GoLang ブロックチェーン入門: 2 つの主要テクノロジーの相乗効果を明らかにする

import (
    "crypto/sha256"
    "encoding/hex"
    "fmt"
    "time"
)

// Block represents a single block in the blockchain.
type Block struct {
    Index         int64
    Timestamp      int64
    Data          string
    PrevBlockHash string
    Hash          string
}

// Blockchain represents a collection of connected blocks.
type Blockchain struct {
    Blocks []*Block
}

// AddBlock adds a new block to the blockchain.
func (bc *Blockchain) AddBlock(block *Block) {
    if len(bc.Blocks) != 0 {
        block.PrevBlockHash = bc.Blocks[len(bc.Blocks)-1].Hash
    }
    block.Hash = calculateHash(block)
    bc.Blocks = append(bc.Blocks, block)
}

// calculateHash calculates the hash of a block.
func calculateHash(block *Block) string {
    data := fmt.Sprintf("%d%d%s%s", block.Index, block.Timestamp, block.Data, block.PrevBlockHash)
    hash := sha256.New()
    hash.Write([]byte(data))
    return hex.EncodeToString(hash.Sum(nil))
}

func main() {
    bc := &Blockchain{}
    bc.AddBlock(&Block{Index: 0, Timestamp: time.Now().Unix(), Data: "Genesis block"})
    bc.AddBlock(&Block{Index: 1, Timestamp: time.Now().Unix(), Data: "Second block"})

    for _, block := range bc.Blocks {
        fmt.Printf("Block #%d: %x\n", block.Index, block.Hash)
    }
}