Use `scm_gc_malloc_pointerless' in various places (improves performance).
[bpt/guile.git] / libguile / fports.c
1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2004, 2006 Free Software Foundation, Inc.
2 *
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.
7 *
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.
12 *
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
16 */
17
18
19 \f
20 #if HAVE_CONFIG_H
21 # include <config.h>
22 #endif
23
24 #include <stdio.h>
25 #include <fcntl.h>
26 #include "libguile/_scm.h"
27 #include "libguile/strings.h"
28 #include "libguile/validate.h"
29 #include "libguile/gc.h"
30 #include "libguile/posix.h"
31 #include "libguile/dynwind.h"
32
33 #include "libguile/fports.h"
34
35 #ifdef HAVE_STRING_H
36 #include <string.h>
37 #endif
38 #ifdef HAVE_UNISTD_H
39 #include <unistd.h>
40 #endif
41 #ifdef HAVE_IO_H
42 #include <io.h>
43 #endif
44 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
45 #include <sys/stat.h>
46 #endif
47
48 #include <errno.h>
49
50 #include "libguile/iselect.h"
51
52 /* Some defines for Windows (native port, not Cygwin). */
53 #ifdef __MINGW32__
54 # include <sys/stat.h>
55 # include <winsock2.h>
56 # define ftruncate(fd, size) chsize (fd, size)
57 #endif /* __MINGW32__ */
58
59
60 scm_t_bits scm_tc16_fport;
61
62
63 /* default buffer size, used if the O/S won't supply a value. */
64 static const size_t default_buffer_size = 1024;
65
66 /* create FPORT buffer with specified sizes (or -1 to use default size or
67 0 for no buffer. */
68 static void
69 scm_fport_buffer_add (SCM port, long read_size, int write_size)
70 #define FUNC_NAME "scm_fport_buffer_add"
71 {
72 scm_t_port *pt = SCM_PTAB_ENTRY (port);
73
74 if (read_size == -1 || write_size == -1)
75 {
76 size_t default_size;
77 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
78 struct stat st;
79 scm_t_fport *fp = SCM_FSTREAM (port);
80
81 default_size = (fstat (fp->fdes, &st) == -1) ? default_buffer_size
82 : st.st_blksize;
83 #else
84 default_size = default_buffer_size;
85 #endif
86 if (read_size == -1)
87 read_size = default_size;
88 if (write_size == -1)
89 write_size = default_size;
90 }
91
92 if (SCM_INPUT_PORT_P (port) && read_size > 0)
93 {
94 pt->read_buf = scm_gc_malloc_pointerless (read_size, "port buffer");
95 pt->read_pos = pt->read_end = pt->read_buf;
96 pt->read_buf_size = read_size;
97 }
98 else
99 {
100 pt->read_pos = pt->read_buf = pt->read_end = &pt->shortbuf;
101 pt->read_buf_size = 1;
102 }
103
104 if (SCM_OUTPUT_PORT_P (port) && write_size > 0)
105 {
106 pt->write_buf = scm_gc_malloc_pointerless (write_size, "port buffer");
107 pt->write_pos = pt->write_buf;
108 pt->write_buf_size = write_size;
109 }
110 else
111 {
112 pt->write_buf = pt->write_pos = &pt->shortbuf;
113 pt->write_buf_size = 1;
114 }
115
116 pt->write_end = pt->write_buf + pt->write_buf_size;
117 if (read_size > 0 || write_size > 0)
118 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) & ~SCM_BUF0);
119 else
120 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) | SCM_BUF0);
121 }
