Tricks of the Windows Gam…ming Gurus (2nd Edition)/Disc2.iso/vc98/crt/src/_ios.cpp

C/C++ Source or Header | 1998-06-17 | 6KB | 313 lines

/***
*ios.cpp - fuctions for ios class.
*
*       Copyright (c) 1990-1997, Microsoft Corporation.  All rights reserved.
*
*Purpose:
*       Functions for ios class.
*
*******************************************************************************/

#include <cruntime.h>
#include <internal.h>
#include <stdlib.h>
#include <iostream.h>
#include <dbgint.h>
#pragma hdrstop

const long ios::basefield = (ios::dec | ios::oct | ios::hex);
const long ios::adjustfield = (ios::left | ios::right | ios::internal);
const long ios::floatfield = (ios::scientific | ios::fixed);

long ios::x_maxbit = 0x8000;    // ios::openprot
int  ios::x_curindex = -1;

#ifdef _MT
#define MAXINDEX 7
long ios::x_statebuf[MAXINDEX+1] = { 0,0,0,0,0,0,0,0 }; // MAXINDEX * 0
int ios::fLockcInit = 0;        // nonzero = static lock initialized
_CRT_CRITICAL_SECTION ios::x_lockc;
#else  /* _MT */
long  * ios::x_statebuf = NULL;
#endif  /* _MT */

/***
*ios::ios() - default constructor.
*
*Purpose:
*   Initializes an ios.
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

ios::ios()
{
    bp = NULL;
    state = ios::badbit;

    ispecial = 0;
    ospecial = 0;
    x_tie = (0);
    x_flags = 0;
    x_precision = 6;
    x_fill = ' ';
    x_width = 0;
    x_delbuf = 0;

#ifdef _MT
    LockFlg = -1;               // default is now : locking
    _mtlockinit(lockptr());
    if (!fLockcInit++)
        {
        _mtlockinit(&x_lockc);
        }
#endif  /* _MT */

}



/***
*ios::ios( streambuf* pSB ) - constructor.
*
*Purpose:
*   Initializes an ios.
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

ios::ios( streambuf* pSB )
{
//  this->ios();

    bp = pSB;
    state = (bp) ? 0 : ios::badbit;

    ispecial = 0;
    ospecial = 0;
    x_tie = (0);
    x_flags = 0;
    x_precision = 6;
    x_fill = ' ';
    x_width = 0;
    x_delbuf = 0;

#ifdef _MT
    LockFlg = -1;               // default is now : locking
    _mtlockinit(lockptr());
    if (!fLockcInit++)
        {
        _mtlockinit(&x_lockc);
        }
#endif  /* _MT */

}

/***
*ios::ios(const ios& _strm) - copy constructor.
*
*Purpose:
*       Copy constructor.
*
*Entry:
*       _strm = ios to copy data members from.
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/
ios::ios(const ios& _strm)      // copy constructor
{
    bp = NULL;
    x_delbuf = 0;

    *this = _strm;              // invoke assignment operator

#ifdef _MT
    LockFlg = -1;               // default is now : locking
    _mtlockinit(lockptr());
    if (!fLockcInit++)
        {
        _mtlockinit(&x_lockc);
        }
#endif  /* _MT */

}


/***
*virtual ios::~ios() - default destructor.
*
*Purpose:
*   Terminates an ios.
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

ios::~ios()
{
#ifdef _MT
    LockFlg = -1;               // default is now : locking
    if (!--fLockcInit)
        {
        _mtlockterm(&x_lockc);
        }
    _mtlockterm(lockptr());
#endif  /* _MT */

    if ((x_delbuf) && (bp))
        delete bp;

    bp = NULL;
    state = badbit;
}


/***
*void ios::init( streambuf* pSB ) - initializes ios
*
*Purpose:
*   Initializes an ios.
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

void ios::init( streambuf* pSB )
{
    if (delbuf() && (bp))       // delete previous bp if necessary
        delete bp;

    bp = pSB;
    if (bp)
        state &= ~ios::badbit;
    else
        state |= ios::badbit;
}



/***
*ios& ios::operator=( const ios& _strm ) - copy an ios.
*
*Purpose:
*   Copy an ios.
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/

ios& ios::operator=(const ios& _strm)
{
        x_tie = _strm.tie();
        x_flags = _strm.flags();
        x_precision = (char)_strm.precision();
        x_fill  = _strm.fill();
        x_width = (char)_strm.width();

        state = _strm.rdstate();
        if (!bp)
            state |= ios::badbit;       // adjust state for uninitialized bp

        return *this;
}

/***
*int ios::xalloc() - ios xalloc member function
*
*Purpose:
*
*Entry:
*       None.
*
*Exit:
*       Returns index of of new entry in new buffer, or EOF if error.
*
*Exceptions:
*       Returns EOF if OM error.
*
*******************************************************************************/
int  ios::xalloc()
{
#ifdef _MT
    // buffer must be static if multithread, since thread can't keep track of
    // validity of pointer otherwise
    int index;
    lockc();
    if (x_curindex >= MAXINDEX)
        index = EOF;
    else
        {
        index = ++x_curindex;
        }
    unlockc();
    return index;
#else  /* _MT */
    long * tptr;
    int i;

    if (!(tptr=_new_crt long[x_curindex+2]))    // allocate new buffer
        return EOF;

    for (i=0; i <= x_curindex; i++)     // copy old buffer, if any
        tptr[i] = x_statebuf[i];

    tptr[++x_curindex] = 0L;            // init new entry, bump size

    if (x_statebuf)                     // delete old buffer, if any
        delete x_statebuf;

    x_statebuf = tptr;                  // and assign new buffer
    return x_curindex;
#endif  /* _MT */
}

/***
*long ios::bitalloc() - ios bitalloc member function
*
*Purpose:
*       Returns a unused bit mask for flags().
*
*Entry:
*       None.
*
*Exit:
*       Returns next available bit maskf.
*
*Exceptions:
*
*******************************************************************************/
long ios::bitalloc()
{
    long b;
    lockc();            // lock to make sure mask in unique (_MT)
    b = (x_maxbit<<=1);
    unlockc();
    return b;
}