neo-go/pkg/core/block/block.go

237 lines
5.7 KiB
Go

package block
import (
"encoding/json"
"errors"
"github.com/Workiva/go-datastructures/queue"
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/nspcc-dev/neo-go/pkg/util"
)
// Block represents one block in the chain.
type Block struct {
// The base of the block.
Base
// Primary index and nonce
ConsensusData ConsensusData `json:"consensus_data"`
// Transaction list.
Transactions []*transaction.Transaction
// True if this block is created from trimmed data.
Trimmed bool
}
// auxBlock is used for JSON i/o.
type auxBlock struct {
ConsensusData ConsensusData `json:"consensus_data"`
Transactions []*transaction.Transaction `json:"tx"`
}
// Header returns the Header of the Block.
func (b *Block) Header() *Header {
return &Header{
Base: b.Base,
}
}
// computeMerkleTree computes Merkle tree based on actual block's data.
func (b *Block) computeMerkleTree() (*hash.MerkleTree, error) {
hashes := make([]util.Uint256, len(b.Transactions)+1)
hashes[0] = b.ConsensusData.Hash()
for i, tx := range b.Transactions {
hashes[i+1] = tx.Hash()
}
return hash.NewMerkleTree(hashes)
}
// RebuildMerkleRoot rebuilds the merkleroot of the block.
func (b *Block) RebuildMerkleRoot() error {
merkle, err := b.computeMerkleTree()
if err != nil {
return err
}
b.MerkleRoot = merkle.Root()
return nil
}
// Verify verifies the integrity of the block.
func (b *Block) Verify() error {
if b.Transactions != nil {
hashes := map[util.Uint256]bool{}
for _, tx := range b.Transactions {
if !hashes[tx.Hash()] {
hashes[tx.Hash()] = true
} else {
return errors.New("transaction duplication is not allowed")
}
}
}
merkle, err := b.computeMerkleTree()
if err != nil {
return err
}
if !b.MerkleRoot.Equals(merkle.Root()) {
return errors.New("MerkleRoot mismatch")
}
return nil
}
// NewBlockFromTrimmedBytes returns a new block from trimmed data.
// This is commonly used to create a block from stored data.
// Blocks created from trimmed data will have their Trimmed field
// set to true.
func NewBlockFromTrimmedBytes(b []byte) (*Block, error) {
block := &Block{
Trimmed: true,
}
br := io.NewBinReaderFromBuf(b)
block.decodeHashableFields(br)
_ = br.ReadB()
block.Script.DecodeBinary(br)
lenHashes := br.ReadVarUint()
if lenHashes > 0 {
var consensusDataHash util.Uint256
consensusDataHash.DecodeBinary(br)
lenTX := lenHashes - 1
block.Transactions = make([]*transaction.Transaction, lenTX)
for i := 0; i < int(lenTX); i++ {
var hash util.Uint256
hash.DecodeBinary(br)
block.Transactions[i] = transaction.NewTrimmedTX(hash)
}
block.ConsensusData.DecodeBinary(br)
}
return block, br.Err
}
// Trim returns a subset of the block data to save up space
// in storage.
// Notice that only the hashes of the transactions are stored.
func (b *Block) Trim() ([]byte, error) {
buf := io.NewBufBinWriter()
b.encodeHashableFields(buf.BinWriter)
buf.WriteB(1)
b.Script.EncodeBinary(buf.BinWriter)
buf.WriteVarUint(uint64(len(b.Transactions)) + 1)
hash := b.ConsensusData.Hash()
hash.EncodeBinary(buf.BinWriter)
for _, tx := range b.Transactions {
h := tx.Hash()
h.EncodeBinary(buf.BinWriter)
}
b.ConsensusData.EncodeBinary(buf.BinWriter)
if buf.Err != nil {
return nil, buf.Err
}
return buf.Bytes(), nil
}
// DecodeBinary decodes the block from the given BinReader, implementing
// Serializable interface.
func (b *Block) DecodeBinary(br *io.BinReader) {
b.Base.DecodeBinary(br)
contentsCount := br.ReadVarUint()
if contentsCount == 0 {
br.Err = errors.New("invalid block format")
return
}
b.ConsensusData.DecodeBinary(br)
txes := make([]*transaction.Transaction, contentsCount-1)
for i := 0; i < int(contentsCount)-1; i++ {
tx := new(transaction.Transaction)
tx.DecodeBinary(br)
txes[i] = tx
}
b.Transactions = txes
if br.Err != nil {
return
}
br.Err = b.Verify()
}
// EncodeBinary encodes the block to the given BinWriter, implementing
// Serializable interface.
func (b *Block) EncodeBinary(bw *io.BinWriter) {
b.Base.EncodeBinary(bw)
bw.WriteVarUint(uint64(len(b.Transactions) + 1))
b.ConsensusData.EncodeBinary(bw)
for i := 0; i < len(b.Transactions); i++ {
b.Transactions[i].EncodeBinary(bw)
}
}
// Compare implements the queue Item interface.
func (b *Block) Compare(item queue.Item) int {
other := item.(*Block)
switch {
case b.Index > other.Index:
return 1
case b.Index == other.Index:
return 0
default:
return -1
}
}
// MarshalJSON implements json.Marshaler interface.
func (b Block) MarshalJSON() ([]byte, error) {
auxb, err := json.Marshal(auxBlock{
ConsensusData: b.ConsensusData,
Transactions: b.Transactions,
})
if err != nil {
return nil, err
}
baseBytes, err := json.Marshal(b.Base)
if err != nil {
return nil, err
}
// Stitch them together.
if baseBytes[len(baseBytes)-1] != '}' || auxb[0] != '{' {
return nil, errors.New("can't merge internal jsons")
}
baseBytes[len(baseBytes)-1] = ','
baseBytes = append(baseBytes, auxb[1:]...)
return baseBytes, nil
}
// UnmarshalJSON implements json.Unmarshaler interface.
func (b *Block) UnmarshalJSON(data []byte) error {
// As Base and auxb are at the same level in json,
// do unmarshalling separately for both structs.
auxb := new(auxBlock)
err := json.Unmarshal(data, auxb)
if err != nil {
return err
}
base := new(Base)
err = json.Unmarshal(data, base)
if err != nil {
return err
}
b.Base = *base
b.Transactions = auxb.Transactions
b.ConsensusData = auxb.ConsensusData
// Some tests rely on hash presence and we're usually precomputing
// other hashes upon deserialization.
_ = b.ConsensusData.Hash()
return nil
}