2002-07-04 12:35:45 +02:00
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|
|
/*
|
|
|
|
* TCP protocol
|
2009-01-19 16:46:40 +01:00
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|
|
* Copyright (c) 2002 Fabrice Bellard
|
2002-07-04 12:35:45 +02:00
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*
|
2006-10-07 17:30:46 +02:00
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|
* This file is part of FFmpeg.
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*
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|
* FFmpeg is free software; you can redistribute it and/or
|
2002-07-04 12:35:45 +02:00
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|
* modify it under the terms of the GNU Lesser General Public
|
|
|
|
* License as published by the Free Software Foundation; either
|
2006-10-07 17:30:46 +02:00
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|
* version 2.1 of the License, or (at your option) any later version.
|
2002-07-04 12:35:45 +02:00
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|
*
|
2006-10-07 17:30:46 +02:00
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|
|
* FFmpeg is distributed in the hope that it will be useful,
|
2002-07-04 12:35:45 +02:00
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|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
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|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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|
|
* Lesser General Public License for more details.
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*
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|
* You should have received a copy of the GNU Lesser General Public
|
2006-10-07 17:30:46 +02:00
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|
|
* License along with FFmpeg; if not, write to the Free Software
|
2006-01-12 23:43:26 +01:00
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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2002-07-04 12:35:45 +02:00
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*/
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#include "avformat.h"
|
2015-07-21 06:10:25 +02:00
|
|
|
#include "libavutil/avassert.h"
|
2011-03-04 01:41:22 +01:00
|
|
|
#include "libavutil/parseutils.h"
|
2012-09-13 02:43:31 +02:00
|
|
|
#include "libavutil/opt.h"
|
2013-03-12 15:25:59 +01:00
|
|
|
#include "libavutil/time.h"
|
2014-10-09 22:05:27 +02:00
|
|
|
|
2010-03-15 00:59:48 +01:00
|
|
|
#include "internal.h"
|
2007-02-04 18:05:44 +01:00
|
|
|
#include "network.h"
|
2007-11-21 17:33:06 +01:00
|
|
|
#include "os_support.h"
|
2011-04-04 20:40:38 +02:00
|
|
|
#include "url.h"
|
2011-01-28 03:12:21 +01:00
|
|
|
#if HAVE_POLL_H
|
|
|
|
#include <poll.h>
|
2008-09-26 04:12:37 +02:00
|
|
|
#endif
|
2002-07-04 12:35:45 +02:00
|
|
|
|
|
|
|
typedef struct TCPContext {
