strstream.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
//    License along with this library; if not, write to the Free
//    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

#ifndef __STRSTREAM_H
#define __STRSTREAM_H
#ifdef __GNUG__
#pragma interface
#endif
#include <iostream.h>

class strstreambuf : public backupbuf {
    _G_size_t _len; // The current length is max(_len, _pptr-_pbase).
    typedef void *(*_alloc_type)(_G_size_t);
    typedef void (*_free_type)(void*);
    _alloc_type _allocate_buffer;
    _free_type _free_buffer;
    void init_dynamic(_alloc_type alloc, _free_type free,
		      int initial_size = 128);
    void init_const() { xsetflags(_S_NO_WRITES); }
    void init_static(char *ptr, int size, char *pstart);
  protected:
    virtual int overflow(int = EOF);
    virtual int underflow();
    virtual int pbackfail(int c);
  public:
    virtual ~strstreambuf();
    strstreambuf() { init_dynamic(0, 0); }
    strstreambuf(int initial_size) { init_dynamic(0, 0, initial_size); }
    strstreambuf(void *(*alloc)(_G_size_t), void (*free)(void*))
	{ init_dynamic(alloc, free); }
    strstreambuf(char *ptr, int size, char *pstart = NULL)
	{ init_static(ptr, size, pstart); }
    strstreambuf(unsigned char *ptr, int size, unsigned char *pstart = NULL)
	{ init_static((char*)ptr, size, (char*)pstart); }
    strstreambuf(const char *ptr, int size)
	{ init_static((char*)ptr, size, NULL); init_const(); }
    strstreambuf(const unsigned char *ptr, int size)
	{ init_static((char*)ptr, size, NULL); init_const(); }
#ifndef _G_BROKEN_SIGNED_CHAR
    strstreambuf(signed char *ptr, int size, signed char *pstart = NULL)
	{ init_static((char*)ptr, size, (char*)pstart); }
    strstreambuf(const signed char *ptr, int size)
	{ init_static((char*)ptr, size, NULL); init_const(); }
#endif
    int frozen() { return _flags & _S_USER_BUF ? 1 : 0; }
    void freeze(int n=1)
	{ if (n) _flags |= _S_USER_BUF; else _flags &= ~_S_USER_BUF; }
    _G_size_t pcount();
    char *str();
    virtual streampos seekoff(streamoff, _seek_dir, int mode=ios::in|ios::out);
};

class strstreambase : virtual public ios {
  public:
    strstreambuf* rdbuf() { return (strstreambuf*)_strbuf; }
  protected:
    strstreambase() { }
    strstreambase(char *cp, int n, int mode=ios::out);
};

class istrstream : public strstreambase, public istream {
  public:
    istrstream(const char*, int=0);
};

class ostrstream : public strstreambase, public ostream {
  public:
    ostrstream();
    ostrstream(char *cp, int n, int mode=ios::out) :strstreambase(cp,n,mode){}
    _G_size_t pcount() { return ((strstreambuf*)_strbuf)->pcount(); }
    char *str() { return ((strstreambuf*)_strbuf)->str(); }
    void freeze(int n = 1) { ((strstreambuf*)_strbuf)->freeze(n); }
    int frozen() { return ((strstreambuf*)_strbuf)->frozen(); }
};

class strstream : public strstreambase, public iostream {
  public:
    strstream() : strstreambase() { init(new strstreambuf()); }
    strstream(char *cp, int n, int mode=ios::out) :strstreambase(cp,n,mode){}
    _G_size_t pcount() { return ((strstreambuf*)_strbuf)->pcount(); }
    char *str() { return ((strstreambuf*)_strbuf)->str(); }
    void freeze(int n = 1) { ((strstreambuf*)_strbuf)->freeze(n); }
    int frozen() { return ((strstreambuf*)_strbuf)->frozen(); }
};

#endif /*!__STRSTREAM_H*/