Elegant and simple! Uniswap V3 accessed on FMZ with 200 lines of code

Elegant and simple! Uniswap V3 accessed on FMZ with 200 lines of code

Uniswap V3 has been one of the topics of interest in the decentralized finance (DeFi) space in recent years with the popularity of the concept of Defi. As a leading decentralized exchange protocol, Uniswap V3 provides a more efficient, secure and superior user experience. Now, with only 200 lines of code, traders and developers can easily access Uniswap V3 on the FMZ platform.

FMZ is a quantitative trading platform that supports the development, retesting, and real-time deployment of quantitative trading strategies. Its easy-to-use interface and powerful features make it easy to understand why FMZ is becoming a top choice for DeFi traders and developers.

The process of integrating Uniswap V3 into FMZ is simple and easy to complete with just 200 lines of code. This means that even if you are a beginner, you can easily connect Uniswap V3 to FMZ and start trading immediately.

FMZ has already packaged a series of basic web3 features, which can be used to pack other DEX exchanges in addition to Uniswap with very little code. Next, let me take you with a zero-sum start to learn the concepts and techniques in the Defi application.

The FMZ platform is openUniswap V3 exchange library

The code is as follows:

/* jshint esversion: 7 */

const ABI_Route = '[{"inputs":[{"internalType":"address","name":"_factoryV2","type":"address"},{"internalType":"address","name":"factoryV3","type":"address"},{"internalType":"address","name":"_positionManager","type":"address"},{"internalType":"address","name":"_WETH9","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"WETH9","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"}],"name":"approveMax","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"}],"name":"approveMaxMinusOne","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"}],"name":"approveZeroThenMax","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"}],"name":"approveZeroThenMaxMinusOne","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"bytes","name":"data","type":"bytes"}],"name":"callPositionManager","outputs":[{"internalType":"bytes","name":"result","type":"bytes"}],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"bytes[]","name":"paths","type":"bytes[]"},{"internalType":"uint128[]","name":"amounts","type":"uint128[]"},{"internalType":"uint24","name":"maximumTickDivergence","type":"uint24"},{"internalType":"uint32","name":"secondsAgo","type":"uint32"}],"name":"checkOracleSlippage","outputs":[],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes","name":"path","type":"bytes"},{"internalType":"uint24","name":"maximumTickDivergence","type":"uint24"},{"internalType":"uint32","name":"secondsAgo","type":"uint32"}],"name":"checkOracleSlippage","outputs":[],"stateMutability":"view","type":"function"},{"inputs":[{"components":[{"internalType":"bytes","name":"path","type":"bytes"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"uint256","name":"amountOutMinimum","type":"uint256"}],"internalType":"struct IV3SwapRouter.ExactInputParams","name":"params","type":"tuple"}],"name":"exactInput","outputs":[{"internalType":"uint256","name":"amountOut","type":"uint256"}],"stateMutability":"payable","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"tokenIn","type":"address"},{"internalType":"address","name":"tokenOut","type":"address"},{"internalType":"uint24","name":"fee","type":"uint24"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"uint256","name":"amountOutMinimum","type":"uint256"},{"internalType":"uint160","name":"sqrtPriceLimitX96","type":"uint160"}],"internalType":"struct IV3SwapRouter.ExactInputSingleParams","name":"params","type":"tuple"}],"name":"exactInputSingle","outputs":[{"internalType":"uint256","name":"amountOut","type":"uint256"}],"stateMutability":"payable","type":"function"},{"inputs":[{"components":[{"internalType":"bytes","name":"path","type":"bytes"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amountOut","type":"uint256"},{"internalType":"uint256","name":"amountInMaximum","type":"uint256"}],"internalType":"struct IV3SwapRouter.ExactOutputParams","name":"params","type":"tuple"}],"name":"exactOutput","outputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"}],"stateMutability":"payable","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"tokenIn","type":"address"},{"internalType":"address","name":"tokenOut","type":"address"},{"internalType":"uint24","name":"fee","type":"uint24"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amountOut","type":"uint256"},{"internalType":"uint256","name":"amountInMaximum","type":"uint256"},{"internalType":"uint160","name":"sqrtPriceLimitX96","type":"uint160"}],"internalType":"struct IV3SwapRouter.ExactOutputSingleParams","name":"params","type":"tuple"}],"name":"exactOutputSingle","outputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"}],"stateMutability":"payable","type":"function"},{"inputs":[],"name":"factory","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"factoryV2","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"getApprovalType","outputs":[{"internalType":"enum IApproveAndCall.ApprovalType","name":"","type":"uint8"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"token0","type":"address"},{"internalType":"address","name":"token1","type":"address"},{"internalType":"uint256","name":"tokenId","type":"uint256"},{"internalType":"uint256","name":"amount0Min","type":"uint256"},{"internalType":"uint256","name":"amount1Min","type":"uint256"}],"internalType":"struct