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fileops.c
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/* Copyright (C) 1993, 1995, 1997-2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Written by Per Bothner <bothner@cygnus.com>.
The GNU C Library 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.
The GNU C 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.
As a special exception, if you link the code in this file with
files compiled with a GNU compiler to produce an executable,
that does not cause the resulting executable to be covered by
the GNU Lesser General Public License. This exception does not
however invalidate any other reasons why the executable file
might be covered by the GNU Lesser General Public License.
This exception applies to code released by its copyright holders
in files containing the exception. */
#ifndef _POSIX_SOURCE
# define _POSIX_SOURCE
#endif
#include "libioP.h"
#include <assert.h>
#include <fcntl.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#ifdef __STDC__
#include <stdlib.h>
#endif
#if _LIBC
# include "../wcsmbs/wcsmbsload.h"
# include "../iconv/gconv_charset.h"
# include "../iconv/gconv_int.h"
# include <shlib-compat.h>
# include <not-cancel.h>
#endif
#ifndef errno
extern int errno;
#endif
#ifndef __set_errno
# define __set_errno(Val) errno = (Val)
#endif
#ifdef _LIBC
# define open(Name, Flags, Prot) __open (Name, Flags, Prot)
# define close(FD) __close (FD)
# define lseek(FD, Offset, Whence) __lseek (FD, Offset, Whence)
# define read(FD, Buf, NBytes) __read (FD, Buf, NBytes)
# define write(FD, Buf, NBytes) __write (FD, Buf, NBytes)
# define _IO_do_write _IO_new_do_write /* For macro uses. */
# define _IO_file_close_it _IO_new_file_close_it
#else
# define _IO_new_do_write _IO_do_write
# define _IO_new_file_attach _IO_file_attach
# define _IO_new_file_close_it _IO_file_close_it
# define _IO_new_file_finish _IO_file_finish
# define _IO_new_file_fopen _IO_file_fopen
# define _IO_new_file_init _IO_file_init
# define _IO_new_file_setbuf _IO_file_setbuf
# define _IO_new_file_sync _IO_file_sync
# define _IO_new_file_overflow _IO_file_overflow
# define _IO_new_file_seekoff _IO_file_seekoff
# define _IO_new_file_underflow _IO_file_underflow
# define _IO_new_file_write _IO_file_write
# define _IO_new_file_xsputn _IO_file_xsputn
#endif
#ifdef _LIBC
extern struct __gconv_trans_data __libio_translit attribute_hidden;
#endif
/* An fstream can be in at most one of put mode, get mode, or putback mode.
Putback mode is a variant of get mode.
In a filebuf, there is only one current position, instead of two
separate get and put pointers. In get mode, the current position
is that of gptr(); in put mode that of pptr().
The position in the buffer that corresponds to the position
in external file system is normally _IO_read_end, except in putback
mode, when it is _IO_save_end.
If the field _fb._offset is >= 0, it gives the offset in
the file as a whole corresponding to eGptr(). (?)
PUT MODE:
If a filebuf is in put mode, then all of _IO_read_ptr, _IO_read_end,
and _IO_read_base are equal to each other. These are usually equal
to _IO_buf_base, though not necessarily if we have switched from
get mode to put mode. (The reason is to maintain the invariant
that _IO_read_end corresponds to the external file position.)
_IO_write_base is non-NULL and usually equal to _IO_base_base.
We also have _IO_write_end == _IO_buf_end, but only in fully buffered mode.
The un-flushed character are those between _IO_write_base and _IO_write_ptr.
GET MODE:
If a filebuf is in get or putback mode, eback() != egptr().
In get mode, the unread characters are between gptr() and egptr().
The OS file position corresponds to that of egptr().
PUTBACK MODE:
Putback mode is used to remember "excess" characters that have
been sputbackc'd in a separate putback buffer.
In putback mode, the get buffer points to the special putback buffer.
