Share indexes among workspaces (#2811)

* Make default index location to be os-specific & add a command to clean shared indexes
* Add sharedIndexes settings as New in 1.14.0 in the README

Signed-off-by: Jinbo Wang <jinbwan@microsoft.com>

Author: testforstephen

README.md

@@ -214,6 +214,16 @@ The following settings are supported:
 * `java.cleanup.actionsOnSave`: The list of clean ups to be run on the current document when it's saved. Clean ups can automatically fix code style or programming mistakes. [Click here](document/_java.learnMoreAboutCleanUps.md#java-clean-ups) to learn more about what each clean up does.
 * `java.import.gradle.annotationProcessing.enabled`: Enable/disable the annotation processing on Gradle projects and delegate to JDT APT. Only works for Gradle 5.2 or higher.
 
+New in 1.14.0
+* `java.sharedIndexes.enabled`: [Experimental] Specify whether to share indexes between different workspaces. Defaults to `auto` and the shared indexes is automatically enabled in Visual Studio Code - Insiders.
+  - auto
+  - on
+  - off
+* `java.sharedIndexes.location`: Specifies a common index location for all workspaces. See default values as follows:  
+  - Windows: First use `"$APPDATA\\.jdt\\index"`, or `"~\\.jdt\\index"` if it does not exist
+  - macOS: `"~/Library/Caches/.jdt/index"`
+  - Linux: First use `"$XDG_CACHE_HOME/.jdt/index"`, or `"~/.cache/.jdt/index"` if it does not exist
+
 Semantic Highlighting
 ===============
 [Semantic Highlighting](https://github.com/redhat-developer/vscode-java/wiki/Semantic-Highlighting) fixes numerous syntax highlighting issues with the default Java Textmate grammar. However, you might experience a few minor issues, particularly a delay when it kicks in, as it needs to be computed by the Java Language server, when opening a new file or when typing. Semantic highlighting can be disabled for all languages using the `editor.semanticHighlighting.enabled` setting, or for Java only using [language-specific editor settings](https://code.visualstudio.com/docs/getstarted/settings#_languagespecific-editor-settings).

package.json

@@ -1039,6 +1039,23 @@
           },
           "default": [],
           "scope": "window"
+        },
+        "java.sharedIndexes.enabled": {
+          "type": "string",
+          "enum": [
+            "auto",
+            "on",
+            "off"
+          ],
+          "default": "auto",
+          "markdownDescription": "[Experimental] Specify whether to share indexes between different workspaces. When set to `auto`, shared indexes will be enabled in Visual Studio Code - Insiders.",
+          "scope": "window"
+        },
+        "java.sharedIndexes.location": {
+          "type": "string",
+          "markdownDescription": "Specifies a common index location for all workspaces. See default values as follows:\n \nWindows: First use `\"$APPDATA\\\\.jdt\\\\index\"`, or `\"~\\\\.jdt\\\\index\"` if it does not exist\n \nmacOS: `\"~/Library/Caches/.jdt/index\"`\n \nLinux: First use `\"$XDG_CACHE_HOME/.jdt/index\"`, or `\"~/.cache/.jdt/index\"` if it does not exist",
+          "default": "",
+          "scope": "window"
         }
       }
     },
@@ -1176,6 +1193,11 @@
         "command": "_java.learnMoreAboutCleanUps",
         "title": "Learn more about Java Clean Ups",
         "category": "Java"
+      },
+      {
+        "command": "java.clean.sharedIndexes",
+        "title": "%java.clean.sharedIndexes%",
+        "category": "Java"
       }
     ],
     "keybindings": [

package.nls.json

@@ -22,5 +22,6 @@
 	"java.action.showSupertypeHierarchy": "Show Supertype Hierarchy",
 	"java.action.showSubtypeHierarchy": "Show Subtype Hierarchy",
 	"java.action.changeBaseType": "Base on this Type",
-	"java.project.createModuleInfo.command": "Create module-info.java"
+	"java.project.createModuleInfo.command": "Create module-info.java",
+	"java.clean.sharedIndexes": "Clean Shared Indexes"
 }

