streambuf.h

早期freebsd实现

//    This is part of the iostream library, providing -*- C++ -*- input/output.
//    Copyright (C) 1991 Per Bothner.
//
//    This library is free software; you can redistribute it and/or
//    modify it under the terms of the GNU Library General Public
//    License as published by the Free Software Foundation; either
//    version 2 of the License, or (at your option) any later version.
//
//    This 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
//    Library General Public License for more details.
//
//    You should have received a copy of the GNU Library General Public


#ifndef _STREAMBUF_H
#define _STREAMBUF_H
#ifdef __GNUG__
#pragma interface
#endif

/* #define _G_IO_THROW */ /* Not implemented:  ios::failure */

#include <_G_config.h>
#ifdef _G_NEED_STDARG_H
#include <stdarg.h>
#endif
#ifndef fpos_t
#define fpos_t _G_fpos_t
#endif

#ifndef EOF
#define EOF (-1)
#endif
#ifndef NULL
#define NULL ((void*)0)
#endif

class ostream; class streambuf; class backupbuf;

// In case some header files defines these as macros.
#undef open
#undef close

#ifdef _G_FRIEND_BUG
extern int __UNDERFLOW(streambuf*);
extern int __OVERFLOW(streambuf*, int);
#endif
extern "C" int __underflow(streambuf*);
extern "C" int __overflow(streambuf*, int);

typedef _G_off_t streamoff;
typedef _G_off_t streampos; // Should perhaps be _G_fpos_t ?

typedef unsigned long __fmtflags;
typedef unsigned char __iostate;

struct _ios_fields { // The data members of an ios.
    streambuf *_strbuf;
    ostream* _tie;
    int _width;
    __fmtflags _flags;
    _G_wchar_t _fill;
    __iostate _state;
    __iostate _exceptions;
    int _precision;
};

#define _IOS_GOOD	0
#define _IOS_EOF	1
#define _IOS_FAIL	2
#define _IOS_BAD	4

#define _IOS_INPUT	1
#define _IOS_OUTPUT	2
#define _IOS_ATEND	4
#define _IOS_APPEND	8
#define _IOS_TRUNC	16
#define _IOS_NOCREATE	32
#define _IOS_NOREPLACE	64
#define _IOS_BIN	128

#ifdef _STREAM_COMPAT
enum state_value {
    _good = _IOS_GOOD,
    _eof = _IOS_EOF,
    _fail = _IOS_FAIL,
    _bad = _IOS_BAD };
enum open_mode {
    input = _IOS_INPUT,
    output = _IOS_OUTPUT,
    atend = _IOS_ATEND,
    append = _IOS_APPEND };
#endif

class ios : public _ios_fields {
  public:
    typedef __fmtflags fmtflags;
    typedef int iostate;
    typedef int openmode;
    enum io_state {
	goodbit = _IOS_GOOD,
	eofbit = _IOS_EOF,
	failbit = _IOS_FAIL,
	badbit = _IOS_BAD };
    enum open_mode {
	in = _IOS_INPUT,
	out = _IOS_OUTPUT,
	ate = _IOS_ATEND,
	app = _IOS_APPEND,
	trunc = _IOS_TRUNC,
	nocreate = _IOS_NOCREATE,
	noreplace = _IOS_NOREPLACE,
	bin = _IOS_BIN };
    enum seek_dir { beg, cur, end};
    // ANSI: typedef enum seek_dir seekdir; etc
    enum { skipws=01, left=02, right=04, internal=010,
	   dec=020, oct=040, hex=0100,
	   showbase=0200, showpoint=0400, uppercase=01000, showpos=02000,
	   scientific=04000, fixed=010000, unitbuf=020000, stdio=040000,
	   dont_close=0x80000000 //Don't delete streambuf on stream destruction
	   };
    enum { // Masks.
	basefield=dec+oct+hex,
	floatfield = scientific+fixed,
	adjustfield = left+right+internal
    };

#ifdef _G_IO_THROW
    class failure : public xmsg {
	ios* _stream;
      public:
	failure(ios* stream) { _stream = stream; }
	failure(string cause, ios* stream) { _stream = stream; }
	ios* rdios() const { return _stream; }
    };
#endif

    ostream* tie() const { return _tie; }
    ostream* tie(ostream* val) { ostream* save=_tie; _tie=val; return save; }

