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Aryan
Aryan

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DAY 4 – Streaming Body Parse

Snippet🤷‍♂️Ever wondered how large file uploads don’t crash servers?

Today, I built a streaming body parser from scratch using raw Node.js TCP sockets — no Express, no frameworks.

--> Accumulate data chunks from the TCP socket
--> Parse HTTP request headers to find Content-Length
--> Read request body safely, waiting for full body based on length
--> Support plain text and JSON parsing for POST requests
--> Avoid memory leaks by handling data in streams rather than buffering everything at once.

Most developers rely on express.json() or middleware like multer for uploads. I wanted to understand what really happens under the hood.

This deep dive helped me build a custom HTTP server that correctly handles POST request bodies — the backbone for handling forms, APIs, and uploads — without third-party dependencies.

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