gstreamer/plugins/elements/gstfdsink.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstfdsink.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.
*/
/**
* SECTION:element-fdsink
* @short_description: write to a unix file descriptor
* @see_also: #GstFdSrc
*
* Write data to a unix file descriptor.
*
* This element will sycnhronize on the clock before writing the data on the
* socket. For file descriptors where this does not make sense (files, ...) the
* ::sync property can be used to disable synchronisation.
*
* Last reviewed on 2006-04-28 (0.10.6)
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "../../gst/gst-i18n-lib.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef _MSC_VER
#include <io.h>
#endif
#include <errno.h>
#include <string.h>
#include "gstfdsink.h"
/* We add a control socket as in fdsrc to make it shutdown quickly when it's blocking on the fd.
* Select is used to determine when the fd is ready for use. When the element state is changed,
* it happens from another thread while fdsink is select'ing on the fd. The state-change thread
* sends a control message, so fdsink wakes up and changes state immediately otherwise
* it would stay blocked until it receives some data. */
/* the select call is also performed on the control sockets, that way
* we can send special commands to unblock the select call */
#define CONTROL_STOP 'S' /* stop the select call */
#define CONTROL_SOCKETS(sink) sink->control_sock
#define WRITE_SOCKET(sink) sink->control_sock[1]
#define READ_SOCKET(sink) sink->control_sock[0]
#define SEND_COMMAND(sink, command) \
G_STMT_START { \
unsigned char c; c = command; \
write (WRITE_SOCKET(sink), &c, 1); \
} G_STMT_END
#define READ_COMMAND(sink, command, res) \
G_STMT_START { \
res = read(READ_SOCKET(sink), &command, 1); \
} G_STMT_END
static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
GST_DEBUG_CATEGORY_STATIC (gst_fd_sink__debug);
#define GST_CAT_DEFAULT gst_fd_sink__debug
static const GstElementDetails gst_fd_sink__details =
GST_ELEMENT_DETAILS ("Filedescriptor Sink",
"Sink/File",
"Write data to a file descriptor",
"Erik Walthinsen <omega@cse.ogi.edu>");
/* FdSink signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
ARG_0,
ARG_FD
};
static void gst_fd_sink_uri_handler_init (gpointer g_iface,
gpointer iface_data);
static void
_do_init (GType gst_fd_sink_type)
{
static const GInterfaceInfo urihandler_info = {
gst_fd_sink_uri_handler_init,
NULL,
NULL
};
g_type_add_interface_static (gst_fd_sink_type, GST_TYPE_URI_HANDLER,
&urihandler_info);
GST_DEBUG_CATEGORY_INIT (gst_fd_sink__debug, "fdsink", 0, "fdsink element");
}
GST_BOILERPLATE_FULL (GstFdSink, gst_fd_sink, GstBaseSink, GST_TYPE_BASE_SINK,
_do_init);
static void gst_fd_sink_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_fd_sink_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_fd_sink_dispose (GObject * obj);
static gboolean gst_fd_sink_query (GstPad * pad, GstQuery * query);
static GstFlowReturn gst_fd_sink_render (GstBaseSink * sink,
GstBuffer * buffer);
static gboolean gst_fd_sink_start (GstBaseSink * basesink);
static gboolean gst_fd_sink_stop (GstBaseSink * basesink);
static gboolean gst_fd_sink_unlock (GstBaseSink * basesink);
static void
gst_fd_sink_base_init (gpointer g_class)
{
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&sinktemplate));
gst_element_class_set_details (gstelement_class, &gst_fd_sink__details);
}
static void
gst_fd_sink_class_init (GstFdSinkClass * klass)
{
GObjectClass *gobject_class;
GstBaseSinkClass *gstbasesink_class;
gobject_class = G_OBJECT_CLASS (klass);
gstbasesink_class = GST_BASE_SINK_CLASS (klass);
gobject_class->set_property = gst_fd_sink_set_property;
gobject_class->get_property = gst_fd_sink_get_property;
gobject_class->dispose = gst_fd_sink_dispose;
gstbasesink_class->get_times = NULL;
