// tslint:disable:no-unnecessary-type-assertion
import { ContractAddresses } from '@0x/contract-addresses';
import * as artifacts from '@0x/contract-artifacts';
import {
AssetBalanceAndProxyAllowanceFetcher,
ContractWrappers,
ERC20TokenApprovalEventArgs,
ERC20TokenEventArgs,
ERC20TokenEvents,
ERC20TokenTransferEventArgs,
ERC721TokenApprovalEventArgs,
ERC721TokenApprovalForAllEventArgs,
ERC721TokenEventArgs,
ERC721TokenEvents,
ERC721TokenTransferEventArgs,
ExchangeCancelEventArgs,
ExchangeCancelUpToEventArgs,
ExchangeEventArgs,
ExchangeEvents,
ExchangeFillEventArgs,
OrderFilledCancelledFetcher,
WETH9DepositEventArgs,
WETH9EventArgs,
WETH9Events,
WETH9WithdrawalEventArgs,
} from '@0x/contract-wrappers';
import { schemas } from '@0x/json-schemas';
import {
assetDataUtils,
BalanceAndProxyAllowanceLazyStore,
OrderFilledCancelledLazyStore,
orderHashUtils,
OrderStateUtils,
} from '@0x/order-utils';
import { AssetProxyId, ExchangeContractErrs, OrderState, SignedOrder, Stats } from '@0x/types';
import { errorUtils, intervalUtils } from '@0x/utils';
import { BlockParamLiteral, LogEntryEvent, LogWithDecodedArgs, Provider } from 'ethereum-types';
import * as _ from 'lodash';
import { orderWatcherPartialConfigSchema } from '../schemas/order_watcher_partial_config_schema';
import { OnOrderStateChangeCallback, OrderWatcherConfig, OrderWatcherError } from '../types';
import { assert } from '../utils/assert';
import { CollisionResistanceAbiDecoder } from './collision_resistant_abi_decoder';
import { DependentOrderHashesTracker } from './dependent_order_hashes_tracker';
import { EventWatcher } from './event_watcher';
import { ExpirationWatcher } from './expiration_watcher';
const MILLISECONDS_IN_A_SECOND = 1000;
type ContractEventArgs = WETH9EventArgs | ExchangeEventArgs | ERC20TokenEventArgs | ERC721TokenEventArgs;
interface OrderByOrderHash {
[orderHash: string]: SignedOrder;
}
interface OrderStateByOrderHash {
[orderHash: string]: OrderState;
}
const DEFAULT_ORDER_WATCHER_CONFIG: OrderWatcherConfig = {
orderExpirationCheckingIntervalMs: 50,
eventPollingIntervalMs: 200,
expirationMarginMs: 0,
// tslint:disable-next-line:custom-no-magic-numbers
cleanupJobIntervalMs: 1000 * 60 * 60, // 1h
isVerbose: true,
};
const STATE_LAYER = BlockParamLiteral.Latest;
/**
* This class includes all the functionality related to watching a set of orders
* for potential changes in order validity/fillability. The orderWatcher notifies
* the subscriber of these changes so that a final decision can be made on whether
* the order should be deemed invalid.
*/
export class OrderWatcher {
private readonly _dependentOrderHashesTracker: DependentOrderHashesTracker;
private readonly _orderStateByOrderHashCache: OrderStateByOrderHash = {};
private readonly _orderByOrderHash: OrderByOrderHash = {};
private readonly _eventWatcher: EventWatcher;
private readonly _provider: Provider;
private readonly _collisionResistantAbiDecoder: CollisionResistanceAbiDecoder;
private readonly _expirationWatcher: ExpirationWatcher;
private readonly _orderStateUtils: OrderStateUtils;
private readonly _orderFilledCancelledLazyStore: OrderFilledCancelledLazyStore;
private readonly _balanceAndProxyAllowanceLazyStore: BalanceAndProxyAllowanceLazyStore;
private readonly _cleanupJobInterval: number;
private _cleanupJobIntervalIdIfExists?: NodeJS.Timer;
private _callbackIfExists?: OnOrderStateChangeCallback;
/**
* Instantiate a new OrderWatcher
* @param provider Web3 provider to use for JSON RPC calls
* @param networkId NetworkId to watch orders on
* @param contractAddresses Optional contract addresses. Defaults to known
* addresses based on networkId.
