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zlib data compression library for the next generation systems
Maintained by Hans Kristian Rosbach aka Dead2 (zlib-ng àt circlestorm dót org)
The motivation for this fork was seeing several 3rd party contributions with new optimizations not getting implemented into the official zlib repository.
Mark Adler has been maintaining zlib for a very long time, and he has done a great job and hopefully he will continue for a long time yet. The idea of zlib-ng is not to replace zlib, but to co-exist as a drop-in replacement with a lower threshold for code change.
zlib has a long history and is incredibly portable, even supporting many systems that predate the Internet.
That is great, but it can complicate further development and maintainability. The zlib code contains many workarounds for really old compilers or to accommodate systems with limitations such as operating in a 16-bit environment.
Many of these workarounds are only maintenance burdens, some of them are pretty huge code-wise. With many workarounds cluttered throughout the code, it makes it harder for new programmers with an idea/interest for zlib to contribute.
I decided to make a fork, merge all the Intel optimizations, some of the Cloudflare optimizations, plus a couple other smaller patches. Then started cleaning out workarounds, various dead code, all contrib and example code.
The result is a better performing and easier to maintain zlib-ng.
A lot of improvements have gone into zlib-ng since its start, and numerous people and companies have contributed both small and big improvements, or valuable testing.
Please read LICENSE.md, it is very simple and very liberal.
There are two ways to build zlib-ng:
To build zlib-ng using the cross-platform makefile generator cmake.
cmake . cmake --build . --config Release ctest --verbose -C Release
Alternatively, you can use the cmake configuration GUI tool ccmake:
ccmake .
To build zlib-ng using the bash configure script:
./configure make make test
| CMake | configure | Description | Default |
|---|---|---|---|
| ZLIB_COMPAT | --zlib-compat | Compile with zlib compatible API | OFF |
| ZLIB_ALIASES | Provide zlib compatible CMake targets | ON | |
| WITH_GZFILEOP | --without-gzfileops | Compile with support for gzFile related functions | ON |
| WITH_OPTIM | --without-optimizations | Build with optimisations | ON |
| WITH_NEW_STRATEGIES | --without-new-strategies | Use new strategies | ON |
| WITH_CRC32_CHORBA | Build with Chorba optimized CRC32 | ON | |
| WITH_REDUCED_MEM | --with-reduced-mem | Reduce zlib-ng memory usage, affects performance and compression ratio | OFF |
| WITH_GTEST | Build tests using GTest framework | ON | |
| WITH_BENCHMARKS | Build benchmarks using Google Benchmark framework | OFF | |
| INSTALL_UTILS | Copy minigzip and minideflate during install | OFF | |
| BUILD_TESTING | Build test binaries | ON |
WARNING: We do not recommend manually installing unless you really know what you are doing, because this can potentially override the system default zlib library, and any incompatibility or wrong configuration of zlib-ng can make the whole system unusable, requiring recovery or reinstall. If you still want a manual install, we recommend using the /opt/ path prefix.
For Linux distros, an alternative way to use zlib-ng (if compiled in zlib-compat mode) instead of zlib, is through the use of the LD_PRELOAD environment variable. If the program is dynamically linked with zlib, then the program will temporarily attempt to use zlib-ng instead, without risking system-wide instability.
LD_PRELOAD=/opt/zlib-ng/libz.so.1.2.13.zlib-ng /usr/bin/program
To install zlib-ng system-wide using cmake:
cmake --build . --target install
To install zlib-ng system-wide using the configure script:
make install
After building with cmake, an installation package can be created using cpack. By default a tgz package is created, but you can append -G <format> to each command to generate alternative packages types (TGZ, ZIP, RPM, DEB). To easily create a rpm or deb package, you would use -G RPM or -G DEB respectively.
cd build cpack --config CPackConfig.cmake cpack --config CPackSourceConfig.cmake
Alternatively, you can build and install zlib-ng using the vcpkg dependency manager:
git clone https://github.com/Microsoft/vcpkg.git cd vcpkg ./bootstrap-vcpkg.sh # "./bootstrap-vcpkg.bat" for powershell ./vcpkg integrate install ./vcpkg install zlib-ng
The zlib-ng port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.
