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mirror of https://github.com/mpv-player/mpv synced 2024-12-30 11:02:10 +00:00
mpv/stream/stream_file.c
wm4 fc76d41194 stream_file: add mode for reading appended files
Do this because retrying reading on higher levels (like the demuxer)
usually causes tons of problems. A hack like this is simpler and could
allow to remove some of the higher level retry behavior.

This works by trying to detect whether the file is appended. If we reach
EOF, check if the file size changed compared to the initial value. If it
did, it means the file was appended at least once, and we set the
p->appending flag. If that flag is set, we simply retry reading more
data every time we encounter EOF. The only way to do this is polling,
and we poll for at most 10 times, after waiting for 200ms every time.
2018-02-21 22:57:39 -08:00

373 lines
10 KiB
C

/*
* Original authors: Albeu, probably Arpi
*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#ifndef __MINGW32__
#include <poll.h>
#endif
#include "osdep/io.h"
#include "common/common.h"
#include "common/msg.h"
#include "stream.h"
#include "options/m_option.h"
#include "options/path.h"
#if HAVE_BSD_FSTATFS
#include <sys/param.h>
#include <sys/mount.h>
#endif
#if HAVE_LINUX_FSTATFS
#include <sys/vfs.h>
#endif
#ifdef _WIN32
#include <windows.h>
#include <winternl.h>
#include <io.h>
#ifndef FILE_REMOTE_DEVICE
#define FILE_REMOTE_DEVICE (0x10)
#endif
#endif
struct priv {
int fd;
bool close;
bool use_poll;
bool regular_file;
bool appending;
int64_t orig_size;
};
// Total timeout = RETRY_TIMEOUT * MAX_RETRIES
#define RETRY_TIMEOUT 0.2
#define MAX_RETRIES 10
static int64_t get_size(stream_t *s)
{
struct priv *p = s->priv;
off_t size = lseek(p->fd, 0, SEEK_END);
lseek(p->fd, s->pos, SEEK_SET);
return size == (off_t)-1 ? -1 : size;
}
static int fill_buffer(stream_t *s, char *buffer, int max_len)
{
struct priv *p = s->priv;
#ifndef __MINGW32__
if (p->use_poll) {
int c = s->cancel ? mp_cancel_get_fd(s->cancel) : -1;
struct pollfd fds[2] = {
{.fd = p->fd, .events = POLLIN},
{.fd = c, .events = POLLIN},
};
poll(fds, c >= 0 ? 2 : 1, -1);
if (fds[1].revents & POLLIN)
return -1;
}
#endif
for (int retries = 0; retries < MAX_RETRIES; retries++) {
int r = read(p->fd, buffer, max_len);
if (r > 0)
return r;
// Try to detect and handle files being appended during playback.
int64_t size = get_size(s);
if (p->regular_file && size > p->orig_size && !p->appending) {
MP_WARN(s, "File is apparently being appended to, will keep "
"retrying with timeouts.\n");
p->appending = true;
}
if (!p->appending || p->use_poll)
break;
if (mp_cancel_wait(s->cancel, RETRY_TIMEOUT))
break;
}
return 0;
}
static int write_buffer(stream_t *s, char *buffer, int len)
{
struct priv *p = s->priv;
int r;
int wr = 0;
while (wr < len) {
r = write(p->fd, buffer, len);
if (r <= 0)
return -1;
wr += r;
buffer += r;
}
return len;
}
static int seek(stream_t *s, int64_t newpos)
{
struct priv *p = s->priv;
return lseek(p->fd, newpos, SEEK_SET) != (off_t)-1;
}
static int control(stream_t *s, int cmd, void *arg)
{
switch (cmd) {
case STREAM_CTRL_GET_SIZE: {
int64_t size = get_size(s);
if (size >= 0) {
*(int64_t *)arg = size;
return 1;
}
break;
}
}
return STREAM_UNSUPPORTED;
}
static void s_close(stream_t *s)
{
struct priv *p = s->priv;
if (p->close)
close(p->fd);
}
// If url is a file:// URL, return the local filename, otherwise return NULL.
char *mp_file_url_to_filename(void *talloc_ctx, bstr url)
{
bstr proto = mp_split_proto(url, &url);
if (bstrcasecmp0(proto, "file") != 0)
return NULL;
char *filename = bstrto0(talloc_ctx, url);
mp_url_unescape_inplace(filename);
#if HAVE_DOS_PATHS
// extract '/' from '/x:/path'
if (filename[0] == '/' && filename[1] && filename[2] == ':')
memmove(filename, filename + 1, strlen(filename)); // including \0
#endif
return filename;
}
// Return talloc_strdup's filesystem path if local, otherwise NULL.
// Unlike mp_file_url_to_filename(), doesn't return NULL if already local.
char *mp_file_get_path(void *talloc_ctx, bstr url)
{
if (mp_split_proto(url, &(bstr){0}).len) {
return mp_file_url_to_filename(talloc_ctx, url);
} else {
return bstrto0(talloc_ctx, url);
}
}
#if HAVE_BSD_FSTATFS
static bool check_stream_network(int fd)
{
struct statfs fs;
const char *stypes[] = { "afpfs", "nfs", "smbfs", "webdav", NULL };
if (fstatfs(fd, &fs) == 0)
for (int i=0; stypes[i]; i++)