|
2012-09-13 02:43:31 +02:00
|
|
|
const AVClass *class;
|
2002-07-04 12:35:45 +02:00
|
|
|
int fd;
|
2012-09-13 02:43:31 +02:00
|
|
|
int listen;
|
2013-07-06 01:33:19 +02:00
|
|
|
int open_timeout;
|
2012-09-13 02:43:31 +02:00
|
|
|
int rw_timeout;
|
|
|
|
int listen_timeout;
|
2016-01-19 19:22:13 +01:00
|
|
|
int recv_buffer_size;
|
|
|
|
int send_buffer_size;
|
2017-11-13 21:20:18 +01:00
|
|
|
int tcp_nodelay;
|
2018-05-06 16:56:01 +02:00
|
|
|
#if !HAVE_WINSOCK2_H
|
|
|
|
int tcp_mss;
|
|
|
|
#endif /* !HAVE_WINSOCK2_H */
|
2002-07-04 12:35:45 +02:00
|
|
|
} TCPContext;
|
|
|
|
|
2012-09-13 02:43:31 +02:00
|
|
|
#define OFFSET(x) offsetof(TCPContext, x)
|
|
|
|
#define D AV_OPT_FLAG_DECODING_PARAM
|
|
|
|
#define E AV_OPT_FLAG_ENCODING_PARAM
|
|
|
|
static const AVOption options[] = {
|
2015-07-21 06:11:10 +02:00
|
|
|
{ "listen", "Listen for incoming connections", OFFSET(listen), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 2, .flags = D|E },
|
2014-11-12 13:52:56 +01:00
|
|
|
{ "timeout", "set timeout (in microseconds) of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
|
2015-02-28 23:20:39 +01:00
|
|
|
{ "listen_timeout", "Connection awaiting timeout (in milliseconds)", OFFSET(listen_timeout), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
|
2016-01-19 19:22:13 +01:00
|
|
|
{ "send_buffer_size", "Socket send buffer size (in bytes)", OFFSET(send_buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
|
|
|
|
{ "recv_buffer_size", "Socket receive buffer size (in bytes)", OFFSET(recv_buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
|
2017-11-13 21:20:18 +01:00
|
|
|
{ "tcp_nodelay", "Use TCP_NODELAY to disable nagle's algorithm", OFFSET(tcp_nodelay), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, .flags = D|E },
|
2018-05-06 16:56:01 +02:00
|
|
|
#if !HAVE_WINSOCK2_H
|
|
|
|
{ "tcp_mss", "Maximum segment size for outgoing TCP packets", OFFSET(tcp_mss), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
|
|
|
|
#endif /* !HAVE_WINSOCK2_H */
|
2014-10-09 22:05:27 +02:00
|
|
|
{ NULL }
|
2012-09-13 02:43:31 +02:00
|
|
|
};
|
|
|
|
|
2014-10-09 22:05:27 +02:00
|
|
|
static const AVClass tcp_class = {
|
2012-09-13 02:43:31 +02:00
|
|
|
.class_name = "tcp",
|
|
|
|
.item_name = av_default_item_name,
|
|
|
|
.option = options,
|
|
|
|
.version = LIBAVUTIL_VERSION_INT,
|
|
|
|
};
|
|
|
|
|
2018-09-11 18:54:59 +02:00
|
|
|
static void customize_fd(void *ctx, int fd)
|
|
|
|
{
|
|
|
|
TCPContext *s = ctx;
|
|
|
|
/* Set the socket's send or receive buffer sizes, if specified.
|
|
|
|
If unspecified or setting fails, system default is used. */
|
|
|
|
if (s->recv_buffer_size > 0) {
|
2018-09-11 20:27:09 +02:00
|
|
|
if (setsockopt (fd, SOL_SOCKET, SO_RCVBUF, &s->recv_buffer_size, sizeof (s->recv_buffer_size))) {
|
|
|
|
ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(SO_RCVBUF)");
|
|
