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2002-01-07  Ulrich Drepper  <drepper@redhat.com>

	* libio/fileops.c (_IO_file_underflow_mmap): New function.
	(_IO_file_close_mmap): New function.
	(_IO_file_jumps_mmap): New variable.
	* libio/wfileops.c (_IO_wfile_underflow): Reset read pointer before
	trying to convert rest of byte buffer.
	(_IO_wfile_underflow_mmap): New function.
	(_IO_wfile_jumps_mmap): New variable.
	* libio/iofopen.c (__fopen_maybe_mmap): New function.
	(__fopen_internal): New function.  Split out from _IO_new_fopen.
	(_IO_new_fopen): Call __fopen_internal.
	* libio/iofopen64.c: Just call __fopen_internal.
	* libio/iofdopen.c: Call __fopen_maybe_mmap before returning
	successfully.
	* libio/iolibio.h: Declare __fopen_internal and __fopen_maybe_mmap.
	* libio/libioP.h: Declare _IO_file_jumps_mmap, _IO_wfile_jumps_mmap,
	_IO_file_close_mmap.

	* sysdeps/gnu/_G_config.h: Define _G_MMAP64.
	* sysdeps/unix/sysv/linux/cris/_G_config.h: Likewise.

	* stdio-common/Makefile (tests): Add tst-rndseek.
	* stdio-common/tst-rndseek.c: New file.
This commit is contained in:
Ulrich Drepper
2002-01-07 09:33:53 +00:00
parent 463918b5f2
commit 0469311e87
11 changed files with 271 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

85
libio/iofopen.c
View File

@ -1,4 +1,4 @@
/* Copyright (C) 1993, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
/* Copyright (C) 1993,1997,1998,1999,2000,2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@ -28,6 +28,7 @@
#include "libioP.h"
#ifdef __STDC__
#include <stdlib.h>
#include <stddef.h>
#endif
#ifdef _LIBC
# include <shlib-compat.h>
@ -36,9 +37,76 @@
#endif
_IO_FILE *
_IO_new_fopen (filename, mode)
__fopen_maybe_mmap (fp)
_IO_FILE *fp;
{
#ifdef _G_HAVE_MMAP
if (fp->_flags & _IO_NO_WRITES)
{
/* We use the file in read-only mode. This could mean we can
mmap the file and use it without any copying. But not all
file descriptors are for mmap-able objects and on 32-bit
machines we don't want to map files which are too large since
this would require too much virtual memory. */
struct _G_stat64 st;
if (_IO_SYSSTAT (fp, &st) == 0
&& S_ISREG (st.st_mode) && st.st_size != 0
/* Limit the file size to 1MB for 32-bit machines. */
&& (sizeof (ptrdiff_t) > 4 || st.st_size < 1*1024*1024))
{
/* Try to map the file. */
void *p;
# ifdef _G_MMAP64
p = _G_MMAP64 (NULL, st.st_size, PROT_READ, MAP_PRIVATE,
fp->_fileno, 0);
# else
p = __mmap (NULL, st.st_size, PROT_READ, MAP_PRIVATE,
fp->_fileno, 0);
# endif
if (p != MAP_FAILED)
{
if (
# ifdef _G_LSEEK64
_G_LSEEK64 (fp->_fileno, st.st_size, SEEK_SET)
# else
__lseek (fp->_fileno, st.st_size, SEEK_SET)
# endif
!= st.st_size)
{
/* We cannot search the file. Don't mmap then. */
__munmap (p, st.st_size);
return fp;
}
/* OK, we managed to map the file. Set the buffer up
and use a special jump table with simplified
underflow functions which never tries to read
anything from the file. */
_IO_setb (fp, p, (char *) p + st.st_size, 0);
_IO_setg (fp, p, p, (char *) p + st.st_size);
if (fp->_mode <= 0)
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps_mmap;
else
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps_mmap;
fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_mmap;
fp->_offset = st.st_size;
}
}
}
#endif
return fp;
}
_IO_FILE *
__fopen_internal (filename, mode, is32)
const char *filename;
const char *mode;
int is32;
{
struct locked_FILE
{
@ -64,13 +132,22 @@ _IO_new_fopen (filename, mode)
#if !_IO_UNIFIED_JUMPTABLES
new_f->fp.vtable = NULL;
#endif
if (_IO_file_fopen ((_IO_FILE *) new_f, filename, mode, 1) != NULL)
return (_IO_FILE *) &new_f->fp;
if (_IO_file_fopen ((_IO_FILE *) new_f, filename, mode, is32) != NULL)
return __fopen_maybe_mmap (&new_f->fp.file);
_IO_un_link (&new_f->fp);
free (new_f);
return NULL;
}
_IO_FILE *
_IO_new_fopen (filename, mode)
const char *filename;
const char *mode;
{
return __fopen_internal (filename, mode, 1);
}
#ifdef _LIBC
strong_alias (_IO_new_fopen, __new_fopen)
versioned_symbol (libc, _IO_new_fopen, _IO_fopen, GLIBC_2_1);