Function decode_frame 

pub fn decode_frame(
    input: &[u8],
    max_frame_size: u32,
) -> Result<(Frame<'_>, usize), Http2Error>

Decodes a frame from a byte slice. Spec §4.1.

Returns the frame and the number of bytes consumed (header + payload).

Errors

• ShortFrameHeader if fewer than 9 bytes are available.
• ShortPayload if the length is larger than the available buffer.
• FrameTooLarge if the length exceeds max_frame_size.
• UnknownFrameType if the type byte is not recognized.