|
|
}
|
2018-09-11 18:54:59 +02:00
|
|
|
}
|
|
|
|
if (s->send_buffer_size > 0) {
|
2018-09-11 20:27:09 +02:00
|
|
|
if (setsockopt (fd, SOL_SOCKET, SO_SNDBUF, &s->send_buffer_size, sizeof (s->send_buffer_size))) {
|
|
|
|
ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(SO_SNDBUF)");
|
|
|
|
}
|
2018-09-11 18:54:59 +02:00
|
|
|
}
|
|
|
|
if (s->tcp_nodelay > 0) {
|
2018-09-11 20:27:09 +02:00
|
|
|
if (setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, &s->tcp_nodelay, sizeof (s->tcp_nodelay))) {
|
|
|
|
ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(TCP_NODELAY)");
|
|
|
|
}
|
2018-09-11 18:54:59 +02:00
|
|
|
}
|
|
|
|
#if !HAVE_WINSOCK2_H
|
|
|
|
if (s->tcp_mss > 0) {
|
2018-09-11 20:27:09 +02:00
|
|
|
if (setsockopt (fd, IPPROTO_TCP, TCP_MAXSEG, &s->tcp_mss, sizeof (s->tcp_mss))) {
|
|
|
|
ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(TCP_MAXSEG)");
|
|
|
|
}
|
2018-09-11 18:54:59 +02:00
|
|
|
}
|
|
|
|
#endif /* !HAVE_WINSOCK2_H */
|
|
|
|
}
|
|
|
|
|
2002-07-04 12:35:45 +02:00
|
|
|
/* return non zero if error */
|
|
|
|
static int tcp_open(URLContext *h, const char *uri, int flags)
|
|
|
|
{
|
2011-06-06 14:13:02 +02:00
|
|
|
struct addrinfo hints = { 0 }, *ai, *cur_ai;
|
2002-07-04 12:35:45 +02:00
|
|
|
int port, fd = -1;
|
2011-12-01 10:44:21 +01:00
|
|
|
TCPContext *s = h->priv_data;
|
2011-03-04 01:41:22 +01:00
|
|
|
const char *p;
|
|
|
|
char buf[256];
|
2011-01-28 03:12:21 +01:00
|
|
|
int ret;
|
2008-08-24 18:22:40 +02:00
|
|
|
char hostname[1024],proto[1024],path[1024];
|
2010-01-11 18:32:40 +01:00
|
|
|
char portstr[10];
|
2013-07-06 01:33:19 +02:00
|
|
|
s->open_timeout = 5000000;
|
2004-08-12 02:09:32 +02:00
|
|
|
|
2010-06-27 16:16:46 +02:00
|
|
|
av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
|
2008-08-23 20:52:26 +02:00
|
|
|
&port, path, sizeof(path), uri);
|
2012-07-24 19:59:53 +02:00
|
|
|
if (strcmp(proto, "tcp"))
|
2008-08-23 20:49:16 +02:00
|
|
|
return AVERROR(EINVAL);
|
2012-07-24 19:59:53 +02:00
|
|
|
if (port <= 0 || port >= 65536) {
|
|
|
|
av_log(h, AV_LOG_ERROR, "Port missing in uri\n");
|
|
|
|
return AVERROR(EINVAL);
|
|
|
|
}
|
2011-03-04 01:41:22 +01:00
|
|
|
p = strchr(uri, '?');
|
|
|
|
if (p) {
|
2013-12-24 16:48:45 +01:00
|
|
|
if (av_find_info_tag(buf, sizeof(buf), "listen", p)) {
|
|
|
|
char *endptr = NULL;
|
|
|
|
s->listen = strtol(buf, &endptr, 10);
|
|
|
|
/* assume if no digits were found it is a request to enable it */
|
|
|
|
if (buf == endptr)
|
|
|
|
s->listen = 1;
|
|
|
|
}
|
2011-05-20 14:09:21 +02:00
|
|
|
if (av_find_info_tag(buf, sizeof(buf), "timeout", p)) {
|
2012-09-13 02:43:31 +02:00
|
|
|
s->rw_timeout = strtol(buf, NULL, 10);
|
2011-05-20 14:09:21 +02:00
|
|
|
}
|
2012-07-04 17:48:10 +02:00
|
|
|
if (av_find_info_tag(buf, sizeof(buf), "listen_timeout", p)) {
|
2012-09-13 02:43:31 +02:00
|
|
|
s->listen_timeout = strtol(buf, NULL, 10);
