Function lo_write

src/interfaces/libpq/fe-lobj.c:298–342

* lo_write * write len bytes of buf into the large object fd * * returns the number of bytes written, or -1 on failure. */

 * returns the number of bytes written, or -1 on failure.
 */
int
lo_write(PGconn *conn, int fd, const char *buf, size_t len)
{
	PQArgBlock	argv[2];
	PGresult   *res;
	int			result_len;
	int			retval;

	if (lo_initialize(conn) < 0)
		return -1;

	/*
	 * Long ago, somebody thought it'd be a good idea to declare this function
	 * as taking size_t ... but the underlying backend function only accepts a
	 * signed int32 length.  So throw error if the given value overflows
	 * int32.
	 */
	if (len > (size_t) INT_MAX)
	{
		appendPQExpBufferStr(&conn->errorMessage,
							 libpq_gettext("argument of lo_write exceeds integer range\n"));
		return -1;
	}

	argv[0].isint = 1;
	argv[0].len = 4;
	argv[0].u.integer = fd;

	argv[1].isint = 0;
	argv[1].len = (int) len;
	argv[1].u.ptr = (int *) unconstify(char *, buf);

	res = PQfn(conn, conn->lobjfuncs->fn_lo_write,
			   &retval, &result_len, 1, argv, 2);
	if (PQresultStatus(res) == PGRES_COMMAND_OK)
	{
		PQclear(res);
		return retval;
	}
	else
	{
		PQclear(res);
		return -1;
	}
}

/*
 * lo_lseek