def METHOD_NAME(jar_path):
    """Compute JAR id.
    Returns sha1 hash of a given JAR file.
    """
    jar_id = ""
    try:
        with open(jar_path, mode="rb") as f:
            m = hashlib.sha1()
            for buf in iter(partial(f.read, 4096), b''):
                m.update(buf)
        jar_id = m.hexdigest()
    except IOError:
        pass
    return jar_id