|
2012-07-04 17:48:10 +02:00
|
|
|
}
|
2021-06-11 21:02:02 +02:00
|
|
|
if (av_find_info_tag(buf, sizeof(buf), "tcp_nodelay", p)) {
|
|
|
|
s->tcp_nodelay = strtol(buf, NULL, 10);
|
|
|
|
}
|
2011-03-04 01:41:22 +01:00
|
|
|
}
|
2013-07-06 01:33:19 +02:00
|
|
|
if (s->rw_timeout >= 0) {
|
|
|
|
s->open_timeout =
|
|
|
|
h->rw_timeout = s->rw_timeout;
|
|
|
|
}
|
2010-01-27 23:31:13 +01:00
|
|
|
hints.ai_family = AF_UNSPEC;
|
2010-01-11 18:32:40 +01:00
|
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
|
|
snprintf(portstr, sizeof(portstr), "%d", port);
|
2012-09-13 02:43:31 +02:00
|
|
|
if (s->listen)
|
2012-06-26 19:21:11 +02:00
|
|
|
hints.ai_flags |= AI_PASSIVE;
|
2012-06-26 19:22:21 +02:00
|
|
|
if (!hostname[0])
|
|
|
|
ret = getaddrinfo(NULL, portstr, &hints, &ai);
|
|
|
|
else
|
|
|
|
ret = getaddrinfo(hostname, portstr, &hints, &ai);
|
2010-08-14 22:34:51 +02:00
|
|
|
if (ret) {
|
2011-04-20 11:40:29 +02:00
|
|
|
av_log(h, AV_LOG_ERROR,
|
2010-08-14 22:34:51 +02:00
|
|
|
"Failed to resolve hostname %s: %s\n",
|
|
|
|
hostname, gai_strerror(ret));
|
2008-08-23 20:49:16 +02:00
|
|
|
return AVERROR(EIO);
|
2010-08-14 22:34:51 +02:00
|
|
|
}
|
2002-07-04 12:35:45 +02:00
|
|
|
|
2010-01-11 18:32:40 +01:00
|
|
|
cur_ai = ai;
|
|
|
|
|
2016-11-06 21:10:24 +01:00
|
|
|
#if HAVE_STRUCT_SOCKADDR_IN6
|
2016-08-24 12:46:41 +02:00
|
|
|
// workaround for IOS9 getaddrinfo in IPv6 only network use hardcode IPv4 address can not resolve port number.
|
|
|
|
if (cur_ai->ai_family == AF_INET6){
|
|
|
|
struct sockaddr_in6 * sockaddr_v6 = (struct sockaddr_in6 *)cur_ai->ai_addr;
|
|
|
|
if (!sockaddr_v6->sin6_port){
|
|
|
|
sockaddr_v6->sin6_port = htons(port);
|
|
|
|
}
|
|
|
|
}
|
2016-11-06 21:10:24 +01:00
|
|
|
#endif
|
2016-08-24 12:46:41 +02:00
|
|
|
|
2018-09-11 18:54:59 +02:00
|
|
|
if (s->listen > 0) {
|
2018-08-10 09:39:41 +02:00
|
|
|
while (cur_ai && fd < 0) {
|
|
|
|
fd = ff_socket(cur_ai->ai_family,
|
|
|
|
cur_ai->ai_socktype,
|
|
|
|
cur_ai->ai_protocol);
|
|
|
|
if (fd < 0) {
|
|
|
|
ret = ff_neterrno();
|
|
|
|
cur_ai = cur_ai->ai_next;
|
|
|
|
}
|
2018-08-04 11:52:16 +02:00
|
|
|
}
|
2018-08-10 09:39:41 +02:00
|
|
|
if (fd < 0)
|
|
|
|
goto fail1;
|
2018-09-11 18:54:59 +02:00
|
|
|
customize_fd(s, fd);
|
2018-05-06 16:56:01 +02:00
|
|
|
}
|
2017-01-09 21:54:47 +01:00
|
|
|
|
2015-07-21 06:11:10 +02:00
|
|
|
if (s->listen == 2) {
|
|
|
|
// multi-client
|
|
|
|
if ((ret = ff_listen(fd, cur_ai->ai_addr, cur_ai->ai_addrlen)) < 0)
|
|
|
|
goto fail1;
|
|
|
|
} else if (s->listen == 1) {
|
|
|
|
// single client
|
2015-09-11 08:31:44 +02:00
|
|
|
if ((ret = ff_listen_bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
|
|
|
|
s->listen_timeout, h)) < 0)
|
2012-05-30 16:35:05 +02:00
|
|
|
goto fail1;
|
2015-09-11 08:31:44 +02:00
|
|
|
// Socket descriptor already closed here. Safe to overwrite to client one.
