等待在 geth 中探勘交易的最佳方式

我目前正在使用以下函式（使用web3.js ）檢查是否已探勘交易：

function waitForTx(tx_hash) {
       var result = null;

       // This is not really efficient but nodejs cannot pause the running process
       while(result === null) {
           result = web3.eth.getTransactionReceipt(tx_hash);
       }
   }

有沒有辦法避免阻塞循環？

Xavier 有一個很好的解決方案，這裡有明確的使用範例：https ://gist.github.com/xavierlepretre/88682e871f4ad07be4534ae560692ee6 。你會得到一個可交易的收據。這是一個非阻塞的解決方案，所以javascript執行緒在等待promise返回時不會卡住。

使用 Promise 可以很好地解決它，並作為 web3 的擴展來實現。將程式碼逐字包含在***getTransactionReceiptMined.js中。***然後，像他的例子一樣與它互動……下面的突出摘錄。

你發送一個交易並獲得交易雜湊（快速），然後呼叫他的函式來設置一個等待交易被探勘的承諾（區塊時間）。然後，使用您探勘的交易收據執行您的程式碼。

從他的例子中提取（添加評論）：

...
 // do something that sends a transaction 
 return meta.sendCoin(account_two, 6, { from: account_one });
})
.then(function (txnHash) {
 // now you have the unmined transaction hash, return receipt promise
 console.log(txnhash); // follow along
 return web3.eth.getTransactionReceiptMined(txnHash);
})
.then(function (receipt) {
 // now you have the mined transaction receipt as "receipt"
 console.log(receipt); // explore it :-) 
 // carry on with the next step
 return meta.getBalance.call(account_two);
})

這是等待探勘合約（或任何交易雜湊）的 ECMAScript 2016 版本：

// await sleep trick
// http://stackoverflow.com/questions/951021/what-is-the-javascript-version-of-sleep
function sleep(ms) {
 return new Promise(resolve => setTimeout(resolve, ms));
}

// We need to wait until any miner has included the transaction
// in a block to get the address of the contract
async function waitBlock() {
 while (true) {
   let receipt = web3.eth.getTransactionReceipt(contract.transactionHash);
   if (receipt && receipt.contractAddress) {
     console.log("Your contract has been deployed at http://testnet.etherscan.io/address/" + receipt.contractAddress);
     console.log("Note that it might take 30 - 90 sceonds for the block to propagate befor it's visible in etherscan.io");
     break;
   }
   console.log("Waiting a mined block to include your contract... currently in block " + web3.eth.blockNumber);
   await sleep(4000);
 }
}

waitBlock();

引用自：https://ethereum.stackexchange.com/questions/7709