* @param partialConfig Optional configurations
*/
constructor(
provider: Provider,
networkId: number,
contractAddresses?: ContractAddresses,
partialConfig: Partial<OrderWatcherConfig> = DEFAULT_ORDER_WATCHER_CONFIG,
) {
assert.isWeb3Provider('provider', provider);
assert.isNumber('networkId', networkId);
assert.doesConformToSchema('partialConfig', partialConfig, orderWatcherPartialConfigSchema);
const config = {
...DEFAULT_ORDER_WATCHER_CONFIG,
...partialConfig,
};
this._provider = provider;
this._collisionResistantAbiDecoder = new CollisionResistanceAbiDecoder(
artifacts.ERC20Token.compilerOutput.abi,
artifacts.ERC721Token.compilerOutput.abi,
[artifacts.WETH9.compilerOutput.abi, artifacts.Exchange.compilerOutput.abi],
);
const contractWrappers = new ContractWrappers(provider, {
networkId,
// Note(albrow): We let the contract-wrappers package handle
// default values for contractAddresses.
contractAddresses,
});
this._eventWatcher = new EventWatcher(provider, config.eventPollingIntervalMs, STATE_LAYER, config.isVerbose);
const balanceAndProxyAllowanceFetcher = new AssetBalanceAndProxyAllowanceFetcher(
contractWrappers.erc20Token,
contractWrappers.erc721Token,
STATE_LAYER,
);
this._balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
balanceAndProxyAllowanceFetcher,
);
const orderFilledCancelledFetcher = new OrderFilledCancelledFetcher(contractWrappers.exchange, STATE_LAYER);
this._orderFilledCancelledLazyStore = new OrderFilledCancelledLazyStore(orderFilledCancelledFetcher);
this._orderStateUtils = new OrderStateUtils(balanceAndProxyAllowanceFetcher, orderFilledCancelledFetcher);
const expirationMarginIfExistsMs = _.isUndefined(config) ? undefined : config.expirationMarginMs;
this._expirationWatcher = new ExpirationWatcher(
expirationMarginIfExistsMs,
config.orderExpirationCheckingIntervalMs,
);
this._cleanupJobInterval = config.cleanupJobIntervalMs;
const zrxTokenAddress = assetDataUtils.decodeERC20AssetData(orderFilledCancelledFetcher.getZRXAssetData())
.tokenAddress;
this._dependentOrderHashesTracker = new DependentOrderHashesTracker(zrxTokenAddress);
}
/**
* Add an order to the orderWatcher. Before the order is added, it's
* signature is verified.
* @param signedOrder The order you wish to start watching.
*/
public async addOrderAsync(signedOrder: SignedOrder): Promise<void> {
assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
await assert.isValidSignatureAsync(this._provider, orderHash, signedOrder.signature, signedOrder.makerAddress);
const expirationUnixTimestampMs = signedOrder.expirationTimeSeconds.times(MILLISECONDS_IN_A_SECOND);
this._expirationWatcher.addOrder(orderHash, expirationUnixTimestampMs);
this._orderByOrderHash[orderHash] = signedOrder;
this._dependentOrderHashesTracker.addToDependentOrderHashes(signedOrder);
const orderAssetDatas = [signedOrder.makerAssetData, signedOrder.takerAssetData];
_.each(orderAssetDatas, assetData => {
const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
if (decodedAssetData.assetProxyId === AssetProxyId.ERC20) {
this._collisionResistantAbiDecoder.addERC20Token(decodedAssetData.tokenAddress);
} else if (decodedAssetData.assetProxyId === AssetProxyId.ERC721) {
this._collisionResistantAbiDecoder.addERC721Token(decodedAssetData.tokenAddress);
}
});
}
/**
* Removes an order from the orderWatcher
* @param orderHash The orderHash of the order you wish to stop watching.
*/
public removeOrder(orderHash: string): void {
assert.doesConformToSchema('orderHash', orderHash, schemas.orderHashSchema);
const signedOrder = this._orderByOrderHash[orderHash];
if (_.isUndefined(signedOrder)) {
return; // noop
}
this._dependentOrderHashesTracker.removeFromDependentOrderHashes(signedOrder);
delete this._orderByOrderHash[orderHash];
this._expirationWatcher.removeOrder(orderHash);
delete this._orderStateByOrderHashCache[orderHash];
}
/**
* Starts an orderWatcher subscription. The callback will be called every time a watched order's
* backing blockchain state has changed. This is a call-to-action for the caller to re-validate the order.