    // Methods to change the format state.
    _G_wchar_t fill() const { return (_G_wchar_t)_fill; }
    _G_wchar_t fill(_G_wchar_t newf)
	{_G_wchar_t oldf = (_G_wchar_t)_fill; _fill = (char)newf; return oldf;}
    fmtflags flags() const { return _flags; }
    fmtflags flags(fmtflags new_val) {
	fmtflags old_val = _flags; _flags = new_val; return old_val; }
    int precision() const { return _precision; }
    int precision(int newp) {
	unsigned short oldp = _precision; _precision = (unsigned short)newp;
	return oldp; }
    fmtflags setf(fmtflags val) {
	fmtflags oldbits = _flags;
	_flags |= val; return oldbits; }
    fmtflags setf(fmtflags val, fmtflags mask) {
	fmtflags oldbits = _flags;
	_flags = (_flags & ~mask) | (val & mask); return oldbits; }
    fmtflags unsetf(fmtflags mask) {
	fmtflags oldbits = _flags & mask;
	_flags &= ~mask; return oldbits; }
    int width() const { return _width; }
    int width(int val) { int save = _width; _width = val; return save; }

#ifdef _G_IO_THROW
    void _throw_failure() { throw new ios::failure(this); }
#else
    void _throw_failure() { }
#endif

    streambuf* rdbuf() const { return _strbuf; }
    void clear(iostate state = 0) {
	_state = _strbuf ? state : state|badbit;
	if (_state & _exceptions) _throw_failure(); }
    void set(iostate flag) { _state |= flag;
	if (_state & _exceptions) _throw_failure(); }
    int good() const { return _state == 0; }
    int eof() const { return _state & ios::eofbit; }
    int fail() const { return _state & (ios::badbit|ios::failbit); }
    int bad() const { return _state & ios::badbit; }
    iostate rdstate() const { return _state; }
    operator void*() const { return fail() ? (void*)0 : (void*)(-1); }
    int operator!() const { return fail(); }
    iostate exception(iostate enable) {
	iostate old = _exceptions; _exceptions = enable;
	if (_state & _exceptions) _throw_failure();
	return old; }

    static int sync_with_stdio(int on);
    static void sync_with_stdio() { sync_with_stdio(1); }

#ifdef _STREAM_COMPAT
    void unset(state_value flag) { _state &= ~flag; }
    void close();
    int is_open();
    int readable();
    int writable();
#endif

  protected:
    ios(streambuf* sb = 0, ostream* tie = 0);
    virtual ~ios();
    void init(streambuf* sb) { _state=0; _strbuf=sb; }
};

#if __GNUG__==1
typedef int _seek_dir;
#else
typedef ios::seek_dir _seek_dir;
#endif

// Magic numbers and bits for the _flags field.
// The magic numbers use the high-order bits of _flags;
// the remaining bits are abailable for variable flags.
// Note: The magic numbers must all be negative if stdio
// emulation is desired.

#define _IO_MAGIC 0xFBAD0000 /* Magic number */
#define _OLD_STDIO_MAGIC 0xFABC0000 /* Emulate old stdio. */
#define _IO_MAGIC_MASK 0xFFFF0000
#define _S_USER_BUF 1 /* User owns buffer; don't delete it on close. */
#define _S_UNBUFFERED 2
#define _S_NO_READS 4 /* Reading not allowed */
#define _S_NO_WRITES 8 /* Writing not allowd */
#define _S_EOF_SEEN 0x10
#define _S_ERR_SEEN 0x20
#define _S_DELETE_DONT_CLOSE 0x40
#define _S_LINKED 0x80 // Set if linked (using _chain) to streambuf::_list_all.
#define _S_IN_BACKUP 0x100
#define _S_LINE_BUF 0x200
#define _S_TIED_PUT_GET 0x400 // Set if put and get pointer logicly tied.
#define _S_CURRENTLY_PUTTING 0x800
#define _S_IS_APPENDING 0x1000
#define _S_IS_BACKUPBUF 0x4000
#define _S_IS_FILEBUF 0x8000

// A streammarker remembers a position in a buffer.
// You are guaranteed to be able to seek back to it if it is saving().
class streammarker {
    friend class streambuf;
#ifdef _G_FRIEND_BUG
    friend int __UNDERFLOW(streambuf*);