Google snappy in C for Linux Kernel
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README Update URL of Google Snappy Aug 18, 2016
TODO set LD_LIBRARY_PATH Apr 18, 2011
block_compressor.c use 8kb work memory to compress 4kb pages, like google's code. Apr 20, 2011
block_compressor_benchmark.txt update userspace benchmarks Apr 30, 2011
cl_tester.c cl_tester -S d test failed on AArch64 when decompressing data without Jul 29, 2015
csnappy.h Fix issue #20 from zeevt/csnappy: include stdint.h Oct 15, 2014
csnappy_compat.h Sereal's csnappy Win32 fixes Feb 28, 2013
csnappy_compress.c Fix 64 bit big endian code path in decoder. Sep 26, 2014
csnappy_decompress.c Fix integer truncation error during decompression Mar 31, 2015
csnappy_internal.h Sereal's csnappy Win32 fixes Feb 28, 2013
csnappy_internal_userspace.h endian.h and mingw (same as PR #27) Nov 11, 2015
debugfs_input.txt zram now uses headerless snappy streams to save 2 bytes and a few cpu… Apr 4, 2011
kernel_3_2_10.patch a current linux kernel patch Mar 13, 2012
snappy_tester.patch update snappy tester patch Feb 28, 2012
unaligned_arm.s ARM optimizations. There will be more. In particular ARMv6 has unalig… Mar 11, 2012
unaligned_test.c tester for ARM on android Mar 11, 2012
userspace_benchmark.txt update userspace benchmarks Apr 30, 2011
zram_benchmark.txt split zram benchmark from readme Apr 15, 2011
zramtest2.sh big endian fixes, courtesy of debian ppc qemu image Apr 6, 2011

README

Google Snappy, available at https://google.github.io/snappy/
is a compression library designed for speed rather than compression ratios.

It is not a new concept by far. The Linux kernel currently uses LZO as the
 default fast compressor. Snappy works faster, though achieves less compression.

Google's code is written in C with a lot of C++. Some of the more interesting
 features that rely on C++ appear to have been elided from the open source
 version of Snappy.

Goals:
To get the codebase into a shape that can be accepted into the mainline
 Linux kernel and used with zram (http://code.google.com/p/compcache/).
Being able to compress vmlinux and initrd with Snappy is a secondary goal.
Same for support in Squashfs and other parts of the kernel that currently
 support LZO.

Results:
I cut out or ported to plain ANSI C the necessary code and headers.
To cause less confusion, I call this project (and files) csnappy.
The API looks right, but I welcome comments.
The code *has* been tested in kernel-space using a patched zram and it works.

The code has been tested in a qemu emulating a PowerPC Mac and ARMv5TE running
 Debian Wheezy.

I also use an ARMv6 Android phone for testing.

Testing on other hardware or platforms is welcome.

Note: The userspace tester is a hack, as is the shared library.

Someone wrote a perl wrapper for csnappy:
http://search.cpan.org/dist/Compress-Snappy/
https://github.com/gray/compress-snappy

Patch for upstream snappy tester is available: snappy_tester.patch
Patch for linux kernel is available: kernel_3_2_10.patch

Benchmark in userspace: userspace_benchmark.txt
Benchmark in kernel space with zram: zram_benchmark.txt