Thank you Sven! Peter On Sun, Jul 23, 2017 at 01:59:41PM +0200, Sven Van Caekenberghe wrote:
On 23 Jul 2017, at 09:55, Peter Uhnak <i.uhnak@gmail.com> wrote:
Ah, ByteArrayMap, I was trying ByteArray.
ByteArrayMap is not a class, it is still a ByteArray, but of size 256 used as an inclusion map for characters that fit a byte.
BTW, using CharacterSet as an abstraction makes the trick easier.
I committed:
=== Name: Neo-CSV-Core-SvenVanCaekenberghe.26 Author: SvenVanCaekenberghe Time: 23 July 2017, 1:54:22.095185 pm UUID: e429f87e-5c11-0d00-a72d-ae5d00db2a8c Ancestors: Neo-CSV-Core-PeterUhnak.25
make the core test in #writeOptionalQuotedField faster by using a primitive when possible
add #testWideOptionalQuoted === Name: Neo-CSV-Tests-SvenVanCaekenberghe.22 Author: SvenVanCaekenberghe Time: 23 July 2017, 1:54:52.133003 pm UUID: 5f81c280-5c11-0d00-a72e-7cd500db2a8c Ancestors: Neo-CSV-Tests-PeterUhnak.21
make the core test in #writeOptionalQuotedField faster by using a primitive when possible
add #testWideOptionalQuoted ===
Extra caution was needed for WideStrings.
Sven
Not sure what the next step is here: should I add it and send you mczs, or will you do it yourself? (it is a simple change).
Peter
On Sat, Jul 22, 2017 at 10:51:42PM +0200, Sven Van Caekenberghe wrote:
Peter,
On 22 Jul 2017, at 22:27, Peter Uhnak <i.uhnak@gmail.com> wrote:
Hi Sven,
my use case was hand-edited CSVs (therefore the quotes are extra clutter), which imples that I would be hand-viewing/editing only small CSVs (no performance issues).
I agree that we should err on the safe side with CR & LF (e.g. tools may sometimes autoconvert line endings).
Regarding performance:
#findFirstInString:inSet:startingAt: didn't work for me (not sure if bug, or I don't know how to use), so I've trried with inCharacterSet:
Yes, it is a bitch to use, the the version you used does not use the primitive.
Try playing with this:
s10 := 'a' repeat: 10. s100 := 'a' repeat: 100.
searchSet := ByteArray new: 256 withAll: 0. ',"', String crlf do: [ :each | searchSet at: each asInteger + 1 put: 1 ].
searchSet := (CharacterSet newFrom: ',"', String crlf) byteArrayMap.
[ ByteString findFirstInString: s10 inSet: searchSet startingAt: 1 ] bench. "15,160,161 per second" [ ByteString findFirstInString: s100 inSet: searchSet startingAt: 1 ] bench. "8,219,081 per second"
ByteString findFirstInString: ',"', String crlf inSet: searchSet startingAt: 1.
Sven
Tested on worst-case scenario - strings don't contain tested symbols.
s10 := 'a' repeat: 10. s100 := 'a' repeat: 100.
[ {'"'. ','. String cr. String lf } anySatisfy: [ :each | s10 includesSubstring: each ] ] bench. "'1,200,046 per second'" [ {'"'. ','. String cr. String lf } anySatisfy: [ :each | s100 includesSubstring: each ] ] bench. "'495,482 per second'"
[ s10 includesAny: { $,. $". Character cr. Character lf } ] bench. "'2,819,416 per second'" [ s100 includesAny: { $,. $". Character cr. Character lf } ] bench. "'2,200,668 per second'"
[ ByteString findFirstInString: s10 inCharacterSet: ',"', String crlf startingAt: 1 ] bench. "'1,187,324 per second'" [ ByteString findFirstInString: s100 inCharacterSet: ',"', String crlf startingAt: 1 ] bench. "'165,526 per second'"
#includesAny: seems to be the best by far.
Storing the tested characters didn't improve it by much.
Peter
On Sat, Jul 22, 2017 at 06:51:31PM +0200, Sven Van Caekenberghe wrote:
Hi Peter,
On 22 Jul 2017, at 14:12, Peter Uhnak <i.uhnak@gmail.com> wrote:
Hi,
this is a continuation of an older thread about quoting fields only when necessary. ( http://forum.world.st/NeoCSVWriter-automatic-quotes-td4924781.html )
I've attached fileouts of NeoCSV packages with the addition (I don't know if Metacello can file-out only changesets).
The change doesn't affect the default behavior, only when explicitly requested.
Peter
I accepted your changes as such, the .mcz's were copied over to the main repositories. This is a pure & clean extension, so that is good. Thank you.
This option is always going to be slower, but the current implementation might be improved, I think.
The key test in #writeOptionalQuotedField:
{ lineEnd asString. separator asString. '"' } anySatisfy: [ :each | string includesSubstring: each ]
will be quite slow.
If we accept a little bit of (over safe) error on EOL and use any occurrence of CR or LF as needing a quote, we could switch to characters to test for. There exists a fast (primitive) test, #findFirstInString:inSet:startingAt: that can do all the testing in one go. If your version turns out to be slow, we could try that, if measurements show a difference.
Regards,
Sven