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fixed ovlog tests 

and updated man page
dev
Yann Collet 2018-12-12 21:09:14 -08:00
parent f2f86d369b
commit 1993f5d412
4 changed files with 14 additions and 13 deletions
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6
lib/zstd.h
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@ -610,12 +610,12 @@ typedef enum {
* It helps preserve compression ratio, while each job is compressed in parallel.
* This value is enforced only when nbWorkers >= 1.
* Larger values increase compression ratio, but decrease speed.
* Values range from 0 to 9 (overlap a full windowSize).
* - 0 means "auto" : value will be determined by the library, depending on strategy
* Possible values range from 0 to 9 :
* - 0 means "default" : value will be determined by the library, depending on strategy
* - 1 means "no overlap"
* - 9 means "full overlap", using a full window size.
* Each intermediate rank increases/decreases load size by a factor 2 :
* 9: full window; 8: w/2; 7: w/4; 6: w/8; 5:w/16; 4: w/32; 3:w/64; 2:w/128; 1:no overlap; 0:auto
* 9: full window; 8: w/2; 7: w/4; 6: w/8; 5:w/16; 4: w/32; 3:w/64; 2:w/128; 1:no overlap; 0:default
* default value varies between 6 and 9, depending on strategy */
/* note : additional experimental parameters are also available

2
programs/zstd.1
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@ -389,7 +389,7 @@ The minimum \fItlen\fR is 0 and the maximum is 999\.
Determine \fBoverlapSize\fR, amount of data reloaded from previous job\. This parameter is only available when multithreading is enabled\. Reloading more data improves compression ratio, but decreases speed\.
.
.IP
The minimum \fIovlog\fR is 0, and the maximum is 9\. 0 means "no overlap", hence completely independent jobs\. 9 means "full overlap", meaning up to \fBwindowSize\fR is reloaded from previous job\. Reducing \fIovlog\fR by 1 reduces the amount of reload by a factor 2\. Default \fIovlog\fR is 6, which means "reload \fBwindowSize / 8\fR"\. Exception : the maximum compression level (22) has a default \fIovlog\fR of 9\.
The minimum \fIovlog\fR is 0, and the maximum is 9\. 1 means "no overlap", hence completely independent jobs\. 9 means "full overlap", meaning up to \fBwindowSize\fR is reloaded from previous job\. Reducing \fIovlog\fR by 1 reduces the reloaded amount by a factor 2\. For example, 8 means "windowSize/2", and 6 means "windowSize/8"\. Value 0 is special and means "default" : \fIovlog\fR is automatically determined by \fBzstd\fR\. In which case, \fIovlog\fR will range from 6 to 9, depending on selected \fIstrat\fR\.
.
.TP
\fBldmHashLog\fR=\fIlhlog\fR, \fBlhlog\fR=\fIlhlog\fR

9
programs/zstd.1.md
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@ -415,11 +415,12 @@ The list of available _options_:
Reloading more data improves compression ratio, but decreases speed.
The minimum _ovlog_ is 0, and the maximum is 9.
0 means "no overlap", hence completely independent jobs.
1 means "no overlap", hence completely independent jobs.
9 means "full overlap", meaning up to `windowSize` is reloaded from previous job.
Reducing _ovlog_ by 1 reduces the amount of reload by a factor 2.
Default _ovlog_ is 6, which means "reload `windowSize / 8`".
Exception : the maximum compression level (22) has a default _ovlog_ of 9.
Reducing _ovlog_ by 1 reduces the reloaded amount by a factor 2.
For example, 8 means "windowSize/2", and 6 means "windowSize/8".
Value 0 is special and means "default" : _ovlog_ is automatically determined by `zstd`.
In which case, _ovlog_ will range from 6 to 9, depending on selected _strat_.
- `ldmHashLog`=_lhlog_, `lhlog`=_lhlog_:
Specify the maximum size for a hash table used for long distance matching.

10
tests/playTests.sh
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@ -748,17 +748,17 @@ then
./datagen -g2MB > tmp
refSize=$($ZSTD tmp -6 -c --zstd=wlog=18 | wc -c)
ov9Size=$($ZSTD tmp -6 -c --zstd=wlog=18,ovlog=9 | wc -c)
ov0Size=$($ZSTD tmp -6 -c --zstd=wlog=18,ovlog=0 | wc -c)
ov1Size=$($ZSTD tmp -6 -c --zstd=wlog=18,ovlog=1 | wc -c)
if [ $refSize -eq $ov9Size ]; then
echo ov9Size should be different from refSize
exit 1
fi
if [ $refSize -eq $ov0Size ]; then
echo ov0Size should be different from refSize
if [ $refSize -eq $ov1Size ]; then
echo ov1Size should be different from refSize
exit 1
fi
if [ $ov9Size -ge $ov0Size ]; then
echo ov9Size=$ov9Size should be smaller than ov0Size=$ov0Size
if [ $ov9Size -ge $ov1Size ]; then
echo ov9Size=$ov9Size should be smaller than ov1Size=$ov1Size
exit 1
fi