使用go语言编写简易Blockchain实现web调用RPC过程 - 区块链技术 - BitMere

在本机端口进行查询由于是第一次运行该链生成创世区块

通过http实现RPC命令的调用  实现添加块

查询当前所有块的信息

这里只做了两个命令分别是get和write
源代码如下
基础功能的实现

package core
import (
      "crypto/sha256"
      "encoding/hex"
      "time"
)
//定义区块
type Block struct {
      Index       int64  //区块编号

Timestamp int64 //区块时间戳
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PrevBlockHash string //上一个区块的hash值6 r, j9 B& Y( N% Y
Hash string //当前区块哈希值7 h+ O" C' M, z4 o/ B3 v9 R9 R
Data string //区块数据
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//计算Hash
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func calculateHash(b *Block) string {
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blockData := string(b.Index) + string(b.Timestamp) + b.PrevBlockHash
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hashInBytes := sha256.Sum256([]byte(blockData)), y/ T) P9 T; B: k0 f
return hex.EncodeToString(hashInBytes[:])
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}

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//生成新的区块
func GenerateNewBlock(preBlock *Block, data string) *Block {
      newBlock := &Block{}
      newBlock.Index = preBlock.Index + 1
      newBlock.PrevBlockHash = preBlock.Hash
      newBlock.Timestamp = time.Now().Unix()
      newBlock.Hash = calculateHash(newBlock)
      newBlock.Data = data
      return newBlock
}

//生成创始区块
func GenerateGenesisBlock() *Block {
      preBlock := &Block{}
      preBlock.Index = -1
      preBlock.Hash = ""
      return GenerateNewBlock(preBlock, "Genesis Block")
}
将基础功能实现的块进行链接实现blockchain
package core

import (
      "fmt"
      "log"
)

//定义区块链
type BlockChain struct {
      Blocks []*Block
}

//创建一个区块链
func NewBlockChain() *BlockChain {
      genesisBlock := GenerateGenesisBlock()
      blockChain := &BlockChain{}
      blockChain.AppendBlock(genesisBlock)
      return blockChain
}

//记录区块数据
func (bc *BlockChain) SendData(data string) {
      preBlock := bc.Blocks[len(bc.Blocks)-1]
      newBlock := GenerateNewBlock(preBlock, data)
      bc.AppendBlock(newBlock)
}

//往区块链添加区块
func (bc *BlockChain) AppendBlock(newBlock *Block) {
      if len(bc.Blocks) == 0 {
            bc.Blocks = append(bc.Blocks, newBlock)
            return
      }
      if isValid(newBlock, bc.Blocks[len(bc.Blocks)-1]) {
            bc.Blocks = append(bc.Blocks, newBlock)
      } else {
            log.Fatal("invalid block")
      }
      return
}

//输出区块链信息
func (bc *BlockChain) Print() {
      for _, block := range bc.Blocks {
            fmt.Printf("Index : %d\n", block.Index)
            fmt.Printf("Prev.Hash : %s\n", block.PrevBlockHash)
            fmt.Printf("Curr.Hash : %s\n", block.Hash)
            fmt.Printf("Curr.Data : %s\n", block.Data)
            fmt.Printf("Curr.Timestamp : %d\n", block.Timestamp)
            fmt.Println("==========================================")
      }
}

//验证区块
func isValid(newBlock *Block, oldBlock *Block) bool {
      if newBlock.Index-1 != oldBlock.Index {
            return false
      }
      if newBlock.PrevBlockHash != oldBlock.Hash {
            return false
      }
      if calculateHash(newBlock) != newBlock.Hash {
            return false
      }
      return true
}
实现RPC接口的交互

package main
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import (
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"encoding/json", `* y! E& `9 P1 a1 a/ w, U
"BlockChain/core"
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"io"# w! P8 ^ `/ G! o ~! ~' O9 r, r/ P% i
"net/http"
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var blockChain *core.BlockChain
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func run() {
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http.HandleFunc("/block_chain/get", blockChainGetHandle)/ b0 l) c8 z! m+ U
http.HandleFunc("/block_chain/write", blockChainWriteHandle)/ P9 p/ V+ c( v1 a
http.ListenAndServe(":8332", nil)4 l: L) u7 q: B1 d( E9 @
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func blockChainGetHandle(w http.ResponseWriter, r *http.Request) {$ w; U( s) s. P l) i. F1 X; {9 s; `
bytes, err := json.Marshal(blockChain). I4 o$ N. o) a$ b+ X
if err != nil {
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http.Error(w, err.Error(), http.StatusInternalServerError)/ Z6 [/ m' o. K8 ~, \7 E
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io.WriteString(w, string(bytes))
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}
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func blockChainWriteHandle(w http.ResponseWriter, r *http.Request) {7 o# y* g. w# d1 B! g5 W+ J9 A
blockData := r.URL.Query().Get("data")' I" r, n1 n4 E
blockChain.SendData(blockData)
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blockChainGetHandle(w, r)
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}
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func main() {! r$ D. I4 ]7 E3 J; l
blockChain = core.NewBlockChain()# o' q Q, d5 A ?; \* q3 p
run()* N! J" s, L9 t) z
}

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通过两部分代码实现简易区块链的RPC调用