You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
87 lines
2.1 KiB
87 lines
2.1 KiB
package blockchain
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/sha256"
|
|
"encoding/gob"
|
|
"fmt"
|
|
"log"
|
|
"time"
|
|
)
|
|
|
|
// Block keeps block headers, transactions and signature.
|
|
type Block struct {
|
|
// Header
|
|
Timestamp int64
|
|
PrevBlockHash [32]byte
|
|
Hash [32]byte
|
|
NumTransactions int32
|
|
TransactionIds [][32]byte
|
|
Transactions []*Transaction // Transactions
|
|
|
|
// Signature...
|
|
}
|
|
|
|
// Serialize serializes the block
|
|
func (b *Block) Serialize() []byte {
|
|
var result bytes.Buffer
|
|
encoder := gob.NewEncoder(&result)
|
|
err := encoder.Encode(b)
|
|
if err != nil {
|
|
log.Panic(err)
|
|
}
|
|
return result.Bytes()
|
|
}
|
|
|
|
// DeserializeBlock deserializes a block
|
|
func DeserializeBlock(d []byte) *Block {
|
|
var block Block
|
|
decoder := gob.NewDecoder(bytes.NewReader(d))
|
|
err := decoder.Decode(&block)
|
|
if err != nil {
|
|
log.Panic(err)
|
|
}
|
|
return &block
|
|
}
|
|
|
|
// Used for debuging.
|
|
func (b *Block) String() string {
|
|
res := fmt.Sprintf("Block created at %v\n", b.Timestamp)
|
|
for id, tx := range b.Transactions {
|
|
res += fmt.Sprintf("Transaction %v: %v\n", id, *tx)
|
|
}
|
|
res += fmt.Sprintf("previous blockhash: %v\n", b.PrevBlockHash)
|
|
res += fmt.Sprintf("hash: %v\n", b.Hash)
|
|
return res
|
|
}
|
|
|
|
// HashTransactions returns a hash of the transactions in the block
|
|
func (b *Block) HashTransactions() []byte {
|
|
var txHashes [][]byte
|
|
var txHash [32]byte
|
|
|
|
for _, tx := range b.Transactions {
|
|
txHashes = append(txHashes, tx.ID[:])
|
|
}
|
|
txHash = sha256.Sum256(bytes.Join(txHashes, []byte{}))
|
|
return txHash[:]
|
|
}
|
|
|
|
// NewBlock creates and returns a neew block.
|
|
func NewBlock(transactions []*Transaction, prevBlockHash [32]byte) *Block {
|
|
numTxs := int32(len(transactions))
|
|
var txIds [][32]byte
|
|
|
|
for _, tx := range transactions {
|
|
txIds = append(txIds, tx.ID)
|
|
}
|
|
block := &Block{time.Now().Unix(), prevBlockHash, [32]byte{}, numTxs, txIds, transactions}
|
|
copy(block.Hash[:], block.HashTransactions()[:]) // TODO(Minh): the blockhash should be a hash of everything in the block
|
|
|
|
return block
|
|
}
|
|
|
|
// NewGenesisBlock creates and returns genesis Block.
|
|
func NewGenesisBlock(coinbase *Transaction) *Block {
|
|
return NewBlock([]*Transaction{coinbase}, [32]byte{})
|
|
}
|
|
|