@lifaon/rx-js-light/src/observable/pipes/built-in/without-notifications/source-related/source-observable-pipe.mjs

Blazing fast Observables

export function sourceObservablePipe(getSource) {
  return subscribe => {
    let unsubscribe;
    let observersCounts = 0;
    const source = getSource();
    return emit => {
      let running = true;
      observersCounts++;
      const unsubscribeSource = source.subscribe(emit);
      if (observersCounts === 1) {
        unsubscribe = subscribe(value => {
          source.emit(value);
        });
      }
      return () => {
        if (running) {
          running = false;
          unsubscribeSource();
          observersCounts--;
          if (observersCounts === 0) {
            unsubscribe();
          }
        }
      };
    };
  };
}