@reactivex/rxjs
Version:
Reactive Extensions for modern JavaScript
228 lines • 6.54 kB
JavaScript
import { ArrayObservable } from '../observable/ArrayObservable';
import { isArray } from '../util/isArray';
import { Subscriber } from '../Subscriber';
import { OuterSubscriber } from '../OuterSubscriber';
import { subscribeToResult } from '../util/subscribeToResult';
import { $$iterator } from '../symbol/iterator';
/**
* @param observables
* @return {Observable<R>}
* @method zip
* @owner Observable
*/
export function zipProto(...observables) {
observables.unshift(this);
return zipStatic.apply(this, observables);
}
/* tslint:enable:max-line-length */
/**
* @param observables
* @return {Observable<R>}
* @static true
* @name zip
* @owner Observable
*/
export function zipStatic(...observables) {
const project = observables[observables.length - 1];
if (typeof project === 'function') {
observables.pop();
}
return new ArrayObservable(observables).lift(new ZipOperator(project));
}
export class ZipOperator {
constructor(project) {
this.project = project;
}
call(subscriber, source) {
return source._subscribe(new ZipSubscriber(subscriber, this.project));
}
}
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
export class ZipSubscriber extends Subscriber {
constructor(destination, project, values = Object.create(null)) {
super(destination);
this.index = 0;
this.iterators = [];
this.active = 0;
this.project = (typeof project === 'function') ? project : null;
this.values = values;
}
_next(value) {
const iterators = this.iterators;
const index = this.index++;
if (isArray(value)) {
iterators.push(new StaticArrayIterator(value));
}
else if (typeof value[$$iterator] === 'function') {
iterators.push(new StaticIterator(value[$$iterator]()));
}
else {
iterators.push(new ZipBufferIterator(this.destination, this, value, index));
}
}
_complete() {
const iterators = this.iterators;
const len = iterators.length;
this.active = len;
for (let i = 0; i < len; i++) {
let iterator = iterators[i];
if (iterator.stillUnsubscribed) {
this.add(iterator.subscribe(iterator, i));
}
else {
this.active--; // not an observable
}
}
}
notifyInactive() {
this.active--;
if (this.active === 0) {
this.destination.complete();
}
}
checkIterators() {
const iterators = this.iterators;
const len = iterators.length;
const destination = this.destination;
// abort if not all of them have values
for (let i = 0; i < len; i++) {
let iterator = iterators[i];
if (typeof iterator.hasValue === 'function' && !iterator.hasValue()) {
return;
}
}
let shouldComplete = false;
const args = [];
for (let i = 0; i < len; i++) {
let iterator = iterators[i];
let result = iterator.next();
// check to see if it's completed now that you've gotten
// the next value.
if (iterator.hasCompleted()) {
shouldComplete = true;
}
if (result.done) {
destination.complete();
return;
}
args.push(result.value);
}
if (this.project) {
this._tryProject(args);
}
else {
destination.next(args);
}
if (shouldComplete) {
destination.complete();
}
}
_tryProject(args) {
let result;
try {
result = this.project.apply(this, args);
}
catch (err) {
this.destination.error(err);
return;
}
this.destination.next(result);
}
}
class StaticIterator {
constructor(iterator) {
this.iterator = iterator;
this.nextResult = iterator.next();
}
hasValue() {
return true;
}
next() {
const result = this.nextResult;
this.nextResult = this.iterator.next();
return result;
}
hasCompleted() {
const nextResult = this.nextResult;
return nextResult && nextResult.done;
}
}
class StaticArrayIterator {
constructor(array) {
this.array = array;
this.index = 0;
this.length = 0;
this.length = array.length;
}
[$$iterator]() {
return this;
}
next(value) {
const i = this.index++;
const array = this.array;
return i < this.length ? { value: array[i], done: false } : { done: true };
}
hasValue() {
return this.array.length > this.index;
}
hasCompleted() {
return this.array.length === this.index;
}
}
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
class ZipBufferIterator extends OuterSubscriber {
constructor(destination, parent, observable, index) {
super(destination);
this.parent = parent;
this.observable = observable;
this.index = index;
this.stillUnsubscribed = true;
this.buffer = [];
this.isComplete = false;
}
[$$iterator]() {
return this;
}
// NOTE: there is actually a name collision here with Subscriber.next and Iterator.next
// this is legit because `next()` will never be called by a subscription in this case.
next() {
const buffer = this.buffer;
if (buffer.length === 0 && this.isComplete) {
return { done: true };
}
else {
return { value: buffer.shift(), done: false };
}
}
hasValue() {
return this.buffer.length > 0;
}
hasCompleted() {
return this.buffer.length === 0 && this.isComplete;
}
notifyComplete() {
if (this.buffer.length > 0) {
this.isComplete = true;
this.parent.notifyInactive();
}
else {
this.destination.complete();
}
}
notifyNext(outerValue, innerValue, outerIndex, innerIndex, innerSub) {
this.buffer.push(innerValue);
this.parent.checkIterators();
}
subscribe(value, index) {
return subscribeToResult(this, this.observable, this, index);
}
}
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