Method startEngine

src/index.ts:88–172

* Starts the C++ background process and waits for the HTTP interface to be ready. * If a service is already running on the target port, it will skip spawning.

()

   * If a service is already running on the target port, it will skip spawning.
   */
  private async startEngine(): Promise<void> {
    this.port = await this.findPort();
    this.baseUrl = `http://localhost:${this.port}`;

    // Check if a service is already running on this port
    try {
      const controller = new AbortController();
      const timeoutId = setTimeout(() => controller.abort(), 200);
      const res = await fetch(`${this.baseUrl}/status`, { signal: controller.signal });
      clearTimeout(timeoutId);
      if (res.ok) {
        // Service already alive, no need to spawn a new one
        return;
      }
    } catch {
      // Not running, proceed to spawn
    }

    if (!this.binaryPath) {
      throw new Error(`Engine binary path is not defined. Please ensure your platform is supported and binaries are correctly bundled.`);
    }

    const args = ["--port", this.port.toString()];
    if (this.initialPath) {
      const dirArg = Array.isArray(this.initialPath) 
        ? this.initialPath.join(" ") 
        : this.initialPath;
      args.push("--source", dirArg);
    }

    const binDir = path.dirname(this.binaryPath);
    const env = { ...process.env };
    if (process.platform === "linux") {
      env.LD_LIBRARY_PATH = binDir + (process.env.LD_LIBRARY_PATH ? `:${process.env.LD_LIBRARY_PATH}` : "");
    } else if (process.platform === "darwin") {
      env.DYLD_LIBRARY_PATH = binDir + (process.env.DYLD_LIBRARY_PATH ? `:${process.env.DYLD_LIBRARY_PATH}` : "");
    }

    return new Promise((resolve, reject) => {
      this.process = spawn(this.binaryPath, args, {
        stdio: "ignore",
        detached: true,
        env: env,
      });

      // Allow the process to stay alive after the parent exits
      this.process.unref();

      this.process.on("error", (err) => {
        this.process = null;
        reject(err);
      });

      this.process.on("exit", (code) => {
        if (code !== 0 && this.process) {
          console.error(`DocsAgent engine exited with code ${code}`);
        }
        this.process = null;