The unread characters are the characters between gptr() and egptr()
in the putback buffer, as well as the area between save_gptr()
and save_egptr(), which point into the original reserve buffer.
(The pointers save_gptr() and save_egptr() are the values
of gptr() and egptr() at the time putback mode was entered.)
The OS position corresponds to that of save_egptr().
LINE BUFFERED OUTPUT:
During line buffered output, _IO_write_base==base() && epptr()==base().
However, ptr() may be anywhere between base() and ebuf().
This forces a call to filebuf::overflow(int C) on every put.
If there is more space in the buffer, and C is not a '\n',
then C is inserted, and pptr() incremented.
UNBUFFERED STREAMS:
If a filebuf is unbuffered(), the _shortbuf[1] is used as the buffer.
*/
#define CLOSED_FILEBUF_FLAGS \
(_IO_IS_FILEBUF+_IO_NO_READS+_IO_NO_WRITES+_IO_TIED_PUT_GET)
void
_IO_new_file_init (fp)
struct _IO_FILE_plus *fp;
{
/* POSIX.1 allows another file handle to be used to change the position
of our file descriptor. Hence we actually don't know the actual
position before we do the first fseek (and until a following fflush). */
fp->file._offset = _IO_pos_BAD;
fp->file._IO_file_flags |= CLOSED_FILEBUF_FLAGS;
INTUSE(_IO_link_in) (fp);
fp->file._fileno = -1;
}
INTDEF2(_IO_new_file_init, _IO_file_init)
int
_IO_new_file_close_it (fp)
_IO_FILE *fp;
{
int write_status, close_status;
if (!_IO_file_is_open (fp))
return EOF;
if ((fp->_flags & _IO_NO_WRITES) == 0
&& (fp->_flags & _IO_CURRENTLY_PUTTING) != 0)
write_status = _IO_do_flush (fp);
else
write_status = 0;
INTUSE(_IO_unsave_markers) (fp);
close_status = _IO_SYSCLOSE (fp);
/* Free buffer. */
if (fp->_mode <= 0)
{
INTUSE(_IO_setb) (fp, NULL, NULL, 0);
_IO_setg (fp, NULL, NULL, NULL);
_IO_setp (fp, NULL, NULL);
}
#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
else
{
if (_IO_have_wbackup (fp))
INTUSE(_IO_free_wbackup_area) (fp);
INTUSE(_IO_wsetb) (fp, NULL, NULL, 0);
_IO_wsetg (fp, NULL, NULL, NULL);
_IO_wsetp (fp, NULL, NULL);
}
#endif
INTUSE(_IO_un_link) ((struct _IO_FILE_plus *) fp);
fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS;
fp->_fileno = -1;
fp->_offset = _IO_pos_BAD;
return close_status ? close_status : write_status;
}
INTDEF2(_IO_new_file_close_it, _IO_file_close_it)
void
_IO_new_file_finish (fp, dummy)
_IO_FILE *fp;
int dummy;
{
if (_IO_file_is_open (fp))
{
_IO_do_flush (fp);
if (!(fp->_flags & _IO_DELETE_DONT_CLOSE))
_IO_SYSCLOSE (fp);
}
INTUSE(_IO_default_finish) (fp, 0);
}
INTDEF2(_IO_new_file_finish, _IO_file_finish)
_IO_FILE *
