Don't overwrite extracted native module (#5)

Author: code-asher

node.patch

@@ -1,11 +1,11 @@
 diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
-index 885546c5d6..f1287bb191 100644
+index 885546c5d6..f21e7993f1 100644
 --- a/lib/internal/bootstrap/node.js
 +++ b/lib/internal/bootstrap/node.js
 @@ -215,11 +215,16 @@
      // are running from a script and running the REPL - but there are a few
      // others like the debugger or running --eval arguments. Here we decide
- 	// which mode we run in.
+     // which mode we run in.
 +
 +    if (NativeModule.exists('_third_party_main')) {
 +	  NativeModule.require('_third_party_main');
@@ -21,7 +21,7 @@ index 885546c5d6..f1287bb191 100644
        // one to drop a file lib/_third_party_main.js into the build
        // directory which will be executed instead of Node's normal loading.
 diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
-index fb3770b729..eb65385afe 100644
+index fb3770b729..f4bad8d6de 100644
 --- a/lib/internal/modules/cjs/loader.js
 +++ b/lib/internal/modules/cjs/loader.js
 @@ -44,6 +44,9 @@ const { getOptionValue } = require('internal/options');
@@ -101,17 +101,19 @@ index fb3770b729..eb65385afe 100644
    try {
      module.exports = JSON.parse(stripBOM(content));
    } catch (err) {
-@@ -715,7 +742,14 @@ Module._extensions['.json'] = function(module, filename) {
+@@ -715,7 +742,16 @@ Module._extensions['.json'] = function(module, filename) {
 
  // Native extension for .node
  Module._extensions['.node'] = function(module, filename) {
 -  return process.dlopen(module, path.toNamespacedPath(filename));
 +  let isInternal = false;
 +  if (nbin.existsSync(filename)) {
-+    const tmpFile = path.join(os.tmpdir(), `.nbin-${path.basename(filename)}`);
-+    fs.writeFileSync(tmpFile, nbin.readFileSync(filename));
-+	filename = tmpFile;
-+	isInternal = true;
++    const tmpFile = path.join(os.tmpdir(), `.nbin${nbin.id}-${path.basename(filename)}`);
++    if (!fs.existsSync(tmpFile)) {
++        fs.writeFileSync(tmpFile, nbin.readFileSync(filename));
++    }
++    filename = tmpFile;
++    isInternal = true;
 +  }
 +  return process.dlopen(module, isInternal ? filename : path.toNamespacedPath(filename));
  };

src/api/bundler.ts

@@ -11,8 +11,6 @@ import { WritableFilesystem } from "../common/filesystem";
 import { createFooter } from "../common/footer";
 import ora, { Ora } from "ora";
 
-declare const __non_webpack_require__: typeof require;
-
 export class Binary implements nbin.Binary {
 	private readonly fs: WritableFilesystem = new WritableFilesystem();
 
@@ -87,6 +85,15 @@ export class Binary implements nbin.Binary {
 	public async build(): Promise<Buffer> {
 		const nodeBuffer = await this.cacheBinary();
 
+		// Create a buffer containing a (most likely) unique ID and its length.
+		const idLength = 6;
+		const possible = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+		const id = Array(idLength).fill(1)
+			.map(() => possible[Math.floor(Math.random() * possible.length)])
+			.join("");
+		const idBuffer = Buffer.alloc(2 + Buffer.byteLength(id));
+		writeString(idBuffer, id);
+
 		// Writing the entrypoint
 		const mainFileBuffer = Buffer.alloc(2 + Buffer.byteLength(this.options.mainFile));
 		writeString(mainFileBuffer, this.options.mainFile);
@@ -99,19 +106,19 @@ export class Binary implements nbin.Binary {
 
