Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

feat: use a symbol to store patched listeners #1356

Merged
merged 8 commits into from
Aug 12, 2020
Merged

feat: use a symbol to store patched listeners #1356

Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
b106fb3
feat: use a symbol to store patched listeners
Flarna Jul 27, 2020
30b7bba
Merge branch 'master' into use-symbol
dyladan Aug 4, 2020
2705b98
Merge branch 'master' into use-symbol
Flarna Aug 4, 2020
452b7e7
Merge branch 'master' into use-symbol
Flarna Aug 7, 2020
677466f
Merge branch 'master' into use-symbol
Flarna Aug 10, 2020
1ef54c1
Merge branch 'master' into use-symbol
dyladan Aug 10, 2020
9bba484
Merge branch 'master' into use-symbol
dyladan Aug 11, 2020
1d91320
Merge branch 'master' into use-symbol
Flarna Aug 12, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 12 additions & 17 deletions packages/opentelemetry-context-async-hooks/src/AbstractAsyncHooksContextManager.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,8 @@
import { ContextManager, Context } from '@opentelemetry/context-base';
import { EventEmitter } from 'events';

const kOtListeners = Symbol('OtListeners');

type Func<T> = (...args: unknown[]) => T;

type PatchedEventEmitter = {
Expand All @@ -25,7 +27,7 @@ type PatchedEventEmitter = {
* version so when the listener is removed by the user, we remove the
* corresponding "patched" function.
*/
__ot_listeners?: { [name: string]: WeakMap<Func<void>, Func<void>> };
[kOtListeners]?: { [name: string]: WeakMap<Func<void>, Func<void>> };
} & EventEmitter;

const ADD_LISTENER_METHODS = [
Expand Down Expand Up @@ -91,8 +93,8 @@ export abstract class AbstractAsyncHooksContextManager
context: Context
): T {
const ee = (target as unknown) as PatchedEventEmitter;
if (ee.__ot_listeners !== undefined) return target;
ee.__ot_listeners = {};
if (ee[kOtListeners] !== undefined) return target;
ee[kOtListeners] = {};

// patch methods that add a listener to propagate context
ADD_LISTENER_METHODS.forEach(methodName => {
Expand Down Expand Up @@ -124,13 +126,10 @@ export abstract class AbstractAsyncHooksContextManager
*/
private _patchRemoveListener(ee: PatchedEventEmitter, original: Function) {
return function (this: {}, event: string, listener: Func<void>) {
if (
ee.__ot_listeners === undefined ||
ee.__ot_listeners[event] === undefined
) {
const events = ee[kOtListeners]?.[event];
if (events === undefined) {
return original.call(this, event, listener);
}
const events = ee.__ot_listeners[event];
const patchedListener = events.get(listener);
return original.call(this, event, patchedListener || listener);
};
Expand All @@ -147,13 +146,9 @@ export abstract class AbstractAsyncHooksContextManager
original: Function
) {
return function (this: {}, event: string) {
if (
ee.__ot_listeners === undefined ||
ee.__ot_listeners[event] === undefined
) {
return original.call(this, event);
if (ee[kOtListeners]?.[event] !== undefined) {
delete ee[kOtListeners]![event];
}
delete ee.__ot_listeners[event];
return original.call(this, event);
};
}
Expand All @@ -172,11 +167,11 @@ export abstract class AbstractAsyncHooksContextManager
) {
const contextManager = this;
return function (this: {}, event: string, listener: Func<void>) {
if (ee.__ot_listeners === undefined) ee.__ot_listeners = {};
let listeners = ee.__ot_listeners[event];
if (ee[kOtListeners] === undefined) ee[kOtListeners] = {};
let listeners = ee[kOtListeners]![event];
if (listeners === undefined) {
listeners = new WeakMap();
ee.__ot_listeners[event] = listeners;
ee[kOtListeners]![event] = listeners;
}
const patchedListener = contextManager.bind(listener, context);
// store a weak reference of the user listener to ours
Expand Down