IApproveAndCall.IncreaseLiquidityParams","name":"params","type":"tuple"}],"name":"increaseLiquidity","outputs":[{"internalType":"bytes","name":"result","type":"bytes"}],"stateMutability":"payable","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"token0","type":"address"},{"internalType":"address","name":"token1","type":"address"},{"internalType":"uint24","name":"fee","type":"uint24"},{"internalType":"int24","name":"tickLower","type":"int24"},{"internalType":"int24","name":"tickUpper","type":"int24"},{"internalType":"uint256","name":"amount0Min","type":"uint256"},{"internalType":"uint256","name":"amount1Min","type":"uint256"},{"internalType":"address","name":"recipient","type":"address"}],"internalType":"struct IApproveAndCall.MintParams","name":"params","type":"tuple"}],"name":"mint","outputs":[{"internalType":"bytes","name":"result","type":"bytes"}],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"bytes32","name":"previousBlockhash","type":"bytes32"},{"internalType":"bytes[]","name":"data","type":"bytes[]"}],"name":"multicall","outputs":[{"internalType":"bytes[]","name":"","type":"bytes[]"}],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"deadline","type":"uint256"},{"internalType":"bytes[]","name":"data","type":"bytes[]"}],"name":"multicall","outputs":[{"internalType":"bytes[]","name":"","type":"bytes[]"}],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"bytes[]","name":"data","type":"bytes[]"}],"name":"multicall","outputs":[{"internalType":"bytes[]","name":"results","type":"bytes[]"}],"stateMutability":"payable","type":"function"},{"inputs":[],"name":"positionManager","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"}],"name":"pull","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[],"name":"refundETH","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"selfPermit","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"nonce","type":"uint256"},{"internalType":"uint256","name":"expiry","type":"uint256"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"selfPermitAllowed","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"nonce","type":"uint256"},{"internalType":"uint256","name":"expiry","type":"uint256"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"selfPermitAllowedIfNecessary","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"selfPermitIfNecessary","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"uint256","name":"amountOutMin","type":"uint256"},{"internalType":"address[]","name":"path","type":"address[]"},{"internalType":"address","name":"to","type":"address"}],"name":"swapExactTokensForTokens","outputs":[{"internalType":"uint256","name":"amountOut","type":"uint256"}],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountOut","type":"uint256"},{"internalType":"uint256","name":"amountInMax","type":"uint256"},{"internalType":"address[]","name":"path","type":"address[]"},{"internalType":"address","name":"to","type":"address"}],"name":"swapTokensForExactTokens","outputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"}],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"address","name":"recipient","type":"address"}],"name":"sweepToken","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amountMinimum","type":"uint256"}],"name":"sweepToken","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"uint256","name":"feeBips","type":"uint256"},{"internalType":"address","name":"feeRecipient","type":"address"}],"name":"sweepTokenWithFee","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"feeBips","type":"uint256"},{"internalType":"address","name":"feeRecipient","type":"address"}],"name":"sweepTokenWithFee","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"int256","name":"amount0Delta","type":"int256"},{"internalType":"int256","name":"amount1Delta","type":"int256"},{"internalType":"bytes","name":"_data","type":"bytes"}],"name":"uniswapV3SwapCallback","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"address","name":"recipient","type":"address"}],"name":"unwrapWETH9","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountMinimum","type":"uint256"}],"name":"unwrapWETH9","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"feeBips","type":"uint256"},{"internalType":"address","name":"feeRecipient","type":"address"}],"name":"unwrapWETH9WithFee","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amountMinimum","type":"uint256"},{"internalType":"uint256","name":"feeBips","type":"uint256"},{"internalType":"address","name":"feeRecipient","type":"address"}],"name":"unwrapWETH9WithFee","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"uint256","name":"value","type":"uint256"}],"name":"wrapETH","outputs":[],"stateMutability":"payable","type":"function"},{"stateMutability":"payable","type":"receive"}]';
