2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
25 #include "gstfilesrc.h"
34 /**********************************************************************
35 * GStreamer Default File Source
38 * This source uses mmap(2) to efficiently load data from a file.
39 * To do this without seriously polluting the applications' memory
40 * space, it must do so in smaller chunks, say 1-4MB at a time.
41 * Buffers are then subdivided from these mmap'd chunks, to directly
42 * make use of the mmap.
44 * To handle refcounting so that the mmap can be freed at the appropriate
45 * time, a buffer will be created for each mmap'd region, and all new
46 * buffers will be sub-buffers of this top-level buffer. As they are
47 * freed, the refcount goes down on the mmap'd buffer and its free()
48 * function is called, which will call munmap(2) on itself.
50 * If a buffer happens to cross the boundaries of an mmap'd region, we
51 * have to decide whether it's more efficient to copy the data into a
52 * new buffer, or mmap() just that buffer. There will have to be a
53 * breakpoint size to determine which will be done. The mmap() size
54 * has a lot to do with this as well, because you end up in double-
55 * jeopardy: the larger the outgoing buffer, the more data to copy when
56 * it overlaps, *and* the more frequently you'll have buffers that *do*
59 * Seeking is another tricky aspect to do efficiently. The initial
60 * implementation of this source won't make use of these features, however.
61 * The issue is that if an application seeks backwards in a file, *and*
62 * that region of the file is covered by an mmap that hasn't been fully
63 * deallocated, we really should re-use it. But keeping track of these
64 * regions is tricky because we have to lock the structure that holds
65 * them. We need to settle on a locking primitive (GMutex seems to be
66 * a really good option...), then we can do that.
70 GstElementDetails gst_filesrc_details = {
73 "Read from arbitrary point in a file",
75 "Erik Walthinsen <omega@cse.ogi.edu>",
79 //#define fs_print(format,args...) g_print(format, ## args)
80 #define fs_print(format,args...)
82 /* FileSrc signals and args */
100 static void gst_filesrc_class_init (GstFileSrcClass *klass);
101 static void gst_filesrc_init (GstFileSrc *filesrc);
103 static void gst_filesrc_set_property (GObject *object, guint prop_id,
104 const GValue *value, GParamSpec *pspec);
105 static void gst_filesrc_get_property (GObject *object, guint prop_id,
106 GValue *value, GParamSpec *pspec);
108 static GstBuffer * gst_filesrc_get (GstPad *pad);
109 static gboolean gst_filesrc_srcpad_event (GstPad *pad, GstEvent *event);
111 static GstElementStateReturn gst_filesrc_change_state (GstElement *element);
114 static GstElementClass *parent_class = NULL;
115 //static guint gst_filesrc_signals[LAST_SIGNAL] = { 0 };
118 gst_filesrc_get_type(void)
120 static GType filesrc_type = 0;
123 static const GTypeInfo filesrc_info = {
124 sizeof(GstFileSrcClass), NULL,
126 (GClassInitFunc)gst_filesrc_class_init,
131 (GInstanceInitFunc)gst_filesrc_init,
133 filesrc_type = g_type_register_static (GST_TYPE_ELEMENT, "GstFileSrc", &filesrc_info, 0);
139 gst_filesrc_class_init (GstFileSrcClass *klass)
141 GObjectClass *gobject_class;
142 GstElementClass *gstelement_class;
144 gobject_class = (GObjectClass*)klass;
145 gstelement_class = (GstElementClass*)klass;
147 parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
149 gst_element_install_std_props (
150 GST_ELEMENT_CLASS (klass),
151 "fd", ARG_FD, G_PARAM_READABLE,
152 "offset", ARG_OFFSET, G_PARAM_READWRITE,
153 "filesize", ARG_FILESIZE, G_PARAM_READABLE,
154 "location", ARG_LOCATION, G_PARAM_READWRITE,