122 #undef FUNC_NAME
123
124 SCM_DEFINE (scm_setvbuf, "setvbuf", 2, 1, 0,
125 (SCM port, SCM mode, SCM size),
126 "Set the buffering mode for @var{port}. @var{mode} can be:\n"
127 "@table @code\n"
128 "@item _IONBF\n"
129 "non-buffered\n"
130 "@item _IOLBF\n"
131 "line buffered\n"
132 "@item _IOFBF\n"
133 "block buffered, using a newly allocated buffer of @var{size} bytes.\n"
134 "If @var{size} is omitted, a default size will be used.\n"
135 "@end table")
136 #define FUNC_NAME s_scm_setvbuf
137 {
138 int cmode;
139 long csize;
140 scm_t_port *pt;
141
142 port = SCM_COERCE_OUTPORT (port);
143
144 SCM_VALIDATE_OPFPORT (1,port);
145 cmode = scm_to_int (mode);
146 if (cmode != _IONBF && cmode != _IOFBF && cmode != _IOLBF)
147 scm_out_of_range (FUNC_NAME, mode);
148
149 if (cmode == _IOLBF)
150 {
151 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) | SCM_BUFLINE);
152 cmode = _IOFBF;
153 }
154 else
155 {
156 SCM_SET_CELL_WORD_0 (port, SCM_CELL_WORD_0 (port) & ~(scm_t_bits)SCM_BUFLINE);
157 }
158
159 if (SCM_UNBNDP (size))
160 {
161 if (cmode == _IOFBF)
162 csize = -1;
163 else
164 csize = 0;
165 }
166 else
167 {
168 csize = scm_to_int (size);
169 if (csize < 0 || (cmode == _IONBF && csize > 0))
170 scm_out_of_range (FUNC_NAME, size);
171 }
172
173 pt = SCM_PTAB_ENTRY (port);
174
175 /* silently discards buffered and put-back chars. */
176 if (pt->read_buf == pt->putback_buf)
177 {
178 pt->read_buf = pt->saved_read_buf;
179 pt->read_pos = pt->saved_read_pos;
180 pt->read_end = pt->saved_read_end;
181 pt->read_buf_size = pt->saved_read_buf_size;
182 }
183 if (pt->read_buf != &pt->shortbuf)
184 scm_gc_free (pt->read_buf, pt->read_buf_size, "port buffer");
185 if (pt->write_buf != &pt->shortbuf)
186 scm_gc_free (pt->write_buf, pt->write_buf_size, "port buffer");
187
188 scm_fport_buffer_add (port, csize, csize);
189 return SCM_UNSPECIFIED;
190 }
191 #undef FUNC_NAME
192
193 /* Move ports with the specified file descriptor to new descriptors,
194 * resetting the revealed count to 0.
195 */
196
197 void
198 scm_evict_ports (int fd)
199 {
200 long i;
201
202 scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
203
204 for (i = 0; i < scm_i_port_table_size; i++)
205 {
206 SCM port = scm_i_port_table[i]->port;
207
208 if (SCM_FPORTP (port))
209 {
210 scm_t_fport *fp = SCM_FSTREAM (port);
211
212 if (fp->fdes == fd)
213 {
214 fp->fdes = dup (fd);
215 if (fp->fdes == -1)
216 scm_syserror ("scm_evict_ports");
217 scm_set_port_revealed_x (port, scm_from_int (0));
218 }
219 }
220 }
221
222 scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
223 }
224
225
226 SCM_DEFINE (scm_file_port_p, "file-port?", 1, 0, 0,
227 (SCM obj),
228 "Determine whether @var{obj} is a port that is related to a file.")
229 #define FUNC_NAME s_scm_file_port_p
230 {
231 return scm_from_bool (SCM_FPORTP (obj));
232 }
233 #undef FUNC_NAME
234
235
236 /* scm_open_file
237 * Return a new port open on a given file.
238 *
239 * The mode string must match the pattern: [rwa+]** which
240 * is interpreted in the usual unix way.
241 *
242 * Return the new port.
