feat(performance): AngularFire Performance Monitoring

[jamesdaniels]

Basic usage

constructor(private afp: AngularFirePerformance, private afs: AngularFirestore) {}

...

ngOnInit() {
  this.articles = afs.collection('articles')
      .collection('articles', ref => ref.orderBy('publishedAt', 'desc'))
      .snapshotChanges()
      .pipe(
        this.afp.trace('getArticles'),
        map(articles => ...)
      );
}

Advanced usage

// rough copy from Space Invaders RXJS example, should flush out
export const gameUpdate = (state: State, input: Input): State => (
  afp.traceComplete('game', {
    pluckMetrics: ['score'],
    attribute$: { user: this.afAuth.user }
  }),
  whileNotGameOver(state, input),
  processInput(state, input),
  updateState(state)
);

API

trace$(...) => Observable<void>

(name:string)
(name:string, options: TraceOptions)

Observable version of firebase/perf's .trace method; the basis for AngularFirePerfomance's pipes.

.subscribe() is equivalent to calling .start()
.unsubscribe() is equivalent to calling .stop()

<T>trace(...) => (Observable<T>) => Observable<T>

(name:string)
(name:string, options: TraceOptions)

Noop pipe, that traces the observable until the emission or completion.

<T>traceComplete(...) => (Observable<T>) => Observable<T>

(name:string)
(name:string, options: TraceOptions)

Noop pipe, that traces the observable until the completion.

<T>traceUntil(...) => (Observable<T>) => Observable<T>

(name:string, test: (T) => Boolean)
(name:string, test: (T) => Boolean, options: TraceOptions)

Noop pipe, that traces the observable until the first emission that passes the provided test.

<T>traceFirst(...) => (Observable<T>) => Observable<T>

(name:string)
(name:string, test: (T) => Boolean)
(name:string, options: TraceOptions)
(name:string, test: (T) => Boolean, options: TraceOptions)

Noop pipe, that traces the observable until the first emission or the first emission that matches the provided test.

TraceOptions

TBD explain how each option is used by .trace$

export type TraceOptions = {
  pluckMetrics?: [string],
  pluckAttributes?: [string],
  metrics?: { [key:string]: number },
  attributes?: { [key:string]: string },
  attribute$?: { [key:string]: Observable<string> },
  incrementMetric$: { [key:string]: Observable<number|void|null|undefined> },
  metric$?: { [key:string]: Observable<number> }
};

[jamesdaniels]

FYI this has been released for testing on @next as of 5.2.0-beta.3

[hiepxanh]

i love this too

[jamesdaniels]

Need to work on the docs but I'm ready for review here.

[jamesdaniels]

@davideast ready for review. Docs and tests could use some work.

[jamesdaniels]

@davideast @jhuleatt gave it another pass.