Closed constfold closed 4 years ago
When compressing data, the result flate2 produced is different from zlib(the C lib). The reason is flate2 uses a different argument to call deflateInit2_.
deflateInit2_
https://github.com/alexcrichton/flate2-rs/blob/962930cb3a1b1c50b710c9f4749f1686365eb70a/src/ffi/c.rs#L267-L277 The mem_level is setted to 9 instead 8 (DEF_MEM_LEVEL zlib used). https://github.com/madler/zlib/blob/cacf7f1d4e3d44d871b605da3b647f07d718623f/zutil.h#L66 https://github.com/madler/zlib/blob/cacf7f1d4e3d44d871b605da3b647f07d718623f/deflate.c#L234-L235
mem_level
DEF_MEM_LEVEL
I think a reason is that miniz use 9 as it's default mem_level, but that makes no sense. https://github.com/Frommi/miniz_oxide/blob/e91d8fca64617b09f236e4b939f4971a891abe27/miniz/miniz.c#L185
Reset that argument to DEF_MEM_LEVEL is useful, because when I using flate2's zlib feature I want to get the same result as using zlib in C.
When compressing data, the result flate2 produced is different from zlib(the C lib). The reason is flate2 uses a different argument to call
deflateInit2_.https://github.com/alexcrichton/flate2-rs/blob/962930cb3a1b1c50b710c9f4749f1686365eb70a/src/ffi/c.rs#L267-L277 The
mem_levelis setted to 9 instead 8 (DEF_MEM_LEVELzlib used). https://github.com/madler/zlib/blob/cacf7f1d4e3d44d871b605da3b647f07d718623f/zutil.h#L66 https://github.com/madler/zlib/blob/cacf7f1d4e3d44d871b605da3b647f07d718623f/deflate.c#L234-L235I think a reason is that miniz use 9 as it's default mem_level, but that makes no sense. https://github.com/Frommi/miniz_oxide/blob/e91d8fca64617b09f236e4b939f4971a891abe27/miniz/miniz.c#L185
Reset that argument to
DEF_MEM_LEVELis useful, because when I using flate2's zlib feature I want to get the same result as using zlib in C.