243 */
244 SCM_DEFINE (scm_open_file, "open-file", 2, 0, 0,
245 (SCM filename, SCM mode),
246 "Open the file whose name is @var{filename}, and return a port\n"
247 "representing that file. The attributes of the port are\n"
248 "determined by the @var{mode} string. The way in which this is\n"
249 "interpreted is similar to C stdio. The first character must be\n"
250 "one of the following:\n"
251 "@table @samp\n"
252 "@item r\n"
253 "Open an existing file for input.\n"
254 "@item w\n"
255 "Open a file for output, creating it if it doesn't already exist\n"
256 "or removing its contents if it does.\n"
257 "@item a\n"
258 "Open a file for output, creating it if it doesn't already\n"
259 "exist. All writes to the port will go to the end of the file.\n"
260 "The \"append mode\" can be turned off while the port is in use\n"
261 "@pxref{Ports and File Descriptors, fcntl}\n"
262 "@end table\n"
263 "The following additional characters can be appended:\n"
264 "@table @samp\n"
265 "@item b\n"
266 "Open the underlying file in binary mode, if supported by the operating system. "
267 "@item +\n"
268 "Open the port for both input and output. E.g., @code{r+}: open\n"
269 "an existing file for both input and output.\n"
270 "@item 0\n"
271 "Create an \"unbuffered\" port. In this case input and output\n"
272 "operations are passed directly to the underlying port\n"
273 "implementation without additional buffering. This is likely to\n"
274 "slow down I/O operations. The buffering mode can be changed\n"
275 "while a port is in use @pxref{Ports and File Descriptors,\n"
276 "setvbuf}\n"
277 "@item l\n"
278 "Add line-buffering to the port. The port output buffer will be\n"
279 "automatically flushed whenever a newline character is written.\n"
280 "@end table\n"
281 "In theory we could create read/write ports which were buffered\n"
282 "in one direction only. However this isn't included in the\n"
283 "current interfaces. If a file cannot be opened with the access\n"
284 "requested, @code{open-file} throws an exception.")
285 #define FUNC_NAME s_scm_open_file
286 {
287 SCM port;
288 int fdes;
289 int flags = 0;
290 char *file;
291 char *md;
292 char *ptr;
293
294 scm_dynwind_begin (0);
295
296 file = scm_to_locale_string (filename);
297 scm_dynwind_free (file);
298
299 md = scm_to_locale_string (mode);
300 scm_dynwind_free (md);
301
302 switch (*md)
303 {
304 case 'r':
305 flags |= O_RDONLY;
306 break;
307 case 'w':
308 flags |= O_WRONLY | O_CREAT | O_TRUNC;
309 break;
310 case 'a':
311 flags |= O_WRONLY | O_CREAT | O_APPEND;
312 break;
313 default:
314 scm_out_of_range (FUNC_NAME, mode);
315 }
316 ptr = md + 1;
317 while (*ptr != '\0')
318 {
319 switch (*ptr)
320 {
321 case '+':
322 flags = (flags & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
323 break;
324 case 'b':
325 #if defined (O_BINARY)
326 flags |= O_BINARY;
327 #endif
328 break;
329 case '0': /* unbuffered: handled later. */
330 case 'l': /* line buffered: handled during output. */
331 break;
332 default:
333 scm_out_of_range (FUNC_NAME, mode);
334 }
335 ptr++;
336 }
337 SCM_SYSCALL (fdes = open (file, flags, 0666));
338 if (fdes == -1)
339 {
340 int en = errno;
341
342 SCM_SYSERROR_MSG ("~A: ~S",
343 scm_cons (scm_strerror (scm_from_int (en)),
344 scm_cons (filename, SCM_EOL)), en);
345 }
346 port = scm_i_fdes_to_port (fdes, scm_i_mode_bits (mode), filename);
347
348 scm_dynwind_end ();
349
350 return port;
351 }
352 #undef FUNC_NAME
353
354 \f
355 #ifdef __MINGW32__
356 /*
357 * Try getting the appropiate file flags for a given file descriptor
358 * under Windows. This incorporates some fancy operations because Windows
359 * differentiates between file, pipe and socket descriptors.
