Refactor subscription hub.

1 files changed, 46 insertions, 60 deletions

diff --git a/Timeline/ClientApp/src/app/data/SubscriptionHub.ts b/Timeline/ClientApp/src/app/data/SubscriptionHub.ts
index 24f1885d..7c24983b 100644
--- a/Timeline/ClientApp/src/app/data/SubscriptionHub.ts
+++ b/Timeline/ClientApp/src/app/data/SubscriptionHub.ts
@@ -3,14 +3,6 @@ import { Observable } from 'rxjs';
 

 export type Subscriber<TData> = (data: TData) => void;

 

-export class Subscription {

-  constructor(private _onUnsubscribe: () => void) {}

-

-  unsubscribe(): void {

-    this._onUnsubscribe();

-  }

-}

-

 export interface ISubscriptionLine<TData> {

   readonly value: undefined | TData;

   next(value: TData): void;

@@ -25,15 +17,14 @@ export class SubscriptionLine<TData> implements ISubscriptionLine<TData> {
     private config?: { destroyable?: (value: TData | undefined) => boolean }

   ) {}

 

-  subscribe(subscriber: Subscriber<TData>): Subscription {

+  subscribe(subscriber: Subscriber<TData>): void {

     this._observers.push(subscriber);

     if (this._current !== undefined) {

       subscriber(this._current);

     }

-    return new Subscription(() => this.unsubscribe(subscriber));

   }

 

-  private unsubscribe(subscriber: Subscriber<TData>): void {

+  unsubscribe(subscriber: Subscriber<TData>): void {

     if (!this._observers.includes(subscriber)) return;

     pull(this._observers, subscriber);

   }

@@ -57,12 +48,7 @@ export class SubscriptionLine<TData> implements ISubscriptionLine<TData> {
   }

 }

 

-export interface ISubscriptionHub<TKey, TData> {

-  subscribe(key: TKey, subscriber: Subscriber<TData>): Subscription;

-}

-

-export class SubscriptionHub<TKey, TData>

-  implements ISubscriptionHub<TKey, TData> {

+export class SubscriptionHub<TKey, TData> {

   private keyToString: (key: TKey) => string;

   private setup?: (

     key: TKey,

@@ -72,10 +58,7 @@ export class SubscriptionHub<TKey, TData>
 

   private readonly subscriptionLineMap = new Map<

     string,

-    {

-      line: SubscriptionLine<TData>;

-      destroyer: (() => void) | undefined;

-    }

+    SubscriptionLine<TData>

   >();

 

   private cleanTimerId = 0;

@@ -83,7 +66,7 @@ export class SubscriptionHub<TKey, TData>
   // setup is called after creating line and if it returns a function as destroyer, then when the line is destroyed the destroyer will be called.

   constructor(config?: {

     keyToString?: (key: TKey) => string;

-    setup?: (key: TKey, line: ISubscriptionLine<TData>) => (() => void) | void;

+    setup?: (key: TKey, line: ISubscriptionLine<TData>) => void;

     destroyable?: (key: TKey, value: TData | undefined) => boolean;

   }) {

     this.keyToString =

@@ -102,9 +85,8 @@ export class SubscriptionHub<TKey, TData>
 

   private cleanLines(): void {

     const toDelete: string[] = [];

-    for (const [key, info] of this.subscriptionLineMap.entries()) {

-      if (info.line.destroyable) {

-        info.destroyer?.();

+    for (const [key, line] of this.subscriptionLineMap.entries()) {

+      if (line.destroyable) {

         toDelete.push(key);

       }

     }

@@ -121,54 +103,58 @@ export class SubscriptionHub<TKey, TData>
     }

   }

 

-  subscribe(key: TKey, subscriber: Subscriber<TData>): Subscription {

+  private createLine(key: TKey, useSetup = true): SubscriptionLine<TData> {

     const keyString = this.keyToString(key);

-    const line = (() => {

-      const info = this.subscriptionLineMap.get(keyString);

-      if (info == null) {

-        const { setup, destroyable } = this;

-        const newLine = new SubscriptionLine<TData>({

-          destroyable:

-            destroyable != null

-              ? (value) => destroyable(key, value)

-              : undefined,

-        });

-        this.subscriptionLineMap.set(keyString, {

-          line: newLine,

-          destroyer: undefined,

-        });

-        const destroyer = setup?.(key, newLine);

-        if (this.subscriptionLineMap.size === 0) {

-          this.cleanTimerId = window.setInterval(

-            this.cleanLines.bind(this),

-            20000

-          );

-        }

-        this.subscriptionLineMap.set(keyString, {

-          line: newLine,

-          destroyer: destroyer != null ? destroyer : undefined,

-        });

-        return newLine;

-      } else {

-        return info.line;

-      }

-    })();

+    const { setup, destroyable } = this;

+    const newLine = new SubscriptionLine<TData>({

+      destroyable:

+        destroyable != null ? (value) => destroyable(key, value) : undefined,

+    });

+    this.subscriptionLineMap.set(keyString, newLine);

+    if (useSetup) {

+      setup?.(key, newLine);

+    }

+    if (this.subscriptionLineMap.size === 1) {

+      this.cleanTimerId = window.setInterval(this.cleanLines.bind(this), 20000);

+    }

+    return newLine;

+  }

+

+  subscribe(key: TKey, subscriber: Subscriber<TData>): void {

+    const keyString = this.keyToString(key);

+    const line =

+      this.subscriptionLineMap.get(keyString) ?? this.createLine(key);

     return line.subscribe(subscriber);

   }

 

+  unsubscribe(key: TKey, subscriber: Subscriber<TData>): void {

+    const keyString = this.keyToString(key);

+    const line = this.subscriptionLineMap.get(keyString);

+    return line?.unsubscribe(subscriber);

+  }

+

   getObservable(key: TKey): Observable<TData> {

     return new Observable((observer) => {

-      const sub = this.subscribe(key, (data) => {

+      const f = (data: TData): void => {

         observer.next(data);

-      });

+      };

+

+      this.subscribe(key, f);

       return () => {

-        sub.unsubscribe();

+        this.unsubscribe(key, f);

       };

     });

   }

 

   getLine(key: TKey): ISubscriptionLine<TData> | null {

     const keyString = this.keyToString(key);

-    return this.subscriptionLineMap.get(keyString)?.line ?? null;

+    return this.subscriptionLineMap.get(keyString) ?? null;

+  }

+

+  getLineOrCreateWithoutSetup(key: TKey): ISubscriptionLine<TData> {

+    const keyString = this.keyToString(key);

+    return (

+      this.subscriptionLineMap.get(keyString) ?? this.createLine(key, false)

+    );

   }

 }