const ABI_Pool = '[{\"inputs\":[],\"stateMutability\":\"nonpayable\",\"type\":\"constructor\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"int24\",\"name\":\"tickLower\",\"type\":\"int24\"},{\"indexed\":true,\"internalType\":\"int24\",\"name\":\"tickUpper\",\"type\":\"int24\"},{\"indexed\":false,\"internalType\":\"uint128\",\"name\":\"amount\",\"type\":\"uint128\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"amount0\",\"type\":\"uint256\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"amount1\",\"type\":\"uint256\"}],\"name\":\"Burn\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"indexed\":false,\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"int24\",\"name\":\"tickLower\",\"type\":\"int24\"},{\"indexed\":true,\"internalType\":\"int24\",\"name\":\"tickUpper\",\"type\":\"int24\"},{\"indexed\":false,\"internalType\":\"uint128\",\"name\":\"amount0\",\"type\":\"uint128\"},{\"indexed\":false,\"internalType\":\"uint128\",\"name\":\"amount1\",\"type\":\"uint128\"}],\"name\":\"Collect\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"indexed\":false,\"internalType\":\"uint128\",\"name\":\"amount0\",\"type\":\"uint128\"},{\"indexed\":false,\"internalType\":\"uint128\",\"name\":\"amount1\",\"type\":\"uint128\"}],\"name\":\"CollectProtocol\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"amount0\",\"type\":\"uint256\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"amount1\",\"type\":\"uint256\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"paid0\",\"type\":\"uint256\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"paid1\",\"type\":\"uint256\"}],\"name\":\"Flash\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":false,\"internalType\":\"uint16\",\"name\":\"observationCardinalityNextOld\",\"type\":\"uint16\"},{\"indexed\":false,\"internalType\":\"uint16\",\"name\":\"observationCardinalityNextNew\",\"type\":\"uint16\"}],\"name\":\"IncreaseObservationCardinalityNext\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":false,\"internalType\":\"uint160\",\"name\":\"sqrtPriceX96\",\"type\":\"uint160\"},{\"indexed\":false,\"internalType\":\"int24\",\"name\":\"tick\",\"type\":\"int24\"}],\"name\":\"Initialize\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":false,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"int24\",\"name\":\"tickLower\",\"type\":\"int24\"},{\"indexed\":true,\"internalType\":\"int24\",\"name\":\"tickUpper\",\"type\":\"int24\"},{\"indexed\":false,\"internalType\":\"uint128\",\"name\":\"amount\",\"type\":\"uint128\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"amount0\",\"type\":\"uint256\"},{\"indexed\":false,\"internalType\":\"uint256\",\"name\":\"amount1\",\"type\":\"uint256\"}],\"name\":\"Mint\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":false,\"internalType\":\"uint8\",\"name\":\"feeProtocol0Old\",\"type\":\"uint8\"},{\"indexed\":false,\"internalType\":\"uint8\",\"name\":\"feeProtocol1Old\",\"type\":\"uint8\"},{\"indexed\":false,\"internalType\":\"uint8\",\"name\":\"feeProtocol0New\",\"type\":\"uint8\"},{\"indexed\":false,\"internalType\":\"uint8\",\"name\":\"feeProtocol1New\",\"type\":\"uint8\"}],\"name\":\"SetFeeProtocol\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"indexed\":false,\"internalType\":\"int256\",\"name\":\"amount0\",\"type\":\"int256\"},{\"indexed\":false,\"internalType\":\"int256\",\"name\":\"amount1\",\"type\":\"int256\"},{\"indexed\":false,\"internalType\":\"uint160\",\"name\":\"sqrtPriceX96\",\"type\":\"uint160\"},{\"indexed\":false,\"internalType\":\"uint128\",\"name\":\"liquidity\",\"type\":\"uint128\"},{\"indexed\":false,\"internalType\":\"int24\",\"name\":\"tick\",\"type\":\"int24\"}],\"name\":\"Swap\",\"type\":\"event\"},{\"inputs\":[{\"internalType\":\"int24\",\"name\":\"tickLower\",\"type\":\"int24\"},{\"internalType\":\"int24\",\"name\":\"tickUpper\",\"type\":\"int24\"},{\"internalType\":\"uint128\",\"name\":\"amount\",\"type\":\"uint128\"}],\"name\":\"burn\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"amount0\",\"type\":\"uint256\"},{\"internalType\":\"uint256\",\"name\":\"amount1\",\"type\":\"uint256\"}],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"internalType\":\"int24\",\"name\":\"tickLower\",\"type\":\"int24\"},{\"internalType\":\"int24\",\"name\":\"tickUpper\",\"type\":\"int24\"},{\"internalType\":\"uint128\",\"name\":\"amount0Requested\",\"type\":\"uint128\"},{\"internalType\":\"uint128\",\"name\":\"amount1Requested\",\"type\":\"uint128\"}],\"name\":\"collect\",\"outputs\":[{\"internalType\":\"uint128\",\"name\":\"amount0\",\"type\":\"uint128\"},{\"internalType\":\"uint128\",\"name\":\"amount1\",\"type\":\"uint128\"}],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"internalType\":\"uint128\",\"name\":\"amount0Requested\",\"type\":\"uint128\"},{\"internalType\":\"uint128\",\"name\":\"amount1Requested\",\"type\":\"uint128\"}],\"name\":\"collectProtocol\",\"outputs\":[{\"internalType\":\"uint128\",\"name\":\"amount0\",\"type\":\"uint128\"},{\"internalType\":\"uint128\",\"name\":\"amount1\",\"type\":\"uint128\"}],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"factory\",\"outputs\":[{\"internalType\":\"address\",\"name\":\"\",\"type\":\"address\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"fee\",\"outputs\":[{\"internalType\":\"uint24\",\"name\":\"\",\"type\":\"uint24\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"feeGrowthGlobal0X128\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"feeGrowthGlobal1X128\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"internalType\":\"uint256\",\"name\":\"amount0\",\"type\":\"uint256\"},{\"internalType\":\"uint256\",\"name\":\"amount1\",\"type\":\"uint256\"},{\"internalType\":\"bytes\",\"name\":\"data\",\"type\":\"bytes\"}],\"name\":\"flash\",\"outputs\":[],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"uint16\",\"name\":\"observationCardinalityNext\",\"type\":\"uint16\"}],\"name\":\"increaseObservationCardinalityNext\",\"outputs\":[],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"uint160\",\"name\":\"sqrtPriceX96\",\"type\":\"uint160\"}],\"name\":\"initialize\",\"outputs\":[],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"liquidity\",\"outputs\":[{\"internalType\":\"uint128\",\"name\":\"\",\"type\":\"uint128\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"maxLiquidityPerTick\",\"outputs\":[{\"internalType\":\"uint128\",\