added new gstfilesrc to replace disksrc eventually

Original commit message from CVS:
added new gstfilesrc to replace disksrc eventually

gst/elements/Makefile.am

@@ -15,6 +15,7 @@ libgstelements_la_SOURCES =	\
 	gstidentity.c		\
 	gstfakesink.c		\
 	gstdisksrc.c		\
+	gstfilesrc.c		\
 	gstdisksink.c		\
 	gstfdsrc.c		\
 	gstfdsink.c		\

gst/elements/gstelements.c

@@ -48,10 +48,16 @@ struct _elements_entry {
   gboolean (*factoryinit) (GstElementFactory *factory);
 };
 
+
+extern GtkType gst_filesrc_get_type(void);
+
+extern GstElementDetails *gst_filesrc_details;
+
 static struct _elements_entry _elements[] = {
   { "fakesrc", 	    gst_fakesrc_get_type, 	&gst_fakesrc_details,		gst_fakesrc_factory_init },
   { "fakesink",     gst_fakesink_get_type, 	&gst_fakesink_details,		gst_fakesink_factory_init },
   { "disksrc", 	    gst_disksrc_get_type, 	&gst_disksrc_details,		NULL },
+  { "filesrc", 	    gst_filesrc_get_type, 	&gst_filesrc_details,		NULL },
   { "disksink",	    gst_disksink_get_type,      &gst_disksink_details, 		NULL },
   { "identity",     gst_identity_get_type,  	&gst_identity_details,		NULL },
   { "fdsink",       gst_fdsink_get_type, 	&gst_fdsink_details,		NULL },