_IO_file_open (fp, filename, posix_mode, prot, read_write, is32not64)
_IO_FILE *fp;
const char *filename;
int posix_mode;
int prot;
int read_write;
int is32not64;
{
int fdesc;
#ifdef _G_OPEN64
fdesc = (is32not64
? open (filename, posix_mode, prot)
: _G_OPEN64 (filename, posix_mode, prot));
#else
fdesc = open (filename, posix_mode, prot);
#endif
if (fdesc < 0)
return NULL;
fp->_fileno = fdesc;
_IO_mask_flags (fp, read_write,_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
if ((read_write & _IO_IS_APPENDING) && (read_write & _IO_NO_READS))
if (_IO_SEEKOFF (fp, (_IO_off64_t)0, _IO_seek_end, _IOS_INPUT|_IOS_OUTPUT)
== _IO_pos_BAD && errno != ESPIPE)
{
close (fdesc);
return NULL;
}
INTUSE(_IO_link_in) ((struct _IO_FILE_plus *) fp);
return fp;
}
libc_hidden_def (_IO_file_open)
_IO_FILE *
_IO_new_file_fopen (fp, filename, mode, is32not64)
_IO_FILE *fp;
const char *filename;
const char *mode;
int is32not64;
{
int oflags = 0, omode;
int read_write;
int oprot = 0666;
int i;
_IO_FILE *result;
#ifdef _LIBC
const char *cs;
const char *last_recognized;
#endif
if (_IO_file_is_open (fp))
return 0;
switch (*mode)
{
case 'r':
omode = O_RDONLY;
read_write = _IO_NO_WRITES;
break;
case 'w':
omode = O_WRONLY;
oflags = O_CREAT|O_TRUNC;
read_write = _IO_NO_READS;
break;
case 'a':
omode = O_WRONLY;
oflags = O_CREAT|O_APPEND;
read_write = _IO_NO_READS|_IO_IS_APPENDING;
break;
default:
__set_errno (EINVAL);
return NULL;
}
#ifdef _LIBC
last_recognized = mode;
#endif
for (i = 1; i < 5; ++i)
{
switch (*++mode)
{
case '\0':
break;
case '+':
omode = O_RDWR;
read_write &= _IO_IS_APPENDING;
#ifdef _LIBC
last_recognized = mode;
#endif
continue;
case 'x':
oflags |= O_EXCL;
#ifdef _LIBC
last_recognized = mode;
#endif
continue;
case 'b':
#ifdef _LIBC
last_recognized = mode;
#endif
continue;
case 'm':
fp->_flags2 |= _IO_FLAGS2_MMAP;
continue;
default:
/* Ignore. */
continue;
}
break;
}
result = _IO_file_open (fp, filename, omode|oflags, oprot, read_write,
is32not64);
#ifdef _LIBC
if (result != NULL)
{
/* Test whether the mode string specifies the conversion. */
cs = strstr (last_recognized + 1, ",ccs=");
if (cs != NULL)
{
/* Yep. Load the appropriate conversions and set the orientation
to wide. */
struct gconv_fcts fcts;
struct _IO_codecvt *cc;
char *endp = __strchrnul (cs + 5, ',');
char ccs[endp - (cs + 5) + 3];
*((char *) __mempcpy (ccs, cs + 5, endp - (cs + 5))) = '\0';
strip (ccs, ccs);
if (__wcsmbs_named_conv (&fcts, ccs[2] == '\0'
? upstr (ccs, cs + 5) : ccs) != 0)
{
/* Something went wrong, we cannot load the conversion modules.