"name\":\"\",\"type\":\"uint128\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"internalType\":\"int24\",\"name\":\"tickLower\",\"type\":\"int24\"},{\"internalType\":\"int24\",\"name\":\"tickUpper\",\"type\":\"int24\"},{\"internalType\":\"uint128\",\"name\":\"amount\",\"type\":\"uint128\"},{\"internalType\":\"bytes\",\"name\":\"data\",\"type\":\"bytes\"}],\"name\":\"mint\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"amount0\",\"type\":\"uint256\"},{\"internalType\":\"uint256\",\"name\":\"amount1\",\"type\":\"uint256\"}],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"uint256\",\"name\":\"\",\"type\":\"uint256\"}],\"name\":\"observations\",\"outputs\":[{\"internalType\":\"uint32\",\"name\":\"blockTimestamp\",\"type\":\"uint32\"},{\"internalType\":\"int56\",\"name\":\"tickCumulative\",\"type\":\"int56\"},{\"internalType\":\"uint160\",\"name\":\"secondsPerLiquidityCumulativeX128\",\"type\":\"uint160\"},{\"internalType\":\"bool\",\"name\":\"initialized\",\"type\":\"bool\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"uint32[]\",\"name\":\"secondsAgos\",\"type\":\"uint32[]\"}],\"name\":\"observe\",\"outputs\":[{\"internalType\":\"int56[]\",\"name\":\"tickCumulatives\",\"type\":\"int56[]\"},{\"internalType\":\"uint160[]\",\"name\":\"secondsPerLiquidityCumulativeX128s\",\"type\":\"uint160[]\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"bytes32\",\"name\":\"\",\"type\":\"bytes32\"}],\"name\":\"positions\",\"outputs\":[{\"internalType\":\"uint128\",\"name\":\"liquidity\",\"type\":\"uint128\"},{\"internalType\":\"uint256\",\"name\":\"feeGrowthInside0LastX128\",\"type\":\"uint256\"},{\"internalType\":\"uint256\",\"name\":\"feeGrowthInside1LastX128\",\"type\":\"uint256\"},{\"internalType\":\"uint128\",\"name\":\"tokensOwed0\",\"type\":\"uint128\"},{\"internalType\":\"uint128\",\"name\":\"tokensOwed1\",\"type\":\"uint128\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"protocolFees\",\"outputs\":[{\"internalType\":\"uint128\",\"name\":\"token0\",\"type\":\"uint128\"},{\"internalType\":\"uint128\",\"name\":\"token1\",\"type\":\"uint128\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"uint8\",\"name\":\"feeProtocol0\",\"type\":\"uint8\"},{\"internalType\":\"uint8\",\"name\":\"feeProtocol1\",\"type\":\"uint8\"}],\"name\":\"setFeeProtocol\",\"outputs\":[],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"slot0\",\"outputs\":[{\"internalType\":\"uint160\",\"name\":\"sqrtPriceX96\",\"type\":\"uint160\"},{\"internalType\":\"int24\",\"name\":\"tick\",\"type\":\"int24\"},{\"internalType\":\"uint16\",\"name\":\"observationIndex\",\"type\":\"uint16\"},{\"internalType\":\"uint16\",\"name\":\"observationCardinality\",\"type\":\"uint16\"},{\"internalType\":\"uint16\",\"name\":\"observationCardinalityNext\",\"type\":\"uint16\"},{\"internalType\":\"uint8\",\"name\":\"feeProtocol\",\"type\":\"uint8\"},{\"internalType\":\"bool\",\"name\":\"unlocked\",\"type\":\"bool\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"int24\",\"name\":\"tickLower\",\"type\":\"int24\"},{\"internalType\":\"int24\",\"name\":\"tickUpper\",\"type\":\"int24\"}],\"name\":\"snapshotCumulativesInside\",\"outputs\":[{\"internalType\":\"int56\",\"name\":\"tickCumulativeInside\",\"type\":\"int56\"},{\"internalType\":\"uint160\",\"name\":\"secondsPerLiquidityInsideX128\",\"type\":\"uint160\"},{\"internalType\":\"uint32\",\"name\":\"secondsInside\",\"type\":\"uint32\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"address\",\"name\":\"recipient\",\"type\":\"address\"},{\"internalType\":\"bool\",\"name\":\"zeroForOne\",\"type\":\"bool\"},{\"internalType\":\"int256\",\"name\":\"amountSpecified\",\"type\":\"int256\"},{\"internalType\":\"uint160\",\"name\":\"sqrtPriceLimitX96\",\"type\":\"uint160\"},{\"internalType\":\"bytes\",\"name\":\"data\",\"type\":\"bytes\"}],\"name\":\"swap\",\"outputs\":[{\"internalType\":\"int256\",\"name\":\"amount0\",\"type\":\"int256\"},{\"internalType\":\"int256\",\"name\":\"amount1\",\"type\":\"int256\"}],\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"int16\",\"name\":\"\",\"type\":\"int16\"}],\"name\":\"tickBitmap\",\"outputs\":[{\"internalType\":\"uint256\",\"name\":\"\",\"type\":\"uint256\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"tickSpacing\",\"outputs\":[{\"internalType\":\"int24\",\"name\":\"\",\"type\":\"int24\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[{\"internalType\":\"int24\",\"name\":\"\",\"type\":\"int24\"}],\"name\":\"ticks\",\"outputs\":[{\"internalType\":\"uint128\",\"name\":\"liquidityGross\",\"type\":\"uint128\"},{\"internalType\":\"int128\",\"name\":\"liquidityNet\",\"type\":\"int128\"},{\"internalType\":\"uint256\",\"name\":\"feeGrowthOutside0X128\",\"type\":\"uint256\"},{\"internalType\":\"uint256\",\"name\":\"feeGrowthOutside1X128\",\"type\":\"uint256\"},{\"internalType\":\"int56\",\"name\":\"tickCumulativeOutside\",\"type\":\"int56\"},{\"internalType\":\"uint160\",\"name\":\"secondsPerLiquidityOutsideX128\",\"type\":\"uint160\"},{\"internalType\":\"uint32\",\"name\":\"secondsOutside\",\"type\":\"uint32\"},{\"internalType\":\"bool\",\"name\":\"initialized\",\"type\":\"bool\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"token0\",\"outputs\":[{\"internalType\":\"address\",\"name\":\"\",\"type\":\"address\"}],\"stateMutability\":\"view\",\"type\":\"function\"},{\"inputs\":[],\"name\":\"token1\",\"outputs\":[{\"internalType\":\"address\",\"name\":\"\",\"type\":\"address\"}],\"stateMutability\":\"view\",\"type\":\"function\"}]'
const ABI_Factory = '[{\"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\"}]'

