From 8f55a3b61f26bbc1ca25d7bed36a022f5b9ec041 Mon Sep 17 00:00:00 2001 From: Erik Walthinsen Date: Wed, 22 Aug 2001 04:30:27 +0000 Subject: [PATCH] added new gstfilesrc to replace disksrc eventually Original commit message from CVS: added new gstfilesrc to replace disksrc eventually --- gst/elements/Makefile.am | 1 + gst/elements/gstelements.c | 6 + gst/elements/gstfilesrc.c | 547 +++++++++++++++++++++++++++++++++++++++++ plugins/elements/Makefile.am | 1 + plugins/elements/gstelements.c | 6 + plugins/elements/gstfilesrc.c | 547 +++++++++++++++++++++++++++++++++++++++++ 6 files changed, 1108 insertions(+) create mode 100644 gst/elements/gstfilesrc.c create mode 100644 plugins/elements/gstfilesrc.c diff --git a/gst/elements/Makefile.am b/gst/elements/Makefile.am index 084ea76..0b2cf62 100644 --- a/gst/elements/Makefile.am +++ b/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 \ diff --git a/gst/elements/gstelements.c b/gst/elements/gstelements.c index 482c7bd..4a9fac5 100644 --- a/gst/elements/gstelements.c +++ b/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 }, diff --git a/gst/elements/gstfilesrc.c b/gst/elements/gstfilesrc.c new file mode 100644 index 0000000..9d1f139 --- /dev/null +++ b/gst/elements/gstfilesrc.c @@ -0,0 +1,547 @@ +/* GStreamer + * Copyright (C) 1999,2000 Erik Walthinsen + * 2000 Wim Taymans + * + * 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 + +#include +#include +#include +#include +#include + + +/********************************************************************** + * 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 ", + "(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,®ion); + + // 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; +} diff --git a/plugins/elements/Makefile.am b/plugins/elements/Makefile.am index 084ea76..0b2cf62 100644 --- a/plugins/elements/Makefile.am +++ b/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 \ diff --git a/plugins/elements/gstelements.c b/plugins/elements/gstelements.c index 482c7bd..4a9fac5 100644 --- a/plugins/elements/gstelements.c +++ b/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 }, diff --git a/plugins/elements/gstfilesrc.c b/plugins/elements/gstfilesrc.c new file mode 100644 index 0000000..9d1f139 --- /dev/null +++ b/plugins/elements/gstfilesrc.c @@ -0,0 +1,547 @@ +/* GStreamer + * Copyright (C) 1999,2000 Erik Walthinsen + * 2000 Wim Taymans + * + * 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 + +#include +#include +#include +#include +#include + + +/********************************************************************** + * 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 ", + "(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,®ion); + + // 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; +} -- 2.7.4