 		// Footer
 		const footerBuffer = createFooter(
-			fsBuffer.header.byteLength + mainFileBuffer.byteLength, // Header byte length
+			fsBuffer.header.byteLength + idBuffer.byteLength + mainFileBuffer.byteLength, // Header byte length
 			nodeBuffer.byteLength, // Header byte offset
 			fsBuffer.fileContents.byteLength, // File contents length
-			nodeBuffer.byteLength + fsBuffer.header.byteLength + mainFileBuffer.byteLength, // File contents offset
-			);
+			nodeBuffer.byteLength + fsBuffer.header.byteLength + idBuffer.byteLength + mainFileBuffer.byteLength, // File contents offset
+		);
 
-		return Buffer.concat([nodeBuffer, mainFileBuffer, fsBuffer.header, fsBuffer.fileContents, footerBuffer]);
+		return Buffer.concat([nodeBuffer, idBuffer, mainFileBuffer, fsBuffer.header, fsBuffer.fileContents, footerBuffer]);
 	}
 
 	private async cacheBinary(): Promise<Buffer> {
 		let nodeBinaryPath = this.options.nodePath || path.join(__dirname, "../../lib/node/out/Release/node");
 		const nodeBinaryName = this.nodeBinaryName;
-		
+
 		const cacheDir = path.join(os.homedir(), ".nbin");
 		if (!fs.existsSync(nodeBinaryPath)) {
 			if (!fs.existsSync(cacheDir)) {

src/patches/nbin.ts

@@ -13,20 +13,23 @@ const nbinFd = fs.openSync(execPath, "r");
 // Footer is located at the end of the file
 const footer = readFooter(nbinFd, execPathStat.size);
 
-// Contains the mainFile and the filesystem
-const mainFileFsBuffer = Buffer.allocUnsafe(footer.headerLength);
-fs.readSync(nbinFd, mainFileFsBuffer, 0, footer.headerLength, footer.headerOffset);
+// Contains the ID, mainFile and the filesystem
+const headerBuffer = Buffer.allocUnsafe(footer.headerLength);
+fs.readSync(nbinFd, headerBuffer, 0, footer.headerLength, footer.headerOffset);
+
+// Reading the ID.
+const id = readString(headerBuffer, 0);
 
 // Reading the mainfile
-const mainFile = readString(mainFileFsBuffer, 0);
+const mainFile = readString(headerBuffer, id.offset);
 
 /**
  * Maximize read perf by storing before any overrides
  */
 const originalRead = fs.read;
 const originalReadSync = fs.readSync;
 
-const fsBuffer = mainFileFsBuffer.slice(mainFile.offset);
+const fsBuffer = headerBuffer.slice(mainFile.offset);
 const readableFs = ReadableFilesystem.fromBuffer(fsBuffer, {
 	readContents: (offset: number, length: number): Promise<Buffer> => {
 		const buffer = Buffer.allocUnsafe(length);
@@ -81,6 +84,8 @@ const createNotFound = (): Error => {
 };
 
 const exported: typeof import("nbin") = {
+	id: id.value,
+
 	mainFile: mainFile.value,
 
 	existsSync: (pathName: string): boolean => {

typings/nbin.d.ts

@@ -39,6 +39,11 @@ declare module 'nbin' {
 	function readFileSync(path: string, encoding?: "buffer", offset?: number, length?: number): Buffer;
 	function readFileSync(path: string, encoding?: "utf8", offset?: number, length?: number): Buffer;
 
+	/**
+	 * Uniquely generated ID for the packaged binary.
+	 */
+	export const id: string;
+
 	/**
 	 * Returns the entrypoint of the application.
 	 */
@@ -97,7 +102,7 @@ declare module '@coder/nbin' {
 		 * Will bundle a module based on path and name.
 		 * Allows you to do `writeModule("/test/bananas/node_modules/frog")` and
 		 * embed the `frog` module within the binary.
-		 * 
+		 *
 		 * All modules by default will be placed in `/node_modules`
 		 */
 		public writeModule(modulePath: string): void;