开源分享:PancakeSwap 自动市场制造商(AMM)模型的核心代码
开源分享:PancakeSwap 自动市场制造商(AMM)模型的核心代码
PancakeSwap是一个去中心化交易所(DEX),基于Binance Smart Chain(BSC)运行。它允许用户在BSC上交易代币,并提供了一种简单易用的交易方式。以下是PancakeSwap的开发逻辑:
- Provide liquidity 交流分享tg: t.me/dexdao123
PancakeSwap是基于自动市场制造商(AMM)模型的,因此需要提供足够的流动性。为此,用户可以通过提供代币对的流动性来获得奖励,并获得交易费用的一部分。
以下是基于PancakeSwap AMM的源码片段:
// 1. 用户提供代币对的流动性 function addLiquidity(uint256 amountADesired, uint256 amountBDesired, uint256 amountAMin, uint256 amountBMin, address to, uint256 deadline) external returns (uint256 amountA, uint256 amountB, uint256 liquidity); // 2. 用户移除代币对的流动性 function removeLiquidity(address tokenA, address tokenB, uint256 liquidity, uint256 amountAMin, uint256 amountBMin, address to, uint256 deadline) external returns (uint256 amountA, uint256 amountB); // 3. 交易 function swapExactTokensForTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts); // 4. 获取代币对当前价格和交易费用 function getReserves() public view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast); function quote(uint256 amountA, uint256 reserveA, uint256 reserveB) internal pure returns (uint256 amountB); function getAmountsOut(uint256 amountIn, address[] memory path) public view returns (uint256[] memory amounts); function getAmountsIn(uint256 amountOut, address[] memory path) public view returns (uint256[] memory amounts);
- Trading 交流分享tg: t.me/dexdao123
用户可以在PancakeSwap上交易代币。在交易时,用户选择要交换的代币,并输入要交换的数量。PancakeSwap将自动计算汇率,并显示最终的交易金额。交易完成后,代币会转移到用户的钱包中。
以下是基于PancakeSwapSWAP模型的源码片段:
import Web3 from 'web3'; import BigNumber from 'bignumber.js'; const web3 = new Web3('https://bsc-dataseed1.binance.org:443'); // Token addresses const fromTokenAddress = '0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c'; // WBNB const toTokenAddress = '0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56'; // BUSD // Token contracts const fromToken = new web3.eth.Contract(abi, fromTokenAddress); const toToken = new web3.eth.Contract(abi, toTokenAddress); // User inputs const fromAmount = new BigNumber(1); // Amount to swap from const slippage = new BigNumber(5); // Maximum slippage percentage const deadline = Math.floor(Date.now() / 1000) + 60 * 20; // 20 minutes from now // Get token prices const fromPrice = await fromToken.methods.getReserves().call(); const toPrice = await toToken.methods.getReserves().call(); // Calculate exchange rate const exchangeRate = new BigNumber(toPrice.reserve0).div(fromPrice.reserve1); // Calculate minimum amount to receive const minToAmount = exchangeRate.times(fromAmount).times(1 - slippage.div(100)); // Approve token transfer await fromToken.methods.approve(pancakeSwapAddress, fromAmount).send({from: userAddress}); // Swap tokens await pancakeSwap.methods.swapExactTokensForTokens( fromAmount.toFixed(), minToAmount.toFixed(), [fromTokenAddress, toTokenAddress], userAddress, deadline ).send({from: userAddress}); 注:上述代码仅作为示例,实际使用时需要根据具体情况进行修改。
PancakeSwap采用的是类似挖矿的奖励机制。当用户提供流动性时,系统会向其提供奖励。这些奖励是由交易费用和PancakeSwap代币的供应量决定的。
以下是一个简单的PancakeSwap奖励机制示例代码:
const pancakeSwapToken = 'PANCAKE_TOKEN_ADDRESS'; const liquidityProviderReward = 0.003; // 0.3% const tradingFee = 0.0025; // 0.25% function calculateRewards(liquidityPoolSize, tradeAmount) { const liquidityProviderShare = liquidityPoolSize / totalLiquidity; const tradingFeeShare = tradeAmount * tradingFee / liquidityPoolSize; const pancakeSwapReward = liquidityProviderShare * tradingFeeShare * liquidityProviderReward; const userReward = (1 - liquidityProviderReward) * tradingFeeShare; // Return the PancakeSwap token reward and the user's reward return { pancakeSwapReward: pancakeSwapReward, userReward: userReward }; } // 以下是一个代码示例,展示了PancakeSwap智能合约的基本结构和功能: pragma solidity ^0.8.0; contract PancakeSwap { // 代币池 mapping(address => mapping(address => uint256)) private _liquidityPools; // 代币交换 function swap(address tokenA, address tokenB, uint256 amountIn) public returns (uint256 amountOut) { // 计算交换比率 uint256 reserveA = _liquidityPools[tokenA][tokenB]; uint256 reserveB = _liquidityPools[tokenB][tokenA]; amountOut = (amountIn * reserveB) / reserveA; // 更新代币池 _liquidityPools[tokenA][tokenB] += amountIn; _liquidityPools[tokenB][tokenA] -= amountOut; // 转移代币 // ... // 分配交易手续费 // ... } // 奖励机制 function provideLiquidity(address tokenA, address tokenB, uint256 amountA, uint256 amountB) public { // 存储代币池信息 _liquidityPools[tokenA][tokenB] += amountA; _liquidityPools[tokenB][tokenA] += amountB; // 发放奖励 // ... } // ... }
