LZ4 v1.10.0 introduces major updates, integrating 600+ commits that significantly enhance its capabilities. This version brings multithreading support to the forefront, harnessing modern multi-core processors to accelerate both compression and decompression processing. It's a good upgrade for users looking to optimize performance in high-throughput environments.

Multithreading support

The most visible upgrade of this version is likely Multithreading support. While LZ4 has historically been recognized for its high-speed compression, the demand for even faster throughput has grown, particularly with the advent of nvme storage technologies that allow for multi-GB/s throughput.
Multithreading is particularly beneficial for High Compression modes, which now perform dramatically faster. The following benchmark table showcases the performance improvements:

Multithreading is less critical for decompression, as modern nvme drives can still be saturated with a single decompression thread. Nonetheless, the new version enhances performance by overlapping I/O operations with decompression processes. Tested on a x64 linux platform, decompressing a 5 GB text file locally takes 5 seconds with v1.9.4; this is reduced to 3 seconds in v1.10.0, corresponding to > +60% performance improvement.

Official support for dictionary compression (and decompression)

Starting from v1.10.0, dictionary compression, previously tagged as "experimental", now receives full support. This upgrade assures stability and ongoing support for the feature, enabling developers to reliably use this functionality in their applications. The new symbols supported by liblz4 are :

• LZ4_loadDictSlow(): minor variant of LZ4_loadDict(), which consumes more initialization time to better reference the dictionary, resulting in slightly improved compression ratios.
• LZ4_attach_dictionary(): use in-place a LZ4 state initialized with a dictionary, to perform dictionary compression (LZ4 Block format) without the initialization costs. Very useful for small data, where dictionary initialization can become a bottleneck. The dictionary state can be used by multiple threads concurrently.
• LZ4_attach_HC_dictionary(): same as LZ4_attach_dictionary(), but for LZ4HC dictionary compression.
• LZ4F_compressBegin_usingDict(): initiate streaming compression to the LZ4Frame format, using a Dictionary.
• LZ4F_decompress_usingDict(): decompress a LZ4Frame requiring a Dictionary
• LZ4F_createCDict() : create a materialized dictionary, ready to start compression without initialization cost. Can be shared across multiple threads.
• LZ4F_compressFrame_usingCDict(): one-shot compression to the LZ4Frame format, using materialized CDict
• LZ4F_compressBegin_usingCDict(): initiate streaming compression to the LZ4Frame format, using materialized CDict

New compression level 2

The new "Level 2" compression effectively fills the substantial gap between the standard "Fast Level 1" and the more intensive "High Compression Level 3." It provides a balanced option, optimizing performance and compression as evidenced in the benchmark results below (i7-9700k, linux):

Level 2 is ideal for applications requiring better compression than lz4 level 1, without the speed trade-offs associated with HC level 3.

Miscellaneous

• The CLI now supports the environment variables LZ4_CLEVEL and LZ4_NBWORKERS, offering flexible control over its behavior in scenarios where direct commands are impractical, or when customized local defaults are necessary.
• The licensing for the CLI and test programs has been clarified to GPL-2.0-or-later to distinguish it from GPL-2.0-only, enhancing transparency. The liblz4 library maintains its BSD-2 clause license.
• Various less common platforms have been validated (loongArch, risc-v, m68k, mips and sparc), and are now continuously tested in CI, to ensure portability.
• Visual Studio solutions are now generated from cmake recipe, in an effort to reduce manual maintenance of multiple Solutions.

One-liner updates

• cli : multithreading compression support: improves speed by X times threads allocated
• cli : overlap decompression with i/o, improving speed by >+60%
• cli : support environment variables LZ4_CLEVEL and LZ4_NBWORKERS
• cli : license of CLI more clearly labelled GPL-2.0-or-later
• cli : fix: refuse to compress directories
• cli : fix dictionary compression benchmark on multiple files
• cli : change: no more implicit stdout (except when input is stdin)
• lib : new level 2, offering mid-way performance (speed and compression)
• lib : Improved lz4frame compression speed for small data (up to +160% at 1KB)
• lib : Slightly faster (+5%) HC compression speed (levels 3-9), by @JunHe77
• lib : dictionary compression support now in stable status
• lib : lz4frame states can be safely reset and reused after a processing error (described by @QrczakMK)
• lib : lz4file API improvements, by @vsolontsov-volant and @t-mat
• lib : new experimental symbol LZ4_compress_destSize_extState()
• build: cmake minimum version raised to 3.5
• build: cmake improvements, by @foxeng, @Ohjurot, @LocalSpook, @teo-tsirpanis, @ur4t and @t-mat
• build: meson scripts are now hosted into build/ directory, by @eli-schwartz
• build: meson improvements, by @tristan957
• build: Visual Studio solutions generated by cmake via scripts
• port : support for loongArch, risc-v, m68k, mips and sparc architectures
• port : improved Visual Studio compatibility, by @t-mat
• port : freestanding support improvements, by @t-mat

