refactor: introduce cache for members list fetched by ZE

Signed-off-by: Aman Prashant <aman.prashant@broadcom.com>

clients/cobol-lsp-vscode-extension/src/__tests__/services/copybook/download/CopybookDownloaderForDsnTest.spec.ts

@@ -132,7 +132,8 @@ describe("Tests Copybook download from DNS", () => {
         "document-uri",
         "DNS.PATH",
       );
-      expect(allMemberMock).toHaveBeenCalledWith("DNS.PATH");
+      // cache resolves the members
+      expect(allMemberMock).not.toHaveBeenCalled();
       expect(getContentMock).toHaveBeenCalledWith("DNS.PATH(copybook)", {
         file: "profile/dsn.path/copybook",
         binary: true,

clients/cobol-lsp-vscode-extension/src/__tests__/services/copybook/download/CopybookDownloaderForUssTest.spec.ts

@@ -132,7 +132,8 @@ describe("Tests Copybook download from USS", () => {
         "document-uri",
         "/uss/path",
       );
-      expect(allUSSFilemembers).toHaveBeenCalledWith("/uss/path");
+      // cache resolves the members
+      expect(allUSSFilemembers).not.toHaveBeenCalled();
       expect(getUSSContentsMock).toHaveBeenCalledWith(
         "/uss/path/uss_copybook",
         {

clients/cobol-lsp-vscode-extension/src/commands/ClearCopybookCacheCommand.ts

@@ -21,7 +21,6 @@ import {
   COPYBOOKS_FOLDER,
   ZOWE_FOLDER,
 } from "../constants";
-import { Utils } from "../services/util/Utils";
 
 /**
  * Clears the downloaded copybook cache folder ({globalStoragePath}/.zowe/.copybooks).

clients/cobol-lsp-vscode-extension/src/extension.ts

@@ -260,6 +260,7 @@ function registerCommands(
       "cobol-lsp.clear.downloaded.copybooks",
       () => {
         clearCache(context.globalStorageUri);
+        copyBooksDownloader.clearCache();
       },
     ),
   );

clients/cobol-lsp-vscode-extension/src/services/copybook/CopybookDownloadService.ts

@@ -23,6 +23,14 @@ export class CopybookName {
 }
 
 export class CopybookDownloadService {
+
+  /**
+   * Clears any cache maintained by downloaders
+   */
+
+  clearCache() {
+    this.downloadResolver.clearCache();
+  }
   private downloadResolver: DownloadStrategyResolver;
 
   constructor(

clients/cobol-lsp-vscode-extension/src/services/copybook/downloader/CopybookDownloaderForDsn.ts

@@ -75,10 +75,20 @@ export class CopybookDownloaderForDsn extends ZoweExplorerDownloader {
   }
 
   private async getAllMembers(profileName: string, dataset: string) {
+    const id = this.createId(profileName, dataset);
+
+    if (this.memberListCache.has(id)) {
+      return this.memberListCache.get(id)!;
+    }
+
+    const profile = DownloadUtil.loadProfile(profileName, this.explorerAPI);
     const response = await this.explorerAPI
-      .getMvsApi(DownloadUtil.loadProfile(profileName, this.explorerAPI))
+      .getMvsApi(profile)
       .allMembers(dataset);
-    return response.apiResponse.items.map((el: any) => el.member);
+    const members = response.apiResponse.items.map((item: any) => item.member);
+
+    this.memberListCache.set(id, members);
+    return members;
   }
 
   /**

clients/cobol-lsp-vscode-extension/src/services/copybook/downloader/CopybookDownloaderForUss.ts

@@ -75,10 +75,20 @@ export class CopybookDownloaderForUss extends ZoweExplorerDownloader {
   }
 
   private async getAllMembers(profileName: string, dataset: string) {
+    const id = this.createId(profileName, dataset);
+
+    if (this.memberListCache.has(id)) {
+      return this.memberListCache.get(id)!;
+    }
+
+    const profile = DownloadUtil.loadProfile(profileName, this.explorerAPI);
     const response = await this.explorerAPI
-      .getUssApi(DownloadUtil.loadProfile(profileName, this.explorerAPI))
+      .getUssApi(profile)
       .fileList(dataset);
-    return response.apiResponse.items.map((el: any) => el.name);
+    const members = response.apiResponse.items.map((el: any) => el.name);
+
+    this.memberListCache.set(id, members);
+    return members;
   }
 
   /**

clients/cobol-lsp-vscode-extension/src/services/copybook/downloader/DownloadStrategyResolver.ts

@@ -77,6 +77,14 @@ export class DownloadStrategyResolver {
     return false;
   }
 
+  /**
+   * Clears downloaders cache
+   */
+  clearCache() {
+    this.dsnDownloader?.clearMemberListCache();
+    this.ussDownloader?.clearMemberListCache();
+  }
+
   private async downloadFromPaths(
     downloader: CopybookDownloaderForDsn | CopybookDownloaderForUss,
     copybook: CopybookName,

clients/cobol-lsp-vscode-extension/src/services/copybook/downloader/ZoweExplorerDownloader.ts

@@ -20,6 +20,7 @@ import { CopybookURI } from "../CopybookURI";
 export abstract class ZoweExplorerDownloader {
   public static profileStore: Map<string, "locked-profile" | "valid-profile"> =
     new Map();
+  protected memberListCache: Map<string, string[]> = new Map();
 
   constructor(
     private readonly storagePath: string,
@@ -96,4 +97,15 @@ export abstract class ZoweExplorerDownloader {
 
     return false;
   }
+
+  protected createId(profileName: string, path: string) {
+    return `${profileName}-${path}`;
+  }
+
+  /**
+   * Clears the member cache for the copybook downloader
+   */
+  public clearMemberListCache() {
+    this.memberListCache.clear();
+  }
 }