以下是PancakeSwap的核心代码示例:
Solidity合约代码:
pragma solidity ^0.6.12; import "@pancakeswap/pancake-swap-lib/contracts/token/BEP20/IBEP20.sol"; import "@pancakeswap/pancake-swap-lib/contracts/access/Ownable.sol"; import "@pancakeswap/pancake-swap-lib/contracts/math/SafeMath.sol"; import "@pancakeswap/pancake-swap-lib/contracts/utils/ReentrancyGuard.sol"; import "./CakeToken.sol"; import "./SyrupBar.sol"; contract MasterChef is Ownable, ReentrancyGuard { using SafeMath for uint256; using SafeBEP20 for IBEP20; // Info of each user. struct UserInfo { uint256 amount; // How many LP tokens the user has provided. uint256 rewardDebt; // Reward debt. See explanation below. // // We do some fancy math here. Basically, any point in time, the amount of CAKEs // entitled to a user but is pending to be distributed is: // // pending reward = (user.amount * pool.accCakePerShare) - user.rewardDebt // // Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens: // 1. The pool's `accCakePerShare` (and `lastRewardBlock`) gets updated. // 2. User receives the pending reward sent to his/her address. // 3. User's `amount` gets updated. // 4. User's `rewardDebt` gets updated. } // Info of each pool. struct PoolInfo { IBEP20 lpToken; // Address of LP token contract. uint256 allocPoint; // How many allocation points assigned to this pool. CAKEs to distribute per block. uint256 lastRewardBlock; // Last block number that CAKEs distribution occurs. uint256 accCakePerShare; // Accumulated CAKEs per share, times 1e12. See below. } // The CAKE TOKEN! CakeToken public cake; // The SYRUP TOKEN! SyrupBar public syrup; // Dev address. address public devaddr; // CAKE tokens created per block. uint256 public cakePerBlock; // Bonus muliplier for early cake makers. uint256 public BONUS_MULTIPLIER = 1; // The block number when CAKE mining starts. uint256 public startBlock; // Total allocation points. Must be the sum of all allocation points in all pools. uint256 public totalAllocPoint = 0; // Info of each pool. PoolInfo[] public poolInfo; // Info of each user that stakes LP tokens. mapping (uint256 => mapping (address => UserInfo)) public userInfo; // The block number when SYRUP mining starts. uint256 public syrupStartBlock; event Deposit(address indexed user, uint256 indexed pid, uint256 amount); event Withdraw(address indexed user, uint256 indexed pid, uint256 amount); event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount); constructor( CakeToken _cake, SyrupBar _syrup, address _devaddr, uint256 _cakePerBlock, uint256 _startBlock, uint256 _syrupStartBlock ) public { cake = _cake; syrup = _syrup; devaddr = _ // 从智能合约中获取交易信息 const tx = await contract.methods.swapExactTokensForTokens( amountIn, amountOutMin, [tokenIn, tokenOut], recipient, deadline ).send({ from: account }); console.log(`Transaction hash: ${tx.transactionHash}`);
这段代码通过调用智能合约中的swapExactTokensForTokens
方法,将输入的代币数量amountIn
交换成目标代币tokenOut
,并且要求输出的代币数量不少于amountOutMin
。同时还需要指定交易的一些参数,比如输入和输出代币的类型、接收地址和截止时间等。交易成功后,可以通过tx.transactionHash
获取交易哈希值,用于查询交易状态。
Copyrights:Dexnav Posted on 2023年3月10日 pm9:45。
Please specify source if reproduced开源分享:PancakeSwap 自动市场制造商(AMM)模型的核心代码 | Dexnav 区块链导航网
Please specify source if reproduced开源分享:PancakeSwap 自动市场制造商(AMM)模型的核心代码 | Dexnav 区块链导航网
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