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import { Order, SignedOrder, ZeroEx } from '0x.js';
import { NonceTrackerSubprovider } from '@0xproject/subproviders';
import { BigNumber } from '@0xproject/utils';
import * as express from 'express';
import * as _ from 'lodash';
import * as Web3 from 'web3';
// HACK: web3 injects XMLHttpRequest into the global scope and ProviderEngine checks XMLHttpRequest
// to know whether it is running in a browser or node environment. We need it to be undefined since
// we are not running in a browser env.
// Filed issue: https://github.com/ethereum/web3.js/issues/844
(global as any).XMLHttpRequest = undefined;
import ProviderEngine = require('web3-provider-engine');
import HookedWalletSubprovider = require('web3-provider-engine/subproviders/hooked-wallet');
import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
import { configs } from './configs';
import { EtherRequestQueue } from './ether_request_queue';
import { idManagement } from './id_management';
import { RequestQueue } from './request_queue';
import { rpcUrls } from './rpc_urls';
import { utils } from './utils';
import { ZRXRequestQueue } from './zrx_request_queue';
interface ItemByNetworkId<T> {
[networkId: string]: T;
}
enum RequestedAssetType {
ETH = 'ETH',
WETH = 'WETH',
ZRX = 'ZRX',
}
const FIVE_DAYS_IN_MS = 4.32e8; // TODO: make this configurable
export class Handler {
private _zeroExByNetworkId: ItemByNetworkId<ZeroEx> = {};
private _etherRequestQueueByNetworkId: ItemByNetworkId<RequestQueue> = {};
private _zrxRequestQueueByNetworkId: ItemByNetworkId<RequestQueue> = {};
private static _dispenseAsset(
req: express.Request,
res: express.Response,
requestQueueByNetworkId: ItemByNetworkId<RequestQueue>,
requestedAssetType: RequestedAssetType,
) {
const requestQueue = _.get(requestQueueByNetworkId, req.params.networkId);
if (_.isUndefined(requestQueue)) {
res.status(400).send('UNSUPPORTED_NETWORK_ID');
return;
}
const didAddToQueue = requestQueue.add(req.params.recipient);
if (!didAddToQueue) {
res.status(503).send('QUEUE_IS_FULL');
return;
}
utils.consoleLog(
`Added ${req.params.recipient} to queue: ${requestedAssetType} networkId: ${req.params.networkId}`,
);
res.status(200).end();
}
private static _createProviderEngine(rpcUrl: string) {
const engine = new ProviderEngine();
engine.addProvider(new NonceTrackerSubprovider());
engine.addProvider(new HookedWalletSubprovider(idManagement));
engine.addProvider(
new RpcSubprovider({
rpcUrl,
}),
);
engine.start();
return engine;
}
constructor() {
_.forIn(rpcUrls, (rpcUrl: string, networkId: string) => {
const providerObj = Handler._createProviderEngine(rpcUrl);
const web3 = new Web3(providerObj);
const zeroExConfig = {
networkId: +networkId,
};
const zeroEx = new ZeroEx(web3.currentProvider, zeroExConfig);
this._zeroExByNetworkId[networkId] = zeroEx;
this._etherRequestQueueByNetworkId[networkId] = new EtherRequestQueue(web3);
this._zrxRequestQueueByNetworkId[networkId] = new ZRXRequestQueue(web3, zeroEx);
});
}
public getQueueInfo(req: express.Request, res: express.Response) {
res.setHeader('Content-Type', 'application/json');
const queueInfo = _.mapValues(rpcUrls, (rpcUrl: string, networkId: string) => {
const etherRequestQueue = this._etherRequestQueueByNetworkId[networkId];
const zrxRequestQueue = this._zrxRequestQueueByNetworkId[networkId];
return {
ether: {
full: etherRequestQueue.isFull(),
size: etherRequestQueue.size(),
},
zrx: {
full: zrxRequestQueue.isFull(),
size: zrxRequestQueue.size(),
},
};
});
const payload = JSON.stringify(queueInfo);
res.status(200).send(payload);
}
public dispenseEther(req: express.Request, res: express.Response) {
Handler._dispenseAsset(req, res, this._etherRequestQueueByNetworkId, RequestedAssetType.ETH);
}
public dispenseZRX(req: express.Request, res: express.Response) {
Handler._dispenseAsset(req, res, this._zrxRequestQueueByNetworkId, RequestedAssetType.ZRX);
}
public async dispenseWETHOrder(req: express.Request, res: express.Response) {
await this._dispenseOrder(req, res, RequestedAssetType.WETH);
}
public async dispenseZRXOrder(req: express.Request, res: express.Response, next: express.NextFunction) {
await this._dispenseOrder(req, res, RequestedAssetType.ZRX);
}
private async _dispenseOrder(req: express.Request, res: express.Response, requestedAssetType: RequestedAssetType) {
const zeroEx = _.get(this._zeroExByNetworkId, req.params.networkId);
if (_.isUndefined(zeroEx)) {
res.status(400).send('UNSUPPORTED_NETWORK_ID');
return;
}
res.setHeader('Content-Type', 'application/json');
const makerTokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(requestedAssetType);
if (_.isUndefined(makerTokenAddress)) {
throw new Error(`Unsupported asset type: ${requestedAssetType}`);
}
const takerTokenSymbol =
requestedAssetType === RequestedAssetType.WETH ? RequestedAssetType.ZRX : RequestedAssetType.WETH;
const takerTokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(takerTokenSymbol);
if (_.isUndefined(takerTokenAddress)) {
throw new Error(`Unsupported asset type: ${requestedAssetType}`);
}
const makerTokenAmount = new BigNumber(0.1);
const takerTokenAmount = new BigNumber(0.1);
const order: Order = {
maker: configs.DISPENSER_ADDRESS,
taker: req.params.recipient,
makerFee: new BigNumber(0),
takerFee: new BigNumber(0),
makerTokenAmount,
takerTokenAmount,
makerTokenAddress,
takerTokenAddress,
salt: ZeroEx.generatePseudoRandomSalt(),
exchangeContractAddress: zeroEx.exchange.getContractAddress(),
feeRecipient: ZeroEx.NULL_ADDRESS,
expirationUnixTimestampSec: new BigNumber(Date.now() + FIVE_DAYS_IN_MS),
};
const orderHash = ZeroEx.getOrderHashHex(order);
const signature = await zeroEx.signOrderHashAsync(orderHash, configs.DISPENSER_ADDRESS, false);
const signedOrder = {
...order,
signature,
};
const signedOrderHash = ZeroEx.getOrderHashHex(signedOrder);
const payload = JSON.stringify(signedOrder);
utils.consoleLog(`Dispensed signed order: ${payload}`);
res.status(200).send(payload);
}
}
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