package.nls.zh-cn.json

@@ -22,5 +22,6 @@
 	"java.action.showSupertypeHierarchy": "显示父类层次结构",
 	"java.action.showSubtypeHierarchy": "显示子类层次结构",
 	"java.action.changeBaseType": "基于此类型",
-	"java.project.createModuleInfo.command": "创建 module-info.java"
+	"java.project.createModuleInfo.command": "创建 module-info.java",
+	"java.clean.sharedIndexes": "清理共享的索引文件"
 }

src/commands.ts

@@ -315,4 +315,9 @@ export namespace Commands {
      * JDT.LS will call this command before set the server to ready state.
      */
     export const REFRESH_BUNDLES_COMMAND = "_java.reloadBundles.command";
+
+    /**
+     * Clean everything in the shared index directory.
+     */
+    export const CLEAN_SHARED_INDEXES = "java.clean.sharedIndexes";
 }

src/extension.ts

@@ -13,7 +13,7 @@ import { ClientErrorHandler } from './clientErrorHandler';
 import { Commands } from './commands';
 import { ClientStatus, ExtensionAPI } from './extension.api';
 import * as fileEventHandler from './fileEventHandler';
-import { HEAP_DUMP_LOCATION, prepareExecutable } from './javaServerStarter';
+import { getSharedIndexCache, HEAP_DUMP_LOCATION, prepareExecutable } from './javaServerStarter';
 import { initializeLogFile, logger } from './log';
 import { cleanupLombokCache } from "./lombokSupport";
 import { markdownPreviewProvider } from "./markdownPreviewProvider";
@@ -304,6 +304,7 @@ export function activate(context: ExtensionContext): Promise<ExtensionAPI> {
 			}));
 
 			context.subscriptions.push(commands.registerCommand(Commands.CLEAN_WORKSPACE, (force?: boolean) => cleanWorkspace(workspacePath, force)));
+			context.subscriptions.push(commands.registerCommand(Commands.CLEAN_SHARED_INDEXES, () => cleanSharedIndexes(context)));
 
 			context.subscriptions.push(commands.registerCommand(Commands.GET_WORKSPACE_PATH, () => workspacePath));
 
@@ -603,6 +604,19 @@ async function cleanWorkspace(workspacePath, force?: boolean) {
 	commands.executeCommand(Commands.RELOAD_WINDOW);
 }
 
+async function cleanSharedIndexes(context: ExtensionContext) {
+	const sharedIndexLocation: string = getSharedIndexCache(context);
+	if (sharedIndexLocation && fs.existsSync(sharedIndexLocation)) {
+		const doIt = 'Clean and Reload';
+		const ans = await window.showWarningMessage('The shared indexes might be in use by other workspaces, do you want to clear it? New indexes will be built after reloading.',
+			doIt, "Cancel");
+		if (ans === doIt) {
+			deleteDirectory(sharedIndexLocation);
+			commands.executeCommand(Commands.RELOAD_WINDOW);
+		}
+	}
+}
+
 function openServerLogFile(workspacePath, column: ViewColumn = ViewColumn.Active): Thenable<boolean> {
 	const serverLogFile = path.join(workspacePath, '.metadata', '.log');
 	return openLogFile(serverLogFile, 'Could not open Java Language Server log file', column);

src/javaServerStarter.ts

@@ -4,7 +4,7 @@ import * as glob from 'glob';
 import * as net from 'net';
 import * as os from 'os';
 import * as path from 'path';
-import { ExtensionContext, workspace } from 'vscode';
+import { ExtensionContext, version, workspace } from 'vscode';
 import { Executable, ExecutableOptions, StreamInfo } from 'vscode-languageclient/node';
 import { logger } from './log';
 import { addLombokParam, isLombokSupportEnabled } from './lombokSupport';
@@ -130,6 +130,11 @@ function prepareParams(requirements: RequirementsData, javaConfiguration, worksp
 		if (vmargs.indexOf(HEAP_DUMP_LOCATION) < 0) {
 			params.push(`${HEAP_DUMP_LOCATION}${path.dirname(workspacePath)}`);
 		}
+
+		const sharedIndexLocation: string = resolveIndexCache(context);
+		if (sharedIndexLocation) {
+			params.push(`-Djdt.core.sharedIndexLocation=${sharedIndexLocation}`);
+		}
 	}
 