let ContractV3Factory = "0x1F98431c8aD98523631AE4a59f267346ea31F984"
let ContractV3SwapRouterV2 = "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45"


function computePoolPrice(decimals0, decimals1, sqrtPriceX96) {
    [decimals0, decimals1, sqrtPriceX96] = [decimals0, decimals1, sqrtPriceX96].map(BigInt);
    const TWO = BigInt(2);
    const TEN = BigInt(10);
    const SIX_TENTH = BigInt(1000000);
    const Q192 = (TWO ** BigInt(96)) ** TWO;
    return (
        Number((sqrtPriceX96 ** TWO * TEN ** decimals0 * SIX_TENTH) / (Q192 * TEN ** decimals1)) /
        Number(SIX_TENTH)
    );
}

function toAmount(s, decimals) {
    return Number((BigDecimal(BigInt(s))/BigDecimal(Math.pow(10, decimals))).toString())
}

function toInnerAmount(n, decimals) {
    return (BigDecimal(n)*BigDecimal(Math.pow(10,decimals))).toFixed(0)
}

$.NewUniswapV3 = function(e) {
    e = e || exchange
    if (e.GetName() !== 'Web3') {
        panic("only support Web3 exchange")
    }


    let self = {
        tokenInfo: {},
        walletAddress: e.IO("address"),
        pool: {}
    }

    // register
    e.IO("abi", ContractV3Factory, ABI_Factory)
    e.IO("abi", ContractV3SwapRouterV2, ABI_Route)

    self.addToken = function(name, address) {
        let ret = e.IO("api", address, "decimals")
        if (!ret) {
            throw "get token decimals failed"
        }
        let decimals = Number(ret)
        self.tokenInfo[name] = {
            name: name,
            decimals: decimals,
            address: address
        }
    }
    self.waitMined = function(tx) {
        while (true) {
            Sleep(1000)
            let info = e.IO("api", "eth", "eth_getTransactionReceipt", tx)
            if (info && info.gasUsed) {
                return true
            }
            Log('Transaction not yet mined', tx)
        }
    }

    self.swapToken = function(tokenIn, amountInDecimal, tokenOut, options) {
        // options like {gasPrice: 11, gasLimit: 111, nonce: 111}
        let tokenInInfo = self.tokenInfo[tokenIn]
        let tokenOutInfo = self.tokenInfo[tokenOut]
        if (!tokenInInfo) {
            throw "not found token info " + tokenIn
        }

        if (!tokenOutInfo) {
            throw "not found token info " + tokenOut
        }
        
        let amountIn = toInnerAmount(amountInDecimal, tokenInInfo.decimals)
        let recipientAddress = self.walletAddress
        if (tokenInInfo.name != 'ETH') {
            let allowanceAmount = e.IO("api", tokenInInfo.address, "allowance", self.walletAddress, ContractV3SwapRouterV2);
            let realAmount = toAmount(allowanceAmount, tokenInInfo.decimals)
            if (realAmount < toAmount(amountIn, tokenInInfo.decimals)) {
                Log("realAmount is", realAmount, "too small, try to approve large amount")
                if (tokenInInfo.name == 'USDT') {
                    // As described in Tether code: To change the approve amount you first have to reduce the addresses allowance to 0 calling approve(spender, 0)
                    let txApprove = e.IO("api", tokenInInfo.address, "approve", ContractV3SwapRouterV2, 0)
                    if (!txApprove) {
                        throw "approve error"
                    }
                    Log("wait reduce approve", txApprove)
                    self.waitMined(txApprove)
                }

                let txApprove = e.IO("api", tokenInInfo.address, "approve", ContractV3SwapRouterV2, '0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff');
                if (!txApprove) {
                    throw "approve error"
                }
                Log("wait approve", txApprove)
                self.waitMined(txApprove)
                Log("approve success amountIn", amountIn)
            } else {
                Log("allowance", realAmount, "no need to approve")
            }
        }

