nodejs: load libsimplex at runtime per backend

packages/simplex-chat-nodejs/src/api.ts

@@ -57,10 +57,8 @@ interface EventSubscriber<K extends CEvt.Tag> {
 }
 
 /**
- * Database configuration. The native library is built against exactly one
- * backend (see `simplex_backend` / `SIMPLEX_BACKEND` at install time); this
- * type makes the caller state which one they are targeting so field names
- * can't lie about their meaning.
+ * Database configuration. `type` selects the libsimplex backend loaded by
+ * `ChatApi.init`; one backend per process.
  */
 export type DbConfig =
   | {
@@ -103,7 +101,7 @@ export class ChatApi {
   private constructor(protected ctrl_: bigint | undefined) {}
 
   /**
-   * Initializes the ChatApi.
+   * Initializes the ChatApi, loading libsimplex for `db.type` (downloaded on first use).
    * @param {DbConfig} db - Database configuration (sqlite or postgres).
    * @param {core.MigrationConfirmation} [confirm=core.MigrationConfirmation.YesUp] - Migration confirmation mode.
    * @param {number} [queueSize] - Size of internal queues, the core default is used when omitted.
@@ -114,6 +112,7 @@ export class ChatApi {
     queueSize?: number
   ): Promise<ChatApi> {
     const [path, key] = dbConfigToMigrateArgs(db)
+    await core.loadLibrary(db.type)
     const ctrl = await core.chatMigrateInit(path, key, confirm, queueSize)
     return new ChatApi(ctrl)
   }

packages/simplex-chat-nodejs/src/core.ts

@@ -1,8 +1,27 @@
 import {ChatEvent, ChatResponse, T} from "@simplex-chat/types"
+import * as libs from "./libs"
 import * as simplex from "./simplex"
 
 export type Backend = "sqlite" | "postgres"
 
+let loading: {backend: Backend, promise: Promise<void>} | undefined
+
+/**
+ * Resolve (downloading on first use) and load libsimplex for the backend.
+ * One libsimplex per process: the Haskell runtime is initialized once, and another backend is rejected.
+ */
+export function loadLibrary(backend: Backend): Promise<void> {
+  if (loading) {
+    if (loading.backend === backend) return loading.promise
+    return Promise.reject(new Error(`libsimplex already loaded with backend=${loading.backend}; cannot switch to ${backend} in the same process`))
+  }
+  const promise = libs.resolveLibsDir(backend).then(dir => simplex.load(libs.libPath(dir)))
+  loading = {backend, promise}
+  // a failed download or load can be retried
+  promise.catch(() => { loading = undefined })
+  return promise
+}
+
 /**
  * Initialize chat controller
  * @param {number} [queueSize] - Size of internal queues, the core default is used when omitted.