 	// "OpenJDK 64-Bit Server VM warning: Options -Xverify:none and -noverify
@@ -165,6 +170,55 @@ function prepareParams(requirements: RequirementsData, javaConfiguration, worksp
 	return params;
 }
 
+function resolveIndexCache(context: ExtensionContext) {
+	let enabled: string = getJavaConfiguration().get("sharedIndexes.enabled");
+	if (enabled === "auto") {
+		enabled = version.includes("insider") ? "on" : "off";
+	}
+
+	if (enabled !== "on") {
+		return;
+	}
+
+	const location: string = getSharedIndexCache(context);
+	if (location) {
+		ensureExists(location);
+		if (!fs.existsSync(location)) {
+			logger.error(`Failed to create the shared index directory '${location}', fall back to local index.`);
+			return;
+		}
+	}
+
+	return location;
+}
+
+export function getSharedIndexCache(context: ExtensionContext): string {
+	let location: string = getJavaConfiguration().get("sharedIndexes.location");
+	if (!location) {
+		switch (process.platform) {
+			case "win32":
+				location = process.env.APPDATA ? path.join(process.env.APPDATA, ".jdt", "index")
+					: path.join(os.homedir(), ".jdt", "index");
+				break;
+			case "darwin":
+				location = path.join(os.homedir(), "Library", "Caches", ".jdt", "index");
+				break;
+			case "linux":
+				location = process.env.XDG_CACHE_HOME ? path.join(process.env.XDG_CACHE_HOME, ".jdt", "index")
+					: path.join(os.homedir(), ".cache", ".jdt", "index");
+				break;
+			default:
+				const globalStoragePath = context.globalStorageUri?.fsPath; // .../Code/User/globalStorage/redhat.java
+				location = globalStoragePath ? path.join(globalStoragePath, "index") : undefined;
+		}
+	} else {
+		// expand homedir
+		location = location.startsWith(`~${path.sep}`) ? path.join(os.homedir(), location.slice(2)) : location;
+	}
+
+	return location;
+}
+
 function resolveConfiguration(context, configDir) {
 	ensureExists(context.globalStoragePath);
 	const extensionPath = path.resolve(context.extensionPath, "package.json");

src/settings.ts

@@ -132,7 +132,8 @@ function hasJavaConfigChanged(oldConfig: WorkspaceConfiguration, newConfig: Work
 		|| hasConfigKeyChanged('home', oldConfig, newConfig)
 		|| hasConfigKeyChanged('jdt.ls.vmargs', oldConfig, newConfig)
 		|| hasConfigKeyChanged('progressReports.enabled', oldConfig, newConfig)
-		|| hasConfigKeyChanged('server.launchMode', oldConfig, newConfig);
+		|| hasConfigKeyChanged('server.launchMode', oldConfig, newConfig)
+		|| hasConfigKeyChanged('sharedIndexes.location', oldConfig, newConfig);;
 }
 
 function hasConfigKeyChanged(key, oldConfig, newConfig) {

test/lightweight-mode-suite/extension.test.ts

@@ -23,6 +23,7 @@ suite('Java Language Extension - LightWeight', () => {
 				Commands.CLEAN_WORKSPACE,
 				Commands.SWITCH_SERVER_MODE,
 				Commands.OPEN_FILE,
+				Commands.CLEAN_SHARED_INDEXES,
 			].sort();
 			const foundJavaCommands = commands.filter((value) => {
 				return JAVA_COMMANDS.indexOf(value)>=0 || value.startsWith('java.');

test/standard-mode-suite/extension.test.ts

@@ -88,6 +88,7 @@ suite('Java Language Extension - Standard', () => {
 				Commands.SHOW_CLASS_HIERARCHY,
 				Commands.LEARN_MORE_ABOUT_CLEAN_UPS,
 				Commands.OPEN_FILE,
+				Commands.CLEAN_SHARED_INDEXES,
 			].sort();
 			const foundJavaCommands = commands.filter((value) => {
 				return JAVA_COMMANDS.indexOf(value)>=0 || value.startsWith('java.');