This means we cannot proceed since the user explicitly asked
for these. */
(void) INTUSE(_IO_file_close_it) (fp);
__set_errno (EINVAL);
return NULL;
}
assert (fcts.towc_nsteps == 1);
assert (fcts.tomb_nsteps == 1);
fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_read_end;
fp->_wide_data->_IO_write_ptr = fp->_wide_data->_IO_write_base;
/* Clear the state. We start all over again. */
memset (&fp->_wide_data->_IO_state, '\0', sizeof (__mbstate_t));
memset (&fp->_wide_data->_IO_last_state, '\0', sizeof (__mbstate_t));
cc = fp->_codecvt = &fp->_wide_data->_codecvt;
/* The functions are always the same. */
*cc = __libio_codecvt;
cc->__cd_in.__cd.__nsteps = fcts.towc_nsteps;
cc->__cd_in.__cd.__steps = fcts.towc;
cc->__cd_in.__cd.__data[0].__invocation_counter = 0;
cc->__cd_in.__cd.__data[0].__internal_use = 1;
cc->__cd_in.__cd.__data[0].__flags = __GCONV_IS_LAST;
cc->__cd_in.__cd.__data[0].__statep = &result->_wide_data->_IO_state;
/* XXX For now no transliteration. */
cc->__cd_in.__cd.__data[0].__trans = NULL;
cc->__cd_out.__cd.__nsteps = fcts.tomb_nsteps;
cc->__cd_out.__cd.__steps = fcts.tomb;
cc->__cd_out.__cd.__data[0].__invocation_counter = 0;
cc->__cd_out.__cd.__data[0].__internal_use = 1;
cc->__cd_out.__cd.__data[0].__flags = __GCONV_IS_LAST;
cc->__cd_out.__cd.__data[0].__statep =
&result->_wide_data->_IO_state;
/* And now the transliteration. */
cc->__cd_out.__cd.__data[0].__trans = &__libio_translit;
/* Set the mode now. */
result->_mode = 1;
}
}
#endif /* GNU libc */
return result;
}
INTDEF2(_IO_new_file_fopen, _IO_file_fopen)
_IO_FILE *
_IO_new_file_attach (fp, fd)
_IO_FILE *fp;
int fd;
{
if (_IO_file_is_open (fp))
return NULL;
fp->_fileno = fd;
fp->_flags &= ~(_IO_NO_READS+_IO_NO_WRITES);
fp->_flags |= _IO_DELETE_DONT_CLOSE;
/* Get the current position of the file. */
/* We have to do that since that may be junk. */
fp->_offset = _IO_pos_BAD;
if (_IO_SEEKOFF (fp, (_IO_off64_t)0, _IO_seek_cur, _IOS_INPUT|_IOS_OUTPUT)
== _IO_pos_BAD && errno != ESPIPE)
return NULL;
return fp;
}
INTDEF2(_IO_new_file_attach, _IO_file_attach)
_IO_FILE *
_IO_new_file_setbuf (fp, p, len)
_IO_FILE *fp;
char *p;
_IO_ssize_t len;
{
if (_IO_default_setbuf (fp, p, len) == NULL)
return NULL;
fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end
= fp->_IO_buf_base;
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
return fp;
}
INTDEF2(_IO_new_file_setbuf, _IO_file_setbuf)
_IO_FILE *
_IO_file_setbuf_mmap (fp, p, len)
_IO_FILE *fp;
char *p;
_IO_ssize_t len;
{
_IO_FILE *result;
/* Change the function table. */
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps;
fp->_wide_data->_wide_vtable = &_IO_wfile_jumps;
/* And perform the normal operation. */
result = _IO_new_file_setbuf (fp, p, len);
/* If the call failed, restore to using mmap. */
if (result == NULL)
{
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps_mmap;
fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_mmap;
}
return result;
}
static int new_do_write __P ((_IO_FILE *, const char *, _IO_size_t));
/* Write TO_DO bytes from DATA to FP.
Then mark FP as having empty buffers. */
int
_IO_new_do_write (fp, data, to_do)
_IO_FILE *fp;
const char *data;
_IO_size_t to_do;
{
return (to_do == 0
|| (_IO_size_t) new_do_write (fp, data, to_do) == to_do) ? 0 : EOF;
}
INTDEF2(_IO_new_do_write, _IO_do_write)
static
int
new_do_write (fp, data, to_do)
_IO_FILE *fp;
const char *data;
_IO_size_t to_do;
{
_IO_size_t count;
if (fp->_flags & _IO_IS_APPENDING)
/* On a system without a proper O_APPEND implementation,
you would need to sys_seek(0, SEEK_END) here, but is
is not needed nor desirable for Unix- or Posix-like systems.
