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 R: j& B: P9 h9 s! M7 l8 i& c: \
PrevBlockHash string //上一个区块的hash值
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Hash string //当前区块哈希值
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Data string //区块数据
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}
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//计算Hash) S' c M& F* _2 h
func calculateHash(b *Block) string {6 p2 ]5 \2 A2 O- {. {! H; d/ C
blockData := string(b.Index) + string(b.Timestamp) + b.PrevBlockHash
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hashInBytes := sha256.Sum256([]byte(blockData)); _5 ^0 @0 x+ H- A- g7 e+ y' Y0 q1 J! h
return hex.EncodeToString(hashInBytes[:]). G0 _: r0 d2 U3 h: c7 X, k! m8 U
}

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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! X/ N/ z7 \. F' W. `5 w6 d+ ~0 x
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import (9 j* r- k+ v) E. X( u
"encoding/json"
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"BlockChain/core" }9 L c* Y5 @
"io"
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"net/http"8 J) n/ g* u4 ^& E8 R9 B" D# }5 A% F
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var blockChain *core.BlockChain
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func run() {
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http.HandleFunc("/block_chain/get", blockChainGetHandle)
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http.HandleFunc("/block_chain/write", blockChainWriteHandle). I" K- C; R7 q3 c6 d1 G
http.ListenAndServe(":8332", nil)
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func blockChainGetHandle(w http.ResponseWriter, r *http.Request) {
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bytes, err := json.Marshal(blockChain)
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if err != nil {% N! v; f8 S+ L3 Y1 n# h& H; ~
http.Error(w, err.Error(), http.StatusInternalServerError)( E7 s0 J& i# P0 [" @; F" t
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}
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io.WriteString(w, string(bytes))4 N/ p' n. g' n4 B1 O( F6 s
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func blockChainWriteHandle(w http.ResponseWriter, r *http.Request) {, m8 ^: N2 o% u( o* I0 ?, a/ D
blockData := r.URL.Query().Get("data"). v$ A( X$ g& p% Y% Z
blockChain.SendData(blockData)2 h% n) |4 ^0 r* {
blockChainGetHandle(w, r): D+ A6 ]3 v. n9 o* m' `" R1 E
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func main() {$ m) m f' i% ^7 |/ N$ w
blockChain = core.NewBlockChain()
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run()
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}

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通过两部分代码实现简易区块链的RPC调用