gst/elements/gstfilesrc.c

@@ -0,0 +1,547 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstfilesrc.c:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <gst/gst.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+
+/**********************************************************************
+ * GStreamer Default File Source
+ * Theory of Operation
+ *
+ * This source uses mmap(2) to efficiently load data from a file.
+ * To do this without seriously polluting the applications' memory
+ * space, it must do so in smaller chunks, say 1-4MB at a time.
+ * Buffers are then subdivided from these mmap'd chunks, to directly
+ * make use of the mmap.
+ *
+ * To handle refcounting so that the mmap can be freed at the appropriate
+ * time, a buffer will be created for each mmap'd region, and all new
+ * buffers will be sub-buffers of this top-level buffer.  As they are 
+ * freed, the refcount goes down on the mmap'd buffer and its free()
+ * function is called, which will call munmap(2) on itself.
+ *
+ * If a buffer happens to cross the boundaries of an mmap'd region, we
+ * have to decide whether it's more efficient to copy the data into a
+ * new buffer, or mmap() just that buffer.  There will have to be a
+ * breakpoint size to determine which will be done.  The mmap() size
+ * has a lot to do with this as well, because you end up in double-
+ * jeopardy: the larger the outgoing buffer, the more data to copy when
+ * it overlaps, *and* the more frequently you'll have buffers that *do*
+ * overlap.
+ *
+ * Seeking is another tricky aspect to do efficiently.  The initial
+ * implementation of this source won't make use of these features, however.
+ * The issue is that if an application seeks backwards in a file, *and*
+ * that region of the file is covered by an mmap that hasn't been fully
+ * deallocated, we really should re-use it.  But keeping track of these
+ * regions is tricky because we have to lock the structure that holds
+ * them.  We need to settle on a locking primitive (GMutex seems to be
+ * a really good option...), then we can do that.
+ */
+
+
+GstElementDetails gst_filesrc_details = {
+  "File Source",
+  "Source/File",
+  "Read from arbitrary point in a file",
+  VERSION,
+  "Erik Walthinsen <omega@cse.ogi.edu>",
+  "(C) 1999",
+};
+
+
+#define GST_TYPE_FILESRC \
+  (gst_filesrc_get_type())
+#define GST_FILESRC(obj) \
+  (GTK_CHECK_CAST((obj),GST_TYPE_FILESRC,GstFileSrc))
+#define GST_FILESRC_CLASS(klass) \
+  (GTK_CHECK_CLASS_CAST((klass),GST_TYPE_FILESRC,GstFileSrcClass)) 
+#define GST_IS_FILESRC(obj) \
+  (GTK_CHECK_TYPE((obj),GST_TYPE_FILESRC))
+#define GST_IS_FILESRC_CLASS(obj) \
+  (GTK_CHECK_CLASS_TYPE((klass),GST_TYPE_FILESRC))
+
+typedef enum {
+  GST_FILESRC_OPEN              = GST_ELEMENT_FLAG_LAST,
+
+  GST_FILESRC_FLAG_LAST = GST_ELEMENT_FLAG_LAST + 2,
+} GstFileSrcFlags;
+
+typedef struct _GstFileSrc GstFileSrc;
+typedef struct _GstFileSrcClass GstFileSrcClass;
+
+struct _GstFileSrc {
+  GstElement element;
+  GstPad *srcpad; 
+ 
+  gchar *filename;			// filename
+  gint fd;				// open file descriptor
+  off_t filelen;			// what's the file length?
+
+  off_t curoffset;			// current offset in file
+  off_t block_size;			// bytes per read
+
+  GstBuffer *mapbuf;
+  off_t mapsize;
+
+  GTree *map_regions;
+  GMutex *map_regions_lock;
+};
+
+struct _GstFileSrcClass {
+  GstElementClass parent_class;
+};
+
+
+/* FileSrc signals and args */
+enum {
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_LOCATION,
+  ARG_BLOCKSIZE,
+  ARG_OFFSET,
+  ARG_SIZE,
+};
+
+
+static void		gst_filesrc_class_init	(GstFileSrcClass *klass);
+static void		gst_filesrc_init	(GstFileSrc *filesrc);
+
+static void		gst_filesrc_set_arg	(GtkObject *object, GtkArg *arg, guint id);
+static void		gst_filesrc_get_arg	(GtkObject *object, GtkArg *arg, guint id);
+
+static GstBuffer *	gst_filesrc_get		(GstPad *pad);
+
+static GstElementStateReturn	gst_filesrc_change_state	(GstElement *element);
+
+
+static GstElementClass *parent_class = NULL;
+//static guint gst_filesrc_signals[LAST_SIGNAL] = { 0 };
+
+GtkType
+gst_filesrc_get_type(void)
+{
+  static GtkType filesrc_type = 0;
+
+  if (!filesrc_type) {
+    static const GtkTypeInfo filesrc_info = {
+      "GstFileSrc",
+      sizeof(GstFileSrc),
+      sizeof(GstFileSrcClass),
+      (GtkClassInitFunc)gst_filesrc_class_init,
+      (GtkObjectInitFunc)gst_filesrc_init,
+      (GtkArgSetFunc)gst_filesrc_set_arg,
+      (GtkArgGetFunc)gst_filesrc_get_arg,
+      (GtkClassInitFunc)NULL,
+    };
+    filesrc_type = gtk_type_unique (GST_TYPE_ELEMENT, &filesrc_info);
+  }
+  return filesrc_type;
+}
+
+static void
+gst_filesrc_class_init (GstFileSrcClass *klass)
+{
+  GtkObjectClass *gtkobject_class;
+  GstElementClass *gstelement_class;
+
+  gtkobject_class = (GtkObjectClass*)klass;
+  gstelement_class = (GstElementClass*)klass;
+
+  parent_class = gtk_type_class (GST_TYPE_ELEMENT);
+
+  gtk_object_add_arg_type ("GstFileSrc::location", GST_TYPE_FILENAME,
+                           GTK_ARG_READWRITE, ARG_LOCATION);
+  gtk_object_add_arg_type ("GstFileSrc::blocksize", GTK_TYPE_INT,
+                           GTK_ARG_READWRITE, ARG_BLOCKSIZE);
+  gtk_object_add_arg_type ("GstFileSrc::offset", GTK_TYPE_LONG,
+                           GTK_ARG_READWRITE, ARG_OFFSET);
+  gtk_object_add_arg_type ("GstFileSrc::size", GTK_TYPE_LONG,
+                           GTK_ARG_READABLE, ARG_SIZE);
+
+  gtkobject_class->set_arg = gst_filesrc_set_arg;
+  gtkobject_class->get_arg = gst_filesrc_get_arg;
+
+  gstelement_class->change_state = gst_filesrc_change_state;
+}
+
+static gint
+gst_filesrc_bufcmp (gconstpointer a, gconstpointer b)
+{
+//  GstBuffer *bufa = (GstBuffer *)a, *bufb = (GstBuffer *)b;
+
+  // sort first by offset, then in reverse by size
+  if (GST_BUFFER_OFFSET(a) < GST_BUFFER_OFFSET(b)) return -1;
