stream-ack

ACK data chunks send over a Node.js stream

This package allow to send and receive messages in a Node.js stream to confirm that some data fragments has arrived to their destination, storing them until the confirmation message is received. In case the transport stream gets closed with some data fragment being confirmed, it's notified to the application so they can be send using another transport stream.

How it works

Sender stream will store written data chunks in a Map object used as cache. When received by the receiver stream, a confirmation message is send back. Confirm stream will receive it and remove the corresponding one from the cache of sended data chunks,

API

Sender

• writable: Writable stream wrapped to send the data and ACK messages
• inFlight: Map object used to cache de data chunks pending for confirmation
• options: options passed to the underlying Transform stream
  • idField: field inside the incoming message that host the confirmation ID

receiver

• writable: Writable stream where to write confirmation messages
• options: options passed to the underlying Transform stream
  • ackPrefix: prefix used to identify the ACK magic message
  • idField: field inside the incoming message that host the confirmation ID

confirm

• readable: Readable stream wrapped to receive incoming ACK messages
• inFlight: Map object used to cache de data chunks pending for confirmation
• options: options passed to the underlying Readable stream
  • ackPrefix: prefix used to identify the ACK magic message

duplex

• duplex: Duplex stream wrapped to send and receive data and ACK messages
• options: options passed to underlying duplexify stream object
  • confirm: options passed to underlying Confirm stream
  • sender: options passed to underlying Sender stream