155 "blocksize", ARG_BLOCKSIZE, G_PARAM_READWRITE,
156 "mmapsize", ARG_MAPSIZE, G_PARAM_READWRITE,
157 "touch", ARG_TOUCH, G_PARAM_READWRITE,
160 gobject_class->set_property = gst_filesrc_set_property;
161 gobject_class->get_property = gst_filesrc_get_property;
163 gstelement_class->change_state = gst_filesrc_change_state;
167 gst_filesrc_bufcmp (gconstpointer a, gconstpointer b)
169 // GstBuffer *bufa = (GstBuffer *)a, *bufb = (GstBuffer *)b;
171 // sort first by offset, then in reverse by size
172 if (GST_BUFFER_OFFSET(a) < GST_BUFFER_OFFSET(b)) return -1;
173 else if (GST_BUFFER_OFFSET(a) > GST_BUFFER_OFFSET(b)) return 1;
174 else if (GST_BUFFER_SIZE(a) > GST_BUFFER_SIZE(b)) return -1;
175 else if (GST_BUFFER_SIZE(a) < GST_BUFFER_SIZE(b)) return 1;
180 gst_filesrc_init (GstFileSrc *src)
182 src->srcpad = gst_pad_new ("src", GST_PAD_SRC);
183 gst_pad_set_get_function (src->srcpad,gst_filesrc_get);
184 gst_pad_set_event_function (src->srcpad,gst_filesrc_srcpad_event);
185 gst_element_add_pad (GST_ELEMENT (src), src->srcpad);
187 src->pagesize = getpagesize();
189 src->filename = NULL;
194 src->block_size = 4096;
198 src->mapsize = 4 * 1024 * 1024; // default is 4MB
200 src->map_regions = g_tree_new(gst_filesrc_bufcmp);
201 src->map_regions_lock = g_mutex_new();
203 src->seek_happened = FALSE;
208 gst_filesrc_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
212 /* it's not null if we got it, but it might not be ours */
213 g_return_if_fail (GST_IS_FILESRC (object));
215 src = GST_FILESRC (object);
219 /* the element must be stopped in order to do this */
220 g_return_if_fail (GST_STATE (src) < GST_STATE_PLAYING);
222 if (src->filename) g_free (src->filename);
223 /* clear the filename if we get a NULL (is that possible?) */
224 if (g_value_get_string (value) == NULL) {
225 gst_element_set_state (GST_ELEMENT (object), GST_STATE_NULL);
226 src->filename = NULL;
227 /* otherwise set the new filename */
229 src->filename = g_strdup (g_value_get_string (value));
233 src->block_size = g_value_get_ulong (value);
236 src->curoffset = g_value_get_int64 (value);
239 if ((src->mapsize % src->pagesize) == 0)
240 src->mapsize = g_value_get_ulong (value);
242 GST_INFO(0, "invalid mapsize, must a multiple of pagesize, which is %d\n",src->pagesize);
245 src->touch = g_value_get_boolean (value);
253 gst_filesrc_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
257 /* it's not null if we got it, but it might not be ours */
258 g_return_if_fail (GST_IS_FILESRC (object));
260 src = GST_FILESRC (object);
264 g_value_set_string (value, src->filename);
267 g_value_set_int64 (value, src->filelen);
270 g_value_set_int (value, src->fd);
273 g_value_set_ulong (value, src->block_size);
276 g_value_set_int64 (value, src->curoffset);
279 g_value_set_ulong (value, src->mapsize);
282 g_value_set_boolean (value, src->touch);
285 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
291 gst_filesrc_free_parent_mmap (GstBuffer *buf)
293 GstFileSrc *src = GST_FILESRC(GST_BUFFER_POOL_PRIVATE(buf));
295 fs_print ("freeing mmap()d buffer at %d+%d\n",GST_BUFFER_OFFSET(buf),GST_BUFFER_SIZE(buf));
297 // remove the buffer from the list of available mmap'd regions
298 g_mutex_lock(src->map_regions_lock);
299 g_tree_remove(src->map_regions,buf);
300 // check to see if the tree is empty
301 if (g_tree_nnodes(src->map_regions) == 0) {
302 // we have to free the bufferpool we don't have yet
304 g_mutex_unlock(src->map_regions_lock);
307 // madvise to tell the kernel what to do with it
308 madvise(GST_BUFFER_DATA(buf),GST_BUFFER_SIZE(buf),MADV_DONTNEED);
310 // now unmap the memory
311 munmap(GST_BUFFER_DATA(buf),GST_BUFFER_MAXSIZE(buf));
315 gst_filesrc_map_region (GstFileSrc *src, off_t offset, size_t size)