packages/simplex-chat-nodejs/src/download-libs.js

@@ -1,266 +0,0 @@
-const https = require('https');
-const fs = require('fs');
-const path = require('path');
-const extract = require('extract-zip');
-
-const GITHUB_REPO = 'simplex-chat/simplex-chat-libs';
-const RELEASE_TAG = 'v7.1.0-beta.4';
-const BACKEND = (process.env.SIMPLEX_BACKEND || process.env.npm_config_simplex_backend || 'sqlite').toLowerCase();
-// A locally built libsimplex, copied into libs/ rather than loaded in place:
-// the addon's RUNPATH is $ORIGIN/../../libs.
-const LIBS_DIR_OVERRIDE = process.env.SIMPLEX_LIBS_DIR || process.env.npm_config_simplex_libs_dir;
-const LIB_NAMES = ['libsimplex.so', 'libsimplex.dylib', 'libsimplex.dll'];
-
-if (BACKEND !== 'sqlite' && BACKEND !== 'postgres') {
-  console.error(`✗ Invalid SIMPLEX_BACKEND: "${BACKEND}". Must be "sqlite" or "postgres".`);
-  process.exit(1);
-}
-
-if (BACKEND === 'postgres' && (process.platform !== 'linux' || process.arch !== 'x64')) {
-  console.error(`✗ SIMPLEX_BACKEND=postgres is only supported on Linux x86_64.`);
-  process.exit(1);
-}
-
-const ROOT_DIR = process.cwd(); // Root of the package being installed
-const LIBS_DIR = path.join(ROOT_DIR, 'libs')
-const INSTALLED_FILE = path.join(LIBS_DIR, 'installed.txt');
-
-// Detect platform and architecture
-function getPlatformInfo() {
-  const platform = process.platform;
-  const arch = process.arch;
-
-  let platformName;
-  let archName;
-
-  if (platform === 'linux') {
-    platformName = 'linux';
-  } else if (platform === 'darwin') {
-    platformName = 'macos';
-  } else if (platform === 'win32') {
-    platformName = 'windows';
-  } else {
-    throw new Error(`Unsupported platform: ${platform}`);
-  }
-
-  if (arch === 'x64') {
-    archName = 'x86_64';
-  } else if (arch === 'arm64') {
-    archName = 'aarch64';
-  } else {
-    throw new Error(`Unsupported architecture: ${arch}`);
-  }
-
-  return { platformName, archName };
-}
-
-// Cleanup on libs version mismatch
-function cleanLibsDirectory() {
-  if (fs.existsSync(LIBS_DIR)) {
-    console.log('Cleaning old libraries...');
-    fs.rmSync(LIBS_DIR, { recursive: true, force: true });
-    fs.mkdirSync(LIBS_DIR, { recursive: true });
-    console.log('✓ Old libraries removed');
-  }
-}
-
-// Check if libraries are already installed with the correct version
-function isAlreadyInstalled() {
-  if (!fs.existsSync(INSTALLED_FILE)) {
-    return false;
-  }
-
-  try {
-    const installedVersion = fs.readFileSync(INSTALLED_FILE, 'utf-8').trim();
-    const expectedVersion = `${RELEASE_TAG}:${BACKEND}`;
-    if (installedVersion === expectedVersion) {
-      console.log(`✓ Libraries version ${RELEASE_TAG}:${BACKEND} already installed`);
-      return true;
-    } else {
-      console.log(`Version mismatch: installed ${installedVersion}, need ${expectedVersion}`);
-      cleanLibsDirectory();
-      return false;
-    }
-  } catch (err) {
-    console.warn(`Could not read installed.txt: ${err.message}`);
-    return false;
-  }
-}
-
-// No version check: the files behind SIMPLEX_LIBS_DIR change on every rebuild.
-function installFromOverride() {
-  if (!fs.existsSync(LIBS_DIR_OVERRIDE)) {
-    throw new Error(`SIMPLEX_LIBS_DIR does not exist: ${LIBS_DIR_OVERRIDE}`);
-  }
-  const lib = LIB_NAMES.find((name) => fs.existsSync(path.join(LIBS_DIR_OVERRIDE, name)));
-  if (!lib) {
-    throw new Error(`No ${LIB_NAMES.join(' / ')} in SIMPLEX_LIBS_DIR: ${LIBS_DIR_OVERRIDE}`);
-  }
-  console.log(`Using libraries from SIMPLEX_LIBS_DIR: ${LIBS_DIR_OVERRIDE}`);
-  cleanLibsDirectory();
-  copyDirSync(LIBS_DIR_OVERRIDE, LIBS_DIR);
-  // Not a release tag: a later install without the variable sees a mismatch
-  // and replaces these files with the released ones.
-  fs.writeFileSync(INSTALLED_FILE, `${LIBS_DIR_OVERRIDE}:${BACKEND}`, 'utf-8');
-  console.log(`✓ Installed ${lib} and its runtime libraries from ${LIBS_DIR_OVERRIDE}`);
-}
-
-async function install() {
-  try {
-    if (LIBS_DIR_OVERRIDE) {
-      installFromOverride();
-      return;
-    }
-
-    // Check if already installed
-    if (isAlreadyInstalled()) {
-      return;
-    }
-
-    const { platformName, archName } = getPlatformInfo();
-    const repoName = GITHUB_REPO.split('/')[1];
-    const backendSuffix = BACKEND === 'postgres' ? '-postgres' : '';
-    const zipFilename = `${repoName}-${platformName}-${archName}${backendSuffix}.zip`;
-    const ZIP_URL = `https://github.com/${GITHUB_REPO}/releases/download/${RELEASE_TAG}/${zipFilename}`;
-    const ZIP_PATH = path.join(ROOT_DIR, zipFilename);
-    const TEMP_EXTRACT_DIR = path.join(ROOT_DIR, '.temp-extract');
-
-    console.log(`Detected: ${platformName} ${archName}`);
