Function max_stored_len 

pub fn max_stored_len(body_len: usize) -> usize

Available on Unix and crate feature pool only.

The largest stored form ExtentCodec::encode may produce for a body_len-byte body: an incompressible-input expansion matching lz4’s worst case plus a four-byte length prefix. The extent store’s size-class ladder is provisioned to this bound, so a codec that exceeds it can strand payloads with no class to hold them (they degrade to unpageable heap fallbacks).