360 */
361 #ifndef O_ACCMODE
362 # define O_ACCMODE 0x0003
363 #endif
364
365 static int getflags (int fdes)
366 {
367 int flags = 0;
368 struct stat buf;
369 int error, optlen = sizeof (int);
370
371 /* Is this a socket ? */
372 if (getsockopt (fdes, SOL_SOCKET, SO_ERROR, (void *) &error, &optlen) >= 0)
373 flags = O_RDWR;
374 /* Maybe a regular file ? */
375 else if (fstat (fdes, &buf) < 0)
376 flags = -1;
377 else
378 {
379 /* Or an anonymous pipe handle ? */
380 if (buf.st_mode & _S_IFIFO)
381 flags = PeekNamedPipe ((HANDLE) _get_osfhandle (fdes), NULL, 0,
382 NULL, NULL, NULL) ? O_RDONLY : O_WRONLY;
383 /* stdin ? */
384 else if (fdes == fileno (stdin) && isatty (fdes))
385 flags = O_RDONLY;
386 /* stdout / stderr ? */
387 else if ((fdes == fileno (stdout) || fdes == fileno (stderr)) &&
388 isatty (fdes))
389 flags = O_WRONLY;
390 else
391 flags = buf.st_mode;
392 }
393 return flags;
394 }
395 #endif /* __MINGW32__ */
396
397 /* Building Guile ports from a file descriptor. */
398
399 /* Build a Scheme port from an open file descriptor `fdes'.
400 MODE indicates whether FILE is open for reading or writing; it uses
401 the same notation as open-file's second argument.
402 NAME is a string to be used as the port's filename.
403 */
404 SCM
405 scm_i_fdes_to_port (int fdes, long mode_bits, SCM name)
406 #define FUNC_NAME "scm_fdes_to_port"
407 {
408 SCM port;
409 scm_t_port *pt;
410 int flags;
411
412 /* test that fdes is valid. */
413 #ifdef __MINGW32__
414 flags = getflags (fdes);
415 #else
416 flags = fcntl (fdes, F_GETFL, 0);
417 #endif
418 if (flags == -1)
419 SCM_SYSERROR;
420 flags &= O_ACCMODE;
421 if (flags != O_RDWR
422 && ((flags != O_WRONLY && (mode_bits & SCM_WRTNG))
423 || (flags != O_RDONLY && (mode_bits & SCM_RDNG))))
424 {
425 SCM_MISC_ERROR ("requested file mode not available on fdes", SCM_EOL);
426 }
427
428 scm_i_scm_pthread_mutex_lock (&scm_i_port_table_mutex);
429
430 port = scm_new_port_table_entry (scm_tc16_fport);
431 SCM_SET_CELL_TYPE(port, scm_tc16_fport | mode_bits);
432 pt = SCM_PTAB_ENTRY(port);
433 {
434 scm_t_fport *fp
435 = (scm_t_fport *) scm_gc_malloc_pointerless (sizeof (scm_t_fport),
436 "file port");
437
438 fp->fdes = fdes;
439 pt->rw_random = SCM_FDES_RANDOM_P (fdes);
440 SCM_SETSTREAM (port, fp);
441 if (mode_bits & SCM_BUF0)
442 scm_fport_buffer_add (port, 0, 0);
443 else
444 scm_fport_buffer_add (port, -1, -1);
445 }
446 SCM_SET_FILENAME (port, name);
447 scm_i_pthread_mutex_unlock (&scm_i_port_table_mutex);
448 return port;
449 }
450 #undef FUNC_NAME
451
452 SCM
453 scm_fdes_to_port (int fdes, char *mode, SCM name)
454 {
455 return scm_i_fdes_to_port (fdes, scm_mode_bits (mode), name);
456 }
457
458 /* Return a lower bound on the number of bytes available for input. */
459 static int
460 fport_input_waiting (SCM port)
461 {
462 #ifdef HAVE_SELECT
463 int fdes = SCM_FSTREAM (port)->fdes;
464 struct timeval timeout;
465 SELECT_TYPE read_set;
466 SELECT_TYPE write_set;
467 SELECT_TYPE except_set;
468
469 FD_ZERO (&read_set);
470 FD_ZERO (&write_set);
471 FD_ZERO (&except_set);
472
473 FD_SET (fdes, &read_set);
474
475 timeout.tv_sec = 0;
476 timeout.tv_usec = 0;
477
478 if (select (SELECT_SET_SIZE,
479 &read_set, &write_set, &except_set, &timeout)
480 < 0)
481 scm_syserror ("fport_input_waiting");
