Constant ZSTD_SMALL_INPUT_THRESHOLD 

pub const ZSTD_SMALL_INPUT_THRESHOLD: usize = _; // 131_072usize

Threshold below which zstd’s ZSTD_compressBound adds extra margin (128 KiB). See: https://github.com/facebook/zstd/blob/dev/lib/zstd.h (ZSTD_compressBound)