock(db ethdb.Database, hash common.Hash) *types.Block {
|
|
// Retrieve the block header and body contents
|
|
header := GetHeader(db, hash)
|
|
if header == nil {
|
|
return nil
|
|
}
|
|
body := GetBody(db, hash)
|
|
if body == nil {
|
|
return nil
|
|
}
|
|
// Reassemble the block and return
|
|
return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles)
|
|
}
|
|
|
|
// GetBlockReceipts retrieves the receipts generated by the transactions included
|
|
// in a block given by its hash.
|
|
func GetBlockReceipts(db ethdb.Database, hash common.Hash) types.Receipts {
|
|
data, _ := db.Get(append(blockReceiptsPrefix, hash[:]...))
|
|
if len(data) == 0 {
|
|
return nil
|
|
}
|
|
storageReceipts := []*types.ReceiptForStorage{}
|
|
if err := rlp.DecodeBytes(data, &storageReceipts); err != nil {
|
|
glog.V(logger.Error).Infof("invalid receipt array RLP for hash %x: %v", hash, err)
|
|
return nil
|
|
}
|
|
receipts := make(types.Receipts, len(storageReceipts))
|
|
for i, receipt := range storageReceipts {
|
|
receipts[i] = (*types.Receipt)(receipt)
|
|
}
|
|
return receipts
|
|
}
|
|
|
|
// GetTransaction retrieves a specific transaction from the database, along with
|
|
// its added positional metadata.
|
|
func GetTransaction(db ethdb.Database, hash common.Hash) (*types.Transaction, common.Hash, uint64, uint64) {
|
|
// Retrieve the transaction itself from the database
|
|
data, _ := db.Get(hash.Bytes())
|
|
if len(data) == 0 {
|
|
return nil, common.Hash{}, 0, 0
|
|
}
|
|
var tx types.Transaction
|
|
if err := rlp.DecodeBytes(data, &tx); err != nil {
|
|
return nil, common.Hash{}, 0, 0
|
|
}
|
|
// Retrieve the blockchain positional metadata
|
|
data, _ = db.Get(append(hash.Bytes(), txMetaSuffix...))
|
|
if len(data) == 0 {
|
|
return nil, common.Hash{}, 0, 0
|
|
}
|
|
var meta struct {
|
|
BlockHash common.Hash
|
|
BlockIndex uint64
|
|
Index uint64
|
|
}
|
|
if err := rlp.DecodeBytes(data, &meta); err != nil {
|
|
return nil, common.Hash{}, 0, 0
|
|
}
|
|
return &tx, meta.BlockHash, meta.BlockIndex, meta.Index
|
|
}
|
|
|
|
// GetReceipt returns a receipt by hash
|
|
func GetReceipt(db ethdb.Database, txHash common.Hash) *types.Receipt {
|
|
data, _ := db.Get(append(receiptsPrefix, txHash[:]...))
|
|
if len(data) == 0 {
|
|
return nil
|
|
}
|
|
var receipt types.ReceiptForStorage
|
|
err := rlp.DecodeBytes(data, &receipt)
|
|
if err != nil {
|
|
glog.V(logger.Core).Infoln("GetReceipt err:", err)
|
|
}
|
|
return (*types.Receipt)(&receipt)
|
|
}
|
|
|
|
// WriteCanonicalHash stores the canonical hash for the given block number.
|
|
func WriteCanonicalHash(db ethdb.Database, hash common.Hash, number uint64) error {
|
|
key := append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...)
|
|
if err := db.Put(key, hash.Bytes()); err != nil {
|
|
glog.Fatalf("failed to store number to hash mapping into database: %v", err)
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// WriteHeadHeaderHash stores the head header's hash.
|
|
func WriteHeadHeaderHash(db ethdb.Database, hash common.Hash) error {
|
|
if err := db.Put(headHeaderKey, hash.Bytes()); err != nil {
|
|
glog.Fatalf("failed to store last header's hash into database: %v", err)
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// WriteHeadBlockHash stores the head block's hash.
|
|
func WriteHeadBlockHash(db ethdb.Database, hash common.Hash) error {
|
|
if err := db.Put(headBlockKey, hash.Bytes()); err != nil {
|
|
glog.Fatalf("failed to store last block's hash into database: %v", err)
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// WriteHeadFastBlockHash stores the fast head block's hash.
