1 /*****************************************************************************
2 * decomp.c : Decompression module for vlc
3 *****************************************************************************
4 * Copyright © 2008-2009 Rémi Denis-Courmont
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU Lesser General Public License as published by
8 * the Free Software Foundation; either version 2.1 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
25 #include <vlc_common.h>
26 #include <vlc_plugin.h>
27 #include <vlc_stream.h>
28 #include <vlc_network.h>
34 # define _POSIX_SPAWN (-1)
37 #if (_POSIX_SPAWN >= 0)
41 #include <sys/ioctl.h>
42 #if defined (__linux__) && defined (HAVE_VMSPLICE)
44 # include <sys/mman.h>
49 static int OpenGzip (vlc_object_t *);
50 static int OpenBzip2 (vlc_object_t *);
51 static int OpenXZ (vlc_object_t *);
52 static void Close (vlc_object_t *);
55 set_category (CAT_INPUT)
56 set_subcategory (SUBCAT_INPUT_STREAM_FILTER)
57 set_capability ("stream_filter", 20)
59 set_description (N_("LZMA decompression"))
60 set_callbacks (OpenXZ, Close)
63 set_description (N_("Burrows-Wheeler decompression"))
64 set_callbacks (OpenBzip2, Close)
65 /* TODO: access shortnames for stream_UrlNew() */
68 set_description (N_("gzip decompression"))
69 set_callbacks (OpenGzip, Close)
88 extern char **environ;
90 static const size_t bufsize = 65536;
92 static void cleanup_mmap (void *addr)
94 munmap (addr, bufsize);
98 static void *Thread (void *data)
100 stream_t *stream = data;
101 stream_sys_t *p_sys = stream->p_sys;
103 const ssize_t page_mask = sysconf (_SC_PAGE_SIZE) - 1;
105 int fd = p_sys->write_fd;
111 int canc = vlc_savecancel ();
113 unsigned char *buf = mmap (NULL, bufsize, PROT_READ|PROT_WRITE,
114 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
115 if (unlikely(buf == MAP_FAILED))
117 vlc_cleanup_push (cleanup_mmap, buf);
119 unsigned char *buf = malloc (bufsize);
120 if (unlikely(buf == NULL))
122 vlc_cleanup_push (free, buf);
125 len = stream_Read (stream->p_source, buf, bufsize);
126 vlc_restorecancel (canc);
129 for (ssize_t i = 0, j; i < len; i += j)
132 if ((len - i) <= page_mask) /* incomplete last page */
133 j = write (fd, buf + i, len - i);
136 struct iovec iov = { buf + i, (len - i) & ~page_mask, };
137 j = vmsplice (fd, &iov, 1, SPLICE_F_GIFT);
139 if (j == -1 && errno == ENOSYS) /* vmsplice() not supported */
141 j = write (fd, buf + i, len - i);
146 msg_Err (stream, "cannot write data (%m)");
151 vlc_cleanup_run (); /* free (buf) */
155 msg_Dbg (stream, "compressed stream at EOF");
156 /* Let child process know about EOF */
157 p_sys->write_fd = -1;
163 static int Peek (stream_t *, const uint8_t **, unsigned int);
165 #define MIN_BLOCK (1 << 10)
166 #define MAX_BLOCK (1 << 20)
168 * Reads decompressed from the decompression program
169 * @return -1 for EAGAIN, 0 for EOF, byte count otherwise.
171 static int Read (stream_t *stream, void *buf, unsigned int buflen)
173 stream_sys_t *p_sys = stream->p_sys;
177 if (buf == NULL) /* caller skips data, get big enough peek buffer */
178 buflen = Peek (stream, &(const uint8_t *){ NULL }, buflen);
180 if ((peeked = p_sys->peeked) != NULL)
181 { /* dequeue peeked data */
182 length = (buflen > peeked->i_buffer) ? peeked->i_buffer : buflen;
185 memcpy (buf, peeked->p_buffer, length);
186 buf = ((char *)buf) + length;
189 peeked->p_buffer += length;
190 peeked->i_buffer -= length;
191 if (peeked->i_buffer == 0)
193 block_Release (peeked);
194 p_sys->peeked = NULL;
196 p_sys->offset += length;
199 length += Read (stream, ((char *)buf) + length, buflen - length);
202 assert ((buf != NULL) || (buflen == 0));
204 length = net_Read (stream, p_sys->read_fd, NULL, buf, buflen, false);
207 p_sys->offset += length;
214 static int Peek (stream_t *stream, const uint8_t **pbuf, unsigned int len)
216 stream_sys_t *p_sys = stream->p_sys;
217 block_t *peeked = p_sys->peeked;
219 int fd = p_sys->read_fd;
222 peeked = block_Alloc (len);
223 else if ((curlen = peeked->i_buffer) < len)
224 peeked = block_Realloc (peeked, 0, len);
226 if ((p_sys->peeked = peeked) == NULL)
231 ssize_t val = net_Read (stream, fd, NULL, peeked->p_buffer + curlen,
236 peeked->i_buffer = curlen;
239 *pbuf = peeked->p_buffer;
246 static int Control (stream_t *stream, int query, va_list args)
248 stream_sys_t *p_sys = stream->p_sys;
252 case STREAM_CAN_SEEK:
253 case STREAM_CAN_FASTSEEK:
254 case STREAM_CAN_PAUSE: /* TODO: support pause */
255 *(va_arg (args, bool *)) = false;
257 case STREAM_CAN_CONTROL_PACE:
258 *(va_arg (args, bool *)) = p_sys->can_pace;
260 case STREAM_GET_POSITION:
261 *(va_arg (args, uint64_t *)) = p_sys->offset;
263 case STREAM_GET_SIZE:
264 *(va_arg (args, uint64_t *)) = 0;
273 * Pipe data through an external executable.
