从零开发区块链应用(十五)--以太坊交易匹配查询

一、获取区块内交易

1.1 获取最新区块中的交易详情

获取最新区块，放到变量num中

num, err := rc.Client.GetLatestBlockNumber()

获取区块的区块信息，放到变量res中

res, err := rc.Client.GetBlockByNumber(num, true)
if err != nil {
	logger.Error("GetBlockMatchTx", "step", "GetBlockByNumber", "err", err.Error())
	return BlockInfo{}, 0, err
}

定义新的对象，以太坊block结构体已在《从零开发区块链应用(九)》中讲解

block := new(taskcommon.Block)

序列化包含区块信息的resB变量，判断序列号是否出现错误，判断反序列化resB变量是否出现错误

resB, err := json.Marshal(res)
if err != nil {
	logger.Error("GetBlockMatchTx", "step", "Marshal res", "err", err.Error())
	return BlockInfo{}, 0, err
}
if err := json.Unmarshal(resB, &block); err != nil {
	logger.Error("GetBlockMatchTx", "step", "Unmarshal block", "err", err.Error())
	return BlockInfo{}, 0, err
}

延迟函数，在此方法结束后进行执行

defer func() {
	if r := recover(); r != nil {
		//fmt.Printf("捕获到的错误：%s\n", r)
		logger.Error("GetBlockMatchTx", "step", "block info", "panic blockNumber", num, "err", r)
	}
}()

获取所查询的区块高度

bnum, _ := common.HexToInt64(block.Number)

返回区块内交易信息，区块高度，错误信息

return BlockInfo{TxDatas: block.TxDatas}, bnum, nil

完整代码

// GetLastBlockTx 获取区块内匹配的交易
func (rc *RequestChain) GetLastBlockTx() (BlockInfo, int64, error) {
    
	num, err := rc.Client.GetLatestBlockNumber()
	res, err := rc.Client.GetBlockByNumber(num, true)
	if err != nil {
		logger.Error("GetBlockMatchTx", "step", "GetBlockByNumber", "err", err.Error())
		return BlockInfo{}, 0, err
	}
	block := new(taskcommon.Block)
	resB, err := json.Marshal(res)
	if err != nil {
		logger.Error("GetBlockMatchTx", "step", "Marshal res", "err", err.Error())
		return BlockInfo{}, 0, err
	}
	if err := json.Unmarshal(resB, &block); err != nil {
		logger.Error("GetBlockMatchTx", "step", "Unmarshal block", "err", err.Error())
		return BlockInfo{}, 0, err
	}
	defer func() {
		if r := recover(); r != nil {
			//fmt.Printf("捕获到的错误：%s\n", r)
			logger.Error("GetBlockMatchTx", "step", "block info", "panic blockNumber", num, "err", r)
		}
	}()
	bnum, _ := common.HexToInt64(block.Number)
	return BlockInfo{TxDatas: block.TxDatas}, bnum, nil
}

1.2 获取指定区块中的交易详情

获取指定区块交易详情与上面的方法是一样的，区别在于需要指定区块需要有一个区块高度的传参，所以此处不再对代码进行赘述

// GetBlockMatchTx 获取区块内匹配的交易
func (rc *RequestChain) GetBlockMatchTx(blockNumber string) (BlockInfo, error) {
	res, err := rc.Client.GetBlockByNumber(blockNumber, true)
	if err != nil {
		logger.Error("GetBlockMatchTx", "step", "GetBlockByNumber", "err", err.Error())
		return BlockInfo{}, err
	}
	block := new(taskcommon.Block)
	resB, err := json.Marshal(res)
	if err != nil {
		logger.Error("GetBlockMatchTx", "step", "Marshal res", "err", err.Error())
		return BlockInfo{}, err
	}
	if err := json.Unmarshal(resB, &block); err != nil {
		logger.Error("GetBlockMatchTx", "step", "Unmarshal block", "err", err.Error())
		return BlockInfo{}, err
	}
	defer func() {
		if r := recover(); r != nil {
			//fmt.Printf("捕获到的错误：%s\n", r)
			logger.Error("GetBlockMatchTx", "step", "block info", "panic blockNumber", blockNumber)
		}
	}()

	return BlockInfo{TxDatas: block.TxDatas}, nil
}

二、 获取匹配交易回执主要信息

查询某个交易的交易回执信息

// 分析回执
res, err := rc.Client.GetTransactionReceipt(hash)
if err != nil {
	logger.Error("GetMatchBuyTxHashInfo", "step", "GetTransactionReceipt", "hash", hash, "err", err.Error())
	return TransferReceiptInfo{}, err
}

定义新的对象，以太坊transaction结构体已在《从零开发区块链应用(九)》中讲解

txReceipt := new(taskcommon.TxReceipt)

序列化包含区块信息的resB变量，判断序列号是否出现错误，判断反序列化resB变量是否出现错误

resB, err := json.Marshal(res)
if err != nil {
	logger.Error("GetMatchBuyTxHashInfo", "step", "Marshal res", "err", err.Error())
	return TransferReceiptInfo{}, err
}
if err := json.Unmarshal(resB, &txReceipt); err != nil {
	logger.Error("GetMatchBuyTxHashInfo", "step", "Unmarshal block", "err", err.Error())
	return TransferReceiptInfo{}, err
}

