What's the difference between end and finish e

2019-01-21 22:08发布

问题:

Node.js streams triggers both end and finish events. What's the difference between both?

回答1:

end and finish are the same event BUT on different types of Streams.

  • stream.Readable fires ONLY end and NEVER finish
  • stream.Writable fires ONLY finish and NEVER end

Source: https://nodejs.org/dist/latest-v5.x/docs/api/stream.html

Why the different naming of the same event?

The only reason I could think of is because of duplex streams (stream.Duplex), which implement both stream.Readable and stream.Writable interfaces (https://nodejs.org/dist/latest-v5.x/docs/api/stream.html#stream_class_stream_duplex) are readable and writable stream at the same time. To differentiate between end of reading and end of writing on the stream you must have a different event fired. SO, for Duplex streams end is end of reading and finish is end of writing.