ensure that, when frequency[symbol]==0,
result is (tableLog + 1) bits
with both upper-bit and fractional-bit estimates.
Also : enable BIT_DEBUG in /tests
ZSTD_decompress() can decompress multiple frames sent as a single input.
But the input size must be the exact sum of all compressed frames, no more.
In the case of a mistake on srcSize, being larger than required,
ZSTD_decompress() will try to decompress a new frame after current one, and fail.
As a consequence, it will issue an error code, ERROR(prefix_unknown).
While the error is technically correct
(the decoder could not recognise the header of _next_ frame),
it's confusing, as users will believe that the first header of the first frame is wrong,
which is not the case (it's correct).
It makes it more difficult to understand that the error is in the source size, which is too large.
This patch changes the error code provided in such a scenario.
If (at least) a first frame was successfully decoded,
and then following bytes are garbage values,
the decoder assumes the provided input size is wrong (too large),
and issue the error code ERROR(srcSize_wrong).
distance between levels is slightly increased
to compensate for level 1 speed improvements
and the will to have stronger level 19
extending the range of speed to cover.
reported by @let-def.
It's actually a bug in ZSTD_compressBegin_usingCDict()
which would pass a wrong pledgedSrcSize value (0 instead of ZSTD_CONTENTSIZE_UNKNOWN)
resulting in wrong window size, resulting in downsized seqStore,
resulting in segfault when writing into the seqStore later in the process.
Added a test in fuzzer to cover this use case (fails before the patch).
The new advanced API basically set `requestedParams = appliedParams` when
using a dictionary. This halted all parameter adjustment, which can hurt
compression ratio if, for example, the window log is small for the first
call, but the rest of the files are large.
This patch fixes the bug, and checks that the `requestedParams` don't change
in the new advanced API when using a dictionary, and generally in the fuzzer.
OpenBSD uses md5 instead of md5sum, and has no device called full.
With this patch, make check runs until #1088. With the assumption made
in the issue make check runs succesfully.
Summary:
Allocate a single input buffer large enough to house each job, as well as
enough space for the IO thread to write 2 extra buffers. One goes in the
`POOL` queue, and one to fill, and then block on a full `POOL` queue.
Since we can't overlap with the prefix, we allocate space for 3 extra
input buffers.
Test Plan:
* CI
* With and without ASAN/UBSAN run zstdmt with different number of threads
on two large binaries, and verify that their checksums match.
* Test on the tip of the zstdmt ldm integration.
Reviewers: cyan
Differential Revision: https://phabricator.intern.facebook.com/D7284007
Tasks: T25664120
The overflow protection is broken when the window log is `> (3U << 29)`, so 31.
It doesn't work when `current` isn't around `1U << windowLog` ahead of `lowLimit`,
and the the assertion `current > newCurrent` fails. This happens when the same
context is used many times over, but with a large window log, like in zstdmt.
Fix it by triggering correction based on `nextSrc - base` instead of `lowLimit`.
The added test fails before the patch, and passes after.
access negative compression levels from command line
for both compression and benchmark modes.
also : ensure proper propagation of parameters
through ZSTD_compress_generic() interface.
added relevant cli tests.
negative compression level trade compression ratio for more compression speed.
They turn off huffman compression of literals,
and use row 0 as baseline with a stepSize = -cLevel.
added associated test in fuzzer
also added : new advanced parameter ZSTD_p_literalCompression
This makes it easier to explain that nbWorkers=0 --> single-threaded mode,
while nbWorkers=1 --> asynchronous mode (one mode thread on top of the "main" caller thread).
No need for an additional asynchronous mode flag.
nbWorkers>=2 works the same as nbThreads>=2 previously.
