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' L( G3 y6 u+ \# }2 l2 W' s/ j; I5 j( ?
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& v; c4 g0 Y, V1 I1 Q; |
}
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//计算Hash" `1 ?0 a7 P( L' J; J
func calculateHash(b *Block) string {1 J9 n4 _0 s7 H* | c' m8 v4 l7 G% t
blockData := string(b.Index) + string(b.Timestamp) + b.PrevBlockHash
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hashInBytes := sha256.Sum256([]byte(blockData))
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return hex.EncodeToString(hashInBytes[:])& \- W$ @) T( e
}

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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 main6 c* H6 g+ ?- @ ]$ G
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import (, v: \& x! r6 I/ X0 @
"encoding/json"
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"BlockChain/core"
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"io"7 M3 h! _$ H0 y$ [
"net/http"1 K* P% H$ q2 k- b% u% Z
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var blockChain *core.BlockChain( ^" k, k, ?) Q7 g, _. s5 h) V
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func run() {
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http.HandleFunc("/block_chain/get", blockChainGetHandle)7 a4 _6 [) s) A0 I0 X% ]7 x( Q) r+ C
http.HandleFunc("/block_chain/write", blockChainWriteHandle)" j0 o/ [% g3 b; j* E! p! w
http.ListenAndServe(":8332", nil)/ h& V; a. F7 W' \1 g9 c
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func blockChainGetHandle(w http.ResponseWriter, r *http.Request) {: x/ ?1 V* j2 m) a! D7 @
bytes, err := json.Marshal(blockChain)2 t* d9 a% T T( Z( B
if err != nil {" P( N6 b, Q6 o& k
http.Error(w, err.Error(), http.StatusInternalServerError)4 U5 Y# r& B+ H; g( I
return4 L" w) L* F2 ]( x8 ^+ a3 F9 r
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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) {
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blockData := r.URL.Query().Get("data")
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blockChain.SendData(blockData)) l6 B( G% A& a5 _) Q
blockChainGetHandle(w, r)" f4 D/ x8 q X; X
}
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func main() {
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blockChain = core.NewBlockChain()' x7 i+ V7 r5 e3 R+ h
run()( A+ t3 J, g% g: M* ~
}

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通过两部分代码实现简易区块链的RPC调用