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#include "postgres.h"
#include "fmgr.h"
#include "mb/pg_wchar.h"
#include <utfasciitable.h>
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
Datum transliteration( PG_FUNCTION_ARGS );
Datum gettokenstring( PG_FUNCTION_ARGS );
void str_replace(char* buffer, int* len, int* changes, char* from, int fromlen, char* to, int tolen, int);
void str_dupspaces(char* buffer);
PG_FUNCTION_INFO_V1( transliteration );
Datum
transliteration( PG_FUNCTION_ARGS )
{
static char * ascii = UTFASCII;
static uint16 asciilookup[65536] = UTFASCIILOOKUP;
char * asciipos;
text *source;
unsigned char *sourcedata;
int sourcedatalength;
unsigned int c1,c2,c3,c4;
unsigned int * wchardata;
unsigned int * wchardatastart;
text *result;
unsigned char *resultdata;
int resultdatalength;
int iLen;
if (GetDatabaseEncoding() != PG_UTF8)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("requires UTF8 database encoding")));
}
if (PG_ARGISNULL(0))
{
PG_RETURN_NULL();
}
// The original string
source = PG_GETARG_TEXT_P(0);
sourcedata = (unsigned char *)VARDATA(source);
sourcedatalength = VARSIZE(source) - VARHDRSZ;
// Intermediate wchar version of string
wchardatastart = wchardata = (unsigned int *)palloc((sourcedatalength+1)*sizeof(int));
// Based on pg_utf2wchar_with_len from wchar.c
// Postgresql strings are not zero terminalted
while (sourcedatalength > 0)
{
if ((*sourcedata & 0x80) == 0)
{
*wchardata = *sourcedata++;
wchardata++;
sourcedatalength--;
}
else if ((*sourcedata & 0xe0) == 0xc0)
{
if (sourcedatalength < 2) break;
c1 = *sourcedata++ & 0x1f;
c2 = *sourcedata++ & 0x3f;
*wchardata = (c1 << 6) | c2;
if (*wchardata < 65536) wchardata++;
sourcedatalength -= 2;
}
else if ((*sourcedata & 0xf0) == 0xe0)
{
if (sourcedatalength < 3) break;
c1 = *sourcedata++ & 0x0f;
c2 = *sourcedata++ & 0x3f;
c3 = *sourcedata++ & 0x3f;
*wchardata = (c1 << 12) | (c2 << 6) | c3;
if (*wchardata < 65536) wchardata++;
sourcedatalength -= 3;
}
else if ((*sourcedata & 0xf8) == 0xf0)
{
if (sourcedatalength < 4) break;
c1 = *sourcedata++ & 0x07;
c2 = *sourcedata++ & 0x3f;
c3 = *sourcedata++ & 0x3f;
c4 = *sourcedata++ & 0x3f;
*wchardata = (c1 << 18) | (c2 << 12) | (c3 << 6) | c4;
if (*wchardata < 65536) wchardata++;
sourcedatalength -= 4;
}
else if ((*sourcedata & 0xfc) == 0xf8)
{
// table does not extend beyond 4 char long, just skip
if (sourcedatalength < 5) break;
sourcedatalength -= 5;
sourcedata += 5;
}
else if ((*sourcedata & 0xfe) == 0xfc)
{
// table does not extend beyond 4 char long, just skip
if (sourcedatalength < 6) break;
sourcedatalength -= 6;
sourcedata += 6;
}
else
{
// assume lenngth 1, silently drop bogus characters
sourcedatalength--;
sourcedata += 1;
}
}
*wchardata = 0;
// calc the length of transliteration string
resultdatalength = 0;
wchardata = wchardatastart;
while(*wchardata)
{
if (*(asciilookup + *wchardata) > 0) resultdatalength += *(ascii + *(asciilookup + *wchardata));
wchardata++;
}
// allocate & create the result
result = (text *)palloc(resultdatalength + VARHDRSZ);
SET_VARSIZE(result, resultdatalength + VARHDRSZ);
resultdata = (unsigned char *)VARDATA(result);
wchardata = wchardatastart;
while(*wchardata)
{
if (*(asciilookup + *wchardata) > 0)
{
asciipos = ascii + *(asciilookup + *wchardata);
for(iLen = *asciipos; iLen > 0; iLen--)
{
asciipos++;
*resultdata = *asciipos;
resultdata++;
}
}
/*else
{
ereport( WARNING, ( errcode( ERRCODE_SUCCESSFUL_COMPLETION ),
