区块链GO源码（内有区块、区块链、交易等代码）

package main import ( bolt "boltdb" "fmt" "os" ) const dbFile = "blockChain.db" const blockBucket = "bucket" const lastHashKey = "key" const genesisInfo = "YuanShuai will be a happy boy" type BlockChain struct { //blocks []*Block db *bolt.DB //数据库操作句柄 tail []byte // 最后一个区块哈希值 } //校验文件是否存在 func isDBExit() bool { _, err := os.Stat(dbFile) if os.IsNotExist(err) { return false } return true } //创建blockChain数据库文件 func InitBlockChain(address string) *BlockChain { if isDBExit() { fmt.Println(" blockChain db exit already,shouldn't created") os.Exit(1) } db, err := bolt.Open(dbFile, 0600, nil) //打开bolt数据库 CheckErr("InitBlockChain", err) // (db *DB) Update(fn func(*Tx) error) error { var lastHash []byte db.Update(func(tx *bolt.Tx) error { //没有bucket ，要去创建创世区块，将数据填写到数据库的bucket中 coinbase := NewCoinbaseTx(address, genesisInfo) genesis := NewGenesisBlock(coinbase) bucket, err := tx.CreateBucket([]byte(blockBucket)) CheckErr("InitBlockChain1", err) //写入数据库操作 bucket.Put(genesis.Hash, genesis.Serialize()) CheckErr("InitBlockChain2", err) bucket.Put([]byte(lastHashKey), genesis.Hash) CheckErr("InitBlockChain3", err) lastHash = genesis.Hash return nil }) return &BlockChain{db, lastHash} } func GetBlockChainHandler() *BlockChain { if !isDBExit() { fmt.Println("Pls create blockChain db") os.Exit(1) } db, err := bolt.Open(dbFile, 0600, nil) //打开bolt数据库 CheckErr("NewBlockChain1", err) var lastHash []byte db.View(func(tx *bolt.Tx) error { bucket := tx.Bucket([]byte(blockBucket)) if bucket != nil { //取出最后区块的哈希值 lastHash = bucket.Get([]byte(lastHashKey)) } return nil }) return &BlockChain{db, lastHash} } func (bc *BlockChain) AddBlock(txs []*Transaction) { //preBlockHash := bc.blocks[len(bc.blocks)-1].Hash //block := NewBlock(data ,preBlockHash) //bc.blocks =append(bc.blocks,block) var prevBlockHash []byte bc.db.View(func(tx *bolt.Tx) error { bucket := tx.Bucket([]byte(blockBucket)) if bucket == nil { os.Exit(1) } prevBlockHash = bucket.Get([]byte(lastHashKey)) return nil }) block := NewBlock(txs, prevBlockHash) err := bc.db.Update(func(tx *bolt.Tx) error { bucket := tx.Bucket([]byte(blockBucket)) if bucket == nil { os.Exit(1) } err := bucket.Put(block.Hash, block.Serialize()) CheckErr("AddBlock1", err) err = bucket.Put([]byte(lastHashKey), block.Hash) CheckErr("AddBlock2", err) bc.tail = block.Hash return nil }) CheckErr("AddBlock3", err) } //迭代器编写，里面包含了一个游标，一直往前移动，完成整个容器的遍历 type BlockChainIterator struct { currHash []byte db *bolt.DB } //创建迭代器，初始化指向最后一个区块 func (bc *BlockChain) NewIterator() *BlockChainIterator { return &BlockChainIterator{currHash: bc.tail, db: bc.db} } func (it *BlockChainIterator) Next() (block *Block) { err := it.db.View(func(tx *bolt.Tx) error { bucket := tx.Bucket([]byte(blockBucket)) if bucket == nil { return nil } data := bucket.Get(it.currHash) block = Deserialize(data) it.currHash = block.PrevBlockHash return nil }) CheckErr("Next()", err) return } //返回指定地址能否支配的UTXO的交易集合 func (bc *BlockChain) FindUTXOTransactions(address string) []Transaction{ var UTXOTransactions []Transaction //包含目标utxo的交易集合 //存储使用过的utxo的集合 map[交易id] []int64(0x1111111:0,1，都是给Alice转账) spentUTXO := make(map[string][]int64) it := bc.NewIterator() for { block := it.Next() //遍历区块 for _, tx := range block.Transactions { //遍历交易 //遍历input，找到已经消耗的utxo，把他们放到一个集合中 //需要两个子弹来标识使用的utxo, 交易ID 和 output 的索引 if !tx.IsCoinbase() { for _, input := range tx.TXInputs { if input.CanUnlockUTXOWith(address) { //map[txid][]int64 spentUTXO[string(input.TXID)] = append(spentUTXO[string(input.TXID)], input.Vout) } } } OUTPUTS: for currIndex, output := range tx.TXOutputs { //遍历output，找到所有可以支配的utxo //检查当前的output是否已经被消耗，如果消耗，那么进行下一个output的校验 if spentUTXO[string(tx.TXID)] != nil { //非空，代表当前交易里有消耗的utxo indexes := spentUTXO[string(tx.TXID)] for _, index := range indexes { //当前的索引和消耗的索引比较，相同，表明这个output肯定被消耗了，直接跳过，进行下一个output判断 if int64(currIndex) == index { continue OUTPUTS } } } if output.CanBeUnlockedWith(address) { //如果当前地址是这个utxo的所有者，满足条件 UTXOTransactions = append(UTXOTransactions, *tx) } } } if len(block.PrevBlockHash) == 0 { break } } return UTXOTransactions } func (bc *BlockChain)FindUTXO(address string) []TXOutput{ var UTXOs []TXOutput txs := bc.FindUTXOTransactions(address) for _,tx := range txs{ //遍历交易 for _,utxo :=range tx.TXOutputs{ // 遍历output if utxo.CanBeUnlockedWith(address){ UTXOs = append(UTXOs ,utxo) } } } return UTXOs } //validUTXOs,total = bc.FindSuitableUTXOs(from , amount) func (bc *BlockChain)FindSuitableUTXOs(address string , amount float64)(map[string][]int64,float64){ txs := bc.FindUTXOTransactions(address) validUTXOs :=make(map[string][]int64) //遍历交易 var total float64 FIND: for _,tx :=range txs{ outputs := tx.TXOutputs //遍历outputs (utxo) for index,output := range outputs{ if output.CanBeUnlockedWith(address){ if total <amount{ //判断当前收集的utxo的总金额是否大于需要花费的金额 total +=output.Value validUTXOs[string(tx.TXID)] = append(validUTXOs[string(tx.TXID)],int64(index)) }else { break FIND } } } } return validUTXOs,total }