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.
* dev:
updated NEWS
fixed MSAN warnings in legacy decoders
Fix cmake build
updated NEWS
Edits as per comments, and change wildcard 'X' to '?'
Fix Visual Studios project
Fix pool.c threading.h import
Fix zstdmt_compress.h include
Fixed commented issues
Updated format specification to be easier to understand
improved #232 fix
Fixed https://github.com/facebook/zstd/issues/232
.travis.yml: different tests for "master" branch
.travis.yml: optimized order of short tests
.travis.yml: test jobs 12-15
JOB_NUMBER -eq 9
improved ZSTD_compressBlock_opt_extDict_generic
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.
fileio.c was continually pushing more content without giving a chance to flush compressed one.
It would block the job queue when input data was accumulated too fast (requiring to define many threads).
Fixed : fileio flushes whatever it can after each input attempt.
Sections 2+ read a bit of data from previous section
in order to improve compression ratio.
This also costs some CPU, to reference read data.
Read data is currently fixed to window>>3 size
By default, section sizes are 4x window size.
This new setting allow manual selection of section sizes.
The larger they are, the (slightly) better the compression ratio,
but also the higher the memory allocation cost,
and eventually the lesser the nb of possible threads,
since each section is compressed by a single thread.
It also introduces a prototype to set generic parameters,
ZSTDMT_setMTCtxParameter()
The idea is that it's possible to add enums
to extend the list of parameters that can be set this way.
This is more long-term oriented than a fixed-size struct.
Consider it as a test.