Any option to add Content-Length header in the response?

[dxps]

Hi everyone!

I love this package! 😍 I'm using it for delivering a WASM file as compressed.

Showing a loading progress for such case is great, but since the Content-Length is missing, this can't be done.

As per this discussion:

gzhttp removes Content-Size instead, since it will do streaming writes.

Unless there is no other option to have this happenning using this package, I guess I should handle that specific request (to that WASM file) in another wrapper, on top of the gzhttp.NewWrapper(...), right?

Thanks.

[klauspost]

@dxps You would need to buffer the output. As a general thing that is rather bad approach - it will reduce Time-To-First-Byte and you risk running the server out of memory.

You could do an upstream HTTP wrapper that buffers writes and writes content-length before writing any data. I wouldn't be opposed to adding it as a separate wrapper for including in gzhttp.

[dxps]

@klauspost Hi Klaus,

Thanks for the feedback!
The file itself should get around 20 MB, so it could be kept in memory as compressed and thus it's size would be known upfront ant delivered as fast as possible.

I believe having a separate wrapper within the library would be great.
Otherwise, indeed my own wrapper could do the job, but I wouldn't be confortable having a wrapper to a wrapper to another Handler.

[klauspost]

The gzhttp is for dynamic compression. If it is static content, you really should just do it yourself - that will avoid having to compress on every download - which sounds like what you really want.

[dxps]

Indeed, that should be the way to go.
But I'd still love this great package.
So, I guess I'll try to use a wrapper on top of gzhttp Wrapper.

Appreciated all the help!