'create conversion' problem - Mailing list pgsql-general

Hello!

There is a database in KOI8-R encoding. And we have a client who is
querying the database:
set client_encoding TO 'ALT'
and then he write some data into the database.
I have a problem with some symbols which exists in ALT encoding and
which are absent in KOI8-R encoding. As result, during inserting strings
with such symbols postgresql returns an error, for example:
ERROR: character 0xfc of encoding "ALT" has no equivalent in "MULE_INTERNAL"
I've decided to write my own converter, so here is my code:

[code]

#include <postgres.h>
#include <fmgr.h>


#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

PG_FUNCTION_INFO_V1(fix_alt_to_koi8r);
PG_FUNCTION_INFO_V1(fix_koi8r_to_alt);

Datum
fix_alt_to_koi8r(PG_FUNCTION_ARGS)
{
        elog(NOTICE,"ALT_TO_KOI8");
    unsigned char *src  = PG_GETARG_CSTRING(*2*);
    unsigned char *dest = PG_GETARG_CSTRING(*3*);
    int        len = PG_GETARG_INT32(*4*);

    Assert(PG_GETARG_INT32(*0*) == PG_ALT);
    Assert(PG_GETARG_INT32(*1*) == PG_KOI8R);
    Assert(len >= *0*);



        static const unsigned char convert866toKOI8[] = {
                *0*,*1*,*2*,*3*,*4*,*5*,*6*,*7*,*8*,*9*,*10*,*11*,*12*,*13*,*14*,*15*,
                *16*,*17*,*18*,*19*,*20*,*21*,*22*,*23*,*24*,*25*,*26*,*27*,*28*,*29*,*30*,*31*,
                *32*,*33*,*34*,*35*,*36*,*37*,*38*,*39*,*40*,*41*,*42*,*43*,*44*,*45*,*46*,*47*,
                *48*,*49*,*50*,*51*,*52*,*53*,*54*,*55*,*56*,*57*,*58*,*59*,*60*,*61*,*62*,*63*,
                *64*,*65*,*66*,*67*,*68*,*69*,*70*,*71*,*72*,*73*,*74*,*75*,*76*,*77*,*78*,*79*,
                *80*,*81*,*82*,*83*,*84*,*85*,*86*,*87*,*88*,*89*,*90*,*91*,*92*,*93*,*94*,*95*,
                *96*,*97*,*98*,*99*,*100*,*101*,*102*,*103*,*104*,*105*,*106*,*107*,*108*,*109*,*110*,*111*,
                *112*,*113*,*114*,*115*,*116*,*117*,*118*,*119*,*120*,*121*,*122*,*123*,*124*,*125*,*126*,*127*,
                *225*,*226*,*247*,*231*,*228*,*229*,*246*,*250*,*233*,*234*,*235*,*236*,*237*,*238*,*239*,*240*,
                *242*,*243*,*244*,*245*,*230*,*232*,*227*,*254*,*251*,*253*,*255*,*249*,*248*,*252*,*224*,*241*,
                *193*,*194*,*215*,*199*,*196*,*197*,*214*,*218*,*201*,*202*,*203*,*204*,*205*,*206*,*207*,*208*,
                *210*,*211*,*212*,*213*,*198*,*200*,*195*,*222*,*219*,*221*,*223*,*217*,*216*,*220*,*192*,*209*,
                *180*,*164*,*183*,*167*,*196*,*197*,*198*,*199*,*200*,*201*,*202*,*203*,*204*,*205*,*206*,*207*,
                *208*,*209*,*210*,*211*,*212*,*213*,*214*,*215*,*216*,*217*,*218*,*219*,*220*,*221*,*222*,*223*,
                *210*,*211*,*212*,*213*,*198*,*200*,*195*,*222*,*219*,*221*,*223*,*217*,*216*,*220*,*192*,*209*,
            *179*,*241*,*242*,*243*,*244*,*245*,*246*,*247*,*248*,*249*,*250*,*251*,*252*,*253*,*254*,*255*
        };



    while(len){
        *dest = convert866toKOI8[(unsigned char)(*src)];
        ++src;
        ++dest;
        --len;
    }

    PG_RETURN_VOID();
}



Datum
fix_koi8r_to_alt(PG_FUNCTION_ARGS)
{
        elog(NOTICE,"KOI8_TO_ALT");
    unsigned char *src  = PG_GETARG_CSTRING(*2*);
    unsigned char *dest = PG_GETARG_CSTRING(*3*);
    int        len = PG_GETARG_INT32(*4*);