Instead, just indicate that offset (before and after) is
unpredictable. */
fp->_offset = _IO_pos_BAD;
else if (fp->_IO_read_end != fp->_IO_write_base)
{
_IO_off64_t new_pos
= _IO_SYSSEEK (fp, fp->_IO_write_base - fp->_IO_read_end, 1);
if (new_pos == _IO_pos_BAD)
return 0;
fp->_offset = new_pos;
}
count = _IO_SYSWRITE (fp, data, to_do);
if (fp->_cur_column && count)
fp->_cur_column = INTUSE(_IO_adjust_column) (fp->_cur_column - 1, data,
count) + 1;
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_buf_base;
fp->_IO_write_end = (fp->_mode <= 0
&& (fp->_flags & (_IO_LINE_BUF+_IO_UNBUFFERED))
? fp->_IO_buf_base : fp->_IO_buf_end);
return count;
}
int
_IO_new_file_underflow (fp)
_IO_FILE *fp;
{
_IO_ssize_t count;
#if 0
/* SysV does not make this test; take it out for compatibility */
if (fp->_flags & _IO_EOF_SEEN)
return (EOF);
#endif
if (fp->_flags & _IO_NO_READS)
{
fp->_flags |= _IO_ERR_SEEN;
__set_errno (EBADF);
return EOF;
}
if (fp->_IO_read_ptr < fp->_IO_read_end)
return *(unsigned char *) fp->_IO_read_ptr;
if (fp->_IO_buf_base == NULL)
{
/* Maybe we already have a push back pointer. */
if (fp->_IO_save_base != NULL)
{
free (fp->_IO_save_base);
fp->_flags &= ~_IO_IN_BACKUP;
}
INTUSE(_IO_doallocbuf) (fp);
}
/* Flush all line buffered files before reading. */
/* FIXME This can/should be moved to genops ?? */
if (fp->_flags & (_IO_LINE_BUF|_IO_UNBUFFERED))
{
#if 0
INTUSE(_IO_flush_all_linebuffered) ();
#else
/* We used to flush all line-buffered stream. This really isn't
required by any standard. My recollection is that
traditional Unix systems did this for stdout. stderr better
not be line buffered. So we do just that here
explicitly. --drepper */
_IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile,
_IO_stdout);
_IO_flockfile (_IO_stdout);
if ((_IO_stdout->_flags & (_IO_LINKED | _IO_NO_WRITES | _IO_LINE_BUF))
== (_IO_LINKED | _IO_LINE_BUF))
_IO_OVERFLOW (_IO_stdout, EOF);
_IO_funlockfile (_IO_stdout);
_IO_cleanup_region_end (0);
#endif
}
INTUSE(_IO_switch_to_get_mode) (fp);
/* This is very tricky. We have to adjust those
pointers before we call _IO_SYSREAD () since
we may longjump () out while waiting for
input. Those pointers may be screwed up. H.J. */
fp->_IO_read_base = fp->_IO_read_ptr = fp->_IO_buf_base;
fp->_IO_read_end = fp->_IO_buf_base;
fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end
= fp->_IO_buf_base;
count = _IO_SYSREAD (fp, fp->_IO_buf_base,
fp->_IO_buf_end - fp->_IO_buf_base);
if (count <= 0)
{
if (count == 0)
fp->_flags |= _IO_EOF_SEEN;
else
fp->_flags |= _IO_ERR_SEEN, count = 0;
}
fp->_IO_read_end += count;
if (count == 0)
return EOF;
if (fp->_offset != _IO_pos_BAD)
_IO_pos_adjust (fp->_offset, count);
return *(unsigned char *) fp->_IO_read_ptr;
}
INTDEF2(_IO_new_file_underflow, _IO_file_underflow)
/* Guts of underflow callback if we mmap the file. This stats the file and
updates the stream state to match. In the normal case we return zero.
