streambuf.h

STL完整源码,实现STL文件的读写和三维体的重建及其分析

    int readable();
    int writable();
#endif

    // Used to initialize standard streams. Not needed in this implementation.
    class Init {
    public:
      Init () { }
    };

  protected:
    inline ios(streambuf* sb = 0, ostream* tie_to = 0);
    inline virtual ~ios();
    inline void init(streambuf* sb, ostream* tie = 0);
};

#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.

// 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 : private _IO_marker {
    friend class streambuf;
    void set_offset(int offset) { _pos = offset; }
  public:
    streammarker(streambuf *sb);
    ~streammarker();
    int saving() { return  1; }
    int delta(streammarker&);
    int delta();
};

struct streambuf : public _IO_FILE { // protected??
    friend class ios;
    friend class istream;
    friend class ostream;
    friend class streammarker;
    const void *&_vtable() { return *(const void**)((_IO_FILE*)this + 1); }
  protected:
    static streambuf* _list_all; /* List of open streambufs. */
    _IO_FILE*& xchain() { return _chain; }
    void _un_link();
    void _link_in();
    char* gptr() const
      { return _IO_file_flags & _IO_IN_BACKUP ? _IO_save_base : _IO_read_ptr; }
    char* pptr() const { return _IO_write_ptr; }
    char* egptr() const
      { return _IO_file_flags & _IO_IN_BACKUP ? _IO_save_end : _IO_read_end; }
    char* epptr() const { return _IO_write_end; }
    char* pbase() const { return _IO_write_base; }
    char* eback() const
      { return _IO_file_flags & _IO_IN_BACKUP ? _IO_save_base : _IO_read_base;}
    char* base() const { return _IO_buf_base; }
    char* ebuf() const { return _IO_buf_end; }
    int blen() const { return _IO_buf_end - _IO_buf_base; }
    void xput_char(char c) { *_IO_write_ptr++ = c; }
    int xflags() { return _IO_file_flags; }
    int xflags(int f) {int fl = _IO_file_flags; _IO_file_flags = f; return fl;}
    void xsetflags(int f) { _IO_file_flags |= f; }
    void xsetflags(int f, int mask)
      { _IO_file_flags = (_IO_file_flags & ~mask) | (f & mask); }
    void gbump(int n)
      { _IO_file_flags & _IO_IN_BACKUP ? (_IO_save_base+=n):(_IO_read_ptr+=n);}
    void pbump(int n) { _IO_write_ptr += n; }
    void setb(char* b, char* eb, int a=0);
    void setp(char* p, char* ep)
      { _IO_write_base=_IO_write_ptr=p; _IO_write_end=ep; }
    void setg(char* eb, char* g, char *eg) {
      if (_IO_file_flags & _IO_IN_BACKUP) _IO_free_backup_area(this); 
      _IO_read_base = eb; _IO_read_ptr = g; _IO_read_end = eg; }
    char *shortbuf() { return _shortbuf; }

    int in_backup() { return _flags & _IO_IN_BACKUP; }
    // The start of the main get area:  FIXME:  wrong for write-mode filebuf?
    char *Gbase() { return in_backup() ? _IO_save_base : _IO_read_base; }
    // The end of the main get area:
    char *eGptr() { return in_backup() ? _IO_save_end : _IO_read_end; }
    // The start of the backup area:
    char *Bbase() { return in_backup() ? _IO_read_base : _IO_save_base; }
    char *Bptr() { return _IO_backup_base; }
    // The end of the backup area:
    char *eBptr() { return in_backup() ? _IO_read_end : _IO_save_end; }
    char *Nbase() { return _IO_save_base; }
    char *eNptr() { return _IO_save_end; }
    int have_backup() { return _IO_save_base != NULL; }
    int have_markers() { return _markers != NULL; }
    void free_backup_area();
    void unsave_markers(); // Make all streammarkers !saving().
    int put_mode() { return _flags & _IO_CURRENTLY_PUTTING; }
    int switch_to_get_mode();
    
    streambuf(int flags=0);
  public:
    static int flush_all();
    static void flush_all_linebuffered(); // Flush all line buffered files.
    virtual ~streambuf();
    virtual int overflow(int c = EOF); // Leave public for now
    virtual int underflow(); // Leave public for now
    virtual int uflow(); // Leave public for now
    virtual int pbackfail(int c);
//    virtual int showmany ();
    virtual streamsize xsputn(const char* s, streamsize n);
    virtual streamsize xsgetn(char* s, streamsize n);
    virtual streampos seekoff(streamoff, _seek_dir, int mode=ios::in|ios::out);
    virtual streampos seekpos(streampos pos, int mode = ios::in|ios::out);

    streampos pubseekoff(streamoff o, _seek_dir d, int mode=ios::in|ios::out)
      { return _IO_seekoff (this, o, d, mode); }
    streampos pubseekpos(streampos pos, int mode = ios::in|ios::out)
      { return _IO_seekpos (this, pos, mode); }
    streampos sseekoff(streamoff, _seek_dir, int mode=ios::in|ios::out);
    streampos sseekpos(streampos pos, int mode = ios::in|ios::out);
    virtual streambuf* setbuf(char* p, int len);
    virtual int sync();
    virtual int doallocate();

