exchange.IO("decode", ...)

exchange.IO("decode", ...)函数用于数据解码操作。

    
    
    
exchange.IO(k, dataFormat, data)

示例

• exchange.IO("encode", ...)函数的逆向操作示例：

  
      javascript
      
      
  function main() {
      var types = "tuple(a uint256,b uint8,c address),bytes"
      var ret = exchange.IO("encode", types, {
          a: 30,
          b: 20,
          c: "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2"
      }, "0011")
      Log("encode: ", ret)
  
      var rawData = exchange.IO("decode", types, ret)
      Log("decode:", rawData)
  }
  

• 以下示例首先对path参数执行encodePacked操作，因为后续需要编码的exactOutput方法调用需要path作为参数。然后对路由合约的exactOutput方法进行编码，该方法只有一个参数，参数类型为tuple类型。exactOutput方法名编码后的结果为：0x09b81346，使用exchange.IO("decode", ...)方法解码得到decodeRaw，其结果与变量dataTuple保持一致。

  
      javascript
      
      
  function main() {
      // register SwapRouter02 abi
      var walletAddress = "0x398a93ca23CBdd2642a07445bCD2b8435e0a373f"
      var routerAddress = "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45"
      var abi = `[{"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"}]`
      exchange.IO("abi", routerAddress, abi)   // abi只使用了局部的exactOutput方法的内容，完整的abi可以在网上搜索
  
      // encode path
      var fee = exchange.IO("encodePacked", "uint24", 3000)
      var tokenInAddress = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2"
      var tokenOutAddress = "0xdac17f958d2ee523a2206206994597c13d831ec7"
      var path = tokenInAddress.slice(2).toLowerCase()
      path += fee + tokenOutAddress.slice(2).toLowerCase()
      Log("path:", path)
  
      var dataTuple = {
          "path" : path,
          "recipient" : walletAddress,
          "amountOut" : 1000,
          "amountInMaximum" : 1,
      }
      // encode SwapRouter02 exactOutput
      var rawData = exchange.IO("encode", routerAddress, "exactOutput", dataTuple)
      Log("method hash:", rawData.slice(0, 8))   // 09b81346
      Log("params hash:", rawData.slice(8))
  
      // decode exactOutput params
      var decodeRaw = exchange.IO("decode", "tuple(path bytes,recipient address,amountOut uint256,amountInMaximum uint256)", rawData.slice(8))
      Log("decodeRaw:", decodeRaw)
  }
  

返回值

参数

备注

exchange.IO()函数支持数据的双向处理，既可以进行编码（encode）操作，也可以进行解码（decode）操作。