Implement DownloadManager for TLS library downloads and refactor Modu…

…leClient to utilize it

src/utils/client.js

@@ -7,6 +7,7 @@ import fetch from 'node-fetch';
 import { fileURLToPath } from 'node:url';
 import os from 'node:os';
 import { isMainThread } from 'worker_threads';
+import DownloadManager from './downloadManager.js';
 
 let __filename, __dirname;
 
@@ -73,25 +74,8 @@ class ModuleClient {
         if (this.customPath) {
             throw new Error('Custom path provided but library does not exist: ' + this.TLS_LIB_PATH);
         }
-        console.log('[tlsClient] Detected missing TLS library');
-        console.log('[tlsClient] DownloadPath: ' + this.tlsDependencyPath.DOWNLOAD_PATH);
-        console.log('[tlsClient] DestinationPath: ' + this.TLS_LIB_PATH);
-        console.log('[tlsClient] Downloading TLS library... This may take a while');
 
-        const response = await fetch(this.tlsDependencyPath.DOWNLOAD_PATH);
-        if (!response.ok) {
-            throw new Error(`Unexpected response ${response.statusText}`);
-        }
-        const fileStream = fs.createWriteStream(this.TLS_LIB_PATH);
-        response.body.pipe(fileStream);
-
-        return new Promise((resolve, reject) => {
-            fileStream.on('finish', () => {
-                console.log('[tlsClient] Successfully downloaded TLS library');
-                resolve();
-            });
-            fileStream.on('error', reject);
-        });
+        await DownloadManager.download(this.tlsDependencyPath.DOWNLOAD_PATH, this.TLS_LIB_PATH);
     }
 
     /**

src/utils/downloadManager.js

@@ -0,0 +1,59 @@
+import fs from 'node:fs';
+import fetch from 'node-fetch';
+
+class DownloadManager {
+    static #downloading = false;
+    static #downloadPromise = null;
+
+    /**
+     * Downloads a file with mutex-like locking to prevent multiple simultaneous downloads
+     * @param {string} url - URL to download from
+     * @param {string} destination - Where to save the file
+     * @returns {Promise<void>}
+     */
+    static async download(url, destination) {
+        // If already downloading, return the existing promise
+        if (this.#downloading) {
+            return this.#downloadPromise;
+        }
+
+        // If file exists, no need to download
+        if (fs.existsSync(destination)) {
+            return Promise.resolve();
+        }
+
+        // Set downloading flag and create new promise
+        this.#downloading = true;
+        this.#downloadPromise = (async () => {
+            try {
+                console.log('[tlsClient] Detected missing TLS library');
+                console.log('[tlsClient] DownloadPath: ' + url);
+                console.log('[tlsClient] DestinationPath: ' + destination);
+                console.log('[tlsClient] Downloading TLS library... This may take a while');
+
+                const response = await fetch(url);
+                if (!response.ok) {
+                    throw new Error(`Unexpected response ${response.statusText}`);
+                }
+
+                const fileStream = fs.createWriteStream(destination);
+                await new Promise((resolve, reject) => {
+                    response.body.pipe(fileStream);
+                    fileStream.on('finish', () => {
+                        console.log('[tlsClient] Successfully downloaded TLS library');
+                        resolve();
+                    });
+                    fileStream.on('error', reject);
+                });
+            } finally {
+                // Reset flags when done or on error
+                this.#downloading = false;
+                this.#downloadPromise = null;
+            }
+        })();
+
+        return this.#downloadPromise;
+    }
+}
+
+export default DownloadManager;

src/utils/path.js

@@ -1,7 +1,6 @@
 import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
-import { execSync } from 'node:child_process';
 import { URL } from 'node:url';
 
 class TlsDependency {