|
|
|
|
fd = ret;
|
2011-03-04 01:41:22 +01:00
|
|
|
} else {
|
2018-09-11 18:54:59 +02:00
|
|
|
ret = ff_connect_parallel(ai, s->open_timeout / 1000, 3, h, &fd, customize_fd, s);
|
2018-08-10 09:39:41 +02:00
|
|
|
if (ret < 0)
|
|
|
|
goto fail1;
|
2003-07-17 12:28:27 +02:00
|
|
|
}
|
2013-05-31 03:05:13 +02:00
|
|
|
|
2008-08-23 20:46:30 +02:00
|
|
|
h->is_streamed = 1;
|
2002-07-04 12:35:45 +02:00
|
|
|
s->fd = fd;
|
2016-01-19 19:22:13 +01:00
|
|
|
|
2010-01-11 18:32:40 +01:00
|
|
|
freeaddrinfo(ai);
|
2002-07-04 12:35:45 +02:00
|
|
|
return 0;
|
|
|
|
|
2003-07-17 12:28:27 +02:00
|
|
|
fail1:
|
2002-07-04 12:35:45 +02:00
|
|
|
if (fd >= 0)
|
2007-01-18 18:22:30 +01:00
|
|
|
closesocket(fd);
|
2010-01-11 18:32:40 +01:00
|
|
|
freeaddrinfo(ai);
|
2003-07-17 12:28:27 +02:00
|
|
|
return ret;
|
2002-07-04 12:35:45 +02:00
|
|
|
}
|
|
|
|
|
2015-07-21 06:10:25 +02:00
|
|
|
static int tcp_accept(URLContext *s, URLContext **c)
|
|
|
|
{
|
|
|
|
TCPContext *sc = s->priv_data;
|
|
|
|
TCPContext *cc;
|
|
|
|
int ret;
|
|
|
|
av_assert0(sc->listen);
|
|
|
|
if ((ret = ffurl_alloc(c, s->filename, s->flags, &s->interrupt_callback)) < 0)
|
|
|
|
return ret;
|
|
|
|
cc = (*c)->priv_data;
|
|
|
|
ret = ff_accept(sc->fd, sc->listen_timeout, s);
|
2018-01-12 19:16:30 +01:00
|
|
|
if (ret < 0) {
|
|
|
|
ffurl_closep(c);
|
2017-04-08 14:21:28 +02:00
|
|
|
return ret;
|
2018-01-12 19:16:30 +01:00
|
|
|
}
|
2015-07-21 06:10:25 +02:00
|
|
|
cc->fd = ret;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2003-02-11 17:35:48 +01:00
|
|
|
static int tcp_read(URLContext *h, uint8_t *buf, int size)
|
2002-07-04 12:35:45 +02:00
|
|
|
{
|
|
|
|
TCPContext *s = h->priv_data;
|
2011-02-04 19:12:38 +01:00
|
|
|
int ret;
|
2002-07-04 12:35:45 +02:00
|
|
|
|
2011-04-04 20:11:19 +02:00
|
|
|
if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
|
2012-10-08 09:39:42 +02:00
|
|
|
ret = ff_network_wait_fd_timeout(s->fd, 0, h->rw_timeout, &h->interrupt_callback);
|
|
|
|
if (ret)
|
2011-02-02 18:45:44 +01:00
|
|
|
return ret;
|
2002-07-04 12:35:45 +02:00
|
|
|
}
|
2011-02-04 19:12:38 +01:00
|
|
|
ret = recv(s->fd, buf, size, 0);
|
2017-12-30 17:44:03 +01:00
|
|
|
if (ret == 0)
|
|
|
|
return AVERROR_EOF;
|
2011-02-04 19:12:38 +01:00
|
|
|
return ret < 0 ? ff_neterrno() : ret;
|
2002-07-04 12:35:45 +02:00
|
|
|
}
|
|
|
|
|
2010-06-01 09:46:23 +02:00
|
|
|
static int tcp_write(URLContext *h, const uint8_t *buf, int size)
|
2002-07-04 12:35:45 +02:00
|
|
|
{
|
|
|
|
TCPContext *s = h->priv_data;
|
2011-02-04 19:12:38 +01:00
|
|
|
int ret;
|
2002-07-04 12:35:45 +02:00
|
|
|
|
2011-04-04 20:11:19 +02:00
|
|
|
if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
|
2012-10-08 09:39:42 +02:00
|
|
|
ret = ff_network_wait_fd_timeout(s->fd, 1, h->rw_timeout, &h->interrupt_callback);
|
|
|
|
if (ret)
|
2011-02-02 18:45:44 +01:00
|
|
|
return ret;
|
2002-07-04 12:35:45 +02:00
|
|
|
}
|
2014-08-20 22:06:07 +02:00
|
|
|
ret = send(s->fd, buf, size, MSG_NOSIGNAL);
|