        if (tokenOutInfo.name == 'ETH' || tokenOutInfo.address.toLowerCase() == '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2') {
            /*
            ADDRESS_THIS https://degencode.substack.com/p/uniswapv3-multicall
            https://etherscan.io/address/0x68b3465833fb72a70ecdf485e0e4c7bd8665fc45#code
            */
            recipientAddress = '0x0000000000000000000000000000000000000002'
        }

        let swapToken = e.IO("encode", ContractV3SwapRouterV2, "swapExactTokensForTokens", amountIn, 1, [tokenInInfo.address, tokenOutInfo.address], recipientAddress)
        let data = [swapToken]
        if (tokenOutInfo.name == 'ETH') {
            data.push(e.IO("encode", ContractV3SwapRouterV2, "unwrapWETH9(uint256,address)", 1, self.walletAddress))
        }
        let tx = e.IO("api", ContractV3SwapRouterV2, "multicall(uint256,bytes[])", (tokenInInfo.name == 'ETH' ? amountIn : 0), (new Date().getTime() / 1000) + 3600, data, options || {})
        if (tx) {
            Log("tx: ", tx)
            self.waitMined(tx)
            Log("swap", tokenInInfo.name, "to", tokenOutInfo.name, "success")
            return true
        } else {
            Log("trans error")
            return false
        }
    }

    self.getETHBalance = function(address) {
        return toAmount(e.IO("api", "eth", "eth_getBalance", address || self.walletAddress, "latest"), 18)
    }

    self.balanceOf = function(token, address) {
        let tokenInfo = self.tokenInfo[token]
        if (!tokenInfo) {
            throw "not found token info " + token
        }

        return toAmount(e.IO("api", tokenInfo.address, "balanceOf", address || self.walletAddress), tokenInfo.decimals)
    }

    self.sendETH = function(to, amount, options) {
        return e.IO("api", "eth", "send", to, toInnerAmount(amount, 18), options || {})
    }

    self.getPrice = function(pair) {
        let arr = pair.split('_')
        let token0 = self.tokenInfo[arr[0]]
        if (!token0) {
            throw "token " + arr[0] + "not found"
        }
        let token1 = self.tokenInfo[arr[1]]
        if (!token1) {
            throw "token " + arr[1] + "not found"
        }
        let reverse = false
        if (BigInt(token0.address) > BigInt(token1.address)) {
            let tmp = token0
            token0 = token1
            token1 = tmp
            reverse = true
        }
        let key = token0.address + '/' + token1.address
        if (typeof(self.pool[key]) == 'undefined') {
            let pool = e.IO("api", ContractV3Factory, "getPool", token0.address, token1.address, 3000)
            if (pool) {
                self.pool[key] = pool
                // register pool address
                e.IO("abi", pool, ABI_Pool)
            }
        }
        if (typeof(self.pool[key]) == 'undefined') {
            throw "pool " + pair + " not found"
        }

        let slot0 = e.IO("api", self.pool[key], "slot0")

        if (!slot0) {
            return null
        }

        let price = computePoolPrice(token0.decimals, token1.decimals, slot0.sqrtPriceX96)
        if (reverse) {
            price = 1 / price
        }
        return price
    }

    return self
}

$.testUniswap = function() {
    let ex = $.NewUniswapV3()
    Log("walletAddress: ", ex.walletAddress)
    let tokenAddressMap = {
        "ETH": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2", // WETH
        "USDT": "0xdac17f958d2ee523a2206206994597c13d831ec7",
        "1INCH": "0x111111111117dC0aa78b770fA6A738034120C302",
    }
    for (let name in tokenAddressMap) {
        ex.addToken(name, tokenAddressMap[name])
    }

    Log(ex.getPrice('ETH_USDT'))
    Log(ex.getPrice('1INCH_USDT'))
    // swap 0.01 ETH to USDT
    Log(ex.swapToken('ETH', 0.01, 'USDT'))
    let usdtBalance = ex.balanceOf('USDT')
    Log("balance of USDT", usdtBalance)
    // swap reverse
    Log(ex.swapToken('USDT', usdtBalance, 'ETH'))
    
    Log("balance of ETH", ex.getETHBalance())
    
    // Log(ex.sendETH('0x11111', 0.02))
}

The Ethereum network

The Ethereum network can be understood as a software infrastructure on which a variety of smart contracts can be deployed to run a variety of functions and application scenarios. The devices that run the Ethereum client form the nodes in the Ethereum network.

Some concepts in Uniswap V3

UnknownUniswap V3Students of the protocol need to understand a few concepts first.Uniswap V3It's also a smart contract that runs on Ethereum.

1, Routing (Route): Routing is also a smart contract used for managingtokenThe exchange. Pool: A pool is also a smart contract used to store two Ethereum tokens and exchange between them. Factory: A factory contract is a smart contract used to create a pool. ABI: An application binary interface is a specification used to describe how a smart contract communicates with the outside world. It specifies the function name, parameter type and return value type of the smart contract, how to encode and decode data, and defines the external interface of the smart contract. It can be understood that to call an interface, it must be called according to the agreed standards of the interface, and what is recorded in ABI is a set of agreed standards.

