Currently the build errors out with:
```
ERROR: This script does not work on Python 3.6 The minimum supported Python version is 3.7. Please use https://bootstrap.pypa.io/pip/3.6/get-pip.py instead.
```
While in theory this advice could be followed to get a better pip on
xenial, Meson has now deprecated python 3.6 support too, and the next
(unreleased) version requires python 3.7
There are a couple solutions to this:
- hold the version of pip, allow pip to only install 3.6-compatible
versions of meson (effectively freezing meson going forward)
- install python 3.7 on xenial
- update to a 2-year-old image instead of a 4-year-old one
Option 3 is the simplest.
While trying to raise an exception on failures, it instead raised an
exception for misusing the exception. CalledProcessError is only
supposed to be used when given a return code and a command, and it
prints:
Command '{cmd}' returned non-zero exit status {ret}
Passing an error message string instead, just errored out with:
TypeError: __init__() missing 1 required positional argument
Instead use the subprocess module's base error which does accept string
messages. Everything that used to error out, still errors out, but now
they do so with a slightly prettier console message.
libm is not guaranteed to exist. POSIX requires the math functions to
exist, but doesn't require to have it be a standalone library.
On platforms where libm exists as a standalone library, it will always
be found by meson -- it is shipped with libc.
If it is not found, then we can safely assume the linker will make the
math functions available by default.
See https://mesonbuild.com/howtox.html#add-math-library-lm-portably
Fixes building with bin_tests=true on Windows.
It's a bug in the test itself, in exceptional circumstances (no more space for additional sequence).
There should be enough room for all cases to work fine from now on,
and if not, we have an additional `assert()` to catch that situation.
credit to oss-fuzz
In rare circumstances, the block-splitter might cut a block at the exact beginning of a repcode.
In which case, since litlength=0, if the repcode expected 1+ literals in front, its signification changes.
This scenario is controlled in ZSTD_seqStore_resolveOffCodes(),
and the repcode is transformed into a raw offset when its new meaning is incorrect.
In more complex scenarios, the previous block might be emitted as uncompressed after all,
thus modifying the expected repcode history.
In the case discovered by oss-fuzz, the first block is emitted as uncompressed,
so the repcode history remains at default values: 1,4,8.
But since the starting repcode is repcode3, and the literal length is == 0,
its meaning is : = repcode1 - 1.
Since repcode1==1, it results in an offset value of 0, which is invalid.
So that's what the `assert()` was verifying : the result of the repcode translation should be a valid offset.
But actually, it doesn't matter, because this result will then be compared to reality,
and since it's an invalid offset, it will necessarily be discarded if incorrect,
then the repcode will be replaced by a raw offset.
So the `assert()` is not useful.
Furthermore, it's incorrect, because it assumes this situation cannot happen, but it does, as described in above scenario.
Knowing the version of zlib/lz4/lzma we're linking against is very
useful for debugging issues with those libraries, so print it out in the
verbosity 4 version output.
Also print this information at the top of `playTests.sh`.
which properly represents the maximum bit size of compressed literals (11) as defined in the specification.
To be preferred from HUF_TABLELOG_DEFAULT which represents the same value but by accident.
Name selected to keep the same convention as existing width definitions,
MLFSELog, LLFSELog and OffFSELog.
In rare cases, the default huffman depth selector is a bit too harsh,
requiring brutal adaptations to the tree,
resulting is some loss of compression ratio.
This new heuristic avoids the worse cases, favoring compression ratio.
As an example, compression of a specific distribution of 771 literals
is now improved to 441 bytes, from 601 bytes before.
-r on empty directory resulted in zstd waiting input from stdin. now zstd exits without error and prints a warning message explaining why no processing happened (no files or directories to process).
* Refactored fileio.c:
- Extracted asyncio code to fileio_asyncio.c/.h
- Moved type definitions to fileio_types.h
- Moved common macro definitions needed by both fileio.c and fileio_asyncio.c to fileio_common.h
* Bugfix - rename fileio_asycio to fileio_asyncio
* Added copyrights & license to new files
* CR fixes
Eli Schwartz