6ac7dd006c
`@0x/asset-swapper`: use gasCost from sampler service cleanup `@0x/asset-swapper`: Handle per-fill gas cost correctly in more places getting multihop back up + refactors for treating all quotes as n-hop multihop with nice breakdowns get vips working get multiplex working get rfq working remove unused functions fix multihop buys plz work multihop buys multihop buys seem ok now. fetch less samples for multihop legs get quote report and price comparisons working clean up
93 lines
3.4 KiB
TypeScript
93 lines
3.4 KiB
TypeScript
import { BigNumber } from '@0x/utils';
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import * as heartbeats from 'heartbeats';
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import fetch from 'axios';
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import { constants } from '../constants';
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import { SwapQuoterError } from '../types';
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const MAX_ERROR_COUNT = 5;
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export class ProtocolFeeUtils {
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private static _instance: ProtocolFeeUtils;
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private readonly _ethGasStationUrl!: string;
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private readonly _gasPriceHeart: any;
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private _gasPriceEstimation: BigNumber = constants.ZERO_AMOUNT;
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private _errorCount: number = 0;
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public static getInstance(
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gasPricePollingIntervalInMs: number,
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ethGasStationUrl: string = constants.ETH_GAS_STATION_API_URL,
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initialGasPrice: BigNumber = constants.ZERO_AMOUNT,
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): ProtocolFeeUtils {
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if (!ProtocolFeeUtils._instance) {
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ProtocolFeeUtils._instance = new ProtocolFeeUtils(
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gasPricePollingIntervalInMs,
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ethGasStationUrl,
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initialGasPrice,
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);
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}
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return ProtocolFeeUtils._instance;
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}
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public async getGasPriceEstimationOrThrowAsync(shouldHardRefresh?: boolean): Promise<BigNumber> {
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if (this._gasPriceEstimation.eq(constants.ZERO_AMOUNT)) {
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return this._getGasPriceFromGasStationOrThrowAsync();
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}
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if (shouldHardRefresh) {
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return this._getGasPriceFromGasStationOrThrowAsync();
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} else {
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return this._gasPriceEstimation;
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}
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}
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/**
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* Destroys any subscriptions or connections.
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*/
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public async destroyAsync(): Promise<void> {
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this._gasPriceHeart.kill();
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}
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private constructor(
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gasPricePollingIntervalInMs: number,
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ethGasStationUrl: string = constants.ETH_GAS_STATION_API_URL,
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initialGasPrice: BigNumber = constants.ZERO_AMOUNT,
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) {
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this._gasPriceHeart = heartbeats.createHeart(gasPricePollingIntervalInMs);
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this._gasPriceEstimation = initialGasPrice;
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this._ethGasStationUrl = ethGasStationUrl;
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this._initializeHeartBeat();
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}
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// tslint:disable-next-line: prefer-function-over-method
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private async _getGasPriceFromGasStationOrThrowAsync(): Promise<BigNumber> {
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try {
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const res = await fetch(this._ethGasStationUrl);
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const gasInfo = res.data;
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// Eth Gas Station result is gwei * 10
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// tslint:disable-next-line:custom-no-magic-numbers
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const BASE_TEN = 10;
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const gasPriceGwei = new BigNumber(gasInfo.fast / BASE_TEN);
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// tslint:disable-next-line:custom-no-magic-numbers
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const unit = new BigNumber(BASE_TEN).pow(9);
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const gasPriceWei = unit.times(gasPriceGwei);
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// Reset the error count to 0 once we have a successful response
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this._errorCount = 0;
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return gasPriceWei;
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} catch (e) {
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this._errorCount++;
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// If we've reached our max error count then throw
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if (this._errorCount > MAX_ERROR_COUNT || this._gasPriceEstimation.isZero()) {
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this._errorCount = 0;
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throw new Error(SwapQuoterError.NoGasPriceProvidedOrEstimated);
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}
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return this._gasPriceEstimation;
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}
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}
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private _initializeHeartBeat(): void {
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this._gasPriceHeart.createEvent(1, async () => {
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this._gasPriceEstimation = await this._getGasPriceFromGasStationOrThrowAsync();
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});
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}
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}
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