Commit 160ee0af authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont

Rewrite the mmap input as a separate access

parent a101ffbd
......@@ -469,7 +469,7 @@ dnl Check for system libs needed
need_libc=false
dnl Check for usual libc functions
AC_CHECK_FUNCS([gettimeofday strtod strtol strtof strtoll strtoull strsep isatty vasprintf asprintf swab sigrelse getpwuid memalign posix_memalign if_nametoindex atoll getenv putenv setenv gmtime_r ctime_r localtime_r lrintf daemon scandir fork bsearch lstat strlcpy strdup strndup strnlen atof lldiv mmap])
AC_CHECK_FUNCS([gettimeofday strtod strtol strtof strtoll strtoull strsep isatty vasprintf asprintf swab sigrelse getpwuid memalign posix_memalign if_nametoindex atoll getenv putenv setenv gmtime_r ctime_r localtime_r lrintf daemon scandir fork bsearch lstat strlcpy strdup strndup strnlen atof lldiv])
AC_CHECK_FUNCS(strcasecmp,,[AC_CHECK_FUNCS(stricmp)])
AC_CHECK_FUNCS(strncasecmp,,[AC_CHECK_FUNCS(strnicmp)])
AC_CHECK_FUNCS(strcasestr,,[AC_CHECK_FUNCS(stristr)])
......@@ -477,6 +477,8 @@ AC_FUNC_ALLOCA
AH_BOTTOM([#include <vlc_fixups.h>])
AC_CHECK_FUNC(mmap, [VLC_ADD_PLUGINS([access_mmap])])
AS_IF([test "${SYS}" = "linux"], [
AC_CHECK_FUNCS(tee)
])
......
......@@ -4,6 +4,7 @@
LIBTOOL=@LIBTOOL@ --tag=CC
SOURCES_access_file = file.c
SOURCES_access_mmap = mmap.c
SOURCES_access_directory = directory.c
SOURCES_access_dv = dv.c
SOURCES_access_udp = udp.c
......
/*****************************************************************************
* mmap.c: memory-mapped file input
*****************************************************************************
* Copyright © 2007-2008 Rémi Denis-Courmont
* $Id$
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <vlc/vlc.h>
#include <vlc_access.h>
#include <vlc_input.h>
#include <vlc_charset.h>
#include <vlc_interface.h>
#include <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#define FILE_MMAP_TEXT N_("Use file memory mapping")
#define FILE_MMAP_LONGTEXT N_( \
"Try to use memory mapping to read files and block devices." )
static int Open (vlc_object_t *);
static void Close (vlc_object_t *);
vlc_module_begin();
set_shortname (_("MMap"));
set_description (_("Memory-mapped file input"));
set_category (CAT_INPUT);
set_subcategory (SUBCAT_INPUT_ACCESS);
set_capability ("access2", 52);
add_shortcut ("file");
set_callbacks (Open, Close);
add_bool ("file-mmap", VLC_TRUE, NULL,
FILE_MMAP_TEXT, FILE_MMAP_LONGTEXT, VLC_TRUE);
vlc_module_end();
static block_t *Block (access_t *);
static int Seek (access_t *, int64_t);
static int Control (access_t *, int, va_list);
struct access_sys_t
{
size_t page_size;
size_t mtu;
int fd;
};
#define MMAP_SIZE (1 << 20)
static int Open (vlc_object_t *p_this)
{
access_t *p_access = (access_t *)p_this;
access_sys_t *p_sys;
const char *path = p_access->psz_path;
int fd;
if (!var_CreateGetBool (p_this, "file-mmap"))
return VLC_EGENERIC; /* disabled */
STANDARD_BLOCK_ACCESS_INIT;
if (!strcmp (p_access->psz_path, "-"))
fd = dup (0);
else
{
msg_Dbg (p_access, "opening file %s", path);
fd = utf8_open (path, O_RDONLY | O_NOCTTY, 0666);
}
if (fd == -1)
{
msg_Warn (p_access, "cannot open %s: %m", path);
goto error;
}
/* mmap() is only safe for regular and block special files.