errmsg( "missing char: %i\n", *wchardata )));
}*/
wchardata++;
}
pfree(wchardatastart);
PG_RETURN_TEXT_P(result);
}
// Set isspace=1 if the replacement _only_ adds a space before the search string. I.e. to == " " + from
void str_replace(char* buffer, int* len, int* changes, char* from, int fromlen, char* to, int tolen, int isspace)
{
char *p;
// Search string is too long to be present
if (fromlen > *len) return;
p = strstr(buffer, from);
while(p)
{
if (!isspace || (p > buffer && *(p-1) != ' '))
{
(*changes)++;
if (tolen != fromlen) memmove(p+tolen, p+fromlen, *len-(p-buffer)+1);
memcpy(p, to, tolen);
*len += tolen - fromlen;
}
p = strstr(p+1, from);
}
}
void str_dupspaces(char* buffer)
{
char *out;
int wasspace;
out = buffer;
wasspace = 0;
while(*buffer)
{
if (wasspace && *buffer != ' ') wasspace = 0;
if (!wasspace)
{
*out = *buffer;
out++;
wasspace = (*buffer == ' ');
}
buffer++;
}
*out = 0;
}
PG_FUNCTION_INFO_V1( gettokenstring );
Datum
gettokenstring( PG_FUNCTION_ARGS )
{
text *source;
unsigned char *sourcedata;
int sourcedatalength;
char * buffer;
int len;
int changes;
text *result;
if (GetDatabaseEncoding() != PG_UTF8)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("requires UTF8 database encoding")));
}
if (PG_ARGISNULL(0))
{
PG_RETURN_NULL();
}
// The original string
source = PG_GETARG_TEXT_P(0);
sourcedata = (unsigned char *)VARDATA(source);
sourcedatalength = VARSIZE(source) - VARHDRSZ;
// Buffer for doing the replace in - string could get slightly longer (double is massive overkill)
buffer = (char *)palloc((sourcedatalength*2)*sizeof(char));
memcpy(buffer+1, sourcedata, sourcedatalength);
buffer[0] = 32;
buffer[sourcedatalength+1] = 32;
buffer[sourcedatalength+2] = 0;
len = sourcedatalength+3;
changes = 1;
str_dupspaces(buffer);
while(changes)
{
changes = 0;
#include <tokenstringreplacements.inc>
str_dupspaces(buffer);
}
// 'and' in various languages
str_replace(buffer, &len, &changes, " and ", 5, " ", 1, 0);
str_replace(buffer, &len, &changes, " und ", 5, " ", 1, 0);
str_replace(buffer, &len, &changes, " en ", 4, " ", 1, 0);
str_replace(buffer, &len, &changes, " et ", 4, " ", 1, 0);
str_replace(buffer, &len, &changes, " y ", 3, " ", 1, 0);
// 'the' (and similar)
str_replace(buffer, &len, &changes, " the ", 5, " ", 1, 0);
str_replace(buffer, &len, &changes, " der ", 5, " ", 1, 0);
str_replace(buffer, &len, &changes, " den ", 5, " ", 1, 0);
str_replace(buffer, &len, &changes, " die ", 5, " ", 1, 0);
str_replace(buffer, &len, &changes, " das ", 5, " ", 1, 0);
str_replace(buffer, &len, &changes, " la ", 4, " ", 1, 0);
str_replace(buffer, &len, &changes, " le ", 4, " ", 1, 0);
str_replace(buffer, &len, &changes, " el ", 4, " ", 1, 0);
str_replace(buffer, &len, &changes, " il ", 4, " ", 1, 0);
// german
str_replace(buffer, &len, &changes, "ae", 2, "a", 1, 0);
str_replace(buffer, &len, &changes, "oe", 2, "o", 1, 0);
str_replace(buffer, &len, &changes, "ue", 2, "u", 1, 0);
str_replace(buffer, &len, &changes, "sss", 3, "ss", 2, 0);
str_replace(buffer, &len, &changes, "ih", 2, "i", 1, 0);
str_replace(buffer, &len, &changes, "eh", 2, "e", 1, 0);
// russian
str_replace(buffer, &len, &changes, "ie", 2, "i", 1, 0);
str_replace(buffer, &len, &changes, "yi", 2, "i", 1, 0);
// allocate & create the result
len--;// Drop the terminating zero
result = (text *)palloc(len + VARHDRSZ);
SET_VARSIZE(result, len + VARHDRSZ);
memcpy(VARDATA(result), buffer, len);
pfree(buffer);
PG_RETURN_TEXT_P(result);
}