* @param callback Receives the orderHash of the order that should be re-validated, together
* with all the order-relevant blockchain state needed to re-validate the order.
*/
public subscribe(callback: OnOrderStateChangeCallback): void {
assert.isFunction('callback', callback);
if (!_.isUndefined(this._callbackIfExists)) {
throw new Error(OrderWatcherError.SubscriptionAlreadyPresent);
}
this._callbackIfExists = callback;
this._eventWatcher.subscribe(this._onEventWatcherCallbackAsync.bind(this));
this._expirationWatcher.subscribe(this._onOrderExpired.bind(this));
this._cleanupJobIntervalIdIfExists = intervalUtils.setAsyncExcludingInterval(
this._cleanupAsync.bind(this),
this._cleanupJobInterval,
(err: Error) => {
this.unsubscribe();
callback(err);
},
);
}
/**
* Ends an orderWatcher subscription.
*/
public unsubscribe(): void {
if (_.isUndefined(this._callbackIfExists) || _.isUndefined(this._cleanupJobIntervalIdIfExists)) {
throw new Error(OrderWatcherError.SubscriptionNotFound);
}
this._balanceAndProxyAllowanceLazyStore.deleteAll();
this._orderFilledCancelledLazyStore.deleteAll();
delete this._callbackIfExists;
this._eventWatcher.unsubscribe();
this._expirationWatcher.unsubscribe();
intervalUtils.clearAsyncExcludingInterval(this._cleanupJobIntervalIdIfExists);
}
/**
* Gets statistics of the OrderWatcher Instance.
*/
public getStats(): Stats {
return {
orderCount: _.size(this._orderByOrderHash),
};
}
private async _cleanupAsync(): Promise<void> {
for (const orderHash of _.keys(this._orderByOrderHash)) {
this._cleanupOrderRelatedState(orderHash);
await this._emitRevalidateOrdersAsync([orderHash]);
}
}
private _cleanupOrderRelatedState(orderHash: string): void {
const signedOrder = this._orderByOrderHash[orderHash];
this._orderFilledCancelledLazyStore.deleteFilledTakerAmount(orderHash);
this._orderFilledCancelledLazyStore.deleteIsCancelled(orderHash);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(signedOrder.makerAssetData, signedOrder.makerAddress);
this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(
signedOrder.makerAssetData,
signedOrder.makerAddress,
);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(signedOrder.takerAssetData, signedOrder.takerAddress);
this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(
signedOrder.takerAssetData,
signedOrder.takerAddress,
);
const zrxAssetData = this._orderFilledCancelledLazyStore.getZRXAssetData();
if (!signedOrder.makerFee.isZero()) {
this._balanceAndProxyAllowanceLazyStore.deleteBalance(zrxAssetData, signedOrder.makerAddress);
this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(zrxAssetData, signedOrder.makerAddress);
}
if (!signedOrder.takerFee.isZero()) {
this._balanceAndProxyAllowanceLazyStore.deleteBalance(zrxAssetData, signedOrder.takerAddress);
this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(zrxAssetData, signedOrder.takerAddress);
}
}
private _onOrderExpired(orderHash: string): void {
const orderState: OrderState = {
isValid: false,
orderHash,
error: ExchangeContractErrs.OrderFillExpired,
};
if (!_.isUndefined(this._orderByOrderHash[orderHash])) {
this.removeOrder(orderHash);
if (!_.isUndefined(this._callbackIfExists)) {
this._callbackIfExists(null, orderState);
}
}
}
private async _onEventWatcherCallbackAsync(err: Error | null, logIfExists?: LogEntryEvent): Promise<void> {
if (!_.isNull(err)) {
if (!_.isUndefined(this._callbackIfExists)) {
this._callbackIfExists(err);
}
return;
}
const maybeDecodedLog = this._collisionResistantAbiDecoder.tryToDecodeLogOrNoop<ContractEventArgs>(
// At this moment we are sure that no error occured and log is defined.