2011-02-04 19:12:38 +01:00
|
|
|
return ret < 0 ? ff_neterrno() : ret;
|
2002-07-04 12:35:45 +02:00
|
|
|
}
|
|
|
|
|
2012-05-21 11:24:55 +02:00
|
|
|
static int tcp_shutdown(URLContext *h, int flags)
|
|
|
|
{
|
|
|
|
TCPContext *s = h->priv_data;
|
|
|
|
int how;
|
|
|
|
|
|
|
|
if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {
|
|
|
|
how = SHUT_RDWR;
|
|
|
|
} else if (flags & AVIO_FLAG_WRITE) {
|
|
|
|
how = SHUT_WR;
|
|
|
|
} else {
|
|
|
|
how = SHUT_RD;
|
|
|
|
}
|
|
|
|
|
|
|
|
return shutdown(s->fd, how);
|
|
|
|
}
|
|
|
|
|
2002-07-04 12:35:45 +02:00
|
|
|
static int tcp_close(URLContext *h)
|
|
|
|
{
|
|
|
|
TCPContext *s = h->priv_data;
|
2002-11-02 11:35:07 +01:00
|
|
|
closesocket(s->fd);
|
2002-07-04 12:35:45 +02:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-03-03 18:04:51 +01:00
|
|
|
static int tcp_get_file_handle(URLContext *h)
|
|
|
|
{
|
|
|
|
TCPContext *s = h->priv_data;
|
|
|
|
return s->fd;
|
|
|
|
}
|
|
|
|
|
HTTP: improve performance by reducing forward seeks
This commit optimizes HTTP performance by reducing forward seeks, instead
favoring a read-ahead and discard on the current connection (referred to
as a short seek) for seeks that are within a TCP window's worth of data.
This improves performance because with TCP flow control, a window's worth
of data will be in the local socket buffer already or in-flight from the
sender once congestion control on the sender is fully utilizing the window.
Note: this approach doesn't attempt to differentiate from a newly opened
connection which may not be fully utilizing the window due to congestion
control vs one that is. The receiver can't get at this information, so we
assume worst case; that full window is in use (we did advertise it after all)
and that data could be in-flight
The previous behavior of closing the connection, then opening a new
with a new HTTP range value results in a massive amounts of discarded
and re-sent data when large TCP windows are used. This has been observed
on MacOS/iOS which starts with an initial window of 256KB and grows up to
1MB depending on the bandwidth-product delay.
When seeking within a window's worth of data and we close the connection,
then open a new one within the same window's worth of data, we discard
from the current offset till the end of the window. Then on the new
connection the server ends up re-sending the previous data from new
offset till the end of old window.
Example (assumes full window utilization):
TCP window size: 64KB
Position: 32KB
Forward seek position: 40KB
* (Next window)
32KB |--------------| 96KB |---------------| 160KB
*
40KB |---------------| 104KB
Re-sent amount: 96KB - 40KB = 56KB
For a real world test example, I have MP4 file of ~25MB, which ffplay
only reads ~16MB and performs 177 seeks. With current ffmpeg, this results
in 177 HTTP GETs and ~73MB worth of TCP data communication. With this
patch, ffmpeg issues 4 HTTP GETs and 3 seeks for a total of ~22MB of TCP data
communication.
