How to call Encode::decode from Perl XS

mje has asked for the wisdom of the Perl Monks concerning the following question:

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Re: How to call Encode::decode from Perl XS by Anonymous Monk on May 09, 2011 at 09:00 UTC
http://perldoc.perl.org/perlapi.html#Callback-Functions, http://perldoc.perl.org/perlguts.html#Unicode-Support, http://perldoc.perl.org/perlapi.html#Unicode-Support	[reply]
Re^2: How to call Encode::decode from Perl XS by Anonymous Monk on May 09, 2011 at 09:06 UTC
http://search.cpan.org/grep?cpanid=CAPTTOFU&release=DBD-mysql-4.019&string=decode&i=1&n=1&C=2 http://cpansearch.perl.org/src/CAPTTOFU/DBD-mysql-4.019/t/55utf8.t http://cpansearch.perl.org/src/CAPTTOFU/DBD-mysql-4.019/dbdimp.h http://cpansearch.perl.org/src/CAPTTOFU/DBD-mysql-4.019/dbdimp.c	[reply]
Re^3: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 09:15 UTC
That code uses sv_utf8_decode not Encode::decode. I already use sv_utf8_decode.	[reply]
Re^2: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 09:16 UTC
Thanks, callback functions looks useful and probably what I was looking for.	[reply]
Re: How to call Encode::decode from Perl XS by Tux (Canon) on May 09, 2011 at 13:48 UTC
Bases on my experience, it could be something like (untested) int encode_loaded = 0; SV m_encode = newSVpvs ("decode"); / Or "Encode::decode", I'm not su +re / SV sv_enc = newSVpvs ("cp1252"); my_foo (char buffer) { int result; if (!encode_loaded) { ENTER; load_module (PERL_LOADMOD_NOIMPORT, newSVpvs ("Encode"), NULL, + NULL, NULL); LEAVE; encode_loaded = 1; } PUSHMARK (sp); EXTEND (sp, 2); PUSHs (sv_enc); PUSHs (newSVpv (buffer)); PUTBACK; result = call_sv (m_encode, G_SCALAR \| G_METHOD); SPAGAIN; if (result) { SV encoded = POPs; /* Do more */ } PUTBACK; } [download] And some `mortal`ization might be needed to not leak. Enjoy, Have FUN! H.Merijn	[reply] [d/l] [select]
Re^2: How to call Encode::decode from Perl XS by Anonymous Monk on May 09, 2011 at 14:24 UTC
all that load checking goes in the .pm file in the form of "use Encode...", kiss :)	[reply]
Re^3: How to call Encode::decode from Perl XS by Tux (Canon) on May 09, 2011 at 15:17 UTC
Yes and no. If you want a module to automatically load another module from XS, and not import all functions/methods, this is a cleaner way to do so. Of course you can croak/fail/die/barf/puke when a user tries to invoke something that he/she did not explicitely load, but as Encode is a CORE module I see no harm in hiding the require from XS and making the underlying module DWIM more. I agree that this is a grey/gray area and opinions may well differ if which case I think you should agree to disagree. XS is a different world and pulling the right strings is sometimes extremely hard compared to how easy perl made it in the language level itself. Enjoy, Have FUN! H.Merijn	[reply]
Re^4: How to call Encode::decode from Perl XS by ikegami (Patriarch) on May 09, 2011 at 15:43 UTC
Re^5: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 16:22 UTC
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Re^2: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 14:40 UTC
Thanks Merijn, I'll look into this.	[reply]
Re: How to call Encode::decode from Perl XS by anonymized user 468275 (Curate) on May 09, 2011 at 09:01 UTC
If the target database is MS SQL-Server, then perhaps DBD::Sybase would be able to handle it more transparently. It's built on top of a Sybase Open Client library that is specifically designed for Sybase and MS SQL Server is pretty much an MS porting of the Sybase Enterprise Server and afaik still relies on Sybase Open Client for its connectivity. One world, one people	[reply]
Re^2: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 09:12 UTC
The rt reporter was using MS SQL Server. See automatic character encoding handling in perl dbi dbdodbc. However, he is also using DBD::ODBC. I've maintained DBD::ODBC for a lot of years and no one has ever reported this to me but I already do some UTF-8 decoding and thought it would be easy to add. There are other issues moving to DBD::Sybase but I don't want to start an argument here.	[reply]
Re^3: How to call Encode::decode from Perl XS by anonymized user 468275 (Curate) on May 09, 2011 at 13:52 UTC
Well, I am not intending any module bias here. But what occurred to me in fact was that Sybase Open Client reads locales.dat and uses it to pass the client character set at login time to SQL Server. I was wondering whether OBDC, being a database independent architecture with a standardised driver interface was bypassing that Sybase-specific step. One world, one people	[reply]
Re^4: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 14:38 UTC
Re^5: How to call Encode::decode from Perl XS by anonymized user 468275 (Curate) on May 09, 2011 at 15:05 UTC
Re^2: How to call Encode::decode from Perl XS by mpeppler (Vicar) on May 17, 2011 at 09:25 UTC
Just a small note - when using DBD::Sybase with MS-SQL you're not using Open Client (or at least not the Sybase Open Client implementation). In that situation you use FreeTDS, which I believe uses libiconv for char conversions. Michael	[reply]