Reading and Writing Streams of Data
WHAT’S IN THIS CHAPTER?
- Introducing the streams interface
- Getting data from a readable stream
- Controlling the flow of a readable stream
- Writing to a writable stream
- Solving the slow client problem
- Using pipe to stitch streams together
Node has a useful abstraction: streams. More specifically, two very useful abstractions: readable streams and writable streams. They are implemented throughout several Node objects, and they represent inbound (readable stream) or outbound (writable stream) flows of data. An example of a stream is a TCP socket that you read from and write to, or a file that you append or read from sequentially. You have already come across some of them, but this chapter introduces them in a more formal and abstract way, paving the way for some more concrete examples.
NOTE A stream is an abstract construct that is implemented by several Node objects. The way you create or obtain a stream depends on the type of stream you are using. For instance, you can explicitly create a read or write stream based on a file, but a server-side TCP socket is a stream that is handed to you when a client connects.
Besides having the characteristics of a readable or a writable stream, an object can contain other properties or behaviors that are particular to it. For instance, a file readable stream also contains a “path” property that may not be present in other streams.
USING A READABLE STREAM
A readable stream is like a data faucet. ...