|
|
func WriteHeadFastBlockHash(db ethdb.Database, hash common.Hash) error {
|
|
if err := db.Put(headFastKey, hash.Bytes()); err != nil {
|
|
glog.Fatalf("failed to store last fast block's hash into database: %v", err)
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// WriteHeader serializes a block header into the database.
|
|
func WriteHeader(db ethdb.Database, header *types.Header) error {
|
|
data, err := rlp.EncodeToBytes(header)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
key := append(append(blockPrefix, header.Hash().Bytes()...), headerSuffix...)
|
|
if err := db.Put(key, data); err != nil {
|
|
glog.Fatalf("failed to store header into database: %v", err)
|
|
return err
|
|
}
|
|
glog.V(logger.Debug).Infof("stored header #%v [%x…]", header.Number, header.Hash().Bytes()[:4])
|
|
return nil
|
|
}
|
|
|
|
// WriteBody serializes the body of a block into the database.
|
|
func WriteBody(db ethdb.Database, hash common.Hash, body *types.Body) error {
|
|
data, err := rlp.EncodeToBytes(body)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
key := append(append(blockPrefix, hash.Bytes()...), bodySuffix...)
|
|
if err := db.Put(key, data); err != nil {
|
|
glog.Fatalf("failed to store block body into database: %v", err)
|
|
return err
|
|
}
|
|
glog.V(logger.Debug).Infof("stored block body [%x…]", hash.Bytes()[:4])
|
|
return nil
|
|
}
|
|
|
|
// WriteTd serializes the total difficulty of a block into the database.
|
|
func WriteTd(db ethdb.Database, hash common.Hash, td *big.Int) error {
|
|
data, err := rlp.EncodeToBytes(td)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
key := append(append(blockPrefix, hash.Bytes()...), tdSuffix...)
|
|
if err := db.Put(key, data); err != nil {
|
|
glog.Fatalf("failed to store block total difficulty into database: %v", err)
|
|
return err
|
|
}
|
|
glog.V(logger.Debug).Infof("stored block total difficulty [%x…]: %v", hash.Bytes()[:4], td)
|
|
return nil
|
|
}
|
|
|
|
// WriteBlock serializes a block into the database, header and body separately.
|
|
func WriteBlock(db ethdb.Database, block *types.Block) error {
|
|
// Store the body first to retain database consistency
|
|
if err := WriteBody(db, block.Hash(), block.Body()); err != nil {
|
|
return err
|
|
}
|
|
// Store the header too, signaling full block ownership
|
|
if err := WriteHeader(db, block.Header()); err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// WriteBlockReceipts stores all the transaction receipts belonging to a block
|
|
// as a single receipt slice. This is used during chain reorganisations for
|
|
// rescheduling dropped transactions.
|
|
func WriteBlockReceipts(db ethdb.Database, hash common.Hash, receipts types.Receipts) error {
|
|
// Convert the receipts into their storage form and serialize them
|
|
storageReceipts := make([]*types.ReceiptForStorage, len(receipts))
|
|
for i, receipt := range receipts {
|
|
storageReceipts[i] = (*types.ReceiptForStorage)(receipt)
|
|
}
|
|
bytes, err := rlp.EncodeToBytes(storageReceipts)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
// Store the flattened receipt slice
|
|
if err := db.Put(append(blockReceiptsPrefix, hash.Bytes()...), bytes); err != nil {
|
|
glog.Fatalf("failed to store block receipts into database: %v", err)
|
|
return err
|
|
}
|
|
glog.V(logger.Debug).Infof("stored block receipts [%x…]", hash.Bytes()[:4])
|
|
return nil
|
|
}
|
|
|
|
// WriteTransactions stores the transactions associated with a specific block
|
|
// into the given database. Beside writing the transaction, the function also
|
|
// stores a metadata entry along with the transaction, detailing the position
|
|
// of this within the blockchain.
