From bbf9b7af3200f81ceaabe545a0f06ce3eacb72a7 Mon Sep 17 00:00:00 2001
From: Roman <ixrock@gmail.com>
Date: Thu, 28 Jan 2021 17:34:52 +0200
Subject: [PATCH] kubeWatchApi refactoring / fine-tuning

Signed-off-by: Roman <ixrock@gmail.com>
---
 src/renderer/api/kube-watch-api.ts | 90 ++++++++++++++++++------------
 src/renderer/item.store.ts         |  2 +-
 src/renderer/kube-object.store.ts  |  7 +--
 3 files changed, 57 insertions(+), 42 deletions(-)

diff --git a/src/renderer/api/kube-watch-api.ts b/src/renderer/api/kube-watch-api.ts
index ea451b4bf7..5947468010 100644
--- a/src/renderer/api/kube-watch-api.ts
+++ b/src/renderer/api/kube-watch-api.ts
@@ -7,6 +7,7 @@ import type { KubeObject } from "./kube-object";
 import type { KubeObjectStore } from "../kube-object.store";
 import type { NamespaceStore } from "../components/+namespaces/namespace.store";
 
+import plimit from "p-limit";
 import debounce from "lodash/debounce";
 import { comparer, computed, observable, reaction } from "mobx";
 import { autobind, EventEmitter } from "../utils";
@@ -27,6 +28,7 @@ export interface IKubeWatchMessage<T extends KubeObject = any> {
 export interface IKubeWatchSubscribeStoreOptions {
   preload?: boolean; // preload store items, default: true
   waitUntilLoaded?: boolean; // subscribe only after loading all stores, default: true
+  cacheLoading?: boolean; // when enabled loading store will be skipped, default: false
 }
 
 export interface IKubeWatchReconnectOptions {
@@ -105,10 +107,15 @@ export class KubeWatchApi {
     return this.subscribers.get(api) || 0;
   }
 
-  subscribeApi(api: KubeApi | KubeApi[]) {
+  isAllowedApi(api: KubeApi): boolean {
+    return this.cluster.isAllowedResource(api.kind);
+  }
+
+  subscribeApi(api: KubeApi | KubeApi[]): () => void {
     const apis: KubeApi[] = [api].flat();
 
     apis.forEach(api => {
+      if (!this.isAllowedApi(api)) return; // skip
       this.subscribers.set(api, this.getSubscribersCount(api) + 1);
     });
 
@@ -123,52 +130,63 @@ export class KubeWatchApi {
   }
 
   subscribeStores(stores: KubeObjectStore[], options: IKubeWatchSubscribeStoreOptions = {}): () => void {
-    const { preload = true, waitUntilLoaded = true } = options;
-    const loading: Promise<any>[] = [];
-    const disposers: Function[] = [];
-    let isDisposed = false;
-
-    async function subscribe() {
-      if (isDisposed) return;
-      const unsubscribeList = await Promise.all(stores.map(store => store.subscribe()));
-
-      disposers.push(...unsubscribeList);
-      if (isDisposed) unsubscribe();
-    }
-
-    function unsubscribe() {
-      isDisposed = true;
-      disposers.forEach(dispose => dispose());
-      disposers.length = 0;
-    }
+    const { preload = true, waitUntilLoaded = true, cacheLoading = false } = options;
+    const limitRequests = plimit(1); // load stores one by one to allow quick skipping when fast clicking btw pages
+    const preloading: Promise<any>[] = [];
+    const apis = new Set(stores.map(store => store.getSubscribeApis()).flat());
+    let isUnsubscribed = false;
 
     if (preload) {
-      loading.push(...stores.map(store => store.loadAll()));
+      for (const store of stores) {
+        preloading.push(limitRequests(async () => {
+          if (cacheLoading && store.isLoaded) return; // skip
+
+          return store.loadAll();
+        }));
+      }
     }
 
-    if (waitUntilLoaded) {
-      Promise.all(loading).then(subscribe, error => {
-        this.log({
-          message: new Error("Loading stores has failed"),
-          meta: { stores, error, options },
+    const subscribe = () => {
+      const unsubscribeList: (() => void)[] = [];
+
+      const subscribeApis = () => {
+        if (isUnsubscribed) return;
+        apis.forEach(api => unsubscribeList.push(this.subscribeApi(api)));
+      };
+
+      if (waitUntilLoaded) {
+        Promise.all(preloading).then(subscribeApis, error => {
+          this.log({
+            message: new Error("Loading stores has failed"),
+            meta: { stores, error, options },
+          });
         });
-      });
-    } else {
-      subscribe();
-    }
+      } else {
+        subscribeApis();
+      }
 
-    return unsubscribe;
+      // unsubscribe
+      return () => {
+        if (isUnsubscribed) return;
+        isUnsubscribed = true;
+        limitRequests.clearQueue();
+        unsubscribeList.forEach(unsubscribe => unsubscribe());
+      };
+    };
+
+    return subscribe();
   }
 
-  protected connectionCheck() {
+  protected async connectionCheck() {
+    if (!this.isConnected) {
+      this.log({ message: "Offline: reconnecting.." });
+      await this.connect();
+    }
+
     this.log({
-      message: "connection check",
+      message: `Connection check: ${this.isConnected ? "online" : "offline"}`,
       meta: { connected: this.isConnected },
     });
-
-    if (this.isConnected) return;
-
-    return this.connect();
   }
 
   protected async connect(apis = this.apis) {
diff --git a/src/renderer/item.store.ts b/src/renderer/item.store.ts
index e09c65d43d..eccd2b52df 100644
--- a/src/renderer/item.store.ts
+++ b/src/renderer/item.store.ts
@@ -167,7 +167,7 @@ export abstract class ItemStore<T extends ItemObject = ItemObject> {
   async removeSelectedItems?(): Promise<any>;
 
   // eslint-disable-next-line unused-imports/no-unused-vars-ts
-  async subscribe(...args: any[]): Promise<() => void> {
+  subscribe(...args: any[]) {
     return noop;
   }
 
diff --git a/src/renderer/kube-object.store.ts b/src/renderer/kube-object.store.ts
index d23626a926..760ebd3335 100644
--- a/src/renderer/kube-object.store.ts
+++ b/src/renderer/kube-object.store.ts
@@ -211,11 +211,8 @@ export abstract class KubeObjectStore<T extends KubeObject = any> extends ItemSt
     return [this.api];
   }
 
-  async subscribe(apis = this.getSubscribeApis()): Promise<() => void> {
-    const cluster = await this.resolveCluster();
-    const allowedApis = apis.filter(api => cluster.isAllowedResource(api.kind));
-
-    return kubeWatchApi.subscribeApi(allowedApis);
+  subscribe(apis = this.getSubscribeApis()) {
+    return kubeWatchApi.subscribeApi(apis);
   }
 
   @action