now works with the `=` variant, which is the recommended one.
Old variant `--dictID #` still works, for compatibility with existing scripts.
Long term objective is to remove the old variant..
forgot to add the dictionary content
(tests were not failing, just compressing less).
Also : added size protections when adding dict content
since hc/bt table filling would fail if size < 8
This decoder variant is detrimental to x86 architecture
likely due to register pressure.
Note that the variant is disabled for all 32-bits targets.
It's unclear if it would help for different architectures,
such as ARM, MIPS or PowerPC.
Previously,
followed by :
would fail to include the static definitions,
because the second include was simply skipped by guard macro.
Now it works as intended :
the missing static part is included during the second include.
XXH_STATIC_LINKING_ONLY protection macro is intended to be triggered just before the include.
The main idea is to keep this setting local :
user module shall explicitly understand and accept the static linking restriction
which becomes transparent when triggering the macro at project level.
Global definition also triggers redefinition warnings for user modules which do locally define the macro.
This new version compiles lib and cli without warning when the macro is set globally.
That's not a scenario to be recommended, since it trades a local effect for a global one,
but it was easy enough to provide from zstd side.
When ZSTD_decompressStream() detects
that there is enough space in dst
to complete decompression in a single pass,
delegates to ZSTD_decompress(),
for an extra ~5% speed boost
There used to be a (very small) chance that
loading prefix from previous segment
would be confused with a real zstd dictionary.
For that to happen, the prefix needs to start
with the same value as dictionary magic.
That's 1 chance in 4 billions if all values have equal probability.
But in fact, since some values are more common (0x00000000 for example)
others are less common, and dictionary magic was selected to be one of them,
so probabilities are likely even lower.
Anyway, this risk is no down to zero
by adding a new CCtx parameter : ZSTD_p_forceRawDict
Current parameter policy : the parameter "stick" to its CCtx,
so any dictionary loading after ZSTD_p_forceRawDict is set
will be loaded in "raw" ("content only") mode,
even if CCtx is re-used multiple times with multiple different dictionary.
It's up to the user to reset this value differently if it needs so.
when zstd is called through a link named gzip, gunzip or gzcat,
provides the same behavior as the related program.
gzip compresses using --format=gz
both gzip and gunzip enable --rm by default
the minimum size condition size is applied transparently (no warning, no error)
like previous minimum section size condition (1 KB) which still applies.
Previous version was requiring a fairly large initial amount of input data
before starting to create compression jobs.
This new version starts the process much sooner.
There is a large buffering effect when using zstdmt in MT mode.
Consequently, data is read first, pushed to workers,
and only later will the compressed result come out.
That means there is no longer immediate correlation
between amount of data read, and amount of data written.
This patch disables the displaying of % compression
when multi-threading is enabled.
It adds the displaying of total size when it can be determined
(it usually can be determined for files, but not for stdin)
so the user has a sense of "how far from the end" the compression compressed is.
There is no modification to decompression side,
since decompression is only single-threaded for now.
In some extraordinary circumstances,
*Length field can be generated from reading a partially uninitialized memory segment.
Data is correctly identified as corrupted later on,
but the read taints some later pointer arithmetic operation.
Yann Collet