If the file is no longer eligible for mmap, its jump tables are reset to
the vanilla ones and we return nonzero. */
static int
mmap_remap_check (_IO_FILE *fp)
{
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))
{
const size_t pagesize = __getpagesize ();
# define ROUNDED(x) (((x) + pagesize - 1) & ~(pagesize - 1))
if (ROUNDED (st.st_size) < ROUNDED (fp->_IO_buf_end
- fp->_IO_buf_base))
{
/* We can trim off some pages past the end of the file. */
(void) __munmap (fp->_IO_buf_base + ROUNDED (st.st_size),
ROUNDED (fp->_IO_buf_end - fp->_IO_buf_base)
- ROUNDED (st.st_size));
fp->_IO_buf_end = fp->_IO_buf_base + st.st_size;
}
else if (ROUNDED (st.st_size) > ROUNDED (fp->_IO_buf_end
- fp->_IO_buf_base))
{
/* The file added some pages. We need to remap it. */
void *p;
#if defined __linux__ /* XXX */
p = __mremap (fp->_IO_buf_base, ROUNDED (fp->_IO_buf_end
- fp->_IO_buf_base),
ROUNDED (st.st_size), MREMAP_MAYMOVE);
if (p == MAP_FAILED)
{
(void) __munmap (fp->_IO_buf_base,
fp->_IO_buf_end - fp->_IO_buf_base);
goto punt;
}
#else
(void) __munmap (fp->_IO_buf_base,
fp->_IO_buf_end - fp->_IO_buf_base);
# ifdef _G_MMAP64
p = _G_MMAP64 (NULL, st.st_size, PROT_READ, MAP_SHARED,
fp->_fileno, 0);
# else
p = __mmap (NULL, st.st_size, PROT_READ, MAP_SHARED,
fp->_fileno, 0);
# endif
if (p == MAP_FAILED)
goto punt;
#endif
fp->_IO_buf_base = p;
fp->_IO_buf_end = fp->_IO_buf_base + st.st_size;
}
else
{
/* The number of pages didn't change. */
fp->_IO_buf_end = fp->_IO_buf_base + st.st_size;
}
# undef ROUNDED
fp->_offset -= fp->_IO_read_end - fp->_IO_read_ptr;
_IO_setg (fp, fp->_IO_buf_base,
fp->_offset < fp->_IO_buf_end - fp->_IO_buf_base
? fp->_IO_buf_base + fp->_offset : fp->_IO_buf_end,
fp->_IO_buf_end);
/* If we are already positioned at or past the end of the file, don't
change the current offset. If not, seek past what we have mapped,
mimicking the position left by a normal underflow reading into its
buffer until EOF. */
if (fp->_offset < fp->_IO_buf_end - fp->_IO_buf_base)
{
if (
# ifdef _G_LSEEK64
_G_LSEEK64
# else
__lseek
# endif
(fp->_fileno, fp->_IO_buf_end - fp->_IO_buf_base, SEEK_SET)
!= fp->_IO_buf_end - fp->_IO_buf_base)
fp->_flags |= _IO_ERR_SEEN;
else
fp->_offset = fp->_IO_buf_end - fp->_IO_buf_base;
}
return 0;
}
else
{
/* Life is no longer good for mmap. Punt it. */
(void) __munmap (fp->_IO_buf_base,
fp->_IO_buf_end - fp->_IO_buf_base);
punt:
fp->_IO_buf_base = fp->_IO_buf_end = NULL;
_IO_setg (fp, NULL, NULL, NULL);
if (fp->_mode <= 0)
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps;
else
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps;
fp->_wide_data->_wide_vtable = &_IO_wfile_jumps;
return 1;
}
}
/* Special callback replacing the underflow callbacks if we mmap the file. */
int
_IO_file_underflow_mmap (_IO_FILE *fp)
{
if (fp->_IO_read_ptr < fp->_IO_read_end)
return *(unsigned char *) fp->_IO_read_ptr;
if (__builtin_expect (mmap_remap_check (fp), 0))
/* We punted to the regular file functions. */
return _IO_UNDERFLOW (fp);
if (fp->_IO_read_ptr < fp->_IO_read_end)
return *(unsigned char *) fp->_IO_read_ptr;