* For other types, it may be some idiosyncrasic interface (e.g. packet
* sockets are a good example), if it works at all. */
struct stat st;
if (fstat (fd, &st))
{
msg_Err (p_access, "cannot stat %s: %m", path);
goto error;
}
if (!S_ISREG (st.st_mode) && !S_ISBLK (st.st_mode))
{
msg_Dbg (p_access, "skipping non regular file %s", path);
goto error;
}
/* Autodetect mmap() support */
if (st.st_size > 0)
{
void *addr = mmap (NULL, 1, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
if (addr != MAP_FAILED)
munmap (addr, 1);
else
goto error;
}
p_sys->page_size = sysconf (_SC_PAGE_SIZE);
p_sys->mtu = MMAP_SIZE;
if (p_sys->mtu < p_sys->page_size)
p_sys->mtu = p_sys->page_size;
p_sys->fd = fd;
p_access->info.i_size = st.st_size;
return VLC_SUCCESS;
error:
if (fd != -1)
close (fd);
free (p_sys);
return VLC_EGENERIC;
}
static void Close (vlc_object_t * p_this)
{
access_t *p_access = (access_t *)p_this;
access_sys_t *p_sys = p_access->p_sys;
close (p_sys->fd); /* don't care about error when only reading */
free (p_sys);
}
static block_t *Block (access_t *p_access)
{
access_sys_t *p_sys = p_access->p_sys;
#ifndef NDEBUG
int64_t dbgpos = lseek (p_sys->fd, 0, SEEK_CUR);
if (dbgpos != p_access->info.i_pos)
msg_Err (p_access, "position: 0x%08llx instead of 0x%08llx",
p_access->info.i_pos, dbgpos);
#endif
if ((uint64_t)p_access->info.i_pos >= (uint64_t)p_access->info.i_size)
{
/* End of file - check if file size changed... */
struct stat st;
if ((fstat (p_sys->fd, &st) == 0)
&& (st.st_size != p_access->info.i_size))
{
p_access->info.i_size = st.st_size;
p_access->info.i_update |= INPUT_UPDATE_SIZE;
}
/* Really at end of file then */
if ((uint64_t)p_access->info.i_pos >= (uint64_t)p_access->info.i_size)
{
p_access->info.b_eof = VLC_TRUE;
msg_Dbg (p_access, "at end of memory mapped file");
return NULL;
}
}
const uintptr_t page_mask = p_sys->page_size - 1;
/* Start the mapping on a page boundary: */
off_t outer_offset = p_access->info.i_pos & ~page_mask;
/* Skip useless bytes at the beginning of the first page: */
size_t inner_offset = p_access->info.i_pos & page_mask;
/* Map no more bytes than remain: */
size_t length = p_sys->mtu;
if (outer_offset + length > p_access->info.i_size)
length = p_access->info.i_size - outer_offset;
assert (outer_offset <= p_access->info.i_pos); /* and */
assert (p_access->info.i_pos < p_access->info.i_size); /* imply */
assert (outer_offset < p_access->info.i_size); /* imply */
assert (length > 0);
/* NOTE: We use PROT_WRITE and MAP_PRIVATE so that the block can be
* modified down the chain, without messing up with the underlying
* original file. This does NOT need open write permission. */
void *addr = mmap (NULL, length, PROT_READ|PROT_WRITE, MAP_PRIVATE,
p_sys->fd, outer_offset);
if (addr == MAP_FAILED)
{
msg_Err (p_access, "memory mapping failed (%m)");
intf_UserFatal (p_access, VLC_FALSE, _("File reading failed"),
_("VLC could not read the file."));
msleep (INPUT_ERROR_SLEEP);
return NULL;
}
block_t *block = block_mmap_Alloc (addr, length);
if (block == NULL)
return NULL;
block->p_buffer += inner_offset;
block->i_buffer -= inner_offset;
#ifndef NDEBUG
msg_Dbg (p_access, "mapped 0x%lx bytes at %p from offset 0x%lx",
(unsigned long)length, addr, (unsigned long)outer_offset);
/* Compare normal I/O with memory mapping */
char *buf = malloc (block->i_buffer);
ssize_t i_read = read (p_sys->fd, buf, block->i_buffer);
if (i_read != (ssize_t)block->i_buffer)
msg_Err (p_access, "read %u instead of %u bytes", (unsigned)i_read,
(unsigned)block->i_buffer);
if (memcmp (buf, block->p_buffer, block->i_buffer))
msg_Err (p_access, "inconsistent data buffer");
free (buf);
#endif
p_access->info.i_pos = outer_offset + length;
return block;
}
static int Seek (access_t *p_access, int64_t i_pos)
{
p_access->info.i_pos = i_pos;
p_access->info.b_eof = VLC_FALSE;
return VLC_SUCCESS;
}
static int Control (access_t *p_access, int query, va_list args)
{
access_sys_t *p_sys = p_access->p_sys;
switch (query)
{
case ACCESS_CAN_SEEK:
case ACCESS_CAN_FASTSEEK:
case ACCESS_CAN_PAUSE:
case ACCESS_CAN_CONTROL_PACE:
*((vlc_bool_t *)va_arg (args, vlc_bool_t *)) = VLC_TRUE;
return VLC_SUCCESS;
case ACCESS_GET_MTU:
*((int *)va_arg (args, int *)) = p_sys->mtu;
return VLC_SUCCESS;
case ACCESS_GET_PTS_DELAY:
*((int64_t *)va_arg (args, int64_t *)) = DEFAULT_PTS_DELAY;
return VLC_SUCCESS;
case ACCESS_GET_TITLE_INFO:
case ACCESS_GET_META:
break;
case ACCESS_SET_PAUSE_STATE:
return VLC_SUCCESS;
case ACCESS_SET_TITLE:
case ACCESS_SET_SEEKPOINT:
case ACCESS_SET_PRIVATE_ID_STATE:
case ACCESS_SET_PRIVATE_ID_CA:
case ACCESS_GET_PRIVATE_ID_STATE:
case ACCESS_GET_CONTENT_TYPE:
break;
default:
msg_Warn (p_access, "unimplemented query %d in control", query);
}
return VLC_EGENERIC;
}
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