C++ PG_GETARG_TEXT_P函数代码示例

Datum
pgstattuple(PG_FUNCTION_ARGS)
{
	text	   *relname = PG_GETARG_TEXT_P(0);
	RangeVar   *relrv;
	Relation	rel;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pgstattuple functions"))));

	/* open relation */
	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
	rel = relation_openrv(relrv, AccessShareLock);

	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
}

Datum
text2ltree(PG_FUNCTION_ARGS)
{
	text	   *in = PG_GETARG_TEXT_P(0);
	char	   *s = (char *) palloc(VARSIZE(in) - VARHDRSZ + 1);
	ltree	   *out;

	memcpy(s, VARDATA(in), VARSIZE(in) - VARHDRSZ);
	s[VARSIZE(in) - VARHDRSZ] = '\0';

	out = (ltree *) DatumGetPointer(DirectFunctionCall1(
														ltree_in,
														PointerGetDatum(s)
														));
	pfree(s);
	PG_FREE_IF_COPY(in, 0);
	PG_RETURN_POINTER(out);
}

Datum
text_char(PG_FUNCTION_ARGS)
{
	text	   *arg1 = PG_GETARG_TEXT_P(0);
	char		result;

	/*
	 * An empty input string is converted to \0 (for consistency with
	 * charin). If the input is longer than one character, the excess data
	 * is silently discarded.
	 */
	if (VARSIZE(arg1) > VARHDRSZ)
		result = *(VARDATA(arg1));
	else
		result = '\0';

	PG_RETURN_CHAR(result);
}

Datum
pg_decrypt(PG_FUNCTION_ARGS)
{
	int			err;
	bytea	   *data,
			   *key,
			   *res;
	text	   *type;
	PX_Combo   *c;
	unsigned	dlen,
				klen,
				rlen;

	type = PG_GETARG_TEXT_P(2);
	c = find_provider(type, (PFN) px_find_combo, "Cipher", 0);

	data = PG_GETARG_BYTEA_P(0);
	key = PG_GETARG_BYTEA_P(1);
	dlen = VARSIZE(data) - VARHDRSZ;
	klen = VARSIZE(key) - VARHDRSZ;

	rlen = px_combo_decrypt_len(c, dlen);
	res = palloc(VARHDRSZ + rlen);

	err = px_combo_init(c, (uint8 *) VARDATA(key), klen, NULL, 0);
	if (!err)
		err = px_combo_decrypt(c, (uint8 *) VARDATA(data), dlen,
							   (uint8 *) VARDATA(res), &rlen);

	px_combo_free(c);

	if (err)
		ereport(ERROR,
				(errcode(ERRCODE_EXTERNAL_ROUTINE_INVOCATION_EXCEPTION),
				 errmsg("decrypt error: %s", px_strerror(err))));

	SET_VARSIZE(res, VARHDRSZ + rlen);

	PG_FREE_IF_COPY(data, 0);
	PG_FREE_IF_COPY(key, 1);
	PG_FREE_IF_COPY(type, 2);

	PG_RETURN_BYTEA_P(res);
}

Datum
headline_byname(PG_FUNCTION_ARGS)
{
	text	   *cfg = PG_GETARG_TEXT_P(0);

	Datum		out;

	SET_FUNCOID();
	out = DirectFunctionCall4(
							  headline,
							  ObjectIdGetDatum(name2id_cfg(cfg)),
							  PG_GETARG_DATUM(1),
							  PG_GETARG_DATUM(2),
				(PG_NARGS() > 3) ? PG_GETARG_DATUM(3) : PointerGetDatum(NULL)
		);

	PG_FREE_IF_COPY(cfg, 0);
	PG_RETURN_DATUM(out);
}

/* fwrite(encode(args[n], encoding), f) */
static int
do_write(PG_FUNCTION_ARGS, int n, FILE *f, int max_linesize, int encoding)
{
	text	   *arg = PG_GETARG_TEXT_P(n);
	char	   *str;
	int			len;

	str = encode_text(encoding, arg, &len);
	CHECK_LENGTH(len);

	if (fwrite(str, 1, len, f) != len)
		CHECK_ERRNO_PUT();

	if (VARDATA(arg) != str)
		pfree(str);
	PG_FREE_IF_COPY(arg, n);

	return len;
}

Datum
to_tsquery_byid(PG_FUNCTION_ARGS)
{
	Oid			cfgid = PG_GETARG_OID(0);
	text	   *in = PG_GETARG_TEXT_P(1);
	TSQuery		query;
	QueryItem  *res;
	int4		len;

	query = parse_tsquery(text_to_cstring(in), pushval_morph, ObjectIdGetDatum(cfgid), false);

	if (query->size == 0)
		PG_RETURN_TSQUERY(query);

