//
|
// Zip+Collection.swift
|
// RxSwift
|
//
|
// Created by Krunoslav Zaher on 8/30/15.
|
// Copyright © 2015 Krunoslav Zaher. All rights reserved.
|
//
|
|
extension ObservableType {
|
/**
|
Merges the specified observable sequences into one observable sequence by using the selector function whenever all of the observable sequences have produced an element at a corresponding index.
|
|
- seealso: [zip operator on reactivex.io](http://reactivex.io/documentation/operators/zip.html)
|
|
- parameter resultSelector: Function to invoke for each series of elements at corresponding indexes in the sources.
|
- returns: An observable sequence containing the result of combining elements of the sources using the specified result selector function.
|
*/
|
public static func zip<Collection: Swift.Collection>(_ collection: Collection, resultSelector: @escaping ([Collection.Element.Element]) throws -> Element) -> Observable<Element>
|
where Collection.Element: ObservableType {
|
ZipCollectionType(sources: collection, resultSelector: resultSelector)
|
}
|
|
/**
|
Merges the specified observable sequences into one observable sequence whenever all of the observable sequences have produced an element at a corresponding index.
|
|
- seealso: [zip operator on reactivex.io](http://reactivex.io/documentation/operators/zip.html)
|
|
- returns: An observable sequence containing the result of combining elements of the sources.
|
*/
|
public static func zip<Collection: Swift.Collection>(_ collection: Collection) -> Observable<[Element]>
|
where Collection.Element: ObservableType, Collection.Element.Element == Element {
|
ZipCollectionType(sources: collection, resultSelector: { $0 })
|
}
|
|
}
|
|
final private class ZipCollectionTypeSink<Collection: Swift.Collection, Observer: ObserverType>
|
: Sink<Observer> where Collection.Element: ObservableConvertibleType {
|
typealias Result = Observer.Element
|
typealias Parent = ZipCollectionType<Collection, Result>
|
typealias SourceElement = Collection.Element.Element
|
|
private let parent: Parent
|
|
private let lock = RecursiveLock()
|
|
// state
|
private var numberOfValues = 0
|
private var values: [Queue<SourceElement>]
|
private var isDone: [Bool]
|
private var numberOfDone = 0
|
private var subscriptions: [SingleAssignmentDisposable]
|
|
init(parent: Parent, observer: Observer, cancel: Cancelable) {
|
self.parent = parent
|
self.values = [Queue<SourceElement>](repeating: Queue(capacity: 4), count: parent.count)
|
self.isDone = [Bool](repeating: false, count: parent.count)
|
self.subscriptions = [SingleAssignmentDisposable]()
|
self.subscriptions.reserveCapacity(parent.count)
|
|
for _ in 0 ..< parent.count {
|
self.subscriptions.append(SingleAssignmentDisposable())
|
}
|
|
super.init(observer: observer, cancel: cancel)
|
}
|
|
func on(_ event: Event<SourceElement>, atIndex: Int) {
|
self.lock.lock(); defer { self.lock.unlock() }
|
switch event {
|
case .next(let element):
|
self.values[atIndex].enqueue(element)
|
|
if self.values[atIndex].count == 1 {
|
self.numberOfValues += 1
|
}
|
|
if self.numberOfValues < self.parent.count {
|
if self.numberOfDone == self.parent.count - 1 {
|
self.forwardOn(.completed)
|
self.dispose()
|
}
|
return
|
}
|
|
do {
|
var arguments = [SourceElement]()
|
arguments.reserveCapacity(self.parent.count)
|
|
// recalculate number of values
|
self.numberOfValues = 0
|
|
for i in 0 ..< self.values.count {
|
arguments.append(self.values[i].dequeue()!)
|
if !self.values[i].isEmpty {
|
self.numberOfValues += 1
|
}
|
}
|
|
let result = try self.parent.resultSelector(arguments)
|
self.forwardOn(.next(result))
|
}
|
catch let error {
|
self.forwardOn(.error(error))
|
self.dispose()
|
}
|
|
case .error(let error):
|
self.forwardOn(.error(error))
|
self.dispose()
|
case .completed:
|
if self.isDone[atIndex] {
|
return
|
}
|
|
self.isDone[atIndex] = true
|
self.numberOfDone += 1
|
|
if self.numberOfDone == self.parent.count {
|
self.forwardOn(.completed)
|
self.dispose()
|
}
|
else {
|
self.subscriptions[atIndex].dispose()
|
}
|
}
|
}
|
|
func run() -> Disposable {
|
var j = 0
|
for i in self.parent.sources {
|
let index = j
|
let source = i.asObservable()
|
|
let disposable = source.subscribe(AnyObserver { event in
|
self.on(event, atIndex: index)
|
})
|
self.subscriptions[j].setDisposable(disposable)
|
j += 1
|
}
|
|
if self.parent.sources.isEmpty {
|
self.forwardOn(.completed)
|
}
|
|
return Disposables.create(subscriptions)
|
}
|
}
|
|
final private class ZipCollectionType<Collection: Swift.Collection, Result>: Producer<Result> where Collection.Element: ObservableConvertibleType {
|
typealias ResultSelector = ([Collection.Element.Element]) throws -> Result
|
|
let sources: Collection
|
let resultSelector: ResultSelector
|
let count: Int
|
|
init(sources: Collection, resultSelector: @escaping ResultSelector) {
|
self.sources = sources
|
self.resultSelector = resultSelector
|
self.count = self.sources.count
|
}
|
|
override func run<Observer: ObserverType>(_ observer: Observer, cancel: Cancelable) -> (sink: Disposable, subscription: Disposable) where Observer.Element == Result {
|
let sink = ZipCollectionTypeSink(parent: self, observer: observer, cancel: cancel)
|
let subscription = sink.run()
|
return (sink: sink, subscription: subscription)
|
}
|
}
|
