glibc/libio/strfile.h

/* Copyright (C) 1993, 1997, 1998, 1999 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
   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.  */

#include <libio.h>
#ifdef TODO
Merge into  libio.h ?
#endif

typedef void *(*_IO_alloc_type) (_IO_size_t);
typedef void (*_IO_free_type) (void*);

struct _IO_str_fields
{
  _IO_alloc_type _allocate_buffer;
  _IO_free_type _free_buffer;
};

/* This is needed for the Irix6 N32 ABI, which has a 64 bit off_t type,
   but a 32 bit pointer type.  In this case, we get 4 bytes of padding
   after the vtable pointer.  Putting them in a structure together solves
   this problem.  */

struct _IO_streambuf
{
  struct _IO_FILE _f;
  const void *_vtable;
};

typedef struct _IO_strfile_
{
  struct _IO_streambuf _sbf;
  struct _IO_str_fields _s;
} _IO_strfile;

/* dynamic: set when the array object is allocated (or reallocated)  as
   necessary to hold a character sequence that can change in length. */
#define _IO_STR_DYNAMIC(FP) ((FP)->_s._allocate_buffer != (_IO_alloc_type)0)

/* frozen: set when the program has requested that the array object not
   be altered, reallocated, or freed. */
#define _IO_STR_FROZEN(FP) ((FP)->_f._IO_file_flags & _IO_USER_BUF)