+  else if (GST_BUFFER_OFFSET(a) > GST_BUFFER_OFFSET(b)) return 1;
+  else if (GST_BUFFER_SIZE(a) > GST_BUFFER_SIZE(b)) return -1;
+  else if (GST_BUFFER_SIZE(a) < GST_BUFFER_SIZE(b)) return 1;
+  else return 0;
+}
+
+static void
+gst_filesrc_init (GstFileSrc *src)
+{
+  src->srcpad = gst_pad_new ("src", GST_PAD_SRC);
+  gst_pad_set_get_function (src->srcpad,gst_filesrc_get);
+  gst_element_add_pad (GST_ELEMENT (src), src->srcpad);
+
+  src->filename = NULL;
+  src->fd = 0;
+  src->filelen = 0;
+
+  src->curoffset = 0;
+  src->block_size = 9216;
+
+  src->mapbuf = NULL;
+  src->mapsize = 1 * 1024 * 1024;		// default is 1MB
+
+  src->map_regions = g_tree_new(gst_filesrc_bufcmp);
+  src->map_regions_lock = g_mutex_new();
+}
+
+
+static void
+gst_filesrc_set_arg (GtkObject *object, GtkArg *arg, guint id)
+{
+  GstFileSrc *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_FILESRC (object));
+
+  src = GST_FILESRC (object);
+
+  switch(id) {
+    case ARG_LOCATION:
+      /* the element must be stopped in order to do this */
+      g_return_if_fail (GST_STATE (src) < GST_STATE_PLAYING);
+
+      if (src->filename) g_free (src->filename);
+      /* clear the filename if we get a NULL (is that possible?) */
+      if (GTK_VALUE_STRING (*arg) == NULL) {
+        gst_element_set_state (GST_ELEMENT (object), GST_STATE_NULL);
+        src->filename = NULL;
+      /* otherwise set the new filename */
+      } else {
+        src->filename = g_strdup (GTK_VALUE_STRING (*arg));
+      }
+      break;
+    case ARG_BLOCKSIZE:
+      src->block_size = GTK_VALUE_INT (*arg);
+      break;
+    case ARG_OFFSET:
+      src->curoffset = GTK_VALUE_LONG (*arg);
+      break;
+    default:
+      break;
+  }
+}
+
+static void
+gst_filesrc_get_arg (GtkObject *object, GtkArg *arg, guint id)
+{
+  GstFileSrc *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_FILESRC (object));
+
+  src = GST_FILESRC (object);
+
+  switch (id) {
+    case ARG_LOCATION:
+      GTK_VALUE_STRING (*arg) = src->filename;
+      break;
+    case ARG_BLOCKSIZE:
+      GTK_VALUE_INT (*arg) = src->block_size;
+      break;
+    case ARG_OFFSET:
+      GTK_VALUE_LONG (*arg) = src->curoffset;
+      break;
+    case ARG_SIZE:
+      GTK_VALUE_LONG (*arg) = src->filelen;
+      break;
+    default:
+      arg->type = GTK_TYPE_INVALID;
+      break;
+  }
+}
+
+static void
+gst_filesrc_free_parent_mmap (GstBuffer *buf)
+{
+  GstFileSrc *src = GST_FILESRC(GST_BUFFER_POOL_PRIVATE(buf));
+
+  // remove the buffer from the list of available mmap'd regions
+  g_mutex_lock(src->map_regions_lock);
+  g_tree_remove(src->map_regions,buf);
+  // check to see if the tree is empty
+  if (g_tree_nnodes(src->map_regions) == 0) {
+    // we have to free the bufferpool we don't have yet
+  }
+  g_mutex_unlock(src->map_regions_lock);
+
+  // now unmap the memory
+  munmap(GST_BUFFER_DATA(buf),GST_BUFFER_MAXSIZE(buf));
+}
+
+static GstBuffer *
+gst_filesrc_map_region (GstFileSrc *src, off_t offset, off_t size)
+{
+  GstBuffer *buf;
+
+  GST_DEBUG(0, "mapping region %d+%d from file into memory\n",offset,size);
+
+  // time to allocate a new mapbuf
+  buf = gst_buffer_new();
+  // mmap() the data into this new buffer
+  GST_BUFFER_DATA(buf) = mmap (NULL, size, PROT_READ, MAP_SHARED, src->fd, offset);
+  if (GST_BUFFER_DATA(buf) == NULL) {
+    fprintf(stderr, "ERROR: gstfilesrc couldn't map file!\n");
+  } else if (GST_BUFFER_DATA(buf) == -1) {
+    perror("gstfilesrc:mmap()");
+  }
+  // fill in the rest of the fields
+  GST_BUFFER_FLAGS(buf) = GST_BUFFER_READONLY | GST_BUFFER_ORIGINAL;
+  GST_BUFFER_SIZE(buf) = size;
+  GST_BUFFER_MAXSIZE(buf) = size;
+  GST_BUFFER_OFFSET(buf) = offset;
+  GST_BUFFER_TIMESTAMP(buf) = -1LL;
+  GST_BUFFER_POOL_PRIVATE(buf) = src;
+  GST_BUFFER_FREE_FUNC(buf) = gst_filesrc_free_parent_mmap;
+
+  g_mutex_lock(src->map_regions_lock);
+  g_tree_insert(src->map_regions,buf,buf);
+  g_mutex_unlock(src->map_regions_lock);
+
+  return buf;
+}
+
+static GstBuffer *
+gst_filesrc_map_small_region (GstFileSrc *src, off_t offset, off_t size)
+{
+  gint pagesize = getpagesize();
+  int mod, mapbase, mapsize;
+  GstBuffer *map;
+
+//  printf("attempting to map a small buffer at %d+%d\n",offset,size);
+
+  // if the offset starts at a non-page boundary, we have to special case
+  if ((mod = offset % pagesize)) {
+    mapbase = offset - mod;
+    mapsize = (((mapbase + size + mod) + (pagesize - 1)) / pagesize) * pagesize - mapbase;
+//    printf("not on page boundaries, resizing map to %d+%d\n",mapbase,mapsize);
+    map = gst_filesrc_map_region(src, mapbase, mapsize);
+    return gst_buffer_create_sub (map, offset - mapbase, size);
+  }
+
+  return gst_filesrc_map_region(src,offset,size);
+}
+
+typedef struct {
+  off_t offset;
+  off_t size;
+} GstFileSrcRegion;
+
+// This allows us to search for a potential mmap region.
+static gint
+gst_filesrc_search_region_match (gpointer a, gpointer b)
+{
+  GstFileSrcRegion *r = (GstFileSrcRegion *)b;
+
+  // trying to walk b down the tree, current node is a
+  if (r->offset < GST_BUFFER_OFFSET(a)) return -1;
+  else if (r->offset >= (GST_BUFFER_OFFSET(a) + GST_BUFFER_SIZE(a))) return 1;
+  else if ((r->offset + r->size) <= (GST_BUFFER_OFFSET(a) + GST_BUFFER_SIZE(a))) return 0;
+
+  return -2;
+}
+
+/**
+ * gst_filesrc_get:
+ * @pad: #GstPad to push a buffer from
+ *
+ * Push a new buffer from the filesrc at the current offset.
+ */
+static GstBuffer *
+gst_filesrc_get (GstPad *pad)
+{
+  GstFileSrc *src;
+  GstBuffer *buf = NULL, *map;
+  off_t readend,mapstart,mapend;
+  GstFileSrcRegion region;
+
+  g_return_val_if_fail (pad != NULL, NULL);
+  src = GST_FILESRC (gst_pad_get_parent (pad));
+  g_return_val_if_fail (GST_FLAG_IS_SET (src, GST_FILESRC_OPEN), NULL);
+
+  // calculate end poiters so we don't have to do so repeatedly later
