mirror of
https://github.com/postgres/postgres.git
synced 2025-11-03 09:13:20 +03:00
131 lines
2.8 KiB
C
131 lines
2.8 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* test_parser.c
|
|
* Simple example of a text search parser
|
|
*
|
|
* Copyright (c) 2007, PostgreSQL Global Development Group
|
|
*
|
|
* IDENTIFICATION
|
|
* $PostgreSQL: pgsql/contrib/test_parser/test_parser.c,v 1.1 2007/10/15 21:36:50 tgl Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include "fmgr.h"
|
|
|
|
PG_MODULE_MAGIC;
|
|
|
|
|
|
/*
|
|
* types
|
|
*/
|
|
|
|
/* self-defined type */
|
|
typedef struct {
|
|
char * buffer; /* text to parse */
|
|
int len; /* length of the text in buffer */
|
|
int pos; /* position of the parser */
|
|
} ParserState;
|
|
|
|
/* copy-paste from wparser.h of tsearch2 */
|
|
typedef struct {
|
|
int lexid;
|
|
char *alias;
|
|
char *descr;
|
|
} LexDescr;
|
|
|
|
/*
|
|
* prototypes
|
|
*/
|
|
PG_FUNCTION_INFO_V1(testprs_start);
|
|
Datum testprs_start(PG_FUNCTION_ARGS);
|
|
|
|
PG_FUNCTION_INFO_V1(testprs_getlexeme);
|
|
Datum testprs_getlexeme(PG_FUNCTION_ARGS);
|
|
|
|
PG_FUNCTION_INFO_V1(testprs_end);
|
|
Datum testprs_end(PG_FUNCTION_ARGS);
|
|
|
|
PG_FUNCTION_INFO_V1(testprs_lextype);
|
|
Datum testprs_lextype(PG_FUNCTION_ARGS);
|
|
|
|
/*
|
|
* functions
|
|
*/
|
|
Datum testprs_start(PG_FUNCTION_ARGS)
|
|
{
|
|
ParserState *pst = (ParserState *) palloc0(sizeof(ParserState));
|
|
pst->buffer = (char *) PG_GETARG_POINTER(0);
|
|
pst->len = PG_GETARG_INT32(1);
|
|
pst->pos = 0;
|
|
|
|
PG_RETURN_POINTER(pst);
|
|
}
|
|
|
|
Datum testprs_getlexeme(PG_FUNCTION_ARGS)
|
|
{
|
|
ParserState *pst = (ParserState *) PG_GETARG_POINTER(0);
|
|
char **t = (char **) PG_GETARG_POINTER(1);
|
|
int *tlen = (int *) PG_GETARG_POINTER(2);
|
|
int type;
|
|
|
|
*tlen = pst->pos;
|
|
*t = pst->buffer + pst->pos;
|
|
|
|
if ((pst->buffer)[pst->pos] == ' ')
|
|
{
|
|
/* blank type */
|
|
type = 12;
|
|
/* go to the next non-white-space character */
|
|
while ((pst->buffer)[pst->pos] == ' ' &&
|
|
pst->pos < pst->len)
|
|
(pst->pos)++;
|
|
} else {
|
|
/* word type */
|
|
type = 3;
|
|
/* go to the next white-space character */
|
|
while ((pst->buffer)[pst->pos] != ' ' &&
|
|
pst->pos < pst->len)
|
|
(pst->pos)++;
|
|
}
|
|
|
|
*tlen = pst->pos - *tlen;
|
|
|
|
/* we are finished if (*tlen == 0) */
|
|
if (*tlen == 0)
|
|
type=0;
|
|
|
|
PG_RETURN_INT32(type);
|
|
}
|
|
|
|
Datum testprs_end(PG_FUNCTION_ARGS)
|
|
{
|
|
ParserState *pst = (ParserState *) PG_GETARG_POINTER(0);
|
|
pfree(pst);
|
|
PG_RETURN_VOID();
|
|
}
|
|
|
|
Datum testprs_lextype(PG_FUNCTION_ARGS)
|
|
{
|
|
/*
|
|
* Remarks:
|
|
* - we have to return the blanks for headline reason
|
|
* - we use the same lexids like Teodor in the default
|
|
* word parser; in this way we can reuse the headline
|
|
* function of the default word parser.
|
|
*/
|
|
LexDescr *descr = (LexDescr *) palloc(sizeof(LexDescr) * (2+1));
|
|
|
|
/* there are only two types in this parser */
|
|
descr[0].lexid = 3;
|
|
descr[0].alias = pstrdup("word");
|
|
descr[0].descr = pstrdup("Word");
|
|
descr[1].lexid = 12;
|
|
descr[1].alias = pstrdup("blank");
|
|
descr[1].descr = pstrdup("Space symbols");
|
|
descr[2].lexid = 0;
|
|
|
|
PG_RETURN_POINTER(descr);
|
|
}
|