fp->_flags |= _IO_EOF_SEEN;
return EOF;
}
static void
decide_maybe_mmap (_IO_FILE *fp)
{
/* 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)
/* Sanity check. */
&& (fp->_offset == _IO_pos_BAD || fp->_offset <= st.st_size))
{
/* Try to map the file. */
void *p;
# ifdef _G_MMAP64
p = _G_MMAP64 (NULL, st.st_size, PROT_READ, MAP_SHARED, fp->_fileno, 0);
# else
p = __mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, fp->_fileno, 0);
# endif
if (p != MAP_FAILED)
{
/* 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. */
if (
# ifdef _G_LSEEK64
_G_LSEEK64
# else
__lseek
# endif
(fp->_fileno, st.st_size, SEEK_SET) != st.st_size)
{
(void) __munmap (p, st.st_size);
fp->_offset = _IO_pos_BAD;
}
else
{
INTUSE(_IO_setb) (fp, p, (char *) p + st.st_size, 0);
if (fp->_offset == _IO_pos_BAD)
fp->_offset = 0;
_IO_setg (fp, p, p + fp->_offset, p + st.st_size);
fp->_offset = 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;
return;
}
}
}
/* We couldn't use mmap, so revert to the vanilla file operations. */
if (fp->_mode <= 0)
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps;
else
_IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_wfile_jumps;
fp->_wide_data->_wide_vtable = &_IO_wfile_jumps;
}
int
_IO_file_underflow_maybe_mmap (_IO_FILE *fp)
{
/* This is the first read attempt. Choose mmap or vanilla operations
and then punt to the chosen underflow routine. */
decide_maybe_mmap (fp);
return _IO_UNDERFLOW (fp);
}
int
_IO_new_file_overflow (f, ch)
_IO_FILE *f;
int ch;
{
if (f->_flags & _IO_NO_WRITES) /* SET ERROR */
{
f->_flags |= _IO_ERR_SEEN;
__set_errno (EBADF);
return EOF;
}
/* If currently reading or no buffer allocated. */
if ((f->_flags & _IO_CURRENTLY_PUTTING) == 0 || f->_IO_write_base == 0)
{
/* Allocate a buffer if needed. */
if (f->_IO_write_base == 0)
{
INTUSE(_IO_doallocbuf) (f);
_IO_setg (f, f->_IO_buf_base, f->_IO_buf_base, f->_IO_buf_base);
}
/* Otherwise must be currently reading.
If _IO_read_ptr (and hence also _IO_read_end) is at the buffer end,
logically slide the buffer forwards one block (by setting the
read pointers to all point at the beginning of the block). This
makes room for subsequent output.
Otherwise, set the read pointers to _IO_read_end (leaving that
alone, so it can continue to correspond to the external position). */
if (f->_IO_read_ptr == f->_IO_buf_end)
f->_IO_read_end = f->_IO_read_ptr = f->_IO_buf_base;
f->_IO_write_ptr = f->_IO_read_ptr;
f->_IO_write_base = f->_IO_write_ptr;
f->_IO_write_end = f->_IO_buf_end;
f->_IO_read_base = f->_IO_read_ptr = f->_IO_read_end;
f->_flags |= _IO_CURRENTLY_PUTTING;
if (f->_mode <= 0 && f->_flags & (_IO_LINE_BUF+_IO_UNBUFFERED))
f->_IO_write_end = f->_IO_write_ptr;
}
if (ch == EOF)
return INTUSE(_IO_do_write) (f, f->_IO_write_base,
f->_IO_write_ptr - f->_IO_write_base);
if (f->_IO_write_ptr == f->_IO_buf_end ) /* Buffer is really full */
if (_IO_do_flush (f) == EOF)
return EOF;
*f->_IO_write_ptr++ = ch;
if ((f->_flags & _IO_UNBUFFERED)
|| ((f->_flags & _IO_LINE_BUF) && ch == '\n'))
if (INTUSE(_IO_do_write) (f, f->_IO_write_base,