274 * @param stream the stream filter object.
275 * @param path path to the executable.
277 static int Open (stream_t *stream, const char *path)
279 stream_sys_t *p_sys = stream->p_sys = malloc (sizeof (*p_sys));
283 stream->pf_read = Read;
284 stream->pf_peek = Peek;
285 stream->pf_control = Control;
289 p_sys->peeked = NULL;
290 stream_Control (stream->p_source, STREAM_CAN_CONTROL_PACE,
293 /* I am not a big fan of the pyramid style, but I cannot think of anything
294 * better here. There are too many failure cases. */
295 int ret = VLC_EGENERIC;
298 /* We use two pipes rather than one stream socket pair, so that we can
299 * use vmsplice() on Linux. */
300 if (vlc_pipe (comp) == 0)
302 p_sys->write_fd = comp[1];
305 if (vlc_pipe (uncomp) == 0)
307 p_sys->read_fd = uncomp[0];
309 #if (_POSIX_SPAWN >= 0)
310 posix_spawn_file_actions_t actions;
311 if (posix_spawn_file_actions_init (&actions) == 0)
313 char *const argv[] = { (char *)path, NULL };
315 if (!posix_spawn_file_actions_adddup2 (&actions, comp[0], 0)
316 && !posix_spawn_file_actions_adddup2 (&actions, uncomp[1], 1)
317 && !posix_spawnp (&p_sys->pid, path, &actions, NULL, argv,
320 if (vlc_clone (&p_sys->thread, Thread, stream,
321 VLC_THREAD_PRIORITY_INPUT) == 0)
326 msg_Err (stream, "Cannot execute %s", path);
329 posix_spawn_file_actions_destroy (&actions);
331 #else /* _POSIX_SPAWN */
332 switch (p_sys->pid = fork ())
335 msg_Err (stream, "Cannot fork (%m)");
340 execlp (path, path, (char *)NULL);
341 exit (1); /* if we get, execlp() failed! */
343 if (vlc_clone (&p_sys->thread, Thread, stream,
344 VLC_THREAD_PRIORITY_INPUT) == 0)
347 #endif /* _POSIX_SPAWN < 0 */
349 if (ret != VLC_SUCCESS)
353 if (ret != VLC_SUCCESS)
357 if (ret == VLC_SUCCESS)
360 if (p_sys->pid != -1)
361 while (waitpid (p_sys->pid, &(int){ 0 }, 0) == -1);
368 * Releases allocate resources.
370 static void Close (vlc_object_t *obj)
372 stream_t *stream = (stream_t *)obj;
373 stream_sys_t *p_sys = stream->p_sys;
376 vlc_cancel (p_sys->thread);
377 close (p_sys->read_fd);
378 vlc_join (p_sys->thread, NULL);
379 if (p_sys->write_fd != -1)
380 /* Killed before EOF? */
381 close (p_sys->write_fd);
383 msg_Dbg (obj, "waiting for PID %u", (unsigned)p_sys->pid);
384 while (waitpid (p_sys->pid, &status, 0) == -1);
385 msg_Dbg (obj, "exit status %d", status);
388 block_Release (p_sys->peeked);
394 * Detects gzip file format
396 static int OpenGzip (vlc_object_t *obj)
398 stream_t *stream = (stream_t *)obj;
401 if (stream_Peek (stream->p_source, &peek, 3) < 3)
404 if (memcmp (peek, "\x1f\x8b\x08", 3))
407 msg_Dbg (obj, "detected gzip compressed stream");
408 return Open (stream, "zcat");
413 * Detects bzip2 file format
415 static int OpenBzip2 (vlc_object_t *obj)
417 stream_t *stream = (stream_t *)obj;
420 /* (Try to) parse the bzip2 header */
421 if (stream_Peek (stream->p_source, &peek, 10) < 10)
424 if (memcmp (peek, "BZh", 3) || (peek[3] < '1') || (peek[3] > '9')
425 || memcmp (peek + 4, "\x31\x41\x59\x26\x53\x59", 6))
428 msg_Dbg (obj, "detected bzip2 compressed stream");
429 return Open (stream, "bzcat");
433 * Detects xz file format
435 static int OpenXZ (vlc_object_t *obj)
437 stream_t *stream = (stream_t *)obj;
440 /* (Try to) parse the xz stream header */
441 if (stream_Peek (stream->p_source, &peek, 8) < 8)
444 if (memcmp (peek, "\xfd\x37\x7a\x58\x5a", 6))
447 msg_Dbg (obj, "detected xz compressed stream");
448 return Open (stream, "xzcat");