/* GStreamer
* Copyright (C) 2011 David Schleef <ds@schleef.org>
* Copyright (C) 2011 Tim-Philipp Müller <tim.muller@collabora.co.uk>
* Copyright (C) 2014 Tim-Philipp Müller <tim@centricular.com>
* Copyright (C) 2014 Vincent Penquerc'h <vincent@collabora.co.uk>
*
* gstelements_private.c: Shared code for core elements
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#include <errno.h>
#include <string.h>
#include <string.h>
#include "gst/gst.h"
#include "gstelements_private.h"
#ifdef G_OS_WIN32
# define WIN32_LEAN_AND_MEAN /* prevents from including too many things */
# include <windows.h>
# undef WIN32_LEAN_AND_MEAN
# ifndef EWOULDBLOCK
# define EWOULDBLOCK EAGAIN
# endif
#endif /* G_OS_WIN32 */
#define BUFFER_FLAG_SHIFT 4
G_STATIC_ASSERT ((1 << BUFFER_FLAG_SHIFT) == GST_MINI_OBJECT_FLAG_LAST);
/* Returns a newly allocated string describing the flags on this buffer */
gchar *
gst_buffer_get_flags_string (GstBuffer * buffer)
{
static const char flag_strings[] =
"\000\000\000\000live\000decode-only\000discont\000resync\000corrupted\000"
"marker\000header\000gap\000droppable\000delta-unit\000tag-memory\000"
"FIXME";
static const guint8 flag_idx[] = { 0, 1, 2, 3, 4, 9, 21, 29, 36, 46, 53,
60, 64, 74, 85, 96
};
int i, max_bytes;
char *flag_str, *end;
/* max size is all flag strings plus a space or terminator after each one */
max_bytes = sizeof (flag_strings);
flag_str = g_malloc (max_bytes);
end = flag_str;
end[0] = '\0';
for (i = BUFFER_FLAG_SHIFT; i < G_N_ELEMENTS (flag_idx); i++) {
if (GST_MINI_OBJECT_CAST (buffer)->flags & (1 << i)) {
strcpy (end, flag_strings + flag_idx[i]);
end += strlen (end);
end[0] = ' ';
end[1] = '\0';
end++;
}
}
return flag_str;
}
/* Returns a newly-allocated string describing the metas on this buffer, or NULL */
gchar *
gst_buffer_get_meta_string (GstBuffer * buffer)
{
gpointer state = NULL;
GstMeta *meta;
GString *s = NULL;
while ((meta = gst_buffer_iterate_meta (buffer, &state))) {
const gchar *desc = g_type_name (meta->info->type);
if (s == NULL)
s = g_string_new (NULL);
else
g_string_append (s, ", ");
g_string_append (s, desc);
}
return (s != NULL) ? g_string_free (s, FALSE) : NULL;
}
/* Define our own iovec structure here, so that we can use it unconditionally
* in the code below and use almost the same code path for systems where
* writev() is supported and those were it's not supported */
#ifndef HAVE_SYS_UIO_H
struct iovec
{
gpointer iov_base;
gsize iov_len;
};
#endif
/* completely arbitrary thresholds */
#define FDSINK_MAX_ALLOCA_SIZE (64 * 1024) /* 64k */
#define FDSINK_MAX_MALLOC_SIZE ( 8 * 1024 * 1024) /* 8M */
/* UIO_MAXIOV is documented in writev(2), but <sys/uio.h> only
* declares it on osx/ios if defined(KERNEL) */
#ifndef UIO_MAXIOV
#define UIO_MAXIOV 512
#endif
static gssize
gst_writev (gint fd, const struct iovec *iov, gint iovcnt, gsize total_bytes)
{
gssize written;
#ifdef HAVE_SYS_UIO_H
if (iovcnt <= UIO_MAXIOV) {
do {
written = writev (fd, iov, iovcnt);
} while (written < 0 && errno == EINTR);
} else
#endif
{
gint i;
/* We merge the memories here because technically write()/writev() is
* supposed to be atomic, which it's not if we do multiple separate
* write() calls. It's very doubtful anyone cares though in our use
* cases, and it's not clear how that can be reconciled with the
* possibility of short writes, so in any case we might want to
* simplify this later or just remove it. */
if (total_bytes <= FDSINK_MAX_MALLOC_SIZE) {
gchar *mem, *p;
if (total_bytes <= FDSINK_MAX_ALLOCA_SIZE)
mem = g_alloca (total_bytes);
else
mem = g_malloc (total_bytes);
p = mem;
for (i = 0; i < iovcnt; ++i) {
memcpy (p, iov[i].iov_base, iov[i].iov_len);