-    console.log(`Backend: ${BACKEND}`);
-    console.log(`Downloading: ${zipFilename}`);
-
-    // Create libs directory
-    if (!fs.existsSync(LIBS_DIR)) {
-      fs.mkdirSync(LIBS_DIR, { recursive: true });
-    }
-
-    // Download zip with error handling
-    await downloadFile(ZIP_URL, ZIP_PATH);
-
-    // Extract to temporary directory
-    console.log('Extracting to temporary directory...');
-    if (!fs.existsSync(TEMP_EXTRACT_DIR)) {
-      fs.mkdirSync(TEMP_EXTRACT_DIR, { recursive: true });
-    }
-    await extract(ZIP_PATH, { dir: TEMP_EXTRACT_DIR });
-
-    // Move libs folder contents to final location
-    console.log('Moving libraries to libs/...');
-    const libsSourcePath = path.join(TEMP_EXTRACT_DIR, 'libs');
-
-    if (fs.existsSync(libsSourcePath)) {
-      // Copy all files from libs folder to LIBS_DIR
-      const files = fs.readdirSync(libsSourcePath);
-      files.forEach(file => {
-        const src = path.join(libsSourcePath, file);
-        const dest = path.join(LIBS_DIR, file);
-
-        if (fs.statSync(src).isDirectory()) {
-          copyDirSync(src, dest);
-        } else {
-          fs.copyFileSync(src, dest);
-        }
-      });
-    } else {
-      throw new Error('libs folder not found in zip archive');
-    }
-
-    // Write installed.txt with version
-    fs.writeFileSync(INSTALLED_FILE, `${RELEASE_TAG}:${BACKEND}`, 'utf-8');
-    console.log(`✓ Wrote version ${RELEASE_TAG}:${BACKEND} to installed.txt`);
-
-    // Cleanup
-    fs.rmSync(TEMP_EXTRACT_DIR, { recursive: true, force: true });
-    fs.unlinkSync(ZIP_PATH);
-    console.log('✓ Installation complete');
-  } catch (err) {
-    console.error('✗ Failed:', err.message);
-    process.exit(1);
-  }
-}
-
-// Helper function to recursively copy directories
-function copyDirSync(src, dest) {
-  if (!fs.existsSync(dest)) {
-    fs.mkdirSync(dest, { recursive: true });
-  }
-  const files = fs.readdirSync(src);
-  files.forEach(file => {
-    const srcFile = path.join(src, file);
-    const destFile = path.join(dest, file);
-    if (fs.statSync(srcFile).isDirectory()) {
-      copyDirSync(srcFile, destFile);
-    } else {
-      fs.copyFileSync(srcFile, destFile);
-    }
-  });
-}
-
-function downloadFile(url, dest) {
-  return new Promise((resolve, reject) => {
-    const file = fs.createWriteStream(dest);
-
-    https.get(url, { headers: { 'User-Agent': 'Node.js' } }, (response) => {
-      // Handle redirects
-      if (response.statusCode === 302 || response.statusCode === 301) {
-        file.destroy();
-        fs.unlink(dest, () => {});
-        return downloadFile(response.headers.location, dest)
-          .then(resolve)
-          .catch(reject);
-      }
-
-      // Handle 404
-      if (response.statusCode === 404) {
-        file.destroy();
-        fs.unlink(dest, () => {});
-        reject(new Error(
-          `Release artifact not found (404). Check:\n` +
-          `  - Repository exists: ${url.split('/releases')[0]}\n` +
-          `  - Release tag exists: ${RELEASE_TAG}\n` +
-          `  - Artifact filename is correct`
-        ));
-        return;
-      }
-
-      // Handle 403
-      if (response.statusCode === 403) {
-        file.destroy();
-        fs.unlink(dest, () => {});
-        reject(new Error(
-          `Access denied (403). The repository may be private.\n` +
-          `Set GITHUB_TOKEN environment variable for private repos.`
-        ));
-        return;
-      }
-
-      // Handle other HTTP errors
-      if (response.statusCode < 200 || response.statusCode >= 300) {
-        file.destroy();
-        fs.unlink(dest, () => {});
-        reject(new Error(
-          `HTTP ${response.statusCode}: Failed to download from ${url}`
-        ));
-        return;
-      }
-
-      response.pipe(file);
-
-      file.on('finish', () => {
-        file.close();
-        resolve();
-      });
-
-      file.on('error', (err) => {
-        fs.unlink(dest, () => {});
-        reject(new Error(`File write error: ${err.message}`));
-      });
-    }).on('error', (err) => {
-      file.destroy();
-      fs.unlink(dest, () => {});
-      reject(new Error(`Download error: ${err.message}`));
-    });
-  });
-}
-
-install();

packages/simplex-chat-nodejs/src/simplex.d.ts

@@ -1,5 +1,6 @@
 // These functions are defined in CPP add-on ../cpp/simplex.cc
 
+export function load(libPath: string): void
 export function chat_migrate_init(dbPath: string, dbKey: string, confirm: string): Promise<[bigint, string]>
 export function chat_migrate_init_queue(dbPath: string, dbKey: string, confirm: string, queueSize: number): Promise<[bigint, string]>
 export function chat_close_store(ctrl: bigint): Promise<string>