+  readend = src->curoffset + src->block_size;		// note this is the byte *after* the read
+  mapstart = GST_BUFFER_OFFSET(src->mapbuf);
+  mapend = mapstart + GST_BUFFER_SIZE(src->mapbuf);	// note this is the byte *after* the map
+
+  // if the start is past the mapstart
+  if (src->curoffset >= mapstart) {
+    // if the end is before the mapend, the buffer is in current mmap region...
+    // ('cause by definition if readend is in the buffer, so's readstart)
+    if (readend <= mapend) {
+//      printf("read buf %d+%d lives in current mapbuf %d+%d, creating subbuffer of mapbuf\n",
+//             src->curoffset,src->block_size,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
+      buf = gst_buffer_create_sub (src->mapbuf, src->curoffset - GST_BUFFER_OFFSET(src->mapbuf),
+                                   src->block_size);
+
+    // if the start actually is within the current mmap region, map an overlap buffer
+    } else if (src->curoffset < mapend) {
+//      printf("read buf %d+%d starts in mapbuf %d+%d but ends outside, creating new mmap\n",
+//             src->curoffset,src->block_size,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
+      buf = gst_filesrc_map_small_region (src, src->curoffset, src->block_size);
+    }
+
+    // the only other option is that buffer is totally outside, which means we search for it
+
+  // now we can assume that the start is *before* the current mmap region
+  // if the readend is past mapstart, we have two options
+  } else if (readend >= mapstart) {
+    // either the read buffer overlaps the start of the mmap region
+    // or the read buffer fully contains the current mmap region
+    // either way, it's really not relevant, we just create a new region anyway
+//    printf("read buf %d+%d starts before mapbuf %d+%d, but overlaps it\n",
+//             src->curoffset,src->block_size,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
+    buf = gst_filesrc_map_small_region (src, src->curoffset, src->block_size);
+  }
+
+  // then deal with the case where the read buffer is totally outside
+  if (buf == NULL) {
+    // first check to see if there's a map that covers the right region already
+//    printf("searching for mapbuf to cover %d+%d\n",src->curoffset,src->block_size);
+    region.offset = src->curoffset;
+    region.size = src->block_size;
+    map = g_tree_search(src->map_regions,gst_filesrc_search_region_match,&region);
+
+    // if we found an exact match, subbuffer it
+    if (map != NULL) {
+//      printf("found mapbuf at %d+%d, creating subbuffer\n",GST_BUFFER_OFFSET(map),GST_BUFFER_SIZE(map));
+      buf = gst_buffer_create_sub (map, src->curoffset - GST_BUFFER_OFFSET(map), src->block_size);
+
+    // otherwise we need to create something out of thin air
+    } else {
+      // if the read buffer crosses a mmap region boundary, create a one-off region
+      if ((src->curoffset / src->mapsize) != ((src->curoffset + src->block_size) / src->mapsize)) {
+//        printf("read buf %d+%d crosses a %d-byte boundary, creating a one-off\n",
+//               src->curoffset,src->block_size,src->mapsize);
+        buf = gst_filesrc_map_small_region (src, src->curoffset, src->block_size);
+
+      // otherwise we will create a new mmap region and set it to the default
+      } else {
+        off_t nextmap = src->curoffset - (src->curoffset % src->mapsize);
+//        printf("read buf %d+%d in new mapbuf at %d+%d, mapping and subbuffering\n",
+//               src->curoffset,src->block_size,nextmap,src->mapsize);
+        // first, we're done with the old mapbuf
+        gst_buffer_unref(src->mapbuf);
+        // create a new one
+        src->mapbuf = gst_filesrc_map_region (src, nextmap, src->mapsize);
+        // subbuffer it
+        buf = gst_buffer_create_sub (src->mapbuf, src->curoffset - GST_BUFFER_OFFSET(src->mapbuf), src->block_size);
+      }
+    }
+  }
+
+  /* we're done, return the buffer */
+  src->curoffset += GST_BUFFER_SIZE(buf);
+  return buf;
+}
+
+/* open the file and mmap it, necessary to go to READY state */
+static gboolean 
+gst_filesrc_open_file (GstFileSrc *src)
+{
+  g_return_val_if_fail (!GST_FLAG_IS_SET (src ,GST_FILESRC_OPEN), FALSE);
+
+  GST_DEBUG(0, "opening file %s\n",src->filename);
+
+  /* open the file */
+  src->fd = open (src->filename, O_RDONLY);
+  if (src->fd < 0) {
+    perror ("open");
+    gst_element_error (GST_ELEMENT (src), g_strconcat("opening file \"", src->filename, "\"", NULL));
+    return FALSE;
+  } else {
+    /* find the file length */
+    src->filelen = lseek (src->fd, 0, SEEK_END);
+    lseek (src->fd, 0, SEEK_SET);
+
+    // allocate the first mmap'd region
+    src->mapbuf = gst_filesrc_map_region (src, 0, src->mapsize);
+
+    src->curoffset = 0;
+
+    GST_FLAG_SET (src, GST_FILESRC_OPEN);
+  }
+  return TRUE;
+}
+
+/* unmap and close the file */
+static void
+gst_filesrc_close_file (GstFileSrc *src)
+{
+  g_return_if_fail (GST_FLAG_IS_SET (src, GST_FILESRC_OPEN));
+
+  /* close the file */
+  close (src->fd);
+
+  /* zero out a lot of our state */
+  src->fd = 0;
+  src->filelen = 0;
+  src->curoffset = 0;
+
+  GST_FLAG_UNSET (src, GST_FILESRC_OPEN);
+}
+
+
+static GstElementStateReturn
+gst_filesrc_change_state (GstElement *element)
+{
+  g_return_val_if_fail (GST_IS_FILESRC (element), GST_STATE_FAILURE);
+
+  if (GST_STATE_PENDING (element) == GST_STATE_NULL) {
+    if (GST_FLAG_IS_SET (element, GST_FILESRC_OPEN))
+      gst_filesrc_close_file (GST_FILESRC (element));
+  } else {
+    if (!GST_FLAG_IS_SET (element, GST_FILESRC_OPEN)) {
+      if (!gst_filesrc_open_file (GST_FILESRC (element)))
+        return GST_STATE_FAILURE;
+    }
+  }
+
+  if (GST_ELEMENT_CLASS (parent_class)->change_state)
+    return GST_ELEMENT_CLASS (parent_class)->change_state (element);
+
+  return GST_STATE_SUCCESS;
+}