if (strcmp(stypes[i], fs.f_fstypename) == 0)
return true;
return false;
}
#elif HAVE_LINUX_FSTATFS
static bool check_stream_network(int fd)
{
struct statfs fs;
const uint32_t stypes[] = {
0x5346414F /*AFS*/, 0x61756673 /*AUFS*/, 0x00C36400 /*CEPH*/,
0xFF534D42 /*CIFS*/, 0x73757245 /*CODA*/, 0x19830326 /*FHGFS*/,
0x65735546 /*FUSEBLK*/,0x65735543 /*FUSECTL*/,0x1161970 /*GFS*/,
0x47504653 /*GPFS*/, 0x6B414653 /*KAFS*/, 0x0BD00BD0 /*LUSTRE*/,
0x564C /*NCP*/, 0x6969 /*NFS*/, 0x6E667364 /*NFSD*/,
0xAAD7AAEA /*PANFS*/, 0x50495045 /*PIPEFS*/, 0x517B /*SMB*/,
0xBEEFDEAD /*SNFS*/, 0xBACBACBC /*VMHGFS*/, 0x7461636f /*OCFS2*/,
0
};
if (fstatfs(fd, &fs) == 0) {
for (int i=0; stypes[i]; i++) {
if (stypes[i] == fs.f_type)
return true;
}
}
return false;
}
#elif defined(_WIN32)
static bool check_stream_network(int fd)
{
NTSTATUS (NTAPI *pNtQueryVolumeInformationFile)(HANDLE,
PIO_STATUS_BLOCK, PVOID, ULONG, FS_INFORMATION_CLASS) = NULL;
// NtQueryVolumeInformationFile is an internal Windows function. It has
// been present since Windows XP, however this code should fail gracefully
// if it's removed from a future version of Windows.
HMODULE ntdll = GetModuleHandleW(L"ntdll.dll");
pNtQueryVolumeInformationFile = (NTSTATUS (NTAPI*)(HANDLE,
PIO_STATUS_BLOCK, PVOID, ULONG, FS_INFORMATION_CLASS))
GetProcAddress(ntdll, "NtQueryVolumeInformationFile");
if (!pNtQueryVolumeInformationFile)
return false;
HANDLE h = (HANDLE)_get_osfhandle(fd);
if (h == INVALID_HANDLE_VALUE)
return false;
FILE_FS_DEVICE_INFORMATION info = { 0 };
IO_STATUS_BLOCK io;
NTSTATUS status = pNtQueryVolumeInformationFile(h, &io, &info,
sizeof(info), FileFsDeviceInformation);
if (!NT_SUCCESS(status))
return false;
return info.DeviceType == FILE_DEVICE_NETWORK_FILE_SYSTEM ||
(info.Characteristics & FILE_REMOTE_DEVICE);
}
#else
static bool check_stream_network(int fd)
{
return false;
}
#endif
static int open_f(stream_t *stream)
{
struct priv *p = talloc_ptrtype(stream, p);
*p = (struct priv) {
.fd = -1
};
stream->priv = p;
stream->is_local_file = true;
bool write = stream->mode == STREAM_WRITE;
int m = O_CLOEXEC | (write ? O_RDWR | O_CREAT | O_TRUNC : O_RDONLY);
char *filename = mp_file_url_to_filename(stream, bstr0(stream->url));
if (filename) {
stream->path = filename;
} else {
filename = stream->path;
}
bool is_fdclose = strncmp(stream->url, "fdclose://", 10) == 0;
if (strncmp(stream->url, "fd://", 5) == 0 || is_fdclose) {
char *begin = strstr(stream->url, "://") + 3, *end = NULL;
p->fd = strtol(begin, &end, 0);
if (!end || end == begin || end[0]) {
MP_ERR(stream, "Invalid FD: %s\n", stream->url);
return STREAM_ERROR;
}
if (is_fdclose)
p->close = true;
} else if (!strcmp(filename, "-")) {
if (!write) {
MP_INFO(stream, "Reading from stdin...\n");
p->fd = 0;
} else {
MP_INFO(stream, "Writing to stdout...\n");
p->fd = 1;
}
} else {
if (bstr_startswith0(bstr0(stream->url), "appending://"))
p->appending = true;
mode_t openmode = S_IRUSR | S_IWUSR;
#ifndef __MINGW32__
openmode |= S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
if (!write)
m |= O_NONBLOCK;
p->use_poll = true;
#endif
p->fd = open(filename, m | O_BINARY, openmode);
if (p->fd < 0) {
MP_ERR(stream, "Cannot open file '%s': %s\n",
filename, mp_strerror(errno));
return STREAM_ERROR;
}
struct stat st;
if (fstat(p->fd, &st) == 0) {
if (S_ISDIR(st.st_mode)) {
p->use_poll = false;
stream->is_directory = true;
stream->allow_caching = false;
MP_INFO(stream, "This is a directory - adding to playlist.\n");
}
#ifndef __MINGW32__
if (S_ISREG(st.st_mode)) {
p->use_poll = false;
p->regular_file = true;
// O_NONBLOCK has weird semantics on file locks; remove it.
int val = fcntl(p->fd, F_GETFL) & ~(unsigned)O_NONBLOCK;
fcntl(p->fd, F_SETFL, val);
}
#endif
}
p->close = true;
}
#ifdef __MINGW32__
setmode(p->fd, O_BINARY);
#endif
off_t len = lseek(p->fd, 0, SEEK_END);
lseek(p->fd, 0, SEEK_SET);
if (len != (off_t)-1) {
stream->seek = seek;
stream->seekable = true;
}
stream->fast_skip = true;
stream->fill_buffer = fill_buffer;
stream->write_buffer = write_buffer;
stream->control = control;
stream->read_chunk = 64 * 1024;
stream->close = s_close;
if (check_stream_network(p->fd))
stream->streaming = true;
p->orig_size = get_size(stream);
return STREAM_OK;
}
const stream_info_t stream_info_file = {
.name = "file",
.open = open_f,
.protocols = (const char*const[]){ "file", "", "fd", "fdclose",
"appending", NULL },
.can_write = true,
.is_safe = true,
};