From 48982cac8418f76f0e2385f434aa552a4d25f121 Mon Sep 17 00:00:00 2001
From: KernelDeimos <eric.alex.dube@gmail.com>
Date: Tue, 9 Sep 2025 03:25:04 -0400
Subject: [PATCH] perf(kernel): parallelize extension installation

This optimization speends up load time for Puter significantly when many
extensions are present. This is also necessary for subsequent changes
which may require prepending code to all the source files inside an
extension, which would be too slow without this optimization.
---
 src/backend/src/Kernel.js | 65 +++++++++++++++++++--------------------
 1 file changed, 32 insertions(+), 33 deletions(-)

diff --git a/src/backend/src/Kernel.js b/src/backend/src/Kernel.js
index affcd5484..4977092a2 100644
--- a/src/backend/src/Kernel.js
+++ b/src/backend/src/Kernel.js
@@ -26,6 +26,9 @@ const { Extension } = require("./Extension");
 const { ExtensionModule } = require("./ExtensionModule");
 const { spawn } = require("node:child_process");
 
+const fs = require('fs');
+const path_ = require('path');
+
 const { quot } = libs.string;
 
 class Kernel extends AdvancedBase {
@@ -205,8 +208,6 @@ class Kernel extends AdvancedBase {
     }
 
     async install_extern_mods_ () {
-        const path_ = require('path');
-        const fs = require('fs');
         
         // In runtime directory, we'll create a `mod_packages` directory.`
         if ( fs.existsSync('mod_packages') ) {
@@ -215,27 +216,34 @@ class Kernel extends AdvancedBase {
         fs.mkdirSync('mod_packages');
         
         const mod_install_root_context = Context.get();
+        
+        const mod_installation_promises = [];
 
         const mod_paths = this.environment.mod_paths;
         for ( const mods_dirpath of mod_paths ) {
-            if ( ! fs.existsSync(mods_dirpath) ) {
-                this.services.logger.error(
-                    `mod directory not found: ${quot(mods_dirpath)}; skipping...`
-                );
-                // intentional delay so error is seen
-                this.services.logger.info('boot will continue in 4 seconds');
-                await new Promise(rslv => setTimeout(rslv, 4000));
-                continue;
-            }
-            const mod_dirnames = fs.readdirSync(mods_dirpath);
-            for ( const mod_dirname of mod_dirnames ) {
-                await this.install_extern_mod_({
-                    mod_install_root_context,
-                    mod_dirname,
-                    mod_path: path_.join(mods_dirpath, mod_dirname),
-                });
-            }
+            const p = (async () => {
+                if ( ! fs.existsSync(mods_dirpath) ) {
+                    this.services.logger.error(
+                        `mod directory not found: ${quot(mods_dirpath)}; skipping...`
+                    );
+                    // intentional delay so error is seen
+                    this.services.logger.info('boot will continue in 4 seconds');
+                    await new Promise(rslv => setTimeout(rslv, 4000));
+                    return;
+                }
+                const mod_dirnames = await fs.promises.readdir(mods_dirpath);
+                for ( const mod_dirname of mod_dirnames ) {
+                    await this.install_extern_mod_({
+                        mod_install_root_context,
+                        mod_dirname,
+                        mod_path: path_.join(mods_dirpath, mod_dirname),
+                    });
+                }
+            })();
+            mod_installation_promises.push(p);
         }
+        
+        await Promise.all(mod_installation_promises);
     }
         
     async install_extern_mod_({
@@ -243,9 +251,6 @@ class Kernel extends AdvancedBase {
         mod_dirname,
         mod_path,
     }) {
-        const path_ = require('path');
-        const fs = require('fs');
-
         let stat = fs.lstatSync(mod_path);
         while ( stat.isSymbolicLink() ) {
             mod_path = fs.readlinkSync(mod_path);
@@ -262,11 +267,11 @@ class Kernel extends AdvancedBase {
         fs.mkdirSync(mod_package_dir);
 
         if ( ! stat.isDirectory() ) {
-            this.create_mod_package_json(mod_package_dir, {
+            await this.create_mod_package_json(mod_package_dir, {
                 name: mod_name,
                 entry: 'main.js'
             });
-            fs.copyFileSync(mod_path, path_.join(mod_package_dir, 'main.js'));
+            await fs.promises.copyFile(mod_path, path_.join(mod_package_dir, 'main.js'));
         } else {
             // If directory is empty, we'll just skip it
             if ( fs.readdirSync(mod_path).length === 0 ) {
@@ -276,7 +281,7 @@ class Kernel extends AdvancedBase {
 
             // Create package.json if it doesn't exist
             if ( ! fs.existsSync(path_.join(mod_path, 'package.json')) ) {
-                this.create_mod_package_json(mod_package_dir, {
+                await this.create_mod_package_json(mod_package_dir, {
                     name: mod_name,
                 });
             }
@@ -318,9 +323,6 @@ class Kernel extends AdvancedBase {
     };
 
     _create_mod_context (parent, options) {
-        const path_ = require('path');
-        const fs = require('fs');
-
         const modapi = {};
 
         let mod_path = options.mod_path;
@@ -359,10 +361,7 @@ class Kernel extends AdvancedBase {
 
     }
     
-    create_mod_package_json (mod_path, { name, entry }) {
-        const fs = require('fs');
-        const path_ = require('path');
-
+    async create_mod_package_json (mod_path, { name, entry }) {
         // Expect main.js or index.js to exist
         const options = ['main.js', 'index.js'];
 
@@ -395,7 +394,7 @@ class Kernel extends AdvancedBase {
         
         console.log('WRITING TO', path_.join(mod_path, 'package.json'));
         
-        fs.writeFileSync(path_.join(mod_path, 'package.json'), data);
+        await fs.promises.writeFile(path_.join(mod_path, 'package.json'), data);
     }
     
     async run_npm_install (path) {