1 /* Copyright (C) 2008 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 /* Exercise `scm_c_read ()' and the port type API. Verify assumptions that
19 can be made by port type implementations. */
30 /* Size of our port's internal buffer. */
31 #define PORT_BUFFER_SIZE 1024
33 /* Return a new port of type PORT_TYPE. */
35 make_port (scm_t_bits port_type)
41 c_buffer = scm_gc_calloc (PORT_BUFFER_SIZE, "custom-port-buffer");
43 port = scm_new_port_table_entry (port_type);
45 /* Associate C_BUFFER with PORT, for test purposes. */
46 SCM_SETSTREAM (port, (scm_t_bits) c_buffer);
48 /* Use C_BUFFER as PORT's internal buffer. */
49 c_port = SCM_PTAB_ENTRY (port);
50 c_port->read_pos = c_port->read_buf = (unsigned char *) c_buffer;
51 c_port->read_end = (unsigned char *) c_buffer + PORT_BUFFER_SIZE;
52 c_port->read_buf_size = PORT_BUFFER_SIZE;
54 /* Mark PORT as open and readable. */
55 SCM_SET_CELL_TYPE (port, port_type | SCM_OPN | SCM_RDNG);
60 /* Read one byte from PORT. */
65 scm_t_port *c_port = SCM_PTAB_ENTRY (port);
67 /* Make sure that C_PORT's internal buffer wasn't changed behind our back.
68 See http://lists.gnu.org/archive/html/guile-devel/2008-11/msg00042.html
69 for an example where this assumption matters. */
70 assert (c_port->read_buf == (unsigned char *) SCM_STREAM (port));
71 assert (c_port->read_buf_size == PORT_BUFFER_SIZE);
73 if (c_port->read_pos >= c_port->read_end)
76 result = (int) *c_port->read_pos++;
81 /* Return true (non-zero) if BUF contains only zeros. */
83 zeroed_buffer_p (const char *buf, size_t len)
87 for (i = 0; i < len; i++)
100 char buffer[PORT_BUFFER_SIZE + (PORT_BUFFER_SIZE / 2)];
101 size_t read, last_read;
103 port_type = scm_make_port_type ("custom-input-port", fill_input, NULL);
104 port = make_port (port_type);
109 last_read = scm_c_read (port, &buffer[read], 123);
110 assert (last_read <= 123);
111 assert (zeroed_buffer_p (&buffer[read], last_read));
115 while (last_read > 0 && read < sizeof (buffer));
117 /* We shouldn't be able to read more than what's in PORT's buffer. */
118 assert (read == PORT_BUFFER_SIZE);
125 main (int argc, char *argv[])
127 scm_with_guile (do_start, NULL);