    Assert(PG_GETARG_INT32(*0*) == PG_KOI8R);
    Assert(PG_GETARG_INT32(*1*) == PG_ALT);
    Assert(len >= *0*);



        static const unsigned char KOI8to866[] = {
            *0*,*1*,*2*,*3*,*4*,*5*,*6*,*7*,*8*,*9*,*10*,*11*,*12*,*13*,*14*,*15*,
            *16*,*17*,*18*,*19*,*20*,*21*,*22*,*23*,*24*,*25*,*26*,*27*,*28*,*29*,*30*,*31*,
            *32*,*33*,*34*,*35*,*36*,*37*,*38*,*39*,*40*,*41*,*42*,*43*,*44*,*45*,*46*,*47*,
            *48*,*49*,*50*,*51*,*52*,*53*,*54*,*55*,*56*,*57*,*58*,*59*,*60*,*61*,*62*,*63*,
            *64*,*65*,*66*,*67*,*68*,*69*,*70*,*71*,*72*,*73*,*74*,*75*,*76*,*77*,*78*,*79*,
            *80*,*81*,*82*,*83*,*84*,*85*,*86*,*87*,*88*,*89*,*90*,*91*,*92*,*93*,*94*,*95*,
            *96*,*97*,*98*,*99*,*100*,*101*,*102*,*103*,*104*,*105*,*106*,*107*,*108*,*109*,*110*,*111*,
            *112*,*113*,*114*,*115*,*116*,*117*,*118*,*119*,*120*,*121*,*122*,*123*,*124*,*125*,*126*,*255*,
            *32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,
            *32*,*32*,*32*,*32*,*32*,*249*,*32*,*32*,*32*,*32*,*32*,*32*,*248*,*32*,*32*,*32*,
            *32*,*32*,*32*,*241*,*193*,*32*,*105*,*195*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,*244*,
            *32*,*32*,*32*,*240*,*192*,*32*,*73*,*194*,*252*,*32*,*32*,*32*,*32*,*32*,*32*,*32*,
            *238*,*160*,*161*,*230*,*164*,*165*,*228*,*163*,*229*,*168*,*169*,*170*,*171*,*172*,*173*,*174*,
            *175*,*239*,*224*,*225*,*226*,*227*,*166*,*162*,*236*,*235*,*167*,*232*,*237*,*233*,*231*,*234*,
            *158*,*128*,*129*,*150*,*132*,*133*,*148*,*131*,*149*,*136*,*137*,*138*,*139*,*140*,*141*,*142*,
            *143*,*159*,*144*,*145*,*146*,*147*,*134*,*130*,*156*,*155*,*135*,*152*,*157*,*153*,*151*,*154*
        };



    while(len){
        *dest = KOI8to866[(unsigned char)(*src)];
        ++src;
        ++dest;
        --len;
    }

    PG_RETURN_VOID();

[/code]

I has copied this library into $libdir/funcs and I was trying to install
the new converter instead of the old one,  in two directions alt->koi8
and koi8->alt:

[code]

db_server=# CREATE FUNCTION fix_koi8r_to_alt(integer,integer,cstring,internal,integer) RETURNS integer AS
'$libdir/funcs/fix_conv.so','fix_koi8r_to_alt'LANGUAGE C STRICT; 
CREATE FUNCTION
db_server=# CREATE FUNCTION fix_alt_to_koi8r(integer,integer,cstring,internal,integer) RETURNS integer AS
'$libdir/funcs/fix_conv.so','fix_alt_to_koi8r'LANGUAGE C STRICT; 
CREATE FUNCTION
db_server=# CREATE DEFAULT CONVERSION koi2alt FOR 'KOI8' TO 'ALT' FROM fix_koi8r_to_alt;
CREATE CONVERSION
db_server=# CREATE DEFAULT CONVERSION alt2koi FOR 'ALT' TO 'KOI8' FROM fix_alt_to_koi8r;
CREATE CONVERSION
db_server=# set client_encoding to 'alt';

[/code]

I thought, that was all, but it was not. During the insert of 'bad' symbol in the test table i had the same error:
ERROR:  character 0xfc of encoding "ALT" has no equivalent in "MULE_INTERNAL"

I think that my conversion functions are not used. I saw in table pg_conversion:
           conname           | connamespace | conowner | conforencoding | contoencoding |     conproc       |
condefault
           koi8_r_to_windows_866 |         *11* |        *1*    |            *21*        |               *23*   |
koi8r_to_alt   | t 
            koi2alt               |         *2200*      |          *1*  |         *21*          |           *23*
|fix_koi8r_to_alt | t 
            windows_866_to_koi8_r         *11*      |    *1*     |              *23*     |             *21*     |
alt_to_koi8r     | t 
            alt2koi                    |         *2200* |        *1*    |            *23*        |     *21*
 | fix_alt_to_koi8r | t 

and deleted two standard conversion functions:
[code]
db_server=# DROP CONVERSION koi8_r_to_windows_866;
DROP CONVERSION
db_server=# DROP CONVERSION windows_866_to_koi8_r;
DROP CONVERSION
[/code]

leaving only my own conversion functions.After this, when I'm trying to set the client encoding to ALT I got an error:

db_server=# set client_encoding to 'alt';
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>

Is anyone can tell me what I'm doing wrong?
Thanks.