	/* clean out any stopword placeholders from the tree */
	res = clean_fakeval(GETQUERY(query), &len);
	if (!res)
	{
		SET_VARSIZE(query, HDRSIZETQ);
		query->size = 0;
		PG_RETURN_POINTER(query);
	}
	memcpy((void *) GETQUERY(query), (void *) res, len * sizeof(QueryItem));

	/*
	 * Removing the stopword placeholders might've resulted in fewer
	 * QueryItems. If so, move the operands up accordingly.
	 */
	if (len != query->size)
	{
		char	   *oldoperand = GETOPERAND(query);
		int4		lenoperand = VARSIZE(query) - (oldoperand - (char *) query);

		Assert(len < query->size);

		query->size = len;
		memmove((void *) GETOPERAND(query), oldoperand, VARSIZE(query) - (oldoperand - (char *) query));
		SET_VARSIZE(query, COMPUTESIZE(len, lenoperand));
	}

	pfree(res);
	PG_RETURN_TSQUERY(query);
}

Datum domainname_parts(PG_FUNCTION_ARGS)
{
	text *in = PG_GETARG_TEXT_P(0);
	const char *s = VARDATA(in);
	const char *b = s, *p = s, *e = s + VARSIZE_ANY_EXHDR(in);
	int nelems = 0;
	int nbytes = ARR_OVERHEAD_NONULLS(1);
	ArrayType *r;
	char *o;

	while (p < e) 
	{
		b = p;
		STRSEARCH(p, e-p, *p == '.');
		nelems ++;
		nbytes += VARHDRSZ + (p-b);
		nbytes = INTALIGN(nbytes);
		p ++;
	}
	r = (ArrayType *)palloc(nbytes);
	SET_VARSIZE(r, nbytes);
	r->ndim = 1;
	r->dataoffset = 0;
	r->elemtype = TEXTOID;
	*ARR_DIMS(r) = nelems;
	*ARR_LBOUND(r) = 1;

	p = s;
	o = ARR_DATA_PTR(r);
	while (p < e)
	{
		b = p;
		STRSEARCH(p, e-p, *p == '.');
		SET_VARSIZE(o, VARHDRSZ+(p-b));
		o = VARDATA(o);
		memcpy(o, b, p-b);
		o += INTALIGN(p-b);
		p ++;
	}

	PG_FREE_IF_COPY(in, 0);
	PG_RETURN_ARRAYTYPE_P(r);
}

Datum
text_int4(PG_FUNCTION_ARGS)
{
	text	   *string = PG_GETARG_TEXT_P(0);
	Datum		result;
	int			len;
	char	   *str;

	len = VARSIZE(string) - VARHDRSZ;

	str = palloc(len + 1);
	memcpy(str, VARDATA(string), len);
	*(str + len) = '\0';

	result = DirectFunctionCall1(int4in, CStringGetDatum(str));
	pfree(str);

	return result;
}

Datum
OptimizeMinidumpFromFile(PG_FUNCTION_ARGS)
{
	char *szFileName = textToString(PG_GETARG_TEXT_P(0));
	char *szResultDXL = COptTasks::SzOptimizeMinidumpFromFile(szFileName);
	if (NULL != szResultDXL)
	{
		text *ptResult = stringToText(szResultDXL);
		gpdb::GPDBFree(szResultDXL);
		PG_RETURN_TEXT_P(ptResult);
	}
	else
	{
		elog(NOTICE, "Execution of UDF 'OptimizeMinidumpFromFile' failed. Consult the LOG for more information.");