plugins/elements/Makefile.am

@@ -15,6 +15,7 @@ libgstelements_la_SOURCES =	\
 	gstidentity.c		\
 	gstfakesink.c		\
 	gstdisksrc.c		\
+	gstfilesrc.c		\
 	gstdisksink.c		\
 	gstfdsrc.c		\
 	gstfdsink.c		\

plugins/elements/gstelements.c

@@ -48,10 +48,16 @@ struct _elements_entry {
   gboolean (*factoryinit) (GstElementFactory *factory);
 };
 
+
+extern GtkType gst_filesrc_get_type(void);
+
+extern GstElementDetails *gst_filesrc_details;
+
 static struct _elements_entry _elements[] = {
   { "fakesrc", 	    gst_fakesrc_get_type, 	&gst_fakesrc_details,		gst_fakesrc_factory_init },
   { "fakesink",     gst_fakesink_get_type, 	&gst_fakesink_details,		gst_fakesink_factory_init },
   { "disksrc", 	    gst_disksrc_get_type, 	&gst_disksrc_details,		NULL },
+  { "filesrc", 	    gst_filesrc_get_type, 	&gst_filesrc_details,		NULL },
   { "disksink",	    gst_disksink_get_type,      &gst_disksink_details, 		NULL },
   { "identity",     gst_identity_get_type,  	&gst_identity_details,		NULL },
   { "fdsink",       gst_fdsink_get_type, 	&gst_fdsink_details,		NULL },