每个事务都有一个收据，其中包含执行事务的结果，例如任何返回值和日志，以及为“1”（成功）或“0”（失败）的事件结果状态。

if txReceipt.Status != "0x1" {
		return TransferReceiptInfo{}, errors.New("contract vm running false")
	}

定义散列哈希及from地址变量

matchTopic := "0x6656db943f28baede9b164738dc5fa235b9da60d5c20a38b0eb0230c21196254"
matchAddr := "0x6e60F5243e1a3F0Be3F407b5AFE9e5395ee82aa2"

以下为nft抢购的部分业务代码，此处忽略

for _, value := range txReceipt.Logs {
	if value.Address != matchAddr {
		continue
	}
	if strings.ToLower(value.Topics[0]) == matchTopic && len(value.Topics) == 4 {
		var record TransferReceiptInfo
		record.OrderId = value.Topics[2][2:]
		record.NftContract = value.Topics[3]
		if len(clearZero(value.Data[2:66])) == 0 {
			record.NftId = "0"
		} else {
			record.NftId = clearZero(value.Data[2:66])
		}
		record.NftNums = clearZero(value.Data[66:130])
		record.NftAmount = clearZero(value.Data[194:258])
		// 计算nft 单价
		nftAmount, _ := new(big.Int).SetString(record.NftAmount, 16)
		nftNums, _ := new(big.Int).SetString(record.NftNums, 16)
		record.UnitPrice = clearZero(hex.EncodeToString(new(big.Int).Div(nftAmount, nftNums).Bytes()))
		return record, nil
	}
}

完整代码

// GetMatchReceiptInfo 获取匹配交易回执主要信息
func (rc *RequestChain) GetMatchReceiptInfo(hash string) (TransferReceiptInfo, error) {
	defer func() {
		if r := recover(); r != nil {
			//fmt.Printf("%s 捕获到的错误：%s\n", hash,r)
			//logger.Error("GetMatchReceiptInfo", "setp", "txReceipt info", "panic hash", hash)
		}
	}()

	// 分析回执
	res, err := rc.Client.GetTransactionReceipt(hash)
	if err != nil {
		logger.Error("GetMatchBuyTxHashInfo", "step", "GetTransactionReceipt", "hash", hash, "err", err.Error())
		return TransferReceiptInfo{}, err
	}
	txReceipt := new(taskcommon.TxReceipt)
	resB, err := json.Marshal(res)
	if err != nil {
		logger.Error("GetMatchBuyTxHashInfo", "step", "Marshal res", "err", err.Error())
		return TransferReceiptInfo{}, err
	}
	if err := json.Unmarshal(resB, &txReceipt); err != nil {
		logger.Error("GetMatchBuyTxHashInfo", "step", "Unmarshal block", "err", err.Error())
		return TransferReceiptInfo{}, err
	}

	if txReceipt.Status != "0x1" {
		return TransferReceiptInfo{}, errors.New("contract vm running false")
	}
	matchTopic := "0x6656db943f28baede9b164738dc5fa235b9da60d5c20a38b0eb0230c21196254"
	matchAddr := "0x7b4452dd6c38597fa9364ac8905c27ea44425832"
	for _, value := range txReceipt.Logs {
		if value.Address != matchAddr {
			continue
		}
		if strings.ToLower(value.Topics[0]) == matchTopic && len(value.Topics) == 4 {
			var record TransferReceiptInfo
			record.OrderId = value.Topics[2][2:]
			record.NftContract = value.Topics[3]
			if len(clearZero(value.Data[2:66])) == 0 {
				record.NftId = "0"
			} else {
				record.NftId = clearZero(value.Data[2:66])
			}
			record.NftNums = clearZero(value.Data[66:130])
			record.NftAmount = clearZero(value.Data[194:258])
			// 计算nft 单价
			nftAmount, _ := new(big.Int).SetString(record.NftAmount, 16)
			nftNums, _ := new(big.Int).SetString(record.NftNums, 16)
			record.UnitPrice = clearZero(hex.EncodeToString(new(big.Int).Div(nftAmount, nftNums).Bytes()))
			return record, nil
		}
	}
	return TransferReceiptInfo{}, errors.New("no record")
}

三、获取区块内交易数量

在不获取块的情况下遍历事务的一种方法是调用客户端的TransactionInBlock方法。 此方法仅接受块哈希和块内事务的索引值。 可以调用TransactionCount来了解块中有多少个事务。

blockHash := common.HexToHash("0x9e8751ebb5069389b855bba72d94902cc385042661498a415979b7b6ee9ba4b9")
count, err := client.TransactionCount(context.Background(), blockHash)
if err != nil {
  log.Fatal(err)
}

for idx := uint(0); idx < count; idx++ {
  tx, err := client.TransactionInBlock(context.Background(), blockHash, idx)
  if err != nil {
    log.Fatal(err)
  }

  fmt.Println(tx.Hash().Hex()) // 0x5d49fcaa394c97ec8a9c3e7bd9e8388d420fb050a52083ca52ff24b3b65bc9c2
}