Automated change log

• Cancel in-progress CI if a new commit workflow supplants it by @tristan957 in https://github.com/lz4/lz4/pull/1142
• allocation optimization for lz4frame compression by @Cyan4973 in https://github.com/lz4/lz4/pull/1158
• fixed a few remaining ubsan warnings in lz4hc by @Cyan4973 in https://github.com/lz4/lz4/pull/1160
• simplify getPosition by @Cyan4973 in https://github.com/lz4/lz4/pull/1161
• build: Support BUILD_SHARED=no by in https://github.com/lz4/lz4/pull/1162
• fix benchmark mode using Dictionary by @Cyan4973 in https://github.com/lz4/lz4/pull/1168
• remove usages of base pointer by @Cyan4973 in https://github.com/lz4/lz4/pull/1163
• fix rare ub by @Cyan4973 in https://github.com/lz4/lz4/pull/1169
• LZ4 HC match finder and parsers use direct offset values by @Cyan4973 in https://github.com/lz4/lz4/pull/1173
• very minor refactor of lz4.c by @Cyan4973 in https://github.com/lz4/lz4/pull/1174
• Update Meson build to 1.9.4 by @tristan957 in https://github.com/lz4/lz4/pull/1139
• Fixed const-ness of src data pointer in lz4file and install lz4file.h by @vsolontsov-volant in https://github.com/lz4/lz4/pull/1192
• Add copying lz4file.h to make install by @vsolontsov-volant in https://github.com/lz4/lz4/pull/1191
• Change the version of lib[x]gcc for clang-(11|12) -mx32 by @t-mat in https://github.com/lz4/lz4/pull/1197
• Remove PATH=$(PATH) prefix from all shell script invocation in tests/Makefile by @t-mat in https://github.com/lz4/lz4/pull/1196
• Add environment check for freestanding test : resolves #1186 by @t-mat in https://github.com/lz4/lz4/pull/1187
• Declare read_long_length_no_check() static by @x4m in https://github.com/lz4/lz4/pull/1188
• uncompressed-blocks: Allow uncompressed blocks for all modes by @alexmohr in https://github.com/lz4/lz4/pull/1178
• fixed usan32 tests by @Cyan4973 in https://github.com/lz4/lz4/pull/1175
• Meson updates by @tristan957 in https://github.com/lz4/lz4/pull/1184
• Fix typo found by codespell by @DimitriPapadopoulos in https://github.com/lz4/lz4/pull/1204
• Clean up generation of internal static library by @tristan957 in https://github.com/lz4/lz4/pull/1206
• build: move meson files from contrib, to go alongside other build systems by @eli-schwartz in https://github.com/lz4/lz4/pull/1207
• Improve LZ4F_decompress() docs by @embg in https://github.com/lz4/lz4/pull/1199
• Add 64-bit detection for LoongArch by @zhaixiaojuan in https://github.com/lz4/lz4/pull/1209
• refuse to compress directories by @Cyan4973 in https://github.com/lz4/lz4/pull/1212
• Fix #1232 : lz4 command line utility sub-project for Visual Studio 2022 missing by @t-mat in https://github.com/lz4/lz4/pull/1233
• Add security policy by @pnacht in https://github.com/lz4/lz4/pull/1238
• fix #1246 by @Cyan4973 in https://github.com/lz4/lz4/pull/1247
• fix: missing LZ4F_freeDecompressionContext by @t-mat in https://github.com/lz4/lz4/pull/1251
• CI: updates (Add gcc-13 and clang-15. Fix msvc2022-x86-release) by @t-mat in https://github.com/lz4/lz4/pull/1245
• Don't clobber default WINDRES in MinGW environments by @uckelman-sf in https://github.com/lz4/lz4/pull/1242
• Reduce usage of variable cpy on decompression by @Nicoshev in https://github.com/lz4/lz4/pull/1226
• lib/Makefile: Support building on legacy OS X by @sevan in https://github.com/lz4/lz4/pull/1220
• Set CMake minimum requirement to 3.5 by @haampie in https://github.com/lz4/lz4/pull/1228
• Adding XXH_NAMESPACE to CMake builds by @Ohjurot in https://github.com/lz4/lz4/pull/1258
• Apply pyupgrade suggestion to Python test scripts by @DimitriPapadopoulos in https://github.com/lz4/lz4/pull/1257
• Remove redundant error check by @Nicoshev in https://github.com/lz4/lz4/pull/1224
• Add packing support for msc by @Nicoshev in https://github.com/lz4/lz4/pull/1225
• Don't conflate the shared library name with the shared library filename by @uckelman-sf in https://github.com/lz4/lz4/pull/1244
• Move GNUInstallDirs include before it is referenced first by @laszlo-dobcsanyi in https://github.com/lz4/lz4/pull/1260
• lz4hc: increase count back search step by @JunHe77 in https://github.com/lz4/lz4/pull/1263
• Update code documentation about stableDst by @Cyan4973 in https://github.com/lz4/lz4/pull/1267
• Fix #1227 by @Cyan4973 in https://github.com/lz4/lz4/pull/1268
• fix x32 CI tests by @Cyan4973 in https://github.com/lz4/lz4/pull/1278
• fix examples by @Cyan4973 in https://github.com/lz4/lz4/pull/1277
• fix: issue #1269 by @t-mat in https://github.com/lz4/lz4/pull/1281
• cmake static lib test (ci.yml) by @t-mat in https://github.com/lz4/lz4/pull/1286
• Ignore Visual Studio Code files in .gitignore by @LocalSpook in https://github.com/lz4/lz4/pull/1288
• Make CMake version number parsing more robust by @LocalSpook in https://github.com/lz4/lz4/pull/1289
• Make Makefile version number parsing more robust by @LocalSpook in https://github.com/lz4/lz4/pull/1290
• Make Meson version number parsing more robust by @LocalSpook in https://github.com/lz4/lz4/pull/1291