Zlib-ng is aiming to be open to contributions, and we would be delighted to receive pull requests on github. Help with testing and reviewing pull requests etc is also very much appreciated.
Please check the Wiki for more info: Contributing
Thanks go out to all the people and companies who have taken the time to contribute code reviews, testing and/or patches. Zlib-ng would not have been nearly as good without you.
The deflate format used by zlib was defined by Phil Katz.
The deflate and zlib specifications were written by L. Peter Deutsch.
zlib was originally created by Jean-loup Gailly (compression) and Mark Adler (decompression).
| CMake | configure | Description | Default |
|---|---|---|---|
| WITH_NATIVE_INSTRUCTIONS | Compiles with full instruction set supported on this host (gcc/clang -march=native) | OFF | |
| WITH_RUNTIME_CPU_DETECTION | Compiles with runtime CPU detection | ON | |
| WITH_SSE2 | x86: Build with SSE2 intrinsics | ON | |
| WITH_SSSE3 | x86: Build with SSSE3 intrinsics | ON | |
| WITH_SSE41 | x86: Build with SSE41 intrinsics | ON | |
| WITH_SSE42 | x86: Build with SSE42 intrinsics | ON | |
| WITH_PCLMULQDQ | x86: Build with PCLMULQDQ intrinsics | ON | |
| WITH_AVX2 | x86: Build with AVX2 intrinsics | ON | |
| WITH_AVX512 | x86: Build with AVX512 intrinsics | ON | |
| WITH_AVX512VNNI | x86: Build with AVX512VNNI intrinsics | ON | |
| WITH_VPCLMULQDQ | x86: Build with VPCLMULQDQ intrinsics | ON | |
| WITH_ARMV6 | --without-armv6 | arm: Build with ARMv6 intrinsics | ON |
| WITH_ARMV8 | --without-armv8 | arm: Build with ARMv8 intrinsics | ON |
| WITH_NEON | --without-neon | arm: Build with NEON intrinsics | ON |
| WITH_ALTIVEC | --without-altivec | ppc: Build with AltiVec (VMX) intrinsics | ON |
| WITH_POWER8 | --without-power8 | ppc: Build with POWER8 intrinsics | ON |
| WITH_POWER9 | --without-power9 | ppc: Build with POWER9 intrinsics | ON |
| WITH_RVV | --without-rvv | riscv: Build with RVV intrinsics | ON |
| WITH_RISCV_ZBC | --without-zbc | riscv: Build with RiscV ZBC intrinsics | ON |
| WITH_S390_VX | --without-s390-vx | s390x: Build with S390 VX intrinsics on IBM Z | ON |
| WITH_DFLTCC_DEFLATE | --with-dfltcc-deflate | s390x: Build with DFLTCC intrinsics for compression on IBM Z | OFF |
| WITH_DFLTCC_INFLATE | --with-dfltcc-inflate | s390x: Build with DFLTCC intrinsics for decompression on IBM Z | OFF |
| WITH_LSX | loongarch: Build with LSX intrinsics | ON | |
| WITH_CRC32_LA | --without-crc32-la | loongarch: Build with vectorized CRC32 | ON |
| WITH_INFLATE_STRICT | Build with strict inflate distance checking | OFF | |
| WITH_INFLATE_ALLOW_INVALID_DIST | Build with zero fill for inflate invalid distances | OFF | |
| WITH_BENCHMARK_APPS | Build benchmark apps (currently libpng) | OFF | |
| WITH_ALL_FALLBACKS | Build with all c-fallbacks (useful for Gbench comparisons) | OFF | |
| WITH_MAINTAINER_WARNINGS | Build with project maintainer warnings | OFF | |
| WITH_SANITIZER | Build with sanitizer (memory, address, undefined) | OFF | |
| WITH_FUZZERS | Build test/fuzz | OFF | |
| WITH_CODE_COVERAGE | Enable code coverage reporting | OFF |