W. Felix Handte [Wed, 8 Sep 2021 16:45:42 +0000 (12:45 -0400)]
Write Back Advanced Hash in Long Matches as Well (+Ratio)
Since we're now hashing the position ahead even if we find a long match and
don't search that next position, we can write it back into the hashtable even
in long matches. This seems to cost us no speed, and improves compression
ratio slightly!
W. Felix Handte [Thu, 2 Sep 2021 16:25:08 +0000 (12:25 -0400)]
Hash Long One Position Ahead (+2.5% Speed)
Aside from maybe a latency win in the loop, this means that when we find a
short match, we've already done the hash we need to check the next long match.
Nick Terrell [Mon, 27 Sep 2021 20:56:07 +0000 (13:56 -0700)]
[huf] Fix OSS-Fuzz assert
PR #2784 introduced a bug in the decompressor that caused some valid
inputs to fail to decompress. The bitstream isn't reloaded after the 4X*
loop if the number of elements remaining is small enough, causing us to
read more bits than are available in the bitcontainer.
This was caught by the MSAN fuzzer in OSS-Fuzz because the assembly
implementation isn't used in the MSAN build.
Norbert Lange [Sun, 26 Sep 2021 08:59:05 +0000 (10:59 +0200)]
zstd_decompress: use a helper function for context create
Multiple ZSTD_createDCtx* functions call other (public)
ZSTD_createDCtx* functions, this makes it harder for humans
and compilers to throw out code that is not used.
This farms out the logic into a static function, if a program
only uses a single ZSTD_createDCtx variant, all others can be easily
dropped and the remaining implementation can be specialized.
[contrib][linux] Fix -Wundef inside Linux kernel tree
Commit d7ef97a013b5
("[build] Fix oss-fuzz build with the dataflow sanitizer") broke
build inside Linux-kernel after 'import', as it no longer can
conditionally remove ZSTD_MEMORY_SANITIZER definition from
the #if DEF_A || DEF_B block. This emits -Wundef warning which
can be treated as error.
Split this preprocessor condition into two separate conditions
to fix this.
Fixes: d7ef97a013b5 ("[build] Fix oss-fuzz build with the dataflow sanitizer") Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Nick Terrell [Thu, 23 Sep 2021 02:56:07 +0000 (19:56 -0700)]
[lib] Make lib compatible with `-Wfall-through` excepting legacy
Switch to a macro `ZSTD_FALLTHROUGH;` instead of a comment. On supported
compilers this uses an attribute, otherwise it becomes a comment.
This is necessary to be compatible with clang's `-Wfall-through`, and
gcc's `-Wfall-through=2` which don't support comments. Without this the
linux build emits a bunch of warnings.
Also add a test to CI to ensure that we don't regress.
turns out, it's possible to constify MatchState* parameter
in some parts of the binary tree algorithm,
making it a pure read-only parameter,
as opposed to a mutable state.
This is supposed to be helpful for both maintenance and the compiler.
[contrib][linux] Add huf_decompress_amd64.o target to Makefile
Commit a5f2c4552803 ("Huffman ASM") added a new ASM source file,
but it wasn't added to the kernel Makefile despite that it received
support for Huffman ASM according to the internal definitions. This
leads to undefined references, as huf_decompress.o now calls those
ASM functions.
Add it to the list of sources when building inside the kernel tree.
Kbuild can handle .S files just fine, so none additional rules
needed.
Fixes: a5f2c4552803 ("Huffman ASM") Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Linux 5.15 introduces a new Kconfig option, CONFIG_WERROR, which
forces -Werror for the entire kernel.
Current in-kernel ZSTD implementation uses functions deprecated
in 1.5.0, and thus fails on -Wdeprecated-declarations.
Turn this particular error into warning to be able to build the
kernel with CONFIG_WERROR. I'm not disabling them completely to
make sure they'll be visible and [hopefully] fixed sooner or later.
Nick Terrell [Thu, 23 Sep 2021 01:13:02 +0000 (18:13 -0700)]
[contrib][linux] Reduce stack usage by 80 bytes
Instead of calling `ZSTD_compress_advanced()` and
`ZSTD_initCStream_advanced()`, which each take a `ZSTD_parameters` by
value, use the new advanced API.
Nick Terrell [Fri, 17 Sep 2021 18:42:08 +0000 (11:42 -0700)]
[build] Add support for ASM files in Make + CMake
* Extract out common portion of `lib/Makefile` into `lib/libzstd.mk`.
Most relevantly, the way we find library files.
* Use `lib/libzstd.mk` in the other Makefiles instead of repeating the
same code.
* Add a test `tests/test-variants.sh` that checks that the builds of
`make -C programs allVariants` are correct, and run it in Actions.
* Adds support for ASM files in the CMake build.
The Meson build is not updated because it lists every file in zstd,
and supports ASM off the bat, so the Huffman ASM commit will just add
the ASM file to the list.
The Visual Studios build is not updated because I'm not adding ASM
support to Visual Studios yet.
Nick Terrell [Tue, 14 Sep 2021 18:57:26 +0000 (11:57 -0700)]
[rsyncable] Fix test failures
Test failures showed up on the daily cron job. They didn't show up
in CI because the condition is somewhat rare, and didn't trigger
during the CI tests.
This PR fixes up the logic in `findSynchronizationPoint()` to correctly
handle the edge case. It also un-comments an assert that helps catch the
issue, and verify that rsyncable mode is calculating the correct hash.
Nick Terrell [Mon, 13 Sep 2021 23:59:20 +0000 (16:59 -0700)]
[rsyncable] Ensure ZSTD_compressBound() is respected
In degenerate cases `--rsyncable` could create very small blocks (1
byte). This causes the compressed output to be larger than
`ZSTD_compressBound()`. Fix the issue by ensuring that rsyncable mode
never outputs blocks smaller than 128 KB.
The minimum job size is 512 KB, so we shouldn't lose many
synchronization points from skipping any that cause blocks smaller than
128 KB. And even if we do, that is fine, because we'll find the next
one.
This fixes the `raw_dictionary_round_trip` oss-fuzz assert.
projects / thirdparty / zstd.git / log