320 g_return_val_if_fail (offset >= 0, NULL);
322 fs_print ("mapping region %08lx+%08lx from file into memory\n",offset,size);
324 // time to allocate a new mapbuf
325 buf = gst_buffer_new();
326 // mmap() the data into this new buffer
327 GST_BUFFER_DATA(buf) = mmap (NULL, size, PROT_READ, MAP_SHARED, src->fd, offset);
328 if (GST_BUFFER_DATA(buf) == NULL) {
329 fprintf (stderr, "ERROR: gstfilesrc couldn't map file!\n");
330 } else if (GST_BUFFER_DATA(buf) == MAP_FAILED) {
331 g_error ("gstfilesrc mmap(0x%x, %d, 0x%llx) : %s",
332 size, src->fd, offset, sys_errlist[errno]);
334 #ifdef MADV_SEQUENTIAL
335 // madvise to tell the kernel what to do with it
336 retval = madvise(GST_BUFFER_DATA(buf),GST_BUFFER_SIZE(buf),MADV_SEQUENTIAL);
338 // fill in the rest of the fields
339 GST_BUFFER_FLAGS(buf) = GST_BUFFER_READONLY | GST_BUFFER_ORIGINAL;
340 GST_BUFFER_SIZE(buf) = size;
341 GST_BUFFER_MAXSIZE(buf) = size;
342 GST_BUFFER_OFFSET(buf) = offset;
343 GST_BUFFER_TIMESTAMP(buf) = -1LL;
344 GST_BUFFER_POOL_PRIVATE(buf) = src;
345 GST_BUFFER_FREE_FUNC(buf) = gst_filesrc_free_parent_mmap;
347 g_mutex_lock(src->map_regions_lock);
348 g_tree_insert(src->map_regions,buf,buf);
349 g_mutex_unlock(src->map_regions_lock);
355 gst_filesrc_map_small_region (GstFileSrc *src, off_t offset, size_t size)
361 // printf("attempting to map a small buffer at %d+%d\n",offset,size);
363 // if the offset starts at a non-page boundary, we have to special case
364 if ((mod = offset % src->pagesize)) {
367 mapbase = offset - mod;
368 mapsize = ((size + mod + src->pagesize - 1) / src->pagesize) * src->pagesize;
369 // printf("not on page boundaries, resizing map to %d+%d\n",mapbase,mapsize);
370 map = gst_filesrc_map_region(src, mapbase, mapsize);
371 ret = gst_buffer_create_sub (map, offset - mapbase, size);
373 gst_buffer_unref (map);
378 return gst_filesrc_map_region(src,offset,size);
386 // This allows us to search for a potential mmap region.
388 gst_filesrc_search_region_match (gpointer a, gpointer b)
390 GstFileSrcRegion *r = (GstFileSrcRegion *)b;
392 // trying to walk b down the tree, current node is a
393 if (r->offset < GST_BUFFER_OFFSET(a)) return -1;
394 else if (r->offset >= (GST_BUFFER_OFFSET(a) + GST_BUFFER_SIZE(a))) return 1;
395 else if ((r->offset + r->size) <= (GST_BUFFER_OFFSET(a) + GST_BUFFER_SIZE(a))) return 0;
402 * @pad: #GstPad to push a buffer from
404 * Push a new buffer from the filesrc at the current offset.
407 gst_filesrc_get (GstPad *pad)
410 GstBuffer *buf = NULL, *map;
412 off_t readend,mapstart,mapend;
413 GstFileSrcRegion region;
416 g_return_val_if_fail (pad != NULL, NULL);
417 src = GST_FILESRC (gst_pad_get_parent (pad));
418 g_return_val_if_fail (GST_FLAG_IS_SET (src, GST_FILESRC_OPEN), NULL);
421 if (src->seek_happened) {
422 src->seek_happened = FALSE;
423 return GST_BUFFER (gst_event_new(GST_EVENT_DISCONTINUOUS));
427 if (src->curoffset == src->filelen) {
428 gst_element_set_state (GST_ELEMENT (src), GST_STATE_PAUSED);
429 return GST_BUFFER (gst_event_new(GST_EVENT_EOS));
432 // calculate end pointers so we don't have to do so repeatedly later
433 readsize = src->block_size;
434 readend = src->curoffset + src->block_size; // note this is the byte *after* the read
435 mapstart = GST_BUFFER_OFFSET(src->mapbuf);
436 mapend = mapstart + GST_BUFFER_SIZE(src->mapbuf); // note this is the byte *after* the map
438 // check to see if we're going to overflow the end of the file
439 if (readend > src->filelen) {
440 readsize = src->filelen - src->curoffset;
441 readend = src->curoffset;
444 // if the start is past the mapstart
445 if (src->curoffset >= mapstart) {
446 // if the end is before the mapend, the buffer is in current mmap region...
