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- #ifdef HAVE_CONFIG_H
- # include <config.h>
- #endif
- #undef NDEBUG
- #include <assert.h>
- #include <string.h>
- #include <libguile.h>
- #define PORT_BUFFER_SIZE 1024
- struct custom_port
- {
- size_t pos;
- size_t len;
- char *buf;
- };
- 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;
- }
- 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;
- }
- 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));
-
- 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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