482 return FD_ISSET (fdes, &read_set) ? 1 : 0;
483
484 #elif HAVE_IOCTL && defined (FIONREAD)
485 /* Note: cannot test just defined(FIONREAD) here, since mingw has FIONREAD
486 (for use with winsock ioctlsocket()) but not ioctl(). */
487 int fdes = SCM_FSTREAM (port)->fdes;
488 int remir;
489 ioctl(fdes, FIONREAD, &remir);
490 return remir;
491
492 #else
493 scm_misc_error ("fport_input_waiting",
494 "Not fully implemented on this platform",
495 SCM_EOL);
496 #endif
497 }
498
499 \f
500 static int
501 fport_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
502 {
503 scm_puts ("#<", port);
504 scm_print_port_mode (exp, port);
505 if (SCM_OPFPORTP (exp))
506 {
507 int fdes;
508 SCM name = SCM_FILENAME (exp);
509 if (scm_is_string (name) || scm_is_symbol (name))
510 scm_display (name, port);
511 else
512 scm_puts (SCM_PTOBNAME (SCM_PTOBNUM (exp)), port);
513 scm_putc (' ', port);
514 fdes = (SCM_FSTREAM (exp))->fdes;
515
516 #ifdef HAVE_TTYNAME
517 if (isatty (fdes))
518 scm_display (scm_ttyname (exp), port);
519 else
520 #endif /* HAVE_TTYNAME */
521 scm_intprint (fdes, 10, port);
522 }
523 else
524 {
525 scm_puts (SCM_PTOBNAME (SCM_PTOBNUM (exp)), port);
526 scm_putc (' ', port);
527 scm_uintprint ((scm_t_bits) SCM_PTAB_ENTRY (exp), 16, port);
528 }
529 scm_putc ('>', port);
530 return 1;
531 }
532
533 #ifndef __MINGW32__
534 /* thread-local block for input on fport's fdes. */
535 static void
536 fport_wait_for_input (SCM port)
537 {
538 int fdes = SCM_FSTREAM (port)->fdes;
539
540 if (!fport_input_waiting (port))
541 {
542 int n;
543 SELECT_TYPE readfds;
544 int flags = fcntl (fdes, F_GETFL);
545
546 if (flags == -1)
547 scm_syserror ("scm_fdes_wait_for_input");
548 if (!(flags & O_NONBLOCK))
549 do
550 {
551 FD_ZERO (&readfds);
552 FD_SET (fdes, &readfds);
553 n = scm_std_select (fdes + 1, &readfds, NULL, NULL, NULL);
554 }
555 while (n == -1 && errno == EINTR);
556 }
557 }
558 #endif /* !__MINGW32__ */
559
560 static void fport_flush (SCM port);
561
562 /* fill a port's read-buffer with a single read. returns the first
563 char or EOF if end of file. */
564 static int
565 fport_fill_input (SCM port)
566 {
567 long count;
568 scm_t_port *pt = SCM_PTAB_ENTRY (port);
569 scm_t_fport *fp = SCM_FSTREAM (port);
570
571 #ifndef __MINGW32__
572 fport_wait_for_input (port);
573 #endif /* !__MINGW32__ */
574 SCM_SYSCALL (count = read (fp->fdes, pt->read_buf, pt->read_buf_size));
575 if (count == -1)
576 scm_syserror ("fport_fill_input");
577 if (count == 0)
578 return EOF;
579 else
580 {
581 pt->read_pos = pt->read_buf;
582 pt->read_end = pt->read_buf + count;
583 return *pt->read_buf;
584 }
585 }
586
587 static off_t
588 fport_seek (SCM port, off_t offset, int whence)
589 {
590 scm_t_port *pt = SCM_PTAB_ENTRY (port);
591 scm_t_fport *fp = SCM_FSTREAM (port);
592 off_t rv;
593 off_t result;
594
595 if (pt->rw_active == SCM_PORT_WRITE)
596 {
597 if (offset != 0 || whence != SEEK_CUR)
598 {
599 fport_flush (port);
600 result = rv = lseek (fp->fdes, offset, whence);
601 }
602 else
603 {
604 /* read current position without disturbing the buffer. */
605 rv = lseek (fp->fdes, offset, whence);
606 result = rv + (pt->write_pos - pt->write_buf);
607 }
608 }
609 else if (pt->rw_active == SCM_PORT_READ)
610 {
611 if (offset != 0 || whence != SEEK_CUR)