|
|
func WriteTransactions(db ethdb.Database, block *types.Block) error {
|
|
batch := db.NewBatch()
|
|
|
|
// Iterate over each transaction and encode it with its metadata
|
|
for i, tx := range block.Transactions() {
|
|
// Encode and queue up the transaction for storage
|
|
data, err := rlp.EncodeToBytes(tx)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := batch.Put(tx.Hash().Bytes(), data); err != nil {
|
|
return err
|
|
}
|
|
// Encode and queue up the transaction metadata for storage
|
|
meta := struct {
|
|
BlockHash common.Hash
|
|
BlockIndex uint64
|
|
Index uint64
|
|
}{
|
|
BlockHash: block.Hash(),
|
|
BlockIndex: block.NumberU64(),
|
|
Index: uint64(i),
|
|
}
|
|
data, err = rlp.EncodeToBytes(meta)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := batch.Put(append(tx.Hash().Bytes(), txMetaSuffix...), data); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
// Write the scheduled data into the database
|
|
if err := batch.Write(); err != nil {
|
|
glog.Fatalf("failed to store transactions into database: %v", err)
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// WriteReceipts stores a batch of transaction receipts into the database.
|
|
func WriteReceipts(db ethdb.Database, receipts types.Receipts) error {
|
|
batch := db.NewBatch()
|
|
|
|
// Iterate over all the receipts and queue them for database injection
|
|
for _, receipt := range receipts {
|
|
storageReceipt := (*types.ReceiptForStorage)(receipt)
|
|
data, err := rlp.EncodeToBytes(storageReceipt)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if err := batch.Put(append(receiptsPrefix, receipt.TxHash.Bytes()...), data); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
// Write the scheduled data into the database
|
|
if err := batch.Write(); err != nil {
|
|
glog.Fatalf("failed to store receipts into database: %v", err)
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// DeleteCanonicalHash removes the number to hash canonical mapping.
|
|
func DeleteCanonicalHash(db ethdb.Database, number uint64) {
|
|
db.Delete(append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...))
|
|
}
|
|
|
|
// DeleteHeader removes all block header data associated with a hash.
|
|
func DeleteHeader(db ethdb.Database, hash common.Hash) {
|
|
db.Delete(append(append(blockPrefix, hash.Bytes()...), headerSuffix...))
|
|
}
|
|
|
|
// DeleteBody removes all block body data associated with a hash.
|
|
func DeleteBody(db ethdb.Database, hash common.Hash) {
|
|
db.Delete(append(append(blockPrefix, hash.Bytes()...), bodySuffix...))
|
|
}
|
|
|
|
// DeleteTd removes all block total difficulty data associated with a hash.
|
|
func DeleteTd(db ethdb.Database, hash common.Hash) {
|
|
db.Delete(append(append(blockPrefix, hash.Bytes()...), tdSuffix...))
|
|
}
|
|
|
|
// DeleteBlock removes all block data associated with a hash.
|
|
func DeleteBlock(db ethdb.Database, hash common.Hash) {
|
|
DeleteBlockReceipts(db, hash)
|
|
DeleteHeader(db, hash)
|
|
DeleteBody(db, hash)
|
|
DeleteTd(db, hash)
|
|
}
|
|
|
|
// DeleteBlockReceipts removes all receipt data associated with a block hash.
|
|
func DeleteBlockReceipts(db ethdb.Database, hash common.Hash) {
|
|
db.Delete(append(blockReceiptsPrefix, hash.Bytes()...))
|
|
}
|
|
|
|
// DeleteTransaction removes all transaction data associated with a hash.
|
|
func DeleteTransaction(db ethdb.Database, hash common.Hash) {
|
|
db.Delete(hash.Bytes())
|
|
db.Delete(append(hash.Bytes(), txMetaSuffix...))
|
|
}
|
|
|
|
// DeleteReceipt removes all receipt data associated with a transaction hash.
|
|
func DeleteReceipt(db ethdb.Database, hash common.Hash) {
|
|
db.Delete(append(receiptsPrefix, hash.Bytes()...))
|
|
}
|
|
|
|
// [deprecated by the header/block split, remove eventually]
|
|
// GetBlockByHashOld returns the old combined block corresponding to the hash
|
|
// or nil if not found. This method is only used by the upgrade mechanism to
|
|
// access the old combined block representation. It will be dropped after the
|
|
// network transitions to eth/63.
