+ ops = compressor_ops[ctype];
+
+ if (compression_level == 0)
+ compression_level = default_compression_levels[ctype];
+ if (compression_level == 0)
+ compression_level = DEFAULT_COMPRESSION_LEVEL;
+
+ if (ops->get_needed_memory) {
+ size = ops->get_needed_memory(max_block_size, compression_level,
+ destructive);
+
+ /* 0 is never valid and indicates an invalid max_block_size. */
+ if (size == 0)