		// return a dummy value
		PG_RETURN_NULL();
	}
}

/*
 *		text_float4		- converts a text string to a float4 number
 */
Datum
text_float4(PG_FUNCTION_ARGS)
{
	text	   *string = PG_GETARG_TEXT_P(0);
	Datum		result;
	int			len;
	char	   *str;

	len = (VARSIZE(string) - VARHDRSZ);
	str = palloc(len + 1);
	memcpy(str, VARDATA(string), len);
	*(str + len) = '\0';

	result = DirectFunctionCall1(float4in, CStringGetDatum(str));

	pfree(str);

	PG_RETURN_DATUM(result);
}

Datum
Optimize(PG_FUNCTION_ARGS)
{
	char *szSQLText = textToString(PG_GETARG_TEXT_P(0));

	Query *pquery = parseSQL(szSQLText);
	Query *pqueryNormalized = preprocess_query_optimizer(pquery, NULL);

	Assert(pqueryNormalized);

	char *szOutput = COptTasks::SzOptimize(pqueryNormalized);

	if (NULL == szOutput)
	{
		elog(ERROR, "Error optimizing query");
	}

	PG_RETURN_TEXT_P(stringToText(szOutput));
}

Datum LWGEOM_asHEXEWKB(PG_FUNCTION_ARGS)
{
	GSERIALIZED *geom = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
	LWGEOM *lwgeom;
	char *hexwkb;
	size_t hexwkb_size;
	uint8_t variant = 0;
	text *result;
	text *type;
	size_t text_size;

	/* If user specified endianness, respect it */
	if ( (PG_NARGS()>1) && (!PG_ARGISNULL(1)) )
	{
		type = PG_GETARG_TEXT_P(1);

		if  ( ! strncmp(VARDATA(type), "xdr", 3) ||
		      ! strncmp(VARDATA(type), "XDR", 3) )
		{
			variant = variant | WKB_XDR;
		}
		else
		{
			variant = variant | WKB_NDR;
		}
	}

	/* Create WKB hex string */
	lwgeom = lwgeom_from_gserialized(geom);
	hexwkb = lwgeom_to_hexwkb(lwgeom, variant | WKB_EXTENDED, &hexwkb_size);
	lwgeom_free(lwgeom);
	
	/* Prepare the PgSQL text return type */
	text_size = hexwkb_size - 1 + VARHDRSZ;
	result = palloc(text_size);
	memcpy(VARDATA(result), hexwkb, hexwkb_size - 1);
	SET_VARSIZE(result, text_size);
	
	/* Clean up and return */
	pfree(hexwkb);
	PG_FREE_IF_COPY(geom, 0);
	PG_RETURN_TEXT_P(result);
}

/*
 * pg_start_backup: set up for taking an on-line backup dump
 *
 * Essentially what this does is to create a backup label file in $PGDATA,
 * where it will be archived as part of the backup dump.  The label file
 * contains the user-supplied label string (typically this would be used
 * to tell where the backup dump will be stored) and the starting time and
 * starting WAL location for the dump.
 */
Datum
pg_start_backup(PG_FUNCTION_ARGS)
{
	text	   *backupid = PG_GETARG_TEXT_P(0);
	bool		fast = PG_GETARG_BOOL(1);
	char	   *backupidstr;
	XLogRecPtr	startpoint;

	backupidstr = text_to_cstring(backupid);

	if (!superuser() && !has_rolreplication(GetUserId()))
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
		   errmsg("must be superuser or replication role to run a backup")));

	startpoint = do_pg_start_backup(backupidstr, fast, NULL, NULL);

	PG_RETURN_LSN(startpoint);
}

Datum
dbms_alert_register(PG_FUNCTION_ARGS)
{
	text *name = PG_GETARG_TEXT_P(0);
	int cycle = 0;
	float8 endtime;
	float8 timeout = 2;

	WATCH_PRE(timeout, endtime, cycle);
	if (ora_lock_shmem(SHMEMMSGSZ, MAX_PIPES, MAX_EVENTS, MAX_LOCKS, false))
	{
		register_event(name);
		LWLockRelease(shmem_lock);
		PG_RETURN_VOID();
	}
	WATCH_POST(timeout, endtime, cycle);
	LOCK_ERROR();
	PG_RETURN_VOID();
}