Cancellable api request

[MichaelMure]

Hi,

Is there a way to cancel a request ?

In particular, I'm doing some ipfs pin add to trigger a download but the request stay active until completion. There is cases where I no longer want to complete the download. How can I do that ?

Thank you

[daviddias]

To have that, we would need cancellable requests which are not supported by the Fetch API (xhr can cancel, but doesn't support streams) and/or evolve our HTTP API as proposed in https://github.com/ipfs/http-api-spec/issues/116.

[MichaelMure]

For the next guy:

• for node, js-ipfs-api use node's http(s) api which is cancellable (https://nodejs.org/api/http.html#http_request_abort)
• for the browser, js-ipfs-api use stream-http: which is also cancellable and claim to support "true-streaming" for chrome and "pseudo-streaming" with a good browser coverage

The following browsers support pseudo-streaming, where the data is available before the request finishes, but the entire response must be held in memory:
Chrome
Safari >= 5, and maybe older
IE >= 10
Most other Webkit-based browsers, including the default Android browser

The problem is that if you want to have cancellable request, http-streaming will not use fetch and will fallback to other methods (depending on browser) which may or may not support streams.

That said, cancel support could be added for node, no ?

[hugomrdias]

This PR #2993 adds this feature.

🙏 Thank you for your input.