compress_safe(),
  though situation has changed in recent versions,
  and now `LZ4_decompress_safe()` can be as fast and sometimes faster than `LZ4_decompress_fast()`.
  Moreover, LZ4_decompress_fast() is not protected vs malformed input, as it doesn't perform full validation of compressed data.
  As a consequence, this function is no longer recommended, and may be deprecated in future versions.
  It's only remaining specificity is that it can decompress data without knowing its compressed size.

  original