如何解析uniswap v3下的muticall的data数据

相信不少朋友在uniswap v3进行swap的时候，去etherscan上查看交易信息总会发现这个data是已传encode data, 如果你用utf-8去decode的时候，结果就如上图一样还是没有明文信息，今天就会交给大家使用web3.js的脚本去解析这个data字段，话不多说直接上教程： 1、我们先拿一笔交易来举例子：https://etherscan.io/tx/0x33104eedcad5fb2dbd2d8de49b8fee81c6e5b9d87cc43ba4d68fd2f55bcb1503

打开之后我们可以看到 这里面有12 byte32的数据，接下来把这12行数据依次拼接出来组成如下的data数据：

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

然后把这个数据放到我的这个脚本里：

const Web3 = require("web3");
const axios = require("axios");
const CALLDATA = "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";
// const CALLDATA = "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"
const web3 = new Web3();

function extractParameters(signature) {
    let params = [];

    const allParameters = /\b[^()]+\((.*)\)$/gm;
    const splitParameters = /((\(.+?\))|([^,() ]+)){1}/gm;

    let _allParameters = allParameters.exec(signature)[1];

    while ((match = splitParameters.exec(_allParameters))) {
        params.push(match[0]);
    }

    return params;
}

async function decode(calldata) {
    let calls = web3.eth.abi.decodeParameters(['uint256', 'bytes[]'], calldata)[1];

    for (let index = 0; index < calls.length; index++) {
        let call = calls[index].replace("0x", "");
        let selector = call.slice(0, 8);
        let data = call.slice(8);
        let request = await axios.get(
            `https://www.4byte.directory/api/v1/signatures/?hex_signature=${selector}`
        );
        let signature = request.data.results[0].text_signature;
        console.log()
        console.log(`步骤 ${index}, 方法: ${signature}`);

        let parameters = extractParameters(signature);
        let decoded = web3.eth.abi.decodeParameters(parameters, data);

        for (let i = 0; i < parameters.length; i++) {
            console.log(`   参数 ${i} - 类型: ${parameters[i]} - 值: ${decoded[i]}`);
        }
    }
}

decode(CALLDATA);

这个脚本的原理就是使用

https://www.4byte.directory/api/v1/signatures

的api来对function的前4个字节去数据库里查找对应的明文信息，然后解析出来打印在控制台里，可以看我下面的执行结果：