plugins/elements/gstfilesrc.c

@@ -0,0 +1,547 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstfilesrc.c:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <gst/gst.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+
+/**********************************************************************
+ * GStreamer Default File Source
+ * Theory of Operation
+ *
+ * This source uses mmap(2) to efficiently load data from a file.
+ * To do this without seriously polluting the applications' memory
+ * space, it must do so in smaller chunks, say 1-4MB at a time.
+ * Buffers are then subdivided from these mmap'd chunks, to directly
+ * make use of the mmap.
+ *
+ * To handle refcounting so that the mmap can be freed at the appropriate
+ * time, a buffer will be created for each mmap'd region, and all new
+ * buffers will be sub-buffers of this top-level buffer.  As they are 
+ * freed, the refcount goes down on the mmap'd buffer and its free()
+ * function is called, which will call munmap(2) on itself.
+ *
+ * If a buffer happens to cross the boundaries of an mmap'd region, we
+ * have to decide whether it's more efficient to copy the data into a
+ * new buffer, or mmap() just that buffer.  There will have to be a
+ * breakpoint size to determine which will be done.  The mmap() size
+ * has a lot to do with this as well, because you end up in double-
+ * jeopardy: the larger the outgoing buffer, the more data to copy when
+ * it overlaps, *and* the more frequently you'll have buffers that *do*
+ * overlap.
+ *
+ * Seeking is another tricky aspect to do efficiently.  The initial
+ * implementation of this source won't make use of these features, however.
+ * The issue is that if an application seeks backwards in a file, *and*
+ * that region of the file is covered by an mmap that hasn't been fully
+ * deallocated, we really should re-use it.  But keeping track of these
+ * regions is tricky because we have to lock the structure that holds
+ * them.  We need to settle on a locking primitive (GMutex seems to be
+ * a really good option...), then we can do that.
+ */
+
+
+GstElementDetails gst_filesrc_details = {
+  "File Source",
+  "Source/File",
+  "Read from arbitrary point in a file",
+  VERSION,
+  "Erik Walthinsen <omega@cse.ogi.edu>",
+  "(C) 1999",
+};
+
+
+#define GST_TYPE_FILESRC \
+  (gst_filesrc_get_type())
+#define GST_FILESRC(obj) \
+  (GTK_CHECK_CAST((obj),GST_TYPE_FILESRC,GstFileSrc))
+#define GST_FILESRC_CLASS(klass) \
+  (GTK_CHECK_CLASS_CAST((klass),GST_TYPE_FILESRC,GstFileSrcClass)) 
+#define GST_IS_FILESRC(obj) \
+  (GTK_CHECK_TYPE((obj),GST_TYPE_FILESRC))
+#define GST_IS_FILESRC_CLASS(obj) \
+  (GTK_CHECK_CLASS_TYPE((klass),GST_TYPE_FILESRC))
+
+typedef enum {
+  GST_FILESRC_OPEN              = GST_ELEMENT_FLAG_LAST,
+
+  GST_FILESRC_FLAG_LAST = GST_ELEMENT_FLAG_LAST + 2,
+} GstFileSrcFlags;
+
+typedef struct _GstFileSrc GstFileSrc;
+typedef struct _GstFileSrcClass GstFileSrcClass;
+
+struct _GstFileSrc {
+  GstElement element;
+  GstPad *srcpad; 
+ 
+  gchar *filename;			// filename
+  gint fd;				// open file descriptor
+  off_t filelen;			// what's the file length?
+
+  off_t curoffset;			// current offset in file
+  off_t block_size;			// bytes per read
+
+  GstBuffer *mapbuf;
+  off_t mapsize;
+
+  GTree *map_regions;
+  GMutex *map_regions_lock;
+};
+
+struct _GstFileSrcClass {
+  GstElementClass parent_class;
+};
+
+
+/* FileSrc signals and args */
+enum {
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_LOCATION,
+  ARG_BLOCKSIZE,
+  ARG_OFFSET,
+  ARG_SIZE,
+};
+
+
+static void		gst_filesrc_class_init	(GstFileSrcClass *klass);
+static void		gst_filesrc_init	(GstFileSrc *filesrc);
+
+static void		gst_filesrc_set_arg	(GtkObject *object, GtkArg *arg, guint id);
+static void		gst_filesrc_get_arg	(GtkObject *object, GtkArg *arg, guint id);
+
+static GstBuffer *	gst_filesrc_get		(GstPad *pad);
+
+static GstElementStateReturn	gst_filesrc_change_state	(GstElement *element);
+
+
+static GstElementClass *parent_class = NULL;
+//static guint gst_filesrc_signals[LAST_SIGNAL] = { 0 };
+
+GtkType
+gst_filesrc_get_type(void)
+{
+  static GtkType filesrc_type = 0;
+
+  if (!filesrc_type) {
+    static const GtkTypeInfo filesrc_info = {
+      "GstFileSrc",
+      sizeof(GstFileSrc),
+      sizeof(GstFileSrcClass),
+      (GtkClassInitFunc)gst_filesrc_class_init,
+      (GtkObjectInitFunc)gst_filesrc_init,
+      (GtkArgSetFunc)gst_filesrc_set_arg,
+      (GtkArgGetFunc)gst_filesrc_get_arg,
+      (GtkClassInitFunc)NULL,
+    };
+    filesrc_type = gtk_type_unique (GST_TYPE_ELEMENT, &filesrc_info);
+  }
+  return filesrc_type;
+}
+
+static void
+gst_filesrc_class_init (GstFileSrcClass *klass)
+{
+  GtkObjectClass *gtkobject_class;
+  GstElementClass *gstelement_class;
+
+  gtkobject_class = (GtkObjectClass*)klass;
+  gstelement_class = (GstElementClass*)klass;
+
+  parent_class = gtk_type_class (GST_TYPE_ELEMENT);
+
+  gtk_object_add_arg_type ("GstFileSrc::location", GST_TYPE_FILENAME,
+                           GTK_ARG_READWRITE, ARG_LOCATION);
+  gtk_object_add_arg_type ("GstFileSrc::blocksize", GTK_TYPE_INT,
+                           GTK_ARG_READWRITE, ARG_BLOCKSIZE);
+  gtk_object_add_arg_type ("GstFileSrc::offset", GTK_TYPE_LONG,
+                           GTK_ARG_READWRITE, ARG_OFFSET);
+  gtk_object_add_arg_type ("GstFileSrc::size", GTK_TYPE_LONG,
+                           GTK_ARG_READABLE, ARG_SIZE);
+
+  gtkobject_class->set_arg = gst_filesrc_set_arg;
+  gtkobject_class->get_arg = gst_filesrc_get_arg;
+
+  gstelement_class->change_state = gst_filesrc_change_state;
+}
+
+static gint
+gst_filesrc_bufcmp (gconstpointer a, gconstpointer b)
+{
+//  GstBuffer *bufa = (GstBuffer *)a, *bufb = (GstBuffer *)b;
+
+  // sort first by offset, then in reverse by size
+  if (GST_BUFFER_OFFSET(a) < GST_BUFFER_OFFSET(b)) return -1;
