aboutsummaryrefslogtreecommitdiffstats
path: root/packages/0x.js/src/order_watcher/event_watcher.ts
diff options
context:
space:
mode:
Diffstat (limited to 'packages/0x.js/src/order_watcher/event_watcher.ts')
-rw-r--r--packages/0x.js/src/order_watcher/event_watcher.ts148
1 files changed, 74 insertions, 74 deletions
diff --git a/packages/0x.js/src/order_watcher/event_watcher.ts b/packages/0x.js/src/order_watcher/event_watcher.ts
index 3e3cd978d..5d05bfb60 100644
--- a/packages/0x.js/src/order_watcher/event_watcher.ts
+++ b/packages/0x.js/src/order_watcher/event_watcher.ts
@@ -9,8 +9,8 @@ import { assert } from '../utils/assert';
const DEFAULT_EVENT_POLLING_INTERVAL_MS = 200;
enum LogEventState {
- Removed,
- Added,
+ Removed,
+ Added,
}
/*
@@ -18,76 +18,76 @@ enum LogEventState {
* depth.
*/
export class EventWatcher {
- private _web3Wrapper: Web3Wrapper;
- private _pollingIntervalMs: number;
- private _intervalIdIfExists?: NodeJS.Timer;
- private _lastEvents: Web3.LogEntry[] = [];
- constructor(web3Wrapper: Web3Wrapper, pollingIntervalIfExistsMs: undefined | number) {
- this._web3Wrapper = web3Wrapper;
- 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<Web3.LogEntry[]> {
- const eventFilter = {
- fromBlock: BlockParamLiteral.Pending,
- toBlock: BlockParamLiteral.Pending,
- };
- const events = await this._web3Wrapper.getLogsAsync(eventFilter);
- return events;
- }
- private async _emitDifferencesAsync(
- logs: Web3.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);
- }
- }
- }
+ private _web3Wrapper: Web3Wrapper;
+ private _pollingIntervalMs: number;
+ private _intervalIdIfExists?: NodeJS.Timer;
+ private _lastEvents: Web3.LogEntry[] = [];
+ constructor(web3Wrapper: Web3Wrapper, pollingIntervalIfExistsMs: undefined | number) {
+ this._web3Wrapper = web3Wrapper;
+ 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<Web3.LogEntry[]> {
+ const eventFilter = {
+ fromBlock: BlockParamLiteral.Pending,
+ toBlock: BlockParamLiteral.Pending,
+ };
+ const events = await this._web3Wrapper.getLogsAsync(eventFilter);
+ return events;
+ }
+ private async _emitDifferencesAsync(
+ logs: Web3.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);
+ }
+ }
+ }
}