帮助!最佳令牌路径，如果为uniswap v2

Question

我想知道在Uniswap v2中是否存在计算最佳令牌交易路径的函数或方法。

我认为在uniswap v3中，它们提供的功能为我们提供了最佳的交易途径。

但是在第2版中，我必须使用哪个函数呢？

如果不存在这样的函数，我应该使用什么算法？

我在github.com中发现了几个项目，但它们没有意义，而且非常复杂。

请任何人知道，救救我！任何想法，任何建议都是欢迎的。谢谢！

Answer 1

使用智能定单路由器：https://github.com/Uniswap/smart-order-router

我有一个在Uniswap冲突中使用的工作示例，这是一个非常基本的代码。

使用智能路由器/自动路由器SDK的<#>working是我修改后的工作版本(这是在一个主干网分叉上测试的设置，但是它使用的是实时数据(因为AlphaRouter只用于主网活动，所以动态数据和分叉数据将随着时间的推移而改变，因此在使用之前请重新设置分叉)

使主网只取出本地提供商，并将所有提供程序更改为主网络提供商。

阿尔法自动路由器正在使用新的uniswap V3v2路由器@0x68b3465833fb72A70ecDF485E0C7bD8665Fc45。

谨慎使用，我不是十全十美的，什么也不保证:检查滑动和所有变量，因为这只是一个例子

这是一个令牌，作为一个令牌Exact_Input交换与魏斯存款1 ETH。若要使用ETH，可以在批准时删除Weth存款和令牌，并将BigNumber.from(typedValueParsed)用作事务的值，而不是0。

由于我不知道EtherJS井的煤气价格和煤气限值为100 gwei &300 K，应按目前的管网煤气价格和估计的煤气限额进行修改。(如果有人有这段代码，我会加上的，如果我不先说)

import { AlphaRouter } from '@uniswap/smart-order-router'
import { Token, CurrencyAmount } from '@uniswap/sdk-core'
import { JSBI, Percent } from "@uniswap/sdk";
import { ethers, BigNumber } from "ethers";


const V3_SWAP_ROUTER_ADDRESS = "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45";

const TokenInput = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2";

const TokenOutput = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";


const web3Provider = new ethers.providers.JsonRpcProvider("https://eth-mainnet.alchemyapi.io/v2/");
const web3 = new ethers.providers.JsonRpcProvider("http://127.0.0.1:8545/");

const privateKey = "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80";
const wallet = new ethers.Wallet(privateKey,web3);
const address = wallet.address;

import * as fs from 'fs';

let UniV3RouterAbi = fs.readFileSync('NewUniRouter.json');
const V3routerAbi = JSON.parse(UniV3RouterAbi);

let ERC20Abi = fs.readFileSync('ERC20.json');
const ERC20 = JSON.parse(ERC20Abi);

let WETHAbij = fs.readFileSync('WETHAbi.json');
const WETHAbi = JSON.parse(WETHAbij);

async function log(inpt){
    console.log(inpt);
    console.log("");
}

async function TokBal(tokens){
    var ERC20contract =  new ethers.Contract(tokens, ERC20, web3);
    var myERC20bal = await ERC20contract.balanceOf(wallet.address);
    return myERC20bal;
}

async function Deposit(amt){
    var WethC =  new ethers.Contract(TokenInput, WETHAbi, web3);
    var datac = await WethC.populateTransaction["deposit"]();
    var ncn = await wallet.getTransactionCount();

    const transaction = {
      data: datac.data,
      nonce: ncn,
      to: TokenInput,
      value: BigNumber.from(amt),
      from: wallet.address,
      gasPrice: '0x174876e800',
      gasLimit: '0x493e0',
    };

    const signedTx = await wallet.signTransaction(transaction);
    const txHash =  await web3.sendTransaction(signedTx);
    log(txHash.hash);
}

async function Approve(Toked, amt){
    var WethC =  new ethers.Contract(Toked, ERC20, web3);
    var datac = await WethC.populateTransaction["approve"](V3_SWAP_ROUTER_ADDRESS, amt);
    var ncn = await wallet.getTransactionCount();

    const transaction = {
      data: datac.data,
      nonce: ncn,
      to: Toked,
      value: BigNumber.from("0"),
      from: wallet.address,
      gasPrice: '0x174876e800',
      gasLimit: '0x493e0',
    };

    const signedTx = await wallet.signTransaction(transaction);
    const txHash =  await web3.sendTransaction(signedTx);
    log(txHash.hash);
    var appFor = await WethC.callStatic.allowance(wallet.address, V3_SWAP_ROUTER_ADDRESS);
    log("Approved : "+appFor.toString());
}


const router = new AlphaRouter({ chainId: 1, provider: web3Provider });
const WETH = new Token(
  router.chainId,
  '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  18,
  'WETH',
  'Wrapped Ether'
);

const USDC = new Token(
  router.chainId,
  '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
  6,
  'USDC',
  'USD//C'
);

const typedValueParsed = '1000000000000000000';
const wethAmount = CurrencyAmount.fromRawAmount(WETH, JSBI.BigInt(typedValueParsed));

const IO = "Exact_Input"
const TradeType = IO == "Exact_Input" ? 0 : 1;


const route = await router.route(
  wethAmount,
  USDC,
  TradeType,
  {
    recipient: wallet.address,
    slippageTolerance: new Percent(5, 100),
    deadline: Math.floor(Date.now()/1000 +1800)
  }
);

var Ebal = await web3.getBalance(wallet.address);
log("Wallet Balance : "+Ebal.toString());

var tbal = await TokBal(TokenOutput);
log("Token Out Balance : "+tbal.toString());

await Deposit("1000000000000000000");
await Approve(TokenInput,"1000000000000000000");
var tbalW = await TokBal(TokenInput);
log("Token In Balance : "+tbalW.toString());

log(`Quote Exact In: ${route.quote.toFixed(wethAmount.currency === WETH ? USDC.decimals : WETH.decimals)}`);
log(`Gas Adjusted Quote In: ${route.quoteGasAdjusted.toFixed(wethAmount.currency === WETH ? USDC.decimals : WETH.decimals)}`);


var nc = await wallet.getTransactionCount();


const transaction = {
  data: route.methodParameters.calldata,
  nonce: nc,
  to: V3_SWAP_ROUTER_ADDRESS,
  value: BigNumber.from(0),
  from: wallet.address,
  gasPrice: BigNumber.from(route.gasPriceWei),
  gasLimit: BigNumber.from(route.estimatedGasUsed).add(BigNumber.from("50000")),
};


const signedTx = await wallet.signTransaction(transaction);


const PretxHash = ethers.utils.keccak256(signedTx);


const txHash =  await web3.sendTransaction(signedTx)
log(txHash.hash);

var Ebal = await web3.getBalance(wallet.address);
log("Wallet Balance : "+Ebal.toString());

var tbal = await TokBal(TokenOutput);
log("Token Out Balance : "+tbal.toString());

var tbalW = await TokBal(TokenInput);
log("Token In Balance : "+tbalW.toString())

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