1. /* Sourced from 0x.js */
    3. import { BigNumber } from '@0xproject/utils';
    4. import * as _ from 'lodash';
    5. import * as Web3 from 'web3';
    6. import * as SolidityCoder from 'web3/lib/solidity/coder';
    8. import { AbiType, ContractEventArgs, DecodedLogArgs, LogWithDecodedArgs, RawLog, SolidityTypes } from '../types';
    9. // abi解码器
    10. export class AbiDecoder {
    11.     private _savedABIs: Web3.AbiDefinition[] = [];
    12.     private _methodIds: { [signatureHash: string]: Web3.EventAbi } = {};
    13. // 填充0
    14.     private static _padZeros(address: string) {
    15.         let formatted = address;
    16.         if (_.startsWith(formatted, '0x')) {
    17.             formatted = formatted.slice(2);
    18.         }
    20.         formatted = _.padStart(formatted, 40, '0');
    21.         return `0x${formatted}`;
    22.     }
    23.     constructor(abiArrays: Web3.AbiDefinition[][]) {
    24.         _.map(abiArrays, this._addABI.bind(this));
    25.     }
    26.     // 此方法只能解码 0x 和 ERC20 智能合约的日志
    27.         // 尝试解码日志或 Noop
    28.     public tryToDecodeLogOrNoop<ArgsType extends ContractEventArgs>(
    29.         log: Web3.LogEntry,
    30.     ): LogWithDecodedArgs<ArgsType> | RawLog {
    31.         const methodId = log.topics[0];
    32.         const event = this._methodIds[methodId];
    33.         if (_.isUndefined(event)) {
    34.             return log;
    35.         }
    36.         const logData = log.data;
    37.         const decodedParams: DecodedLogArgs = {};
    38.         let dataIndex = 0;
    39.         let topicsIndex = 1;
    41.         const nonIndexedInputs = _.filter(event.inputs, input => !input.indexed);
    42.         const dataTypes = _.map(nonIndexedInputs, input => input.type);
    43.         const decodedData = SolidityCoder.decodeParams(dataTypes, logData.slice('0x'.length));
    45.         _.map(event.inputs, (param: Web3.EventParameter) => {
    46.             // 索引参数存储在主题中。解码数据中的非索引项
    47.             let value = param.indexed ? log.topics[topicsIndex++] : decodedData[dataIndex++];
    48.             if (param.type === SolidityTypes.Address) {
    49.                 value = AbiDecoder._padZeros(new BigNumber(value).toString(16));
    50.             } else if (
    51.                 param.type === SolidityTypes.Uint256 ||
    52.                 param.type === SolidityTypes.Uint8 ||
    53.                 param.type === SolidityTypes.Uint
    54.             ) {
    55.                 value = new BigNumber(value);
    56.             }
    57.             decodedParams[param.name] = value;
    58.         });
    60.         return {
    61.             ...log,
    62.             event: event.name,
    63.             args: decodedParams,
    64.         };
    65.     }
    66.     private _addABI(abiArray: Web3.AbiDefinition[]): void {
    67.         _.map(abiArray, (abi: Web3.AbiDefinition) => {
    68.             if (abi.type === AbiType.Event) {
    69.                 const signature = `${abi.name}(${_.map(abi.inputs, input => input.type).join(',')})`;
    70.                 const signatureHash = new Web3().sha3(signature);
    71.                 this._methodIds[signatureHash] = abi;
    72.             }
    73.         });
    74.         this._savedABIs = this._savedABIs.concat(abiArray);
    75.     }
    76. }