pub fn encode_b64_slice(raw: &[u8], skip: usize, take: usize) -> Option<Vec<u8>>Expand description
Encode raw (the bytes named by a B64Window) and return exactly take
output chars starting at skip. Returns None when the encoded output is
shorter than skip + take — i.e. raw was shorter than the window the
caller resolved against art_total (a truncated art blob). A checked read
rather than a panic, so the serve path can surface this as BackingChanged
like the other base64-art arms (#526).