|
|
func GetBlockByHashOld(db ethdb.Database, hash common.Hash) *types.Block {
|
|
data, _ := db.Get(append(blockHashPrefix, hash[:]...))
|
|
if len(data) == 0 {
|
|
return nil
|
|
}
|
|
var block types.StorageBlock
|
|
if err := rlp.Decode(bytes.NewReader(data), &block); err != nil {
|
|
glog.V(logger.Error).Infof("invalid block RLP for hash %x: %v", hash, err)
|
|
return nil
|
|
}
|
|
return (*types.Block)(&block)
|
|
}
|
|
|
|
// returns a formatted MIP mapped key by adding prefix, canonical number and level
|
|
//
|
|
// ex. fn(98, 1000) = (prefix || 1000 || 0)
|
|
func mipmapKey(num, level uint64) []byte {
|
|
lkey := make([]byte, 8)
|
|
binary.BigEndian.PutUint64(lkey, level)
|
|
key := new(big.Int).SetUint64(num / level * level)
|
|
|
|
return append(mipmapPre, append(lkey, key.Bytes()...)...)
|
|
}
|
|
|
|
// WriteMapmapBloom writes each address included in the receipts' logs to the
|
|
// MIP bloom bin.
|
|
func WriteMipmapBloom(db ethdb.Database, number uint64, receipts types.Receipts) error {
|
|
batch := db.NewBatch()
|
|
for _, level := range MIPMapLevels {
|
|
key := mipmapKey(number, level)
|
|
bloomDat, _ := db.Get(key)
|
|
bloom := types.BytesToBloom(bloomDat)
|
|
for _, receipt := range receipts {
|
|
for _, log := range receipt.Logs {
|
|
bloom.Add(log.Address.Big())
|
|
}
|
|
}
|
|
batch.Put(key, bloom.Bytes())
|
|
}
|
|
if err := batch.Write(); err != nil {
|
|
return fmt.Errorf("mipmap write fail for: %d: %v", number, err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// GetMipmapBloom returns a bloom filter using the number and level as input
|
|
// parameters. For available levels see MIPMapLevels.
|
|
func GetMipmapBloom(db ethdb.Database, number, level uint64) types.Bloom {
|
|
bloomDat, _ := db.Get(mipmapKey(number, level))
|
|
return types.BytesToBloom(bloomDat)
|
|
}
|
|
|
|
// GetBlockChainVersion reads the version number from db.
|
|
func GetBlockChainVersion(db ethdb.Database) int {
|
|
var vsn uint
|
|
enc, _ := db.Get([]byte("BlockchainVersion"))
|
|
rlp.DecodeBytes(enc, &vsn)
|
|
return int(vsn)
|
|
}
|
|
|
|
// WriteBlockChainVersion writes vsn as the version number to db.
|
|
func WriteBlockChainVersion(db ethdb.Database, vsn int) {
|
|
enc, _ := rlp.EncodeToBytes(uint(vsn))
|
|
db.Put([]byte("BlockchainVersion"), enc)
|
|
}
|
|
|
|
// WriteChainConfig writes the chain config settings to the database.
|
|
func WriteChainConfig(db ethdb.Database, hash common.Hash, cfg *ChainConfig) error {
|
|
// short circuit and ignore if nil config. GetChainConfig
|
|
// will return a default.
|
|
if cfg == nil {
|
|
return nil
|
|
}
|
|
|
|
jsonChainConfig, err := json.Marshal(cfg)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return db.Put(append(configPrefix, hash[:]...), jsonChainConfig)
|
|
}
|
|
|
|
// GetChainConfig will fetch the network settings based on the given hash.
|
|
func GetChainConfig(db ethdb.Database, hash common.Hash) (*ChainConfig, error) {
|
|
jsonChainConfig, _ := db.Get(append(configPrefix, hash[:]...))
|
|
if len(jsonChainConfig) == 0 {
|
|
return nil, ChainConfigNotFoundErr
|
|
}
|
|
|
|
var config ChainConfig
|
|
if err := json.Unmarshal(jsonChainConfig, &config); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &config, nil
|
|
}
|