- * @chunk: Uncompressed data of the chunk.
- * @chunk_size: Size of the uncompressed chunk in bytes.
- * @compressed_chunk: Pointer to output buffer of size at least
- * (@chunk_size - 1) bytes.
- * @compressed_chunk_len_ret: Pointer to an unsigned int into which the size
- * of the compressed chunk will be
- * returned.
+ * @chunk: Uncompressed data of the chunk.
+ * @chunk_size: Size of the uncompressed chunk, in bytes.
+ * @out: Pointer to output buffer of size at least (@chunk_size - 1) bytes.
+ *
+ * Returns the size of the compressed data written to @out in bytes, or 0 if the
+ * data could not be compressed to (@chunk_size - 1) bytes or fewer.
+ *
+ * As a special requirement, the compression code is optimized for the WIM
+ * format and therefore requires (@chunk_size <= 32768).