使用Node.js中的Crypto从一个流生成多个哈希值

I am working on a Node.js application. Readable stream from a child process' output is being piped into a writable stream from a Crypto module to generate 4 hash values (md5, sha1, sha256 and sha512). This module only allows to generate one hash at a time. After hashes are created, both this stream and hash values should be somehow passed further in order to be recorded to a file. I am currently stuck at creating the first hash value. How can I solve this problem? Part of the code can be seen below.I am working on a Node.js application. Readable