Function tryServe

apps/memos-local-plugin/server/middleware/static.ts:51–94

(
  res: ServerResponse,
  root: string,
  relative: string,
)

}

async function tryServe(
  res: ServerResponse,
  root: string,
  relative: string,
): Promise<boolean> {
  const resolvedRoot = path.resolve(root);
  const target = path.resolve(resolvedRoot, "." + relative);
  if (!target.startsWith(resolvedRoot)) {
    writeText(res, 403, "forbidden");
    return true;
  }
  try {
    const st = await stat(target);
    if (!st.isFile()) {
      writeNotFound(res);
      return true;
    }
    const ext = path.extname(target).toLowerCase();
    res.writeHead(200, {
      "content-type": MIME[ext] ?? "application/octet-stream",
      "content-length": String(st.size),
      "cache-control": "public, max-age=60",
    });
    // For small files (≤128 KiB) read to buffer and end atomically;
    // for larger, stream and wait on the response's finish event.
    if (st.size <= 128 * 1024) {
      const buf = await readFile(target);
      res.end(buf);
    } else {
      await new Promise<void>((resolve, reject) => {
        const stream = createReadStream(target);
        stream.on("error", reject);
        res.on("finish", () => resolve());
        res.on("close", () => resolve());
        stream.pipe(res);
      });
    }
    return true;
  } catch (err: any) {
    if (err?.code === "ENOENT") return false; // let the caller write 404
    writeText(res, 500, "static: " + (err instanceof Error ? err.message : String(err)));
    return true;
  }
}