• Introduce the .clang-format rule file by @LocalSpook in https://github.com/lz4/lz4/pull/1287
• Use -Wpedantic instead of -pedantic for consistency with other -W* options by @LocalSpook in https://github.com/lz4/lz4/pull/1294
• Add null pointer check before FREEMEM() by @LocalSpook in https://github.com/lz4/lz4/pull/1297
• added new qemu targets for CI (MIPS, M68K, RISC-V) by @Cyan4973 in https://github.com/lz4/lz4/pull/1299
• Enable basic support for riscv64 by @Hamlin-Li in https://github.com/lz4/lz4/pull/1298
• lz4: remove unnecessary check of ip by @JunHe77 in https://github.com/lz4/lz4/pull/1301
• decomp: refine read_variable_length codegen layout by @JunHe77 in https://github.com/lz4/lz4/pull/1312
• updated code documentation by @Cyan4973 in https://github.com/lz4/lz4/pull/1314
• Add LZ4_compress_fast_extState_destSize() API by @tristan957 in https://github.com/lz4/lz4/pull/1308
• Minor refactor by @Cyan4973 in https://github.com/lz4/lz4/pull/1322
• fix minor conversion warnings by @Cyan4973 in https://github.com/lz4/lz4/pull/1325
• ensure make install target doesn't create files by @Cyan4973 in https://github.com/lz4/lz4/pull/1326
• minor: lz4file API provides more accurate error codes by @Cyan4973 in https://github.com/lz4/lz4/pull/1327
• Make hashes identical between LE and BE platforms by @ltrk2 in https://github.com/lz4/lz4/pull/1253
• Makefile refactor by @Cyan4973 in https://github.com/lz4/lz4/pull/1328
• fix 1308 by @Cyan4973 in https://github.com/lz4/lz4/pull/1333
• Add multi-threading compression by @Cyan4973 in https://github.com/lz4/lz4/pull/1336
• Compile-time constants by @Cyan4973 in https://github.com/lz4/lz4/pull/1343
• change INSTALL_DIR into MAKE_DIR by @Cyan4973 in https://github.com/lz4/lz4/pull/1350
• added a lorem ipsum generator by @Cyan4973 in https://github.com/lz4/lz4/pull/1356
• Fix Python 3.6 string interpolation by @likema in https://github.com/lz4/lz4/pull/1353
• Datagen uses lorem ipsum generator by default by @Cyan4973 in https://github.com/lz4/lz4/pull/1357
• Fix seed 571 test by @Cyan4973 in https://github.com/lz4/lz4/pull/1361
• add sparc compilation test by @Cyan4973 in https://github.com/lz4/lz4/pull/1360
• LZ4 Level 2 by @Cyan4973 in https://github.com/lz4/lz4/pull/1363
• updated lorem ipsum generator by @Cyan4973 in https://github.com/lz4/lz4/pull/1369
• Added preprocessor checks for Clang on Windows by @Razakhel in https://github.com/lz4/lz4/pull/1370
• Add unified CMake target if building only a shared or statric library, by @teo-tsirpanis in https://github.com/lz4/lz4/pull/1372
• Introduce Async I/O for decompression by @Cyan4973 in https://github.com/lz4/lz4/pull/1376
• fix #1374 by @Cyan4973 in https://github.com/lz4/lz4/pull/1380
• Suppress VS2022 warnings by @jonrumsey in https://github.com/lz4/lz4/pull/1383
• benchmark results are displayed to stdout by @Cyan4973 in https://github.com/lz4/lz4/pull/1390
• Prefer OR over ADD for splicing numbers from byte-addressed memory by @AtariDreams in https://github.com/lz4/lz4/pull/1404
• len should be unsigned by @AtariDreams in https://github.com/lz4/lz4/pull/1403
• Define mlen = MINMATCH at the start of the loop by @AtariDreams in https://github.com/lz4/lz4/pull/1405
• Update function comment by @Nicoshev in https://github.com/lz4/lz4/pull/1401
• CMake: Separate symlinks creation and installation by @ur4t in https://github.com/lz4/lz4/pull/1395
• [cmake] minor refactor of the symlink installation paragraph by @Cyan4973 in https://github.com/lz4/lz4/pull/1406
• [cmake] Always create lz4 target. by @teo-tsirpanis in https://github.com/lz4/lz4/pull/1413
• add status update when decompressing legacy frames by @Cyan4973 in https://github.com/lz4/lz4/pull/1426
• Async-IO for LZ4F decompression by @Cyan4973 in https://github.com/lz4/lz4/pull/1428
• Support Multithreading for Windows by @Cyan4973 in https://github.com/lz4/lz4/pull/1429
• Control nb threads via environment variable LZ4_NBWORKERS by @Cyan4973 in https://github.com/lz4/lz4/pull/1430
• fix cpuload measurements on Windows by @Cyan4973 in https://github.com/lz4/lz4/pull/1432
• minor threadpool refactor by @Cyan4973 in https://github.com/lz4/lz4/pull/1433
• automatically enable multithreading by default on Windows by @Cyan4973 in https://github.com/lz4/lz4/pull/1434
• add support for environment variable LZ4_CLEVEL by @Cyan4973 in https://github.com/lz4/lz4/pull/1435
• Linked Blocks compression (-BD) can employ multiple threads by @Cyan4973 in https://github.com/lz4/lz4/pull/1436
• update gpl license text to 2.0-or-later by @Cyan4973 in https://github.com/lz4/lz4/pull/1438
• removed implicit stdout by @Cyan4973 in https://github.com/lz4/lz4/pull/1442
• Generate Visual Studio solutions from cmake by @Cyan4973 in https://github.com/lz4/lz4/pull/1440
• Ensure --list output is sent to stdout by @Cyan4973 in https://github.com/lz4/lz4/pull/1446
• exit on invalid frame by @Cyan4973 in https://github.com/lz4/lz4/pull/1448
• promote dictionary API to stable by @Cyan4973 in https://github.com/lz4/lz4/pull/1443

