can I get full content-length from a ranged request from other than metadata?

[ash-hashtag]

I want to make a video streaming server.

I'm using cloudflare r2, I used workers till now, and with ranged requests they actually return full length, and I have to calculate the body length on the worker, so it never was hassle, but with sdk, the content_length returned is just the ranged length, and couldn't find anything in metadata, I don't know how cloudflare r2 sends data, Should I be asking this in cloudflare forums or here? I thought since, workers get the response with full length, that should be how r2 sending, so it needs to be somewhere in the GetObjectOutput, but where? So If I can't have the full content-length, either I have to request again for just head