gstbasesink_class->render = GST_DEBUG_FUNCPTR (gst_fd_sink_render);
gstbasesink_class->start = GST_DEBUG_FUNCPTR (gst_fd_sink_start);
gstbasesink_class->stop = GST_DEBUG_FUNCPTR (gst_fd_sink_stop);
gstbasesink_class->unlock = GST_DEBUG_FUNCPTR (gst_fd_sink_unlock);
gstbasesink_class->event = NULL;
g_object_class_install_property (gobject_class, ARG_FD,
g_param_spec_int ("fd", "fd", "An open file descriptor to write to",
0, G_MAXINT, 1, G_PARAM_READWRITE));
}
static void
gst_fd_sink_init (GstFdSink * fdsink, GstFdSinkClass * klass)
{
GstPad *pad;
pad = GST_BASE_SINK_PAD (fdsink);
gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_fd_sink_query));
fdsink->fd = 1;
fdsink->uri = g_strdup_printf ("fd://%d", fdsink->fd);
fdsink->bytes_written = 0;
GST_BASE_SINK (fdsink)->sync = TRUE;
}
static void
gst_fd_sink_dispose (GObject * obj)
{
GstFdSink *fdsink = GST_FD_SINK (obj);
g_free (fdsink->uri);
fdsink->uri = NULL;
G_OBJECT_CLASS (parent_class)->dispose (obj);
}
static gboolean
gst_fd_sink_query (GstPad * pad, GstQuery * query)
{
GstFdSink *fdsink;
GstFormat format;
fdsink = GST_FD_SINK (GST_PAD_PARENT (pad));
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_POSITION:
gst_query_parse_position (query, &format, NULL);
switch (format) {
case GST_FORMAT_DEFAULT:
case GST_FORMAT_BYTES:
gst_query_set_position (query, GST_FORMAT_BYTES,
fdsink->bytes_written);
return TRUE;
default:
return FALSE;
}
case GST_QUERY_FORMATS:
gst_query_set_formats (query, 2, GST_FORMAT_DEFAULT, GST_FORMAT_BYTES);
return TRUE;
default:
return gst_pad_query_default (pad, query);
}
}
static GstFlowReturn
gst_fd_sink_render (GstBaseSink * sink, GstBuffer * buffer)
{
GstFdSink *fdsink;
#ifndef HAVE_WIN32
fd_set readfds;
fd_set writefds;
gint retval;
#endif
guint8 *data;
guint size;
gint written;
fdsink = GST_FD_SINK (sink);
g_return_val_if_fail (fdsink->fd >= 0, GST_FLOW_ERROR);
data = GST_BUFFER_DATA (buffer);
size = GST_BUFFER_SIZE (buffer);
again:
#ifndef HAVE_WIN32
FD_ZERO (&readfds);
FD_SET (READ_SOCKET (fdsink), &readfds);
FD_ZERO (&writefds);
FD_SET (fdsink->fd, &writefds);
do {
GST_DEBUG_OBJECT (fdsink, "going into select, have %d bytes to write",
size);
retval = select (FD_SETSIZE, &readfds, &writefds, NULL, NULL);
} while ((retval == -1 && errno == EINTR));
if (retval == -1)
goto select_error;
if (FD_ISSET (READ_SOCKET (fdsink), &readfds)) {
/* read all stop commands */
while (TRUE) {
gchar command;
int res;
READ_COMMAND (fdsink, command, res);
if (res < 0) {
GST_LOG_OBJECT (fdsink, "no more commands");
/* no more commands */
break;
}
}
goto stopped;
}
#endif
GST_DEBUG_OBJECT (fdsink, "writing %d bytes to file descriptor %d", size,
fdsink->fd);
written = write (fdsink->fd, data, size);
/* check for errors */
if (G_UNLIKELY (written < 0)) {
/* try to write again on non-fatal errors */
if (errno == EAGAIN || errno == EINTR)
goto again;
/* else go to our error handler */
goto write_error;
}
/* all is fine when we get here */
size -= written;
data += written;
fdsink->bytes_written += written;
GST_DEBUG_OBJECT (fdsink, "wrote %d bytes, %d left", written, size);
/* short write, select and try to write the remainder */
if (G_UNLIKELY (size > 0))
goto again;
return GST_FLOW_OK;
#ifndef HAVE_WIN32
select_error:
{
GST_ELEMENT_ERROR (fdsink, RESOURCE, READ, (NULL),
("select on file descriptor: %s.", g_strerror (errno)));
GST_DEBUG_OBJECT (fdsink, "Error during select");
return GST_FLOW_ERROR;
}
stopped:
{
GST_DEBUG_OBJECT (fdsink, "Select stopped");
return GST_FLOW_WRONG_STATE;
}
#endif
write_error:
{
switch (errno) {
case ENOSPC:
GST_ELEMENT_ERROR (fdsink, RESOURCE, NO_SPACE_LEFT, (NULL), (NULL));
break;
default:{
GST_ELEMENT_ERROR (fdsink, RESOURCE, WRITE,
(_("Error while writing to file descriptor \"%d\"."), fdsink->fd),
("%s", g_strerror (errno)));
}
}