612 {
613 /* could expand to avoid a second seek. */
614 scm_end_input (port);
615 result = rv = lseek (fp->fdes, offset, whence);
616 }
617 else
618 {
619 /* read current position without disturbing the buffer
620 (particularly the unread-char buffer). */
621 rv = lseek (fp->fdes, offset, whence);
622 result = rv - (pt->read_end - pt->read_pos);
623
624 if (pt->read_buf == pt->putback_buf)
625 result -= pt->saved_read_end - pt->saved_read_pos;
626 }
627 }
628 else /* SCM_PORT_NEITHER */
629 {
630 result = rv = lseek (fp->fdes, offset, whence);
631 }
632
633 if (rv == -1)
634 scm_syserror ("fport_seek");
635
636 return result;
637 }
638
639 static void
640 fport_truncate (SCM port, off_t length)
641 {
642 scm_t_fport *fp = SCM_FSTREAM (port);
643
644 if (ftruncate (fp->fdes, length) == -1)
645 scm_syserror ("ftruncate");
646 }
647
648 /* helper for fport_write: try to write data, using multiple system
649 calls if required. */
650 #define FUNC_NAME "write_all"
651 static void write_all (SCM port, const void *data, size_t remaining)
652 {
653 int fdes = SCM_FSTREAM (port)->fdes;
654
655 while (remaining > 0)
656 {
657 size_t done;
658
659 SCM_SYSCALL (done = write (fdes, data, remaining));
660
661 if (done == -1)
662 SCM_SYSERROR;
663 remaining -= done;
664 data = ((const char *) data) + done;
665 }
666 }
667 #undef FUNC_NAME
668
669 static void
670 fport_write (SCM port, const void *data, size_t size)
671 {
672 /* this procedure tries to minimize the number of writes/flushes. */
673 scm_t_port *pt = SCM_PTAB_ENTRY (port);
674
675 if (pt->write_buf == &pt->shortbuf
676 || (pt->write_pos == pt->write_buf && size >= pt->write_buf_size))
677 {
678 /* "unbuffered" port, or
679 port with empty buffer and data won't fit in buffer. */
680 write_all (port, data, size);
681 return;
682 }
683
684 {
685 off_t space = pt->write_end - pt->write_pos;
686
687 if (size <= space)
688 {
689 /* data fits in buffer. */
690 memcpy (pt->write_pos, data, size);
691 pt->write_pos += size;
692 if (pt->write_pos == pt->write_end)
693 {
694 fport_flush (port);
695 /* we can skip the line-buffering check if nothing's buffered. */
696 return;
697 }
698 }
699 else
700 {
701 memcpy (pt->write_pos, data, space);
702 pt->write_pos = pt->write_end;
703 fport_flush (port);
704 {
705 const void *ptr = ((const char *) data) + space;
706 size_t remaining = size - space;
707
708 if (size >= pt->write_buf_size)
709 {
710 write_all (port, ptr, remaining);
711 return;
712 }
713 else
714 {
715 memcpy (pt->write_pos, ptr, remaining);
716 pt->write_pos += remaining;
717 }
718 }
719 }
720
721 /* handle line buffering. */
722 if ((SCM_CELL_WORD_0 (port) & SCM_BUFLINE) && memchr (data, '\n', size))
723 fport_flush (port);
724 }
725 }
726
727 /* becomes 1 when process is exiting: normal exception handling won't
728 work by this time. */
729 extern int scm_i_terminating;
730
731 static void
732 fport_flush (SCM port)
733 {
734 scm_t_port *pt = SCM_PTAB_ENTRY (port);
735 scm_t_fport *fp = SCM_FSTREAM (port);
736 unsigned char *ptr = pt->write_buf;
737 long init_size = pt->write_pos - pt->write_buf;
738 long remaining = init_size;
739
740 while (remaining > 0)
741 {
742 long count;
743
744 SCM_SYSCALL (count = write (fp->fdes, ptr, remaining));
745 if (count < 0)
746 {