    int seekmark(streammarker& mark, int delta = 0);
    int sputbackc(char c);
    int sungetc();
    int unbuffered() { return _flags & _IO_UNBUFFERED ? 1 : 0; }
    int linebuffered() { return _flags & _IO_LINE_BUF ? 1 : 0; }
    void unbuffered(int i)
	{ if (i) _flags |= _IO_UNBUFFERED; else _flags &= ~_IO_UNBUFFERED; }
    void linebuffered(int i)
	{ if (i) _flags |= _IO_LINE_BUF; else _flags &= ~_IO_LINE_BUF; }
    int allocate() { // For AT&T compatibility
	if (base() || unbuffered()) return 0;
	else return doallocate(); }
    // Allocate a buffer if needed; use _shortbuf if appropriate.
    void allocbuf() { if (base() == NULL) doallocbuf(); }
    void doallocbuf();
    int in_avail() { return _IO_read_end - _IO_read_ptr; }
    int out_waiting() { return _IO_write_ptr - _IO_write_base; }
    streamsize sputn(const char* s, streamsize n) { return xsputn(s, n); }
    streamsize padn(char pad, streamsize n) { return _IO_padn(this, pad, n); }
    streamsize sgetn(char* s, streamsize n) { return _IO_sgetn(this, s, n); }
    int ignore(int);
    int get_column();
    int set_column(int);
    long sgetline(char* buf, _IO_size_t n, char delim, int putback_delim);
    int sputc(int c) { return _IO_putc(c, this); }
    int sbumpc() { return _IO_getc(this); }
    int sgetc() { return _IO_peekc(this); }
    int snextc() {
	if (_IO_read_ptr >= _IO_read_end && __underflow(this) == EOF)
	  return EOF;
	else return _IO_read_ptr++, sgetc(); }
    void stossc() { if (_IO_read_ptr < _IO_read_end) _IO_read_ptr++; }
    int vscan(char const *fmt0, _IO_va_list ap, ios* stream = NULL);
    int scan(char const *fmt0 ...);
    int vform(char const *fmt0, _IO_va_list ap);
    int form(char const *fmt0 ...);
#if 0 /* Work in progress */
    int column();  // Current column number (of put pointer). -1 is unknown.
    void column(int c);  // Set column number of put pointer to c.
#endif
    virtual streamsize sys_read(char* buf, streamsize size);
    virtual streamsize sys_write(const char*, streamsize);
    virtual streampos sys_seek(streamoff, _seek_dir);
    virtual int sys_close();
    virtual int sys_stat(void*); // Actually, a (struct stat*)
#if _G_IO_IO_FILE_VERSION == 0x20001
    virtual int showmanyc();
    virtual void imbue(void *);
#endif
};

// A backupbuf is a streambuf with full backup and savepoints on reading.
// All standard streambufs in the GNU iostream library are backupbufs.

class filebuf : public streambuf {
  protected:
    void init();
  public:
    static const int openprot; // Non-ANSI AT&T-ism:  Default open protection.
    filebuf();
    filebuf(int fd);
    filebuf(int fd, char* p, int len);
#if !_IO_UNIFIED_JUMPTABLES
    static filebuf *__new();
#endif
    ~filebuf();
    filebuf* attach(int fd);
    filebuf* open(const char *filename, const char *mode);
    filebuf* open(const char *filename, ios::openmode mode, int prot = 0664);
    virtual int underflow();
    virtual int overflow(int c = EOF);
    int is_open() const { return _fileno >= 0; }
    int fd() const { return is_open() ? _fileno : EOF; }
    filebuf* close();
    virtual int doallocate();
    virtual streampos seekoff(streamoff, _seek_dir, int mode=ios::in|ios::out);
    virtual streambuf* setbuf(char* p, int len);
    streamsize xsputn(const char* s, streamsize n);
    streamsize xsgetn(char* s, streamsize n);
    virtual int sync();
  protected: // See documentation in filebuf.C.
//    virtual int pbackfail(int c);
    int is_reading() { return eback() != egptr(); }
    char* cur_ptr() { return is_reading() ?  gptr() : pptr(); }
    /* System's idea of pointer */
    char* file_ptr() { return eGptr(); }
    // Low-level operations (Usually invoke system calls.)
    virtual streamsize sys_read(char* buf, streamsize size);
    virtual streampos sys_seek(streamoff, _seek_dir);
    virtual streamsize sys_write(const char*, streamsize);
    virtual int sys_stat(void*); // Actually, a (struct stat*)
    virtual int sys_close();
#if 0
    virtual uflow;
    virtual showmany;
#endif
};

inline void ios::init(streambuf* sb, ostream* tie_to) {
		_state = sb ? ios::goodbit : ios::badbit; _exceptions=0;
		_strbuf=sb; _tie = tie_to; _width=0; _fill=' ';
#ifdef _IO_NEW_STREAMS
		_flags=ios::skipws|ios::dec;
#else
		_flags=ios::skipws|ios::dec|ios::dont_close;
#endif
		_precision=6; _arrays = 0; }

inline ios::ios(streambuf* sb, ostream* tie_to) { init(sb, tie_to); }

inline ios::~ios() {
#ifndef _IO_NEW_STREAMS
    if (!(_flags & (unsigned int)ios::dont_close)) delete rdbuf();
#endif
    if (_arrays) delete [] _arrays;
}
} // extern "C++"
#endif /* _STREAMBUF_H */