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From Dmitriy Setrakyan <dsetrak...@apache.org>
Subject Re: Custom string encoding
Date Sun, 02 Jul 2017 17:07:33 GMT
On Sun, Jul 2, 2017 at 9:50 AM, Vladimir Ozerov <vozerov@gridgain.com>
wrote:

> There is no need for custom encoders, as they are already built-in to Java.
>

Will non-ASCII encodings fit into 1 byte? The whole point here is to save
space.


>
> вс, 2 июля 2017 г. в 19:16, Dmitriy Setrakyan <dsetrakyan@apache.org>:
>
> > Vladimir, how would you plugin custom encoders in your design?
> >
> > On Sat, Jul 1, 2017 at 11:53 PM, Vladimir Ozerov <vozerov@gridgain.com>
> > wrote:
> >
> > > Valya,
> > >
> > > Personally I vote against this feature. BinaryConfiguration is proven
> to
> > be
> > > inconvenient, since it has to be configured before node start, it
> cannot
> > be
> > > changed in runtime, and it requires classes on the server. Moreover, if
> > you
> > > decide to change encoding at some point, it would be impossible.
> > >
> > > I think, we should add this feature on API level instead. If string is
> > > written in non-UTF8 form, we will write in different format:
> > > [encoding_code][string]
> > >
> > > BInaryWriter.writeString(String fieldName, String val);
> > > BInaryWriter.writeString(String fieldName, String val, *String
> > encoding*);
> > >
> > > BinaryReader.readString(String fieldName);
> > > BinaryReader.readString(String fieldName, *String encoding*);
> > >
> > > BinaryObjectBuilder.writeString(String fieldName, String val, *String
> > > encoding*);
> > >
> > > class MyClass {
> > >     *@BinaryString(encoding = "Cp1251")*
> > >     private String myCyrillicString;
> > > }
> > >
> > > Vladimir.
> > >
> > > On Sat, Jul 1, 2017 at 7:26 PM, Dmitriy Setrakyan <
> dsetrakyan@apache.org
> > >
> > > wrote:
> > >
> > > > On Sat, Jul 1, 2017 at 2:24 AM, Sergi Vladykin <
> > sergi.vladykin@gmail.com
> > > >
> > > > wrote:
> > > >
> > > > > In SQL indexes we may store partial strings and assume them to be
> in
> > > > UTF-8,
> > > > > I don't think this can be abstracted away. But may be this is not
a
> > big
> > > > > deal if in indexes we still will use UTF-8.
> > > > >
> > > >
> > > > Sergi, why does it matter if it is UTF8 or custom encoding? Why can't
> > we
> > > > use our own compact encoding in indexes?
> > > >
> > > >
> > > > >
> > > > > 2017-07-01 10:13 GMT+03:00 Dmitriy Setrakyan <
> dsetrakyan@apache.org
> > >:
> > > > >
> > > > > > Val, do you know how we compare strings in SQL queries? Will
we
> be
> > > able
> > > > > to
> > > > > > use this encoder?
> > > > > >
> > > > > > Additionally, I think that the encoder is a bit too abstract.
Why
> > not
> > > > go
> > > > > > even further and allow users create their own ASCII table for
> > > encoding?
> > > > > >
> > > > > > D.
> > > > > >
> > > > > > On Fri, Jun 30, 2017 at 6:49 PM, Valentin Kulichenko <
> > > > > > valentin.kulichenko@gmail.com> wrote:
> > > > > >
> > > > > > > Andrey,
> > > > > > >
> > > > > > > Can you elaborate more on this? What is your concern?
> > > > > > >
> > > > > > > -Val
> > > > > > >
> > > > > > > On Fri, Jun 30, 2017 at 6:17 PM Andrey Mashenkov <
> > > > > > > andrey.mashenkov@gmail.com>
> > > > > > > wrote:
> > > > > > >
> > > > > > > > Val,
> > > > > > > >
> > > > > > > > Looks like make sense.
> > > > > > > >
> > > > > > > > This will not affect FullText index, as Lucene has
own format
> > for
> > > > > > storing
> > > > > > > > data.
> > > > > > > >
> > > > > > > > But.. would it be compatible with H2 indexing ? I
doubt.
> > > > > > > >
> > > > > > > > 1 июля 2017 г. 2:27 пользователь
"Valentin Kulichenko" <
> > > > > > > > valentin.kulichenko@gmail.com> написал:
> > > > > > > >
> > > > > > > > > Folks,
> > > > > > > > >
> > > > > > > > > Currently binary marshaller always encodes strings
in
> UTF-8.
> > > > > However,
> > > > > > > > > sometimes it can be useful to customize this.
For example,
> if
> > > > data
> > > > > > > > contains
> > > > > > > > > a lot of Cyrillic, Chinese or other symbols,
but not so
> many
> > > > Latin
> > > > > > > > symbols,
> > > > > > > > > memory is used very inefficiently. In this case
it would be
> > > great
> > > > > to
> > > > > > > > encode
> > > > > > > > > most frequently used symbols in one byte instead
of two or
> > > three.
> > > > > > > > >
> > > > > > > > > I propose to introduce BinaryStringEncoder interface
that
> > will
> > > > > > convert
> > > > > > > > > strings to byte arrays and back, and make it
pluggable via
> > > > > > > > > BinaryConfiguration. This will allow users to
plug in any
> > > > encoding
> > > > > > > > > algorithms based on their requirements.
> > > > > > > > >
> > > > > > > > > Thoughts?
> > > > > > > > >
> > > > > > > > > https://issues.apache.org/jira/browse/IGNITE-5655
> > > > > > > > >
> > > > > > > > > -Val
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

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