Once a smart contract is deployed on Ethereum, there is an address.

Analyze the code of the Uniswap V3 transaction library

Uniswap V3 trading library code is mainly divided into four parts, which we will explain one by one.

Part 1: Constants used when interacting with Uniswap V3

const ABI_Route = '[{"inputs":[{"internalType":"address...
const ABI_Pool = '[{\"inputs\":[],\"stateMutability\":\"nonpayable...
const ABI_Factory = '[{\"inputs\":[],\"stateMutability\":\"...

let ContractV3Factory = "0x1F98431c8aD98523631AE4a59f267346ea31F984"
let ContractV3SwapRouterV2 = "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45"

It's easy to understand here with the basic concept of preheating above.

ABI_RouteThe string stored in this constant is the ABI of a routing smart contract.ABI_PoolThe ABI of the storage pool contract.ABI_FactoryABI, the factory contractor.

Since these strings are long, they are simply selected. These content provide the program with the criteria for calling the smart contract method (e.g. what are the parameters of this smart contract interface, how many parameters, what are the types, what type of data is returned, etc.).

As we mentioned earlier, once a smart contract is deployed on Ethereum, there is an address.

ContractV3FactoryThe address of the factory contract is recorded.ContractV3SwapRouterV2Note: Uniswap V3 routers have V1, V2, Uniswap V3 routers also have V1, V2, different contract addresses are different.

Part 2: The tool functions

1、computePoolPriceThe function is used to calculate the price of tokens in the pool.

function computePoolPrice(decimals0, decimals1, sqrtPriceX96) {
    [decimals0, decimals1, sqrtPriceX96] = [decimals0, decimals1, sqrtPriceX96].map(BigInt);   // 使用BigInt函数处理，因为JavaScript语言数值精度的原因，需要使用FMZ的一个底层处理函数BigInt来处理
    const TWO = BigInt(2);     // 定义常量2用于计算
    const TEN = BigInt(10);    // 定义常量10用于计算
    const SIX_TENTH = BigInt(1000000);    // 定义常量10的6次方，即1e6
    const Q192 = (TWO ** BigInt(96)) ** TWO;  // 2^192
    return (
        Number((sqrtPriceX96 ** TWO * TEN ** decimals0 * SIX_TENTH) / (Q192 * TEN ** decimals1)) /
        Number(SIX_TENTH)
    );
}

If the transaction is correct.ETH_USDTSo, what?token0Yes, it is.ETH，token1Yes, it is.USDT。decimals0That is.token0The accuracy of the data,decimals1That is.token1The data is accurate.sqrtPriceX96This is price-related data (not a direct price value) that can be collected from the pool of contracts.slot0How to get it.

The current price of the pool as a sqrt ((token1/token0) Q64.96 value Q64.96 is a data processing storage standard.

decimals0，decimals1， sqrtPriceX96These three data are transmitted as parameters.computePoolPriceThe function can calculate the transaction pairs.ETH_USDTThe price of the function.returnThe algorithm in the sentence is tosqrtPriceX96Reducedtoken1/token0In this case, the number of tokens 0 (ETH) in the pool is 1, and the number of tokens 1 (USDT) is 1100.1100/1=1100The current transactionETH_USDTThe price in the pool is 1100 ⋅.

2、toAmountA function is used to convert the numerical data on the chain into readable data.

function toAmount(s, decimals) {
    return Number((BigDecimal(BigInt(s))/BigDecimal(Math.pow(10, decimals))).toString())
}

Simply put, for example, an ETH token represents a number on the chain as 1e18, which is the 18th power of 10, because the precision data for ETH is 18; not all tokens have the precision of 18, and the precision of USDT is different from that of ETH.toAmountThe function is to convert 1e18 to 1⁄2.

3、toInnerAmountThe function istoAmountRather, it is the numerical value that converts the readable data into the value used on the chain.

function toInnerAmount(n, decimals) {
    return (BigDecimal(n)*BigDecimal(Math.pow(10,decimals))).toFixed(0)
}

Next, let's break down the code for the Uniswap V3 trading library.

Part 3: Construction of Uniswap V3 operating objects

The core of this template library is the Uniswap V3 Operating Object, which implements the basic operations on Uniswap V3. More features may be upgraded in the future. By parsing this code example, even without the FMZ platform, you can increase the performance of the Uniswap V3 Operating Object.UniswapThis oneDEXWe will now learn how these basic functions are designed and implemented on FMZ.

