path: root/core/types/block.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 types contains data types related to Ethereum consensus.
package types

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"io"
	"math/big"
	"reflect"
	"sync"
	"sync/atomic"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/rlp"
	"golang.org/x/crypto/sha3"
)

var (
	EmptyRootHash  = common.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
	EmptyUncleHash = rlpHash([]*Header(nil))
)

// A BlockNonce is a 64-bit hash which proves (combined with the
// mix-hash) that a sufficient amount of computation has been carried
// out on a block.
type BlockNonce [8]byte

// EncodeNonce converts the given integer to a block nonce.
func EncodeNonce(i uint64) BlockNonce {
	var n BlockNonce
	binary.BigEndian.PutUint64(n[:], i)
	return n
}

// Uint64 returns the integer value of a block nonce.
func (n BlockNonce) Uint64() uint64 {
	return binary.BigEndian.Uint64(n[:])
}

// MarshalText encodes n as a hex string with 0x prefix.
func (n BlockNonce) MarshalText() ([]byte, error) {
	return hexutil.Bytes(n[:]).MarshalText()
}

// UnmarshalText implements encoding.TextUnmarshaler.
func (n *BlockNonce) UnmarshalText(input []byte) error {
	return hexutil.UnmarshalFixedText("BlockNonce", input, n[:])
}

//go:generate gencodec -type Header -field-override headerMarshaling -out gen_header_json.go

// Header represents a block header in the Ethereum blockchain.
type Header struct {
	ParentHash  common.Hash    `json:"parentHash"       gencodec:"required"`
	UncleHash   common.Hash    `json:"sha3Uncles"       gencodec:"required"`
	Coinbase    common.Address `json:"miner"            gencodec:"required"`
	Root        common.Hash    `json:"stateRoot"        gencodec:"required"`
	TxHash      common.Hash    `json:"transactionsRoot" gencodec:"required"`
	ReceiptHash common.Hash    `json:"receiptsRoot"     gencodec:"required"`
	Bloom       Bloom          `json:"logsBloom"        gencodec:"required"`
	Difficulty  *big.Int       `json:"difficulty"       gencodec:"required"`
	Number      *big.Int       `json:"number"           gencodec:"required"`
	GasLimit    uint64         `json:"gasLimit"         gencodec:"required"`
	GasUsed     uint64         `json:"gasUsed"          gencodec:"required"`
	Time        uint64         `json:"timestamp"        gencodec:"required"`
	Extra       []byte         `json:"extraData"        gencodec:"required"`
	MixDigest   common.Hash    `json:"mixHash"`
	Nonce       BlockNonce     `json:"nonce"`
	ExtDataHash common.Hash    `json:"extDataHash"		gencodec:"required"`
}

// field type overrides for gencodec
type headerMarshaling struct {
	Difficulty *hexutil.Big
	Number     *hexutil.Big
	GasLimit   hexutil.Uint64
	GasUsed    hexutil.Uint64
	Time       hexutil.Uint64
	Extra      hexutil.Bytes
	Hash       common.Hash `json:"hash"` // adds call to Hash() in MarshalJSON
}

// Hash returns the block hash of the header, which is simply the keccak256 hash of its
// RLP encoding.
func (h *Header) Hash() common.Hash {
	return rlpHash(h)
}

var headerSize = common.StorageSize(reflect.TypeOf(Header{}).Size())

// Size returns the approximate memory used by all internal contents. It is used
// to approximate and limit the memory consumption of various caches.
func (h *Header) Size() common.StorageSize {
	return headerSize + common.StorageSize(len(h.Extra)+(h.Difficulty.BitLen()+h.Number.BitLen())/8)
}

// SanityCheck checks a few basic things -- these checks are way beyond what
// any 'sane' production values should hold, and can mainly be used to prevent
// that the unbounded fields are stuffed with junk data to add processing
// overhead
func (h *Header) SanityCheck() error {
	if h.Number != nil && !h.Number.IsUint64() {
		return fmt.Errorf("too large block number: bitlen %d", h.Number.BitLen())
	}
	if h.Difficulty != nil {
		if diffLen := h.Difficulty.BitLen(); diffLen > 80 {
			return fmt.Errorf("too large block difficulty: bitlen %d", diffLen)
		}
	}
	if eLen := len(h.Extra); eLen > 100*1024 {
		return fmt.Errorf("too large block extradata: size %d", eLen)
	}
	return nil
}

