javascript - 使用 web3js 在 uniswap 和 sushiswap 交易所获得硬币价格而不使用他们的 api

Question

我想通过使用 web.js 获取 uniswap 和 sushiswap 交易所的代币价格
我是加密开发世界的新手，所以请尽可能详细地说明，如果可能的话，一个例子将是救命稻草。
这是我能拍到的最好的照片……但不知道如何获得 V3_pool_ABI值(value)

const JSBI = require('jsbi');
const Web3 = require('web3');

(async () => {
  const web3 = new Web3(new Web3.providers.HttpProvider('https://mainnet.infura.io/v3/d5658a9beace4cd98d2c1216cf66b56a'));
  
  var factoryV3 = new web3.eth.Contract(
    [{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"uint24","name":"fee","type":"uint24"},{"indexed":true,"internalType":"int24","name":"tickSpacing","type":"int24"}],"name":"FeeAmountEnabled","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"oldOwner","type":"address"},{"indexed":true,"internalType":"address","name":"newOwner","type":"address"}],"name":"OwnerChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"token0","type":"address"},{"indexed":true,"internalType":"address","name":"token1","type":"address"},{"indexed":true,"internalType":"uint24","name":"fee","type":"uint24"},{"indexed":false,"internalType":"int24","name":"tickSpacing","type":"int24"},{"indexed":false,"internalType":"address","name":"pool","type":"address"}],"name":"PoolCreated","type":"event"},{"inputs":[{"internalType":"address","name":"tokenA","type":"address"},{"internalType":"address","name":"tokenB","type":"address"},{"internalType":"uint24","name":"fee","type":"uint24"}],"name":"createPool","outputs":[{"internalType":"address","name":"pool","type":"address"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint24","name":"fee","type":"uint24"},{"internalType":"int24","name":"tickSpacing","type":"int24"}],"name":"enableFeeAmount","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint24","name":"","type":"uint24"}],"name":"feeAmountTickSpacing","outputs":[{"internalType":"int24","name":"","type":"int24"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"},{"internalType":"uint24","name":"","type":"uint24"}],"name":"getPool","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"parameters","outputs":[{"internalType":"address","name":"factory","type":"address"},{"internalType":"address","name":"token0","type":"address"},{"internalType":"address","name":"token1","type":"address"},{"internalType":"uint24","name":"fee","type":"uint24"},{"internalType":"int24","name":"tickSpacing","type":"int24"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_owner","type":"address"}],"name":"setOwner","outputs":[],"stateMutability":"nonpayable","type":"function"}], 
    '0x1F98431c8aD98523631AE4a59f267346ea31F984'
  );
  var pool_address = await factoryV3.methods.getPool('0x6b175474e89094c44da98b954eedeac495271d0f', '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2', 3000).call();
  var pool_1 = new web3.eth.Contract(V3_pool_ABI, pool_address);
  var pool_balance = await pool_1.methods.slot0.call().call();
  var sqrtPriceX96 = pool_balance[0];
  var number_1 =JSBI.BigInt(sqrtPriceX96 *sqrtPriceX96* (1e18)/(1e18)/JSBI.BigInt(2) ** (JSBI.BigInt(192)));
})();

Answer 1

答案是使用预言机合约，许多 Defi 应用程序也取决于那里的价格。
你将如何获得它的稳固性:(link to blog)

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

contract PriceConsumerV3 {

    AggregatorV3Interface internal priceFeed;

    /**
     * Network: Kovan
     * Aggregator: ETH/USD
     * Address: 0x9326BFA02ADD2366b30bacB125260Af641031331
     */
    constructor() {
        priceFeed = AggregatorV3Interface(0x9326BFA02ADD2366b30bacB125260Af641031331);
    }

    /**
     * Returns the latest price
     */
    function getLatestPrice() public view returns (int) {
        (
            uint80 roundID, 
            int price,
            uint startedAt,
            uint timeStamp,
            uint80 answeredInRound
        ) = priceFeed.latestRoundData();
        return price;
    }
}

这可以使用 web3 库在 js 中复制，只需获取此契约(Contract)并使用其功能即可。