The order you set parameters in the advanced API is not supposed to matter.
However, once you call `ZSTD_CCtx_refCDict()` the compression parameters
cannot be changed. Remove that restriction, and document what parameters
are used when using a CDict.
If the CCtx is in dictionary mode, then the CDict's parameters are used.
If the CCtx is not in dictionary mode, then its requested parameters are
used.
Introduces a new utility function `ZSTD_findFrameCompressedSize_internal` which
is equivalent to `ZSTD_findFrameCompressSize`, but accepts an additional output
parameter `bound` that computes an upper-bound for the compressed data in the frame.
The new API function is named `ZSTD_decompressBound` to be consistent with
`zstd_compressBound` (the inverse operation). Clients will now be able to compute an upper-bound for
their compressed payloads instead of guessing a large size.
Implements https://github.com/facebook/zstd/issues/1536.
* Move all ZSTDMT parameter setting code to ZSTD_CCtxParams_*Parameter().
ZSTDMT now calls these functions, so we can keep all the logic in the
same place.
* Clean up `ZSTD_CCtx_setParameter()` to only add extra checks where needed.
* Clean up `ZSTDMT_initJobCCtxParams()` by copying all parameters by default,
and then zeroing the ones that need to be zeroed. We've missed adding several
parameters here, and it makes more sense to only have to update it if you
change something in ZSTDMT.
* Add `ZSTDMT_cParam_clampBounds()` to clamp a parameter into its valid
range. Use this to keep backwards compatibility when setting ZSTDMT parameters,
which clamp into the valid range.
Test a positive compression level with uncompressed literals,
and a negative compression level with compressed literals.
I double checked the `results.csv` and made sure that the compressed
sizes make sense.
Pull request #1499 added a new test, which uses 'head -c'. The '-c'
option is non-portable (not in POSIX). Instead use 'dd'. Similar issue
has been resolved in the past (#1321).
fseek() doesn't indicate when it moves past the end of a file.
Consequently, if a file is truncated within its last block, the error would't be detected.
This PR adds a test scenario that induces this situation using a small compressed file of only one block in size.
This test is added to tests/playTests.sh
Check is implemented by ensuring that the filehandle position is equal to the filesize upon exit.
On Windows, the equivalent of `/dev/null` is `NUL`.
When tests are run under msys2/minGW,
the environment identifies itself as Windows,
hence the script uses `NUL` instead of `/dev/null`
but the environment will consider `NUL` to be a regular file name.
Consequently, `NUL` will be overwritten during tests,
triggering an error.
This patch uses flag `-f` to force such overwrite
passing the test.
as suggested in #1441.
generally U32 and unsigned are the same thing,
except when they are not ...
case : 32-bit compilation for MIPS (uint32_t == unsigned long)
A vast majority of transformation consists in transforming U32 into unsigned.
In rare cases, it's the other way around (typically for internal code, such as seeds).
Among a few issues this patches solves :
- some parameters were declared with type `unsigned` in *.h,
but with type `U32` in their implementation *.c .
- some parameters have type unsigned*,
but the caller user a pointer to U32 instead.
These fixes are useful.
However, the bulk of changes is about %u formating,
which requires unsigned type,
but generally receives U32 values instead,
often just for brevity (U32 is shorter than unsigned).
These changes are generally minor, or even annoying.
As a consequence, the amount of code changed is larger than I would expect for such a patch.
Testing is also a pain :
it requires manually modifying `mem.h`,
in order to lie about `U32`
and force it to be an `unsigned long` typically.
On a 64-bit system, this will break the equivalence unsigned == U32.
Unfortunately, it will also break a few static_assert(), controlling structure sizes.
So it also requires modifying `debug.h` to make `static_assert()` a noop.
And then reverting these changes.
So it's inconvenient, and as a consequence,
this property is currently not checked during CI tests.
Therefore, these problems can emerge again in the future.
I wonder if it is worth ensuring proper distinction of U32 != unsigned in CI tests.
It's another restriction for coding, adding more frustration during merge tests,
since most platforms don't need this distinction (hence contributor will not see it),
and while this can matter in theory, the number of platforms impacted seems minimal.
Thoughts ?
The problem was already masked,
due to no longer accepting tiny blocks for statistics.
But in case it could still happen with not-so-tiny blocks,
there is a stricter control which ensures that
nothing was already loaded prior to statistics collection.
* Add configs that test multithreading, LDM, and setting explicit
parameters.
* Update the `compress cctx` method to accept `ZSTD_parameters`.
* Compile against the multithreaded `libzstd.a`.
* Update `results.csv` for the new configs.
Unless you think there are more configs/methods I should test, I think
we have a fairly wide set of configs/methods, so I'll pause adding
more for now.