To support this feature, the short seek logic in avio_seek() has been
extended to call a function to get the short seek threshold value. This
callback has been plumbed to the URLProtocol structure, which now has
infrastructure in HTTP and TCP to get the underlying receiver window size
via SO_RCVBUF. If the underlying URL and protocol don't support returning
a short seek threshold, the default s->short_seek_threshold is used
This feature has been tested on Windows 7 and MacOS/iOS. Windows support
is slightly complicated by the fact that when TCP window auto-tuning is
enabled, SO_RCVBUF doesn't report the real window size, but it does if
SO_RCVBUF was manually set (disabling auto-tuning). So we can only use
this optimization on Windows in the later case
Signed-off-by: Joel Cunningham <joel.cunningham@me.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2017-01-30 17:00:44 +01:00
|
|
|
static int tcp_get_window_size(URLContext *h)
|
|
|
|
{
|
|
|
|
TCPContext *s = h->priv_data;
|
|
|
|
int avail;
|
2017-11-12 15:23:14 +01:00
|
|
|
socklen_t avail_len = sizeof(avail);
|
HTTP: improve performance by reducing forward seeks
This commit optimizes HTTP performance by reducing forward seeks, instead
favoring a read-ahead and discard on the current connection (referred to
as a short seek) for seeks that are within a TCP window's worth of data.
This improves performance because with TCP flow control, a window's worth
of data will be in the local socket buffer already or in-flight from the
sender once congestion control on the sender is fully utilizing the window.
Note: this approach doesn't attempt to differentiate from a newly opened
connection which may not be fully utilizing the window due to congestion
control vs one that is. The receiver can't get at this information, so we
assume worst case; that full window is in use (we did advertise it after all)
and that data could be in-flight
The previous behavior of closing the connection, then opening a new
with a new HTTP range value results in a massive amounts of discarded
and re-sent data when large TCP windows are used. This has been observed
on MacOS/iOS which starts with an initial window of 256KB and grows up to
1MB depending on the bandwidth-product delay.
When seeking within a window's worth of data and we close the connection,
then open a new one within the same window's worth of data, we discard
from the current offset till the end of the window. Then on the new
connection the server ends up re-sending the previous data from new
offset till the end of old window.
Example (assumes full window utilization):
TCP window size: 64KB
Position: 32KB
Forward seek position: 40KB
* (Next window)
32KB |--------------| 96KB |---------------| 160KB
*
40KB |---------------| 104KB
Re-sent amount: 96KB - 40KB = 56KB
For a real world test example, I have MP4 file of ~25MB, which ffplay
only reads ~16MB and performs 177 seeks. With current ffmpeg, this results
in 177 HTTP GETs and ~73MB worth of TCP data communication. With this
patch, ffmpeg issues 4 HTTP GETs and 3 seeks for a total of ~22MB of TCP data
communication.
To support this feature, the short seek logic in avio_seek() has been
extended to call a function to get the short seek threshold value. This
callback has been plumbed to the URLProtocol structure, which now has
infrastructure in HTTP and TCP to get the underlying receiver window size
via SO_RCVBUF. If the underlying URL and protocol don't support returning
a short seek threshold, the default s->short_seek_threshold is used
This feature has been tested on Windows 7 and MacOS/iOS. Windows support
is slightly complicated by the fact that when TCP window auto-tuning is
enabled, SO_RCVBUF doesn't report the real window size, but it does if
SO_RCVBUF was manually set (disabling auto-tuning). So we can only use
this optimization on Windows in the later case
Signed-off-by: Joel Cunningham <joel.cunningham@me.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2017-01-30 17:00:44 +01:00
|
|
|
|
|
|
|
#if HAVE_WINSOCK2_H
|
|
|
|
/* SO_RCVBUF with winsock only reports the actual TCP window size when
|
|
|
|
auto-tuning has been disabled via setting SO_RCVBUF */
|
|
|
|
if (s->recv_buffer_size < 0) {
|
|
|
|
return AVERROR(ENOSYS);
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
if (getsockopt(s->fd, SOL_SOCKET, SO_RCVBUF, &avail, &avail_len)) {
|
|
|
|
return ff_neterrno();
|
|
|
|
}
|
|
|
|
return avail;
|
|
|
|
}
|
|
|
|
|
2016-02-19 10:39:29 +01:00
|
|
|
const URLProtocol ff_tcp_protocol = {
|
2011-04-08 07:41:47 +02:00
|
|
|
.name = "tcp",
|
|
|
|
.url_open = tcp_open,
|
2015-07-21 06:10:25 +02:00
|
|
|
.url_accept = tcp_accept,
|
2011-04-08 07:41:47 +02:00
|
|
|
.url_read = tcp_read,
|
|
|
|
.url_write = tcp_write,
|
|
|
|
.url_close = tcp_close,
|
2009-03-03 18:04:51 +01:00
|
|
|
.url_get_file_handle = tcp_get_file_handle,
|
HTTP: improve performance by reducing forward seeks
This commit optimizes HTTP performance by reducing forward seeks, instead
favoring a read-ahead and discard on the current connection (referred to
as a short seek) for seeks that are within a TCP window's worth of data.
