Function decode_range 

fn decode_range(
    stored: &[u8],
    codec: &dyn ExtentCodec,
    body_len: usize,
    offset: usize,
    dst: &mut [u8],
)

Available on Unix and crate feature pool only.

Decodes the byte range [offset, offset + dst.len()) of the body_len-byte body whose stored form is stored into dst.