logIfExists as LogEntryEvent,
);
const isLogDecoded = !_.isUndefined(((maybeDecodedLog as any) as LogWithDecodedArgs<ContractEventArgs>).event);
if (!isLogDecoded) {
return; // noop
}
const decodedLog = (maybeDecodedLog as any) as LogWithDecodedArgs<ContractEventArgs>;
const transactionHash = decodedLog.transactionHash;
switch (decodedLog.event) {
case ERC20TokenEvents.Approval:
case ERC721TokenEvents.Approval: {
// ERC20 and ERC721 Transfer events have the same name so we need to distinguish them by args
if (!_.isUndefined(decodedLog.args._value)) {
// ERC20
// Invalidate cache
const args = decodedLog.args as ERC20TokenApprovalEventArgs;
const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(tokenAssetData, args._owner);
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
args._owner,
tokenAssetData,
);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
} else {
// ERC721
// Invalidate cache
const args = decodedLog.args as ERC721TokenApprovalEventArgs;
const tokenAssetData = assetDataUtils.encodeERC721AssetData(decodedLog.address, args._tokenId);
this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(tokenAssetData, args._owner);
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
args._owner,
tokenAssetData,
);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
}
}
case ERC20TokenEvents.Transfer:
case ERC721TokenEvents.Transfer: {
// ERC20 and ERC721 Transfer events have the same name so we need to distinguish them by args
if (!_.isUndefined(decodedLog.args._value)) {
// ERC20
// Invalidate cache
const args = decodedLog.args as ERC20TokenTransferEventArgs;
const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._from);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._to);
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
args._from,
tokenAssetData,
);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
} else {
// ERC721
// Invalidate cache
const args = decodedLog.args as ERC721TokenTransferEventArgs;
const tokenAssetData = assetDataUtils.encodeERC721AssetData(decodedLog.address, args._tokenId);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._from);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._to);
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
args._from,
tokenAssetData,
);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
}
}
case ERC721TokenEvents.ApprovalForAll: {
// Invalidate cache
const args = decodedLog.args as ERC721TokenApprovalForAllEventArgs;
const tokenAddress = decodedLog.address;
this._balanceAndProxyAllowanceLazyStore.deleteAllERC721ProxyAllowance(tokenAddress, args._owner);
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByERC721ByMaker(
args._owner,
tokenAddress,
);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
}
case WETH9Events.Deposit: {
// Invalidate cache
const args = decodedLog.args as WETH9DepositEventArgs;
const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._owner);
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
args._owner,
tokenAssetData,
);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
}
case WETH9Events.Withdrawal: {
// Invalidate cache
const args = decodedLog.args as WETH9WithdrawalEventArgs;
const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._owner);
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
args._owner,
tokenAssetData,
);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
}
case ExchangeEvents.Fill: {
// Invalidate cache
const args = decodedLog.args as ExchangeFillEventArgs;
this._orderFilledCancelledLazyStore.deleteFilledTakerAmount(args.orderHash);
// Revalidate orders
const orderHash = args.orderHash;
const isOrderWatched = !_.isUndefined(this._orderByOrderHash[orderHash]);
if (isOrderWatched) {
await this._emitRevalidateOrdersAsync([orderHash], transactionHash);
}
break;
}
case ExchangeEvents.Cancel: {
// Invalidate cache
const args = decodedLog.args as ExchangeCancelEventArgs;
this._orderFilledCancelledLazyStore.deleteIsCancelled(args.orderHash);
// Revalidate orders
const orderHash = args.orderHash;
const isOrderWatched = !_.isUndefined(this._orderByOrderHash[orderHash]);
if (isOrderWatched) {
await this._emitRevalidateOrdersAsync([orderHash], transactionHash);
}
break;
}
case ExchangeEvents.CancelUpTo: {
// TODO(logvinov): Do it smarter and actually look at the salt and order epoch
// Invalidate cache
const args = decodedLog.args as ExchangeCancelUpToEventArgs;
this._orderFilledCancelledLazyStore.deleteAllIsCancelled();
// Revalidate orders
const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByMaker(args.makerAddress);
await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
break;
}
default:
throw errorUtils.spawnSwitchErr('decodedLog.event', decodedLog.event);
}
}
private async _emitRevalidateOrdersAsync(orderHashes: string[], transactionHash?: string): Promise<void> {
for (const orderHash of orderHashes) {
const signedOrder = this._orderByOrderHash[orderHash];
// Most of these calls will never reach the network because the data is fetched from stores
// and only updated when cache is invalidated
const orderState = await this._orderStateUtils.getOpenOrderStateAsync(signedOrder, transactionHash);
if (_.isUndefined(this._callbackIfExists)) {
break; // Unsubscribe was called
}
if (_.isEqual(orderState, this._orderStateByOrderHashCache[orderHash])) {
// Actual order state didn't change
continue;
} else {
this._orderStateByOrderHashCache[orderHash] = orderState;
}
this._callbackIfExists(null, orderState);
}
}
}