// hasherPool holds LegacyKeccak hashers.
var hasherPool = sync.Pool{
	New: func() interface{} {
		return sha3.NewLegacyKeccak256()
	},
}

func rlpHash(x interface{}) (h common.Hash) {
	sha := hasherPool.Get().(crypto.KeccakState)
	defer hasherPool.Put(sha)
	sha.Reset()
	rlp.Encode(sha, x)
	sha.Read(h[:])
	return h
}

// EmptyBody returns true if there is no additional 'body' to complete the header
// that is: no transactions and no uncles.
func (h *Header) EmptyBody() bool {
	return h.TxHash == EmptyRootHash && h.UncleHash == EmptyUncleHash
}

// EmptyReceipts returns true if there are no receipts for this header/block.
func (h *Header) EmptyReceipts() bool {
	return h.ReceiptHash == EmptyRootHash
}

// Body is a simple (mutable, non-safe) data container for storing and moving
// a block's data contents (transactions and uncles) together.
type Body struct {
	Transactions []*Transaction
	Uncles       []*Header
	Version      uint32
	ExtData      *[]byte `rlp:"nil"`
}

// Block represents an entire block in the Ethereum blockchain.
type Block struct {
	header       *Header
	uncles       []*Header
	transactions Transactions
	version      uint32
	extdata      *[]byte

	// caches
	hash atomic.Value
	size atomic.Value

	// Td is used by package core to store the total difficulty
	// of the chain up to and including the block.
	td *big.Int

	// These fields are used by package eth to track
	// inter-peer block relay.
	ReceivedAt   time.Time
	ReceivedFrom interface{}
}

// DeprecatedTd is an old relic for extracting the TD of a block. It is in the
// code solely to facilitate upgrading the database from the old format to the
// new, after which it should be deleted. Do not use!
func (b *Block) DeprecatedTd() *big.Int {
	return b.td
}

// [deprecated by eth/63]
// StorageBlock defines the RLP encoding of a Block stored in the
// state database. The StorageBlock encoding contains fields that
// would otherwise need to be recomputed.
type StorageBlock Block

// "external" block encoding. used for eth protocol, etc.
type extblock struct {
	Header *Header
	Txs    []*Transaction
	Uncles []*Header
}

type myextblock struct {
	Header  *Header
	Txs     []*Transaction
	Uncles  []*Header
	Version uint32
	ExtData *[]byte `rlp:"nil"`
}

// [deprecated by eth/63]
// "storage" block encoding. used for database.
type storageblock struct {
	Header *Header
	Txs    []*Transaction
	Uncles []*Header
	TD     *big.Int
}

// NewBlock creates a new block. The input data is copied,
// changes to header and to the field values will not affect the
// block.
//
// The values of TxHash, UncleHash, ReceiptHash and Bloom in header
// are ignored and set to values derived from the given txs, uncles
// and receipts.
func NewBlock(header *Header, txs []*Transaction, uncles []*Header, receipts []*Receipt, hasher Hasher, extdata *[]byte) *Block {
	b := &Block{header: CopyHeader(header), td: new(big.Int)}

	// TODO: panic if len(txs) != len(receipts)
	if len(txs) == 0 {
		b.header.TxHash = EmptyRootHash
	} else {
		b.header.TxHash = DeriveSha(Transactions(txs), hasher)
		b.transactions = make(Transactions, len(txs))
		copy(b.transactions, txs)
	}

	if len(receipts) == 0 {
		b.header.ReceiptHash = EmptyRootHash
	} else {
		b.header.ReceiptHash = DeriveSha(Receipts(receipts), hasher)
		b.header.Bloom = CreateBloom(receipts)
	}

	if len(uncles) == 0 {
		b.header.UncleHash = EmptyUncleHash
	} else {
		b.header.UncleHash = CalcUncleHash(uncles)
		b.uncles = make([]*Header, len(uncles))
		for i := range uncles {
			b.uncles[i] = CopyHeader(uncles[i])
		}
	}

	if extdata != nil {
		data := make([]byte, len(*extdata))
		b.extdata = &data
		copy(*b.extdata, *extdata)
	}

	return b
}

// NewBlockWithHeader creates a block with the given header data. The
// header data is copied, changes to header and to the field values
// will not affect the block.
func NewBlockWithHeader(header *Hea