747 /* error. assume nothing was written this call, but
748 fix up the buffer for any previous successful writes. */
749 long done = init_size - remaining;
750
751 if (done > 0)
752 {
753 int i;
754
755 for (i = 0; i < remaining; i++)
756 {
757 *(pt->write_buf + i) = *(pt->write_buf + done + i);
758 }
759 pt->write_pos = pt->write_buf + remaining;
760 }
761 if (scm_i_terminating)
762 {
763 const char *msg = "Error: could not flush file-descriptor ";
764 char buf[11];
765
766 write (2, msg, strlen (msg));
767 sprintf (buf, "%d\n", fp->fdes);
768 write (2, buf, strlen (buf));
769
770 count = remaining;
771 }
772 else if (scm_gc_running_p)
773 {
774 /* silently ignore the error. scm_error would abort if we
775 called it now. */
776 count = remaining;
777 }
778 else
779 scm_syserror ("fport_flush");
780 }
781 ptr += count;
782 remaining -= count;
783 }
784 pt->write_pos = pt->write_buf;
785 pt->rw_active = SCM_PORT_NEITHER;
786 }
787
788 /* clear the read buffer and adjust the file position for unread bytes. */
789 static void
790 fport_end_input (SCM port, int offset)
791 {
792 scm_t_fport *fp = SCM_FSTREAM (port);
793 scm_t_port *pt = SCM_PTAB_ENTRY (port);
794
795 offset += pt->read_end - pt->read_pos;
796
797 if (offset > 0)
798 {
799 pt->read_pos = pt->read_end;
800 /* will throw error if unread-char used at beginning of file
801 then attempting to write. seems correct. */
802 if (lseek (fp->fdes, -offset, SEEK_CUR) == -1)
803 scm_syserror ("fport_end_input");
804 }
805 pt->rw_active = SCM_PORT_NEITHER;
806 }
807
808 static int
809 fport_close (SCM port)
810 {
811 scm_t_fport *fp = SCM_FSTREAM (port);
812 scm_t_port *pt = SCM_PTAB_ENTRY (port);
813 int rv;
814
815 fport_flush (port);
816 SCM_SYSCALL (rv = close (fp->fdes));
817 if (rv == -1 && errno != EBADF)
818 {
819 if (scm_gc_running_p)
820 /* silently ignore the error. scm_error would abort if we
821 called it now. */
822 ;
823 else
824 scm_syserror ("fport_close");
825 }
826 if (pt->read_buf == pt->putback_buf)
827 pt->read_buf = pt->saved_read_buf;
828 if (pt->read_buf != &pt->shortbuf)
829 scm_gc_free (pt->read_buf, pt->read_buf_size, "port buffer");
830 if (pt->write_buf != &pt->shortbuf)
831 scm_gc_free (pt->write_buf, pt->write_buf_size, "port buffer");
832 scm_gc_free (fp, sizeof (*fp), "file port");
833 return rv;
834 }
835
836 static size_t
837 fport_free (SCM port)
838 {
839 fport_close (port);
840 return 0;
841 }
842
843 static scm_t_bits
844 scm_make_fptob ()
845 {
846 scm_t_bits tc = scm_make_port_type ("file", fport_fill_input, fport_write);
847
848 scm_set_port_free (tc, fport_free);
849 scm_set_port_print (tc, fport_print);
850 scm_set_port_flush (tc, fport_flush);
851 scm_set_port_end_input (tc, fport_end_input);
852 scm_set_port_close (tc, fport_close);
853 scm_set_port_seek (tc, fport_seek);
854 scm_set_port_truncate (tc, fport_truncate);
855 scm_set_port_input_waiting (tc, fport_input_waiting);
856
857 return tc;
858 }
859
860 void
861 scm_init_fports ()
862 {
863 scm_tc16_fport = scm_make_fptob ();
864
865 scm_c_define ("_IOFBF", scm_from_int (_IOFBF));
866 scm_c_define ("_IOLBF", scm_from_int (_IOLBF));
867 scm_c_define ("_IONBF", scm_from_int (_IONBF));
868
869 #include "libguile/fports.x"
870 }
871
872 /*
873 Local Variables:
874 c-file-style: "gnu"
875 End:
876 */