return GST_FLOW_ERROR;
}
}
static gboolean
gst_fd_sink_check_fd (GstFdSink * fdsink, int fd)
{
struct stat stat_results;
off_t result;
/* see that it is a valid file descriptor */
if (fstat (fd, &stat_results) < 0)
goto invalid;
if (!S_ISREG (stat_results.st_mode))
goto not_seekable;
/* see if it is a seekable stream */
result = lseek (fd, 0, SEEK_CUR);
if (result == -1) {
switch (errno) {
case EINVAL:
case EBADF:
goto invalid;
case ESPIPE:
goto not_seekable;
}
} else
GST_DEBUG_OBJECT (fdsink, "File descriptor \"%d\" is seekable", fd);
return TRUE;
invalid:
{
GST_ELEMENT_ERROR (fdsink, RESOURCE, WRITE,
(_("File descriptor \"%d\" is not valid."), fd),
("%s", g_strerror (errno)));
return FALSE;
}
not_seekable:
{
GST_DEBUG_OBJECT (fdsink, "File descriptor \"%d\" is a pipe", fd);
return TRUE;
}
}
static gboolean
gst_fd_sink_start (GstBaseSink * basesink)
{
GstFdSink *fdsink;
gint control_sock[2];
fdsink = GST_FD_SINK (basesink);
if (!gst_fd_sink_check_fd (fdsink, fdsink->fd))
return FALSE;
if (socketpair (PF_UNIX, SOCK_STREAM, 0, control_sock) < 0)
goto socket_pair;
READ_SOCKET (fdsink) = control_sock[0];
WRITE_SOCKET (fdsink) = control_sock[1];
fcntl (READ_SOCKET (fdsink), F_SETFL, O_NONBLOCK);
fcntl (WRITE_SOCKET (fdsink), F_SETFL, O_NONBLOCK);
return TRUE;
/* ERRORS */
socket_pair:
{
GST_ELEMENT_ERROR (fdsink, RESOURCE, OPEN_READ_WRITE, (NULL),
GST_ERROR_SYSTEM);
return FALSE;
}
}
static gboolean
gst_fd_sink_stop (GstBaseSink * basesink)
{
GstFdSink *fdsink = GST_FD_SINK (basesink);
close (READ_SOCKET (fdsink));
close (WRITE_SOCKET (fdsink));
return TRUE;
}
static gboolean
gst_fd_sink_unlock (GstBaseSink * basesink)
{
GstFdSink *fdsink = GST_FD_SINK (basesink);
SEND_COMMAND (fdsink, CONTROL_STOP);
return TRUE;
}
static gboolean
gst_fd_sink_update_fd (GstFdSink * fdsink, int new_fd)
{
if (new_fd < 0)
return FALSE;
if (!gst_fd_sink_check_fd (fdsink, new_fd))
goto invalid;
/* assign the fd */
GST_OBJECT_LOCK (fdsink);
fdsink->fd = new_fd;
g_free (fdsink->uri);
fdsink->uri = g_strdup_printf ("fd://%d", fdsink->fd);
GST_OBJECT_UNLOCK (fdsink);
return TRUE;
invalid:
{
return FALSE;
}
}
static void
gst_fd_sink_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstFdSink *fdsink;
g_return_if_fail (GST_IS_FD_SINK (object));
fdsink = GST_FD_SINK (object);
switch (prop_id) {
case ARG_FD:{
int fd;
fd = g_value_get_int (value);
gst_fd_sink_update_fd (fdsink, fd);
break;
}
default:
break;
}
}
static void
gst_fd_sink_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstFdSink *fdsink;
g_return_if_fail (GST_IS_FD_SINK (object));
fdsink = GST_FD_SINK (object);
switch (prop_id) {
case ARG_FD:
g_value_set_int (value, fdsink->fd);
break;
default:
break;
}
}
/*** GSTURIHANDLER INTERFACE *************************************************/
static GstURIType
gst_fd_sink_uri_get_type (void)
{
return GST_URI_SINK;
}
static gchar **
gst_fd_sink_uri_get_protocols (void)
{
static gchar *protocols[] = { "fd", NULL };
return protocols;
}
static const gchar *
gst_fd_sink_uri_get_uri (GstURIHandler * handler)
{
GstFdSink *sink = GST_FD_SINK (handler);
return sink->uri;
}
static gboolean
gst_fd_sink_uri_set_uri (GstURIHandler * handler, const gchar * uri)
{
gchar *protocol;
GstFdSink *sink = GST_FD_SINK (handler);
gint fd;
protocol = gst_uri_get_protocol (uri);
if (strcmp (protocol, "fd") != 0) {
g_free (protocol);
return FALSE;
}
g_free (protocol);
if (sscanf (uri, "fd://%d", &fd) != 1)
return FALSE;
return gst_fd_sink_update_fd (sink, fd);
}
static void
gst_fd_sink_uri_handler_init (gpointer g_iface, gpointer iface_data)
{
GstURIHandlerInterface *iface = (GstURIHandlerInterface *) g_iface;
iface->get_type = gst_fd_sink_uri_get_type;
iface->get_protocols = gst_fd_sink_uri_get_protocols;
iface->get_uri = gst_fd_sink_uri_get_uri;
iface->set_uri = gst_fd_sink_uri_set_uri;
}