RXSwift 原理图

ObserverOn<Element>

let subscribeHandler: SubscribeHandler

传递 Event<Element>

Observable<ob.Element>

Producer<SourceType>

1. subscribeOn

    private let state = AtomicInt(0)    private var sink: Disposable?    private var subscription: Disposable?

3. observer.on(event:)

6.  run  创建SubscribeOnSink

Observer<Element>

subscribeHandler(AnyObserver(Sink))

fileprivate let observer: Observerfileprivate let cancel: Cancelable

Observable<SourceType>

Sink<Observer: ObserverType>

Observer

Sink

SubscribeOn<Ob: ObservableType>

subscribe

9. observer.on(event<Element>)

Observable

sink 即 AnonymousObservableSink，维护Observer 和 Obserable 之间的订阅状态subscription 即 subscribeHandler 执行返回的值，维护 subscribeHandler 执行中一些状态SinkDisposer 即用来维护 Observable ， Observer 以及 它们之间的订阅关系状态

AnonymousObservable<Element>

Observable<Element>

3. subscribe

SinkDisposer

ObserveOnSink<Observer: ObserverType>

Observable<ResultType>

7.  disaptch_asyn{subcribe} 

AnonymousObservableSink<Observer: ObserverType> : ObserverType

observer.on(event<SourceType>)

AnonymousObservable<SourceType>

2. Produce.run()subscribeHandler(AnyObserver(Sink))

let scheduler: ImmediateSchedulerType let source: Observable<Element>

Obserable Create

Disposable

11. dispatch_asyncobserver.on(event<Element>)

10. observer.on(event<Element>)

Producer<ob.Element>

Map 操作

Cancelable

Producer<.Element>

AnonymousObservableSink

    let source: Ob    let scheduler: ImmediateSchedulerType

8.  run subscribeHandler(AnyObserver(Sink))

1.  订阅关系 subscribe

2. observerOn

Scheduler

observer.on(event<ResultType>)

4.  run 创建ObservableOnSink

订阅关系 subscribe

创建 MapSink， 建立MapSink 与 上一节 sink的关联

5. subscribe

Operator Map

Producer<ResultType>

let source: Observable<SourceType>let transform: Transform

MapSink

Producer<Element>

创建了新的Observable 即 Map