比特币是由C++开发，其他的以太坊、hyperledger等都是用go开发，除了并发优势，在运维上也很方便。下面也是用go作为开发语言。
先实现一个最简单的区块链，其块只包含时间戳、前一个块的HASH,当前块的HASH以及数据。其中HASH由Timestamp +PrevBlockHash +Data 再用SHA-256计算得来。代码如下：
package main
import (
"fmt"
"strconv"
"time"
"bytes"
"crypto/sha256"
)
type Block struct {
Timestamp int64
Data []byte
PrevBlockHash []byte
Hash []byte
}
type Blockchain struct {
blocks []*Block
}
func (b *Block) SetHash() {
timestamp := []byte(strconv.FormatInt(b.Timestamp, 10))
headers := bytes.Join([][]byte{b.PrevBlockHash, b.Data, timestamp}, []byte{})
hash := sha256.Sum256(headers)
b.Hash = hash[:]
}
func NewBlock(data string, prevBlockHash []byte) *Block {
block := &Block{time.Now().Unix(), []byte(data), prevBlockHash, []byte{}}
block.SetHash()
return block
}
func NewGenesisBlock() *Block {
return NewBlock("Genesis Block", []byte{})
}
func NewBlockchain() *Blockchain {
return &Blockchain{[]*Block{NewGenesisBlock()}}
}
func (bc *Blockchain) AddBlock(data string) {
prevBlock := bc.blocks[len(bc.blocks)-1]
newBlock := NewBlock(data, prevBlock.Hash)
bc.blocks = append(bc.blocks, newBlock)
}
func main() {
bc := NewBlockchain()
bc.AddBlock("Send 1 BTC to Ivan")
bc.AddBlock("Send 2 more BTC to Ivan")
for _, block := range bc.blocks {
fmt.Printf("Prev. hash: %x\n", block.PrevBlockHash)
fmt.Printf("Data: %s\n", block.Data)
fmt.Printf("Timestamp: %x\n", block.Timestamp)
fmt.Printf("Hash: %x\n", block.Hash)
fmt.Println()
}
}编译执行后，输出结果如下：
Prev. hash:
Data: Genesis Block
Timestamp: 5a6016f6
Hash: 9ba83b854bdbdb06887b0d070a33d722603c17d4193d28d669ecc0a765ac8d31
Prev. hash: 9ba83b854bdbdb06887b0d070a33d722603c17d4193d28d669ecc0a765ac8d31
Data: Send 1 BTC to Ivan
Timestamp: 5a6016f6
Hash: 6e54323bea1f195df2d7932d6aab12db43925cbc09efe8fd17f059cae74205a7
Prev. hash: 6e54323bea1f195df2d7932d6aab12db43925cbc09efe8fd17f059cae74205a7
Data: Send 2 more BTC to Ivan
Timestamp: 5a6016f6
Hash: 7d3c48b31fb01fd56b64edaa0abec3b48dfc6b920fffac4c5ba49bae4b9d1159
