Function parse_s3_request 

pub fn parse_s3_request(
    method: &Method,
    uri_path: &str,
    query: Option<&str>,
    headers: &HeaderMap,
    host_style: HostStyle,
) -> Result<S3Operation, ProxyError>

Extract the bucket and key from a path-style S3 request.

Path-style: /{bucket}/{key} Virtual-hosted-style: Host header {bucket}.s3.example.com with path /{key}