Implementing pagination for large datasets using Deno.serve()

Managing Large Dataset Responses

When building a server with Deno.serve(), returning a large dataset in a single JSON response can lead to memory exhaustion or heap overflows due to the way V8 handles large object allocations.

To mitigate this, developers often implement pagination by parsing URLSearchParams from the request object to define limits and offsets. However, for datasets that exceed available memory even when paginated, there is a need to transition from standard response bodies to a streaming approach.

While ReadableStream is supported in the Web Fetch API implementation, the specific interaction between stream chunking and the HTTP response lifecycle in Deno requires clarification to ensure optimal throughput.

Technical Constraints

• Must adhere to the Web Fetch API standard.
• Must avoid loading the entire dataset into memory before transmission.
• Requires compatibility with the Deno security sandbox (--allow-net).

What is the most efficient way to integrate ReadableStream with Deno.serve() to paginate and stream a large dataset without blocking the event loop? Which specific stream controller methods are recommended to maintain backpressure when the client consumes data slower than the server produces it?