The constructor function code for the Uniswap V3 operating object:

$.NewUniswapV3 = function(e) {
    e = e || exchange                          // 如果没有传参数e，就使用交易所对象exchange，即策略上第一个添加的交易所
    if (e.GetName() !== 'Web3') {              // 判断交易所对象是否是Web3，因为这个模板只支持Web3交易所对象
        panic("only support Web3 exchange")
    }


    let self = {                               // 当前函数是一个构造函数，构造的对象就是self这个对象
        tokenInfo: {},                         // self对象的成员变量，用于记录token的注册信息
        walletAddress: e.IO("address"),        // 记录当前交易所对象绑定的钱包地址
        pool: {}                               // 用于记录注册的池信息
    }

    // register
    e.IO("abi", ContractV3Factory, ABI_Factory)       // 注册工厂合约的ABI
    e.IO("abi", ContractV3SwapRouterV2, ABI_Route)    // 注册路由合约的ABI

    self.addToken = function(name, address) {         // 用于注册token
        let ret = e.IO("api", address, "decimals")    // 调用decimals方法，获取token精度信息
        if (!ret) {
            throw "get token decimals failed"
        }
        let decimals = Number(ret)
        self.tokenInfo[name] = {
            name: name,
            decimals: decimals,
            address: address
        }
    }
    self.waitMined = function(tx) {             // 用于等待以太坊上某个操作的结果，哈希为tx参数
        while (true) {
            Sleep(1000)
            let info = e.IO("api", "eth", "eth_getTransactionReceipt", tx)  // 查询结果使用eth_getTransactionReceipt方法，没有查询到，循环继续查询
            if (info && info.gasUsed) {
                return true
            }
            Log('Transaction not yet mined', tx)
        }
    }

    self.swapToken = function(tokenIn, amountInDecimal, tokenOut, options) {   // 用于token兑换
        // options like {gasPrice: 11, gasLimit: 111, nonce: 111}
        let tokenInInfo = self.tokenInfo[tokenIn]      // 拿到兑换出去的token的信息
        let tokenOutInfo = self.tokenInfo[tokenOut]    // 拿到兑换回来的token的信息
        if (!tokenInInfo) {
            throw "not found token info " + tokenIn
        }

        if (!tokenOutInfo) {
            throw "not found token info " + tokenOut
        }
        
        let amountIn = toInnerAmount(amountInDecimal, tokenInInfo.decimals)  // 转换为智能合约上使用的数据
        let recipientAddress = self.walletAddress
        if (tokenInInfo.name != 'ETH') {
            let allowanceAmount = e.IO("api", tokenInInfo.address, "allowance", self.walletAddress, ContractV3SwapRouterV2);   // 查询授权的数量
            let realAmount = toAmount(allowanceAmount, tokenInInfo.decimals)
            if (realAmount < toAmount(amountIn, tokenInInfo.decimals)) {    // 如果授权数量不足
                Log("realAmount is", realAmount, "too small, try to approve large amount")
                if (tokenInInfo.name == 'USDT') {
                    // As described in Tether code: To change the approve amount you first have to reduce the addresses allowance to 0 calling approve(spender, 0)
                    let txApprove = e.IO("api", tokenInInfo.address, "approve", ContractV3SwapRouterV2, 0)  // 如果授权的token是USDT，需要先授权为0
                    if (!txApprove) {
                        throw "approve error"
                    }
                    Log("wait reduce approve", txApprove)
                    self.waitMined(txApprove)
                }

                let txApprove = e.IO("api", tokenInInfo.address, "approve", ContractV3SwapRouterV2, '0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff');  // 授权Router合约操作钱包的代币
                if (!txApprove) {
                    throw "approve error"
                }
                Log("wait approve", txApprove)
                self.waitMined(txApprove)
                Log("approve success amountIn", amountIn)
            } else {
                Log("allowance", realAmount, "no need to approve")
            }
        }

        if (tokenOutInfo.name == 'ETH' || tokenOutInfo.address.toLowerCase() == '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2') {
            /*
            ADDRESS_THIS https://degencode.substack.com/p/uniswapv3-multicall
            https://etherscan.io/address/0x68b3465833fb72a70ecdf485e0e4c7bd8665fc45#code
            */
            recipientAddress = '0x0000000000000000000000000000000000000002'
            // 其它币换成 WETH的时候，要让合约HOLD住WETH才可以赎回
        }

        let swapToken = e.IO("encode", ContractV3SwapRouterV2, "swapExactTokensForTokens", amountIn, 1, [tokenInInfo.address, tokenOutInfo.address], recipientAddress)   // 打包swapExactTokensForTokens调用
        let data = [swapToken]
        if (tokenOutInfo.name == 'ETH') {    // 如果兑换时，兑换回来的token是ETH，这里实际是WETH，则需要解包
            data.push(e.IO("encode", ContractV3SwapRouterV2, "unwrapWETH9(uint256,address)", 1, self.walletAddress))   // 所以这里再打包一个unwrapWETH9解包调用
        }
        let tx = e.IO("api", ContractV3SwapRouterV2, "multicall(uint256,bytes[])", (tokenInInfo.name == 'ETH' ? amountIn : 0), (new Date().getTime() / 1000) + 3600, data, options || {})   // 使用multicall执行这些打包的操作（swapExactTokensForTokens、unwrapWETH9）
        if (tx) {
            Log("tx: ", tx)
            self.waitMined(tx)
            Log("swap", tokenInInfo.name, "to", tokenOutInfo.name, "success")
            return true
        } else {
            Log("trans error")
            return false
        }
    }

    self.getETHBalance = function(address) {   // 查询钱包的ETH余额
        return toAmount(e.IO("api", "eth", "eth_getBalance", address || self.walletAddress, "latest"), 18)
    }

    self.balanceOf = function(token, address) {  // 查询钱包的某个token余额（根据参数确定）
        let tokenInfo = self.tokenInfo[token]
        if (!tokenInfo) {
            throw "not found token info " + token