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/* Copyright 2008,2014,2018
Free Software Foundation, Inc.
This file is part of Guile.
Guile is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Guile is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public
License along with Guile. If not, see
<https://www.gnu.org/licenses/>. */
/* Exercise `scm_c_read ()' and the port type API. Verify assumptions that
can be made by port type implementations. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#undef NDEBUG
#include <assert.h>
#include <string.h>
#include <libguile.h>
/* Size of our port's internal buffer. */
#define PORT_BUFFER_SIZE 1024
struct custom_port
{
size_t pos;
size_t len;
char *buf;
};
/* Return a new port of type PORT_TYPE. */
static inline SCM
make_port (scm_t_port_type *port_type)
{
struct custom_port *stream = scm_gc_typed_calloc (struct custom_port);
stream->pos = 0;
stream->len = PORT_BUFFER_SIZE;
stream->buf = scm_gc_calloc (stream->len, "custom-port-buffer");
return scm_c_make_port (port_type, SCM_RDNG, (scm_t_bits) stream);
}
static size_t
custom_port_read (SCM port, SCM dst, size_t start, size_t count)
{
size_t to_copy = count;
struct custom_port *stream = (void *) SCM_STREAM (port);
if (stream->pos + to_copy > stream->len)
to_copy = stream->len - stream->pos;
memcpy (SCM_BYTEVECTOR_CONTENTS (dst) + start,
stream->buf + stream->pos, to_copy);
stream->pos += to_copy;
return to_copy;
}
/* Return true (non-zero) if BUF contains only zeros. */
static inline int
zeroed_buffer_p (const char *buf, size_t len)
{
size_t i;
for (i = 0; i < len; i++)
if (buf[i] != 0)
return 0;
return 1;
}
/* Run the test. */
static void *
do_start (void *arg)
{
SCM port;
scm_t_port_type *port_type;
char buffer[PORT_BUFFER_SIZE + (PORT_BUFFER_SIZE / 2)];
size_t read, last_read;
port_type = scm_make_port_type ("custom-input-port", custom_port_read, NULL);
port = make_port (port_type);
read = 0;
do
{
last_read = scm_c_read (port, &buffer[read], 123);
assert (last_read <= 123);
assert (zeroed_buffer_p (&buffer[read], last_read));
read += last_read;
}
while (last_read > 0 && read < sizeof (buffer));
/* We shouldn't be able to read more than what's in PORT's buffer. */
assert (read == PORT_BUFFER_SIZE);
return NULL;
}
int
main (int argc, char *argv[])
{
scm_with_guile (do_start, NULL);
return 0;
}
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