mirror of https://github.com/tongzx/nt5src
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
444 lines
8.6 KiB
444 lines
8.6 KiB
/***
|
|
*streamb.cpp - fuctions for streambuf class.
|
|
*
|
|
* Copyright (c) 1990-2001, Microsoft Corporation. All rights reserved.
|
|
*
|
|
*Purpose:
|
|
* Functions for streambuf class.
|
|
*
|
|
*Revision History:
|
|
* 09-10-90 WAJ Initial version.
|
|
* 07-02-91 KRS Initial version completed.
|
|
* 08-20-91 KRS Treat chars as unsigned; fix sgetn() function.
|
|
* 09-06-91 KRS Do a sync() in ~streambuf before destroying buffer.
|
|
* 11-18-91 KRS Split off stream1.cxx for input-specific code.
|
|
* 12-09-91 KRS Fix up xsputn/xsgetn usage.
|
|
* 03-03-92 KRS Added mthread lock init calls to constructors.
|
|
* 06-02-92 KRS CAV #1745: Don't confuse 0xFF with EOF in xsputn()
|
|
* call to overflow().
|
|
* 04-06-93 JWM Changed constructors to enable locking by default.
|
|
* 10-28-93 SKS Add call to _mttermlock() in streamb::~streamb to clean
|
|
* up o.s. resources associated with a Critical Section.
|
|
* 09-06-94 CFW Replace MTHREAD with _MT.
|
|
* 01-12-95 CFW Debug CRT allocs.
|
|
* 03-17-95 CFW Change debug delete scheme.
|
|
* 03-21-95 CFW Remove _delete_crt.
|
|
* 06-14-95 CFW Comment cleanup.
|
|
* 03-04-98 RKP Restrict size to 2GB on 64 bit systems.
|
|
*
|
|
*******************************************************************************/
|
|
|
|
#include <cruntime.h>
|
|
#include <internal.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <iostream.h>
|
|
#include <dbgint.h>
|
|
#pragma hdrstop
|
|
|
|
|
|
#ifndef BUFSIZ
|
|
#define BUFSIZ 512
|
|
#endif
|
|
|
|
/***
|
|
*streambuf::streambuf() -
|
|
*
|
|
*Purpose:
|
|
* Default constructor.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
streambuf::streambuf()
|
|
{
|
|
_fAlloc = 0;
|
|
_fUnbuf = 0;
|
|
x_lastc = EOF;
|
|
_base = NULL;
|
|
_ebuf = NULL;
|
|
_pbase = NULL;
|
|
_pptr = NULL;
|
|
_epptr = NULL;
|
|
_eback = NULL;
|
|
_gptr = NULL;
|
|
_egptr = NULL;
|
|
|
|
#ifdef _MT
|
|
LockFlg = -1; // default is now : locking
|
|
_mtlockinit(lockptr());
|
|
#endif /* _MT */
|
|
|
|
}
|
|
|
|
/***
|
|
*streambuf::streambuf(char* pBuf, int cbBuf) -
|
|
*
|
|
*Purpose:
|
|
* Constructor which specifies a buffer area.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
streambuf::streambuf( char* pBuf, int cbBuf )
|
|
{
|
|
_fAlloc = 0;
|
|
_fUnbuf = 0;
|
|
x_lastc = EOF;
|
|
_base = pBuf;
|
|
_ebuf = pBuf + (unsigned)cbBuf;
|
|
_pbase = NULL;
|
|
_pptr = NULL;
|
|
_epptr = NULL;
|
|
_eback = NULL;
|
|
_gptr = NULL;
|
|
_egptr = NULL;
|
|
|
|
if( pBuf == NULL || cbBuf == 0 ){
|
|
_fUnbuf = 1;
|
|
_base = NULL;