p += iov[i].iov_len;
}
do {
written = write (fd, mem, total_bytes);
} while (written < 0 && errno == EINTR);
if (total_bytes > FDSINK_MAX_ALLOCA_SIZE)
g_free (mem);
} else {
gssize ret;
written = 0;
for (i = 0; i < iovcnt; ++i) {
do {
ret = write (fd, iov[i].iov_base, iov[i].iov_len);
} while (ret < 0 && errno == EINTR);
if (ret > 0)
written += ret;
if (ret != iov[i].iov_len)
break;
}
}
}
return written;
}
static gsize
fill_vectors (struct iovec *vecs, GstMapInfo * maps, guint n, GstBuffer * buf)
{
GstMemory *mem;
gsize size = 0;
guint i;
g_assert (gst_buffer_n_memory (buf) == n);
for (i = 0; i < n; ++i) {
mem = gst_buffer_peek_memory (buf, i);
if (gst_memory_map (mem, &maps[i], GST_MAP_READ)) {
vecs[i].iov_base = maps[i].data;
vecs[i].iov_len = maps[i].size;
} else {
GST_WARNING ("Failed to map memory %p for reading", mem);
vecs[i].iov_base = (void *) "";
vecs[i].iov_len = 0;
}
size += vecs[i].iov_len;
}
return size;
}
GstFlowReturn
gst_writev_buffers (GstObject * sink, gint fd, GstPoll * fdset,
GstBuffer ** buffers, guint num_buffers, guint8 * mem_nums,
guint total_mem_num, guint64 * bytes_written, guint64 skip)
{
struct iovec *vecs;
GstMapInfo *map_infos;
GstFlowReturn flow_ret;
gsize size = 0;
guint i, j;
GST_LOG_OBJECT (sink, "%u buffers, %u memories", num_buffers, total_mem_num);
vecs = g_newa (struct iovec, total_mem_num);
map_infos = g_newa (GstMapInfo, total_mem_num);
/* populate output vectors */
for (i = 0, j = 0; i < num_buffers; ++i) {
size += fill_vectors (&vecs[j], &map_infos[j], mem_nums[i], buffers[i]);
j += mem_nums[i];
}
/* now write it all out! */
{
gssize ret, left;
guint n_vecs = total_mem_num;
left = size;
if (skip) {
ret = skip;
errno = 0;
goto skip_first;
}
do {
#ifndef HAVE_WIN32
if (fdset != NULL) {
do {
GST_DEBUG_OBJECT (sink, "going into select, have %" G_GSSIZE_FORMAT
" bytes to write", left);
ret = gst_poll_wait (fdset, GST_CLOCK_TIME_NONE);
} while (ret == -1 && (errno == EINTR || errno == EAGAIN));
if (ret == -1) {
if (errno == EBUSY)
goto stopped;
else
goto select_error;
}
}
#endif
ret = gst_writev (fd, vecs, n_vecs, left);
if (ret > 0) {
if (bytes_written)
*bytes_written += ret;
}
skip_first:
if (ret == left)
break;
if (ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
/* do nothing, try again */
} else if (ret < 0) {
goto write_error;
} else if (ret < left) {
/* skip vectors that have been written in full */
while (ret >= vecs[0].iov_len) {
ret -= vecs[0].iov_len;
left -= vecs[0].iov_len;
++vecs;
--n_vecs;
}
g_assert (n_vecs > 0);
/* skip partially written vector data */
if (ret > 0) {
vecs[0].iov_len -= ret;
vecs[0].iov_base = ((guint8 *) vecs[0].iov_base) + ret;
left -= ret;
}
}
#ifdef HAVE_WIN32
/* do short sleep on windows where we don't use gst_poll(),
* to avoid excessive busy looping */
if (fdset != NULL)
g_usleep (1000);
#endif
}
while (left > 0);
}
flow_ret = GST_FLOW_OK;
out:
for (i = 0; i < total_mem_num; ++i)
gst_memory_unmap (map_infos[i].memory, &map_infos[i]);
return flow_ret;
/* ERRORS */
#ifndef HAVE_WIN32
select_error:
{
GST_ELEMENT_ERROR (sink, RESOURCE, READ, (NULL),
("select on file descriptor: %s", g_strerror (errno)));
GST_DEBUG_OBJECT (sink, "Error during select: %s", g_strerror (errno));
flow_ret = GST_FLOW_ERROR;
goto out;
}
stopped:
{
GST_DEBUG_OBJECT (sink, "Select stopped");
flow_ret = GST_FLOW_FLUSHING;
goto out;
}
#endif
write_error:
{
switch (errno) {
case ENOSPC:
GST_ELEMENT_ERROR (sink, RESOURCE, NO_SPACE_LEFT, (NULL), (NULL));
break;
default:{
GST_ELEMENT_ERROR (sink, RESOURCE, WRITE, (NULL),
("Error while writing to file descriptor %d: %s",
fd, g_strerror (errno)));
}
}
flow_ret = GST_FLOW_ERROR;
goto out;
}
}