+  else if (GST_BUFFER_OFFSET(a) > GST_BUFFER_OFFSET(b)) return 1;
+  else if (GST_BUFFER_SIZE(a) > GST_BUFFER_SIZE(b)) return -1;
+  else if (GST_BUFFER_SIZE(a) < GST_BUFFER_SIZE(b)) return 1;
+  else return 0;
+}
+
+static void
+gst_filesrc_init (GstFileSrc *src)
+{
+  src->srcpad = gst_pad_new ("src", GST_PAD_SRC);
+  gst_pad_set_get_function (src->srcpad,gst_filesrc_get);
+  gst_element_add_pad (GST_ELEMENT (src), src->srcpad);
+
+  src->filename = NULL;
+  src->fd = 0;
+  src->filelen = 0;
+
+  src->curoffset = 0;
+  src->block_size = 9216;
+
+  src->mapbuf = NULL;
+  src->mapsize = 1 * 1024 * 1024;		// default is 1MB
+
+  src->map_regions = g_tree_new(gst_filesrc_bufcmp);
+  src->map_regions_lock = g_mutex_new();
+}
+
+
+static void
+gst_filesrc_set_arg (GtkObject *object, GtkArg *arg, guint id)
+{
+  GstFileSrc *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_FILESRC (object));
+
+  src = GST_FILESRC (object);
+
+  switch(id) {
+    case ARG_LOCATION:
+      /* the element must be stopped in order to do this */
+      g_return_if_fail (GST_STATE (src) < GST_STATE_PLAYING);
+
+      if (src->filename) g_free (src->filename);
+      /* clear the filename if we get a NULL (is that possible?) */
+      if (GTK_VALUE_STRING (*arg) == NULL) {
+        gst_element_set_state (GST_ELEMENT (object), GST_STATE_NULL);
+        src->filename = NULL;
+      /* otherwise set the new filename */
+      } else {
+        src->filename = g_strdup (GTK_VALUE_STRING (*arg));
+      }
+      break;
+    case ARG_BLOCKSIZE:
+      src->block_size = GTK_VALUE_INT (*arg);
+      break;
+    case ARG_OFFSET:
+      src->curoffset = GTK_VALUE_LONG (*arg);
+      break;
+    default:
+      break;
+  }
+}
+
+static void
+gst_filesrc_get_arg (GtkObject *object, GtkArg *arg, guint id)
+{
+  GstFileSrc *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_FILESRC (object));
+
+  src = GST_FILESRC (object);
+
+  switch (id) {
+    case ARG_LOCATION:
+      GTK_VALUE_STRING (*arg) = src->filename;
+      break;
+    case ARG_BLOCKSIZE:
+      GTK_VALUE_INT (*arg) = src->block_size;
+      break;
+    case ARG_OFFSET:
+      GTK_VALUE_LONG (*arg) = src->curoffset;
+      break;
+    case ARG_SIZE:
+      GTK_VALUE_LONG (*arg) = src->filelen;
+      break;
+    default:
+      arg->type = GTK_TYPE_INVALID;
+      break;
+  }
+}
+
+static void
+gst_filesrc_free_parent_mmap (GstBuffer *buf)
+{
+  GstFileSrc *src = GST_FILESRC(GST_BUFFER_POOL_PRIVATE(buf));
+
+  // remove the buffer from the list of available mmap'd regions
+  g_mutex_lock(src->map_regions_lock);
+  g_tree_remove(src->map_regions,buf);
+  // check to see if the tree is empty
+  if (g_tree_nnodes(src->map_regions) == 0) {
+    // we have to free the bufferpool we don't have yet
+  }
+  g_mutex_unlock(src->map_regions_lock);
+
+  // now unmap the memory
+  munmap(GST_BUFFER_DATA(buf),GST_BUFFER_MAXSIZE(buf));
+}
+
+static GstBuffer *
+gst_filesrc_map_region (GstFileSrc *src, off_t offset, off_t size)
+{
+  GstBuffer *buf;
+
+  GST_DEBUG(0, "mapping region %d+%d from file into memory\n",offset,size);
+
+  // time to allocate a new mapbuf
+  buf = gst_buffer_new();
+  // mmap() the data into this new buffer
+  GST_BUFFER_DATA(buf) = mmap (NULL, size, PROT_READ, MAP_SHARED, src->fd, offset);
+  if (GST_BUFFER_DATA(buf) == NULL) {
+    fprintf(stderr, "ERROR: gstfilesrc couldn't map file!\n");
+  } else if (GST_BUFFER_DATA(buf) == -1) {
+    perror("gstfilesrc:mmap()");
+  }
+  // fill in the rest of the fields
+  GST_BUFFER_FLAGS(buf) = GST_BUFFER_READONLY | GST_BUFFER_ORIGINAL;
+  GST_BUFFER_SIZE(buf) = size;
+  GST_BUFFER_MAXSIZE(buf) = size;
+  GST_BUFFER_OFFSET(buf) = offset;
+  GST_BUFFER_TIMESTAMP(buf) = -1LL;
+  GST_BUFFER_POOL_PRIVATE(buf) = src;
+  GST_BUFFER_FREE_FUNC(buf) = gst_filesrc_free_parent_mmap;
+
+  g_mutex_lock(src->map_regions_lock);
+  g_tree_insert(src->map_regions,buf,buf);
+  g_mutex_unlock(src->map_regions_lock);
+
+  return buf;
+}
+
+static GstBuffer *
+gst_filesrc_map_small_region (GstFileSrc *src, off_t offset, off_t size)
+{
+  gint pagesize = getpagesize();
+  int mod, mapbase, mapsize;
+  GstBuffer *map;
+
+//  printf("attempting to map a small buffer at %d+%d\n",offset,size);
+
+  // if the offset starts at a non-page boundary, we have to special case
+  if ((mod = offset % pagesize)) {
+    mapbase = offset - mod;
+    mapsize = (((mapbase + size + mod) + (pagesize - 1)) / pagesize) * pagesize - mapbase;
+//    printf("not on page boundaries, resizing map to %d+%d\n",mapbase,mapsize);
+    map = gst_filesrc_map_region(src, mapbase, mapsize);
+    return gst_buffer_create_sub (map, offset - mapbase, size);
+  }
+
+  return gst_filesrc_map_region(src,offset,size);
+}
+
+typedef struct {
+  off_t offset;
+  off_t size;
+} GstFileSrcRegion;
+
+// This allows us to search for a potential mmap region.
+static gint
+gst_filesrc_search_region_match (gpointer a, gpointer b)
+{
+  GstFileSrcRegion *r = (GstFileSrcRegion *)b;
+
+  // trying to walk b down the tree, current node is a
+  if (r->offset < GST_BUFFER_OFFSET(a)) return -1;
+  else if (r->offset >= (GST_BUFFER_OFFSET(a) + GST_BUFFER_SIZE(a))) return 1;
+  else if ((r->offset + r->size) <= (GST_BUFFER_OFFSET(a) + GST_BUFFER_SIZE(a))) return 0;
+
+  return -2;
+}
+
+/**
+ * gst_filesrc_get:
+ * @pad: #GstPad to push a buffer from
+ *
+ * Push a new buffer from the filesrc at the current offset.
+ */
+static GstBuffer *
+gst_filesrc_get (GstPad *pad)
+{
+  GstFileSrc *src;
+  GstBuffer *buf = NULL, *map;
+  off_t readend,mapstart,mapend;
+  GstFileSrcRegion region;
+
+  g_return_val_if_fail (pad != NULL, NULL);
+  src = GST_FILESRC (gst_pad_get_parent (pad));
+  g_return_val_if_fail (GST_FLAG_IS_SET (src, GST_FILESRC_OPEN), NULL);
+
+  // calculate end poiters so we don't have to do so repeatedly later
