Streams & Buffers

Buffers

• Fixed-size bytes outside V8’s heap.
• Encodings are chosen at read-time: utf8, hex, base64, binary.
• Buffer.alloc(n) zero-fills; Buffer.allocUnsafe(n) doesn’t — cheaper, dirtier.

Streams at a glance

• Readable — source (file, socket, process.stdin).
• Writable — sink (process.stdout, socket, file).
• Duplex — both.
• Transform — Duplex where output is a function of input.

Backpressure rule

• write() returns false when buffered data passes highWaterMark.
• Pause the producer; resume on 'drain'.
• pipe + pipeline handle this for you — prefer them over manual write.

If you remember nothing else

Streams move bytes lazily. Backpressure is how you don’t OOM.