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-rw-r--r--packages/0x.js/src/order_watcher/event_watcher.ts99
1 files changed, 0 insertions, 99 deletions
diff --git a/packages/0x.js/src/order_watcher/event_watcher.ts b/packages/0x.js/src/order_watcher/event_watcher.ts
deleted file mode 100644
index de5a99a46..000000000
--- a/packages/0x.js/src/order_watcher/event_watcher.ts
+++ /dev/null
@@ -1,99 +0,0 @@
-import { BlockParamLiteral, LogEntry } from '@0xproject/types';
-import { intervalUtils } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import * as _ from 'lodash';
-
-import { EventWatcherCallback, ZeroExError } from '../types';
-import { assert } from '../utils/assert';
-
-const DEFAULT_EVENT_POLLING_INTERVAL_MS = 200;
-
-enum LogEventState {
- Removed,
- Added,
-}
-
-/**
- * The EventWatcher watches for blockchain events at the specified block confirmation
- * depth.
- */
-export class EventWatcher {
- private _web3Wrapper: Web3Wrapper;
- private _pollingIntervalMs: number;
- private _intervalIdIfExists?: NodeJS.Timer;
- private _lastEvents: LogEntry[] = [];
- private _stateLayer: BlockParamLiteral;
- constructor(
- web3Wrapper: Web3Wrapper,
- pollingIntervalIfExistsMs: undefined | number,
- stateLayer: BlockParamLiteral = BlockParamLiteral.Latest,
- ) {
- this._web3Wrapper = web3Wrapper;
- this._stateLayer = stateLayer;
- this._pollingIntervalMs = _.isUndefined(pollingIntervalIfExistsMs)
- ? DEFAULT_EVENT_POLLING_INTERVAL_MS
- : pollingIntervalIfExistsMs;
- }
- public subscribe(callback: EventWatcherCallback): void {
- assert.isFunction('callback', callback);
- if (!_.isUndefined(this._intervalIdIfExists)) {
- throw new Error(ZeroExError.SubscriptionAlreadyPresent);
- }
- this._intervalIdIfExists = intervalUtils.setAsyncExcludingInterval(
- this._pollForBlockchainEventsAsync.bind(this, callback),
- this._pollingIntervalMs,
- (err: Error) => {
- this.unsubscribe();
- callback(err);
- },
- );
- }
- public unsubscribe(): void {
- this._lastEvents = [];
- if (!_.isUndefined(this._intervalIdIfExists)) {
- intervalUtils.clearAsyncExcludingInterval(this._intervalIdIfExists);
- delete this._intervalIdIfExists;
- }
- }
- private async _pollForBlockchainEventsAsync(callback: EventWatcherCallback): Promise<void> {
- const pendingEvents = await this._getEventsAsync();
- if (_.isUndefined(pendingEvents)) {
- // HACK: This should never happen, but happens frequently on CI due to a ganache bug
- return;
- }
- if (pendingEvents.length === 0) {
- // HACK: Sometimes when node rebuilds the pending block we get back the empty result.
- // We don't want to emit a lot of removal events and bring them back after a couple of miliseconds,
- // that's why we just ignore those cases.
- return;
- }
- const removedEvents = _.differenceBy(this._lastEvents, pendingEvents, JSON.stringify);
- const newEvents = _.differenceBy(pendingEvents, this._lastEvents, JSON.stringify);
- await this._emitDifferencesAsync(removedEvents, LogEventState.Removed, callback);
- await this._emitDifferencesAsync(newEvents, LogEventState.Added, callback);
- this._lastEvents = pendingEvents;
- }
- private async _getEventsAsync(): Promise<LogEntry[]> {
- const eventFilter = {
- fromBlock: this._stateLayer,
- toBlock: this._stateLayer,
- };
- const events = await this._web3Wrapper.getLogsAsync(eventFilter);
- return events;
- }
- private async _emitDifferencesAsync(
- logs: LogEntry[],
- logEventState: LogEventState,
- callback: EventWatcherCallback,
- ): Promise<void> {
- for (const log of logs) {
- const logEvent = {
- removed: logEventState === LogEventState.Removed,
- ...log,
- };
- if (!_.isUndefined(this._intervalIdIfExists)) {
- callback(null, logEvent);
- }
- }
- }
-}