vscode: add version and storage parameters to github binary source

editors/code/src/client.ts

@@ -11,7 +11,7 @@ export async function createClient(config: Config): Promise<null | lc.LanguageCl
     // It might be a good idea to test if the uri points to a file.
     const workspaceFolderPath = vscode.workspace.workspaceFolders?.[0]?.uri.fsPath ?? '.';
 
-    const serverPath = await ensureServerBinary(config.serverBinarySource);
+    const serverPath = await ensureServerBinary(config.serverSource);
     if (!serverPath) return null;
 
     const run: lc.Executable = {

editors/code/src/config.ts

@@ -24,6 +24,19 @@ export class Config {
     ]
     .map(opt => `${Config.rootSection}.${opt}`);
 
+    private static readonly extensionVersion: string = (() => {
+        const packageJsonVersion = vscode
+            .extensions
+            .getExtension("matklad.rust-analyzer")!
+            .packageJSON
+            .version as string; // n.n.YYYYMMDD
+
+        const realVersionRegexp = /^\d+\.\d+\.(\d{4})(\d{2})(\d{2})/;
+        const [, yyyy, mm, dd] = packageJsonVersion.match(realVersionRegexp)!;
+
+        return `${yyyy}-${mm}-${dd}`;
+    })();
+
     private cfg!: vscode.WorkspaceConfiguration;
 
     constructor(private readonly ctx: vscode.ExtensionContext) {
@@ -98,7 +111,7 @@ export class Config {
         }
     }
 
-    get serverBinarySource(): null | BinarySource {
+    get serverSource(): null | BinarySource {
         const serverPath = RA_LSP_DEBUG ?? this.cfg.get<null | string>("raLspServerPath");
 
         if (serverPath) {
@@ -116,6 +129,8 @@ export class Config {
             type: BinarySource.Type.GithubRelease,
             dir:  this.ctx.globalStoragePath,
             file: prebuiltBinaryName,
+            storage: this.ctx.globalState,
+            version: Config.extensionVersion,
             repo: {
                 name: "rust-analyzer",
                 owner: "rust-analyzer",

editors/code/src/ctx.ts

@@ -60,6 +60,10 @@ export class Ctx {
         this.pushCleanup(d);
     }
 
+    get globalState(): vscode.Memento {
+        return this.extCtx.globalState;
+    }
+
     get subscriptions(): Disposable[] {
         return this.extCtx.subscriptions;
     }

editors/code/src/installation/interfaces.ts

@@ -1,3 +1,5 @@
+import * as vscode from "vscode";
+
 export interface GithubRepo {
     name: string;
     owner: string;
@@ -50,6 +52,17 @@ export namespace BinarySource {
          * and in local `.dir`.
          */
         file: string;
+
+        /**
+         * Tag of github release that denotes a version required by this extension.
+         */
+        version: string;
+
+        /**
+         * Object that provides `get()/update()` operations to store metadata
+         * about the actual binary, e.g. its actual version.
+         */
+        storage: vscode.Memento;
     }
 
 }