+  readend = src->curoffset + src->block_size;		// note this is the byte *after* the read
+  mapstart = GST_BUFFER_OFFSET(src->mapbuf);
+  mapend = mapstart + GST_BUFFER_SIZE(src->mapbuf);	// note this is the byte *after* the map
+
+  // if the start is past the mapstart
+  if (src->curoffset >= mapstart) {
+    // if the end is before the mapend, the buffer is in current mmap region...
+    // ('cause by definition if readend is in the buffer, so's readstart)
+    if (readend <= mapend) {
+//      printf("read buf %d+%d lives in current mapbuf %d+%d, creating subbuffer of mapbuf\n",
+//             src->curoffset,src->block_size,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
+      buf = gst_buffer_create_sub (src->mapbuf, src->curoffset - GST_BUFFER_OFFSET(src->mapbuf),
+                                   src->block_size);
+
+    // if the start actually is within the current mmap region, map an overlap buffer
+    } else if (src->curoffset < mapend) {
+//      printf("read buf %d+%d starts in mapbuf %d+%d but ends outside, creating new mmap\n",
+//             src->curoffset,src->block_size,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
+      buf = gst_filesrc_map_small_region (src, src->curoffset, src->block_size);
+    }
+
+    // the only other option is that buffer is totally outside, which means we search for it
+
+  // now we can assume that the start is *before* the current mmap region
+  // if the readend is past mapstart, we have two options
+  } else if (readend >= mapstart) {
+    // either the read buffer overlaps the start of the mmap region
+    // or the read buffer fully contains the current mmap region
+    // either way, it's really not relevant, we just create a new region anyway
+//    printf("read buf %d+%d starts before mapbuf %d+%d, but overlaps it\n",
+//             src->curoffset,src->block_size,GST_BUFFER_OFFSET(src->mapbuf),GST_BUFFER_SIZE(src->mapbuf));
+    buf = gst_filesrc_map_small_region (src, src->curoffset, src->block_size);
+  }
+
+  // then deal with the case where the read buffer is totally outside
+  if (buf == NULL) {
+    // first check to see if there's a map that covers the right region already
+//    printf("searching for mapbuf to cover %d+%d\n",src->curoffset,src->block_size);
+    region.offset = src->curoffset;
+    region.size = src->block_size;
+    map = g_tree_search(src->map_regions,gst_filesrc_search_region_match,&region);
+
+    // if we found an exact match, subbuffer it
+    if (map != NULL) {
+//      printf("found mapbuf at %d+%d, creating subbuffer\n",GST_BUFFER_OFFSET(map),GST_BUFFER_SIZE(map));
+      buf = gst_buffer_create_sub (map, src->curoffset - GST_BUFFER_OFFSET(map), src->block_size);
+
+    // otherwise we need to create something out of thin air
+    } else {
+      // if the read buffer crosses a mmap region boundary, create a one-off region
+      if ((src->curoffset / src->mapsize) != ((src->curoffset + src->block_size) / src->mapsize)) {
+//        printf("read buf %d+%d crosses a %d-byte boundary, creating a one-off\n",
+//               src->curoffset,src->block_size,src->mapsize);
+        buf = gst_filesrc_map_small_region (src, src->curoffset, src->block_size);
+
+      // otherwise we will create a new mmap region and set it to the default
+      } else {
+        off_t nextmap = src->curoffset - (src->curoffset % src->mapsize);
+//        printf("read buf %d+%d in new mapbuf at %d+%d, mapping and subbuffering\n",
+//               src->curoffset,src->block_size,nextmap,src->mapsize);
+        // first, we're done with the old mapbuf
+        gst_buffer_unref(src->mapbuf);
+        // create a new one
+        src->mapbuf = gst_filesrc_map_region (src, nextmap, src->mapsize);
+        // subbuffer it
+        buf = gst_buffer_create_sub (src->mapbuf, src->curoffset - GST_BUFFER_OFFSET(src->mapbuf), src->block_size);
+      }
+    }
+  }
+
+  /* we're done, return the buffer */
+  src->curoffset += GST_BUFFER_SIZE(buf);
+  return buf;
+}
+
+/* open the file and mmap it, necessary to go to READY state */
+static gboolean 
+gst_filesrc_open_file (GstFileSrc *src)
+{
+  g_return_val_if_fail (!GST_FLAG_IS_SET (src ,GST_FILESRC_OPEN), FALSE);
+
+  GST_DEBUG(0, "opening file %s\n",src->filename);
+
+  /* open the file */
+  src->fd = open (src->filename, O_RDONLY);
+  if (src->fd < 0) {
+    perror ("open");
+    gst_element_error (GST_ELEMENT (src), g_strconcat("opening file \"", src->filename, "\"", NULL));
+    return FALSE;
+  } else {
+    /* find the file length */
+    src->filelen = lseek (src->fd, 0, SEEK_END);
+    lseek (src->fd, 0, SEEK_SET);
+
+    // allocate the first mmap'd region
+    src->mapbuf = gst_filesrc_map_region (src, 0, src->mapsize);
+
+    src->curoffset = 0;
+
+    GST_FLAG_SET (src, GST_FILESRC_OPEN);
+  }
+  return TRUE;
+}
+
+/* unmap and close the file */
+static void
+gst_filesrc_close_file (GstFileSrc *src)
+{
+  g_return_if_fail (GST_FLAG_IS_SET (src, GST_FILESRC_OPEN));
+
+  /* close the file */
+  close (src->fd);
+
+  /* zero out a lot of our state */
+  src->fd = 0;
+  src->filelen = 0;
+  src->curoffset = 0;
+
+  GST_FLAG_UNSET (src, GST_FILESRC_OPEN);
+}
+
+
+static GstElementStateReturn
+gst_filesrc_change_state (GstElement *element)
+{
+  g_return_val_if_fail (GST_IS_FILESRC (element), GST_STATE_FAILURE);
+
+  if (GST_STATE_PENDING (element) == GST_STATE_NULL) {
+    if (GST_FLAG_IS_SET (element, GST_FILESRC_OPEN))
+      gst_filesrc_close_file (GST_FILESRC (element));
+  } else {
+    if (!GST_FLAG_IS_SET (element, GST_FILESRC_OPEN)) {
+      if (!gst_filesrc_open_file (GST_FILESRC (element)))
+        return GST_STATE_FAILURE;
+    }
+  }
+
+  if (GST_ELEMENT_CLASS (parent_class)->change_state)
+    return GST_ELEMENT_CLASS (parent_class)->change_state (element);
+
+  return GST_STATE_SUCCESS;
+}