This improves performance because with TCP flow control, a window's worth
of data will be in the local socket buffer already or in-flight from the
sender once congestion control on the sender is fully utilizing the window.
Note: this approach doesn't attempt to differentiate from a newly opened
connection which may not be fully utilizing the window due to congestion
control vs one that is. The receiver can't get at this information, so we
assume worst case; that full window is in use (we did advertise it after all)
and that data could be in-flight
The previous behavior of closing the connection, then opening a new
with a new HTTP range value results in a massive amounts of discarded
and re-sent data when large TCP windows are used. This has been observed
on MacOS/iOS which starts with an initial window of 256KB and grows up to
1MB depending on the bandwidth-product delay.
When seeking within a window's worth of data and we close the connection,
then open a new one within the same window's worth of data, we discard
from the current offset till the end of the window. Then on the new
connection the server ends up re-sending the previous data from new
offset till the end of old window.
Example (assumes full window utilization):
TCP window size: 64KB
Position: 32KB
Forward seek position: 40KB
* (Next window)
32KB |--------------| 96KB |---------------| 160KB
*
40KB |---------------| 104KB
Re-sent amount: 96KB - 40KB = 56KB
For a real world test example, I have MP4 file of ~25MB, which ffplay
only reads ~16MB and performs 177 seeks. With current ffmpeg, this results
in 177 HTTP GETs and ~73MB worth of TCP data communication. With this
patch, ffmpeg issues 4 HTTP GETs and 3 seeks for a total of ~22MB of TCP data
communication.
To support this feature, the short seek logic in avio_seek() has been
extended to call a function to get the short seek threshold value. This
callback has been plumbed to the URLProtocol structure, which now has
infrastructure in HTTP and TCP to get the underlying receiver window size
via SO_RCVBUF. If the underlying URL and protocol don't support returning
a short seek threshold, the default s->short_seek_threshold is used
This feature has been tested on Windows 7 and MacOS/iOS. Windows support
is slightly complicated by the fact that when TCP window auto-tuning is
enabled, SO_RCVBUF doesn't report the real window size, but it does if
SO_RCVBUF was manually set (disabling auto-tuning). So we can only use
this optimization on Windows in the later case
Signed-off-by: Joel Cunningham <joel.cunningham@me.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2017-01-30 17:00:44 +01:00
|
|
|
.url_get_short_seek = tcp_get_window_size,
|
2012-05-21 11:24:55 +02:00
|
|
|
.url_shutdown = tcp_shutdown,
|
2011-12-01 10:44:21 +01:00
|
|
|
.priv_data_size = sizeof(TCPContext),
|
2011-12-30 10:38:05 +01:00
|
|
|
.flags = URL_PROTOCOL_FLAG_NETWORK,
|
2014-10-09 22:05:27 +02:00
|
|
|
.priv_data_class = &tcp_class,
|
2002-07-04 12:35:45 +02:00
|
|
|
};
|