New Contributors

• @foxeng made their first contribution in https://github.com/lz4/lz4/pull/1162
• @vsolontsov-volant made their first contribution in https://github.com/lz4/lz4/pull/1192
• @x4m made their first contribution in https://github.com/lz4/lz4/pull/1188
• @embg made their first contribution in https://github.com/lz4/lz4/pull/1199
• @zhaixiaojuan made their first contribution in https://github.com/lz4/lz4/pull/1209
• @IgorWiecz made their first contribution in https://github.com/lz4/lz4/pull/1235
• @pnacht made their first contribution in https://github.com/lz4/lz4/pull/1238
• @uckelman-sf made their first contribution in https://github.com/lz4/lz4/pull/1242
• @Nicoshev made their first contribution in https://github.com/lz4/lz4/pull/1226
• @sevan made their first contribution in https://github.com/lz4/lz4/pull/1220
• @haampie made their first contribution in https://github.com/lz4/lz4/pull/1228
• @Ohjurot made their first contribution in https://github.com/lz4/lz4/pull/1258
• @laszlo-dobcsanyi made their first contribution in https://github.com/lz4/lz4/pull/1260
• @JunHe77 made their first contribution in https://github.com/lz4/lz4/pull/1263
• @LocalSpook made their first contribution in https://github.com/lz4/lz4/pull/1288
• @Hamlin-Li made their first contribution in https://github.com/lz4/lz4/pull/1298
• @ltrk2 made their first contribution in https://github.com/lz4/lz4/pull/1253
• @likema made their first contribution in https://github.com/lz4/lz4/pull/1353
• @Razakhel made their first contribution in https://github.com/lz4/lz4/pull/1370
• @teo-tsirpanis made their first contribution in https://github.com/lz4/lz4/pull/1372
• @deining made their first contribution in https://github.com/lz4/lz4/pull/1375
• @RoboSchmied made their first contribution in https://github.com/lz4/lz4/pull/1384
• @AtariDreams made their first contribution in https://github.com/lz4/lz4/pull/1404
• @ur4t made their first contribution in https://github.com/lz4/lz4/pull/1395

Full Changelog: https://github.com/lz4/lz4/compare/v1.9.4...v1.10.0

edit : the lz4-1.10.0.tar.gz artifact was updated because the earlier version was embedding some macos specific stuff.