Module fetch 

Non-blocking / streaming HTTP fetch for Oxide guest modules.

The legacy api_fetch import (in crate::capabilities) blocks the guest until the entire response body has been downloaded. That prevents guests from rendering frames during large downloads and makes LLM-style token-streaming, chunked feeds, or progressive image loads impossible.

This module exposes a second fetch API that is fully async from the guest’s perspective. The shape mirrors crate::websocket:

• api_fetch_begin dispatches a request and returns a handle immediately.
• api_fetch_state / api_fetch_status report progress.
• api_fetch_recv pulls the next body chunk from an in-memory queue.
• api_fetch_abort cancels an in-flight request.
• api_fetch_remove frees host-side resources once the guest is done.

A background tokio task per request drives reqwest’s bytes_stream(), pushing chunks into a VecDeque<Vec<u8>> drained by the guest.

Structs

FetchState

All streaming-fetch state for a host. Lazily initialised on the first api_fetch_begin call.

Constants

FETCH_ABORTED

Request was aborted by the guest.

FETCH_DONE

Body fully delivered and the queue may still contain trailing chunks.

FETCH_ERROR

Request failed. Use api_fetch_error to retrieve the message.

FETCH_PENDING

Request dispatched; waiting for response headers.

FETCH_STREAMING

Headers received; body chunks may be streaming in.

Functions

register_fetch_functions

Register all api_fetch_* streaming host functions on the given linker.