f->_IO_write_ptr - f->_IO_write_base) == EOF)
return EOF;
return (unsigned char) ch;
}
INTDEF2(_IO_new_file_overflow, _IO_file_overflow)
int
_IO_new_file_sync (fp)
_IO_FILE *fp;
{
_IO_ssize_t delta;
int retval = 0;
/* char* ptr = cur_ptr(); */
if (fp->_IO_write_ptr > fp->_IO_write_base)
if (_IO_do_flush(fp)) return EOF;
delta = fp->_IO_read_ptr - fp->_IO_read_end;
if (delta != 0)
{
#ifdef TODO
if (_IO_in_backup (fp))
delta -= eGptr () - Gbase ();
#endif
_IO_off64_t new_pos = _IO_SYSSEEK (fp, delta, 1);
if (new_pos != (_IO_off64_t) EOF)
fp->_IO_read_end = fp->_IO_read_ptr;
#ifdef ESPIPE
else if (errno == ESPIPE)
; /* Ignore error from unseekable devices. */
#endif
else
retval = EOF;
}
if (retval != EOF)
fp->_offset = _IO_pos_BAD;
/* FIXME: Cleanup - can this be shared? */
/* setg(base(), ptr, ptr); */
return retval;
}
INTDEF2(_IO_new_file_sync, _IO_file_sync)
static int
_IO_file_sync_mmap (_IO_FILE *fp)
{
if (fp->_IO_read_ptr != fp->_IO_read_end)
{
#ifdef TODO
if (_IO_in_backup (fp))
delta -= eGptr () - Gbase ();
#endif
if (
# ifdef _G_LSEEK64
_G_LSEEK64
# else
__lseek
# endif
(fp->_fileno, fp->_IO_read_ptr - fp->_IO_buf_base, SEEK_SET)
!= fp->_IO_read_ptr - fp->_IO_buf_base)
{
fp->_flags |= _IO_ERR_SEEN;
return EOF;
}
}
fp->_offset = fp->_IO_read_ptr - fp->_IO_buf_base;
fp->_IO_read_end = fp->_IO_read_ptr = fp->_IO_read_base;
return 0;
}
_IO_off64_t
_IO_new_file_seekoff (fp, offset, dir, mode)
_IO_FILE *fp;
_IO_off64_t offset;
int dir;
int mode;
{
_IO_off64_t result;
_IO_off64_t delta, new_offset;
long count;
/* POSIX.1 8.2.3.7 says that after a call the fflush() the file
offset of the underlying file must be exact. */
int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end
&& fp->_IO_write_base == fp->_IO_write_ptr);
if (mode == 0)
dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */
/* Flush unwritten characters.
(This may do an unneeded write if we seek within the buffer.
But to be able to switch to reading, we would need to set
egptr to ptr. That can't be done in the current design,
which assumes file_ptr() is eGptr. Anyway, since we probably
end up flushing when we close(), it doesn't make much difference.)
FIXME: simulate mem-papped files. */
if (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp))
if (INTUSE(_IO_switch_to_get_mode) (fp))
return EOF;
if (fp->_IO_buf_base == NULL)
{
/* It could be that we already have a pushback buffer. */
if (fp->_IO_read_base != NULL)
{
free (fp->_IO_read_base);
fp->_flags &= ~_IO_IN_BACKUP;
}
INTUSE(_IO_doallocbuf) (fp);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
}
switch (dir)
{
case _IO_seek_cur:
/* Adjust for read-ahead (bytes is buffer). */
offset -= fp->_IO_read_end - fp->_IO_read_ptr;
if (fp->_offset == _IO_pos_BAD)
goto dumb;
/* Make offset absolute, assuming current pointer is file_ptr(). */
offset += fp->_offset;
if (offset < 0)
{
__set_errno (EINVAL);
return EOF;
}
dir = _IO_seek_set;
break;
case _IO_seek_set:
break;
case _IO_seek_end:
{
struct _G_stat64 st;
if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode))
{
offset += st.st_size;