447 // ('cause by definition if readend is in the buffer, so's readstart)
448 if (readend <= mapend) {
449 fs_print ("read buf %d+%d lives in current mapbuf %d+%d, creating subbuffer of mapbuf\n",
450 src->curoffset,readsize,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
451 buf = gst_buffer_create_sub (src->mapbuf, src->curoffset - GST_BUFFER_OFFSET(src->mapbuf),
454 // if the start actually is within the current mmap region, map an overlap buffer
455 } else if (src->curoffset < mapend) {
456 fs_print ("read buf %d+%d starts in mapbuf %d+%d but ends outside, creating new mmap\n",
457 src->curoffset,readsize,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
458 buf = gst_filesrc_map_small_region (src, src->curoffset, readsize);
461 // the only other option is that buffer is totally outside, which means we search for it
463 // now we can assume that the start is *before* the current mmap region
464 // if the readend is past mapstart, we have two options
465 } else if (readend >= mapstart) {
466 // either the read buffer overlaps the start of the mmap region
467 // or the read buffer fully contains the current mmap region
468 // either way, it's really not relevant, we just create a new region anyway
469 fs_print ("read buf %d+%d starts before mapbuf %d+%d, but overlaps it\n",
470 src->curoffset,readsize,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
471 buf = gst_filesrc_map_small_region (src, src->curoffset, readsize);
474 // then deal with the case where the read buffer is totally outside
476 // first check to see if there's a map that covers the right region already
477 fs_print ("searching for mapbuf to cover %d+%d\n",src->curoffset,readsize);
478 region.offset = src->curoffset;
479 region.size = readsize;
480 map = g_tree_search (src->map_regions,
481 (GCompareFunc) gst_filesrc_search_region_match,
484 // if we found an exact match, subbuffer it
486 fs_print ("found mapbuf at %d+%d, creating subbuffer\n",GST_BUFFER_OFFSET(map),GST_BUFFER_SIZE(map));
487 buf = gst_buffer_create_sub (map, src->curoffset - GST_BUFFER_OFFSET(map), readsize);
489 // otherwise we need to create something out of thin air
491 // if the read buffer crosses a mmap region boundary, create a one-off region
492 if ((src->curoffset / src->mapsize) != (readend / src->mapsize)) {
493 fs_print ("read buf %d+%d crosses a %d-byte boundary, creating a one-off\n",
494 src->curoffset,readsize,src->mapsize);
495 buf = gst_filesrc_map_small_region (src, src->curoffset, readsize);
497 // otherwise we will create a new mmap region and set it to the default
499 off_t nextmap = src->curoffset - (src->curoffset % src->mapsize);
500 fs_print ("read buf %d+%d in new mapbuf at %d+%d, mapping and subbuffering\n",
501 src->curoffset,readsize,nextmap,src->mapsize);
502 // first, we're done with the old mapbuf
503 gst_buffer_unref(src->mapbuf);
505 src->mapbuf = gst_filesrc_map_region (src, nextmap, src->mapsize);
507 buf = gst_buffer_create_sub (src->mapbuf, src->curoffset - GST_BUFFER_OFFSET(src->mapbuf), readsize);
512 /* if we need to touch the buffer (to bring it into memory), do so */
514 for (i=0;i<GST_BUFFER_SIZE(buf);i+=src->pagesize)
515 *(GST_BUFFER_DATA(buf)+i) = *(GST_BUFFER_DATA(buf)+i);
518 /* we're done, return the buffer */
519 src->curoffset += GST_BUFFER_SIZE(buf);
523 /* open the file and mmap it, necessary to go to READY state */
525 gst_filesrc_open_file (GstFileSrc *src)
527 g_return_val_if_fail (!GST_FLAG_IS_SET (src ,GST_FILESRC_OPEN), FALSE);
529 GST_DEBUG(0, "opening file %s\n",src->filename);
532 src->fd = open (src->filename, O_RDONLY);
535 gst_element_error (GST_ELEMENT (src), g_strconcat("opening file \"", src->filename, "\"", NULL));
538 /* find the file length */
539 src->filelen = lseek (src->fd, 0, SEEK_END);
540 lseek (src->fd, 0, SEEK_SET);
542 // allocate the first mmap'd region
543 src->mapbuf = gst_filesrc_map_region (src, 0, src->mapsize);
547 GST_FLAG_SET (src, GST_FILESRC_OPEN);
552 /* unmap and close the file */
554 gst_filesrc_close_file (GstFileSrc *src)
556 g_return_if_fail (GST_FLAG_IS_SET (src, GST_FILESRC_OPEN));
562 /* zero out a lot of our state */
567 GST_FLAG_UNSET (src, GST_FILESRC_OPEN);
571 static GstElementStateReturn
572 gst_filesrc_change_state (GstElement *element)
574 g_return_val_if_fail (GST_IS_FILESRC (element), GST_STATE_FAILURE);
576 if (GST_STATE_PENDING (element) == GST_STATE_NULL) {
577 if (GST_FLAG_IS_SET (element, GST_FILESRC_OPEN))
578 gst_filesrc_close_file (GST_FILESRC (element));
580 if (!GST_FLAG_IS_SET (element, GST_FILESRC_OPEN)) {
581 if (!gst_filesrc_open_file (GST_FILESRC (element)))
582 return GST_STATE_FAILURE;
586 if (GST_ELEMENT_CLASS (parent_class)->change_state)
587 return GST_ELEMENT_CLASS (parent_class)->change_state (element);
589 return GST_STATE_SUCCESS;
593 gst_filesrc_srcpad_event (GstPad *pad, GstEvent *event)
595 GstFileSrc *src = GST_FILESRC(GST_PAD_PARENT(pad));
597 switch (GST_EVENT_TYPE (event)) {
599 src->curoffset = (guint64) GST_EVENT_SEEK_OFFSET (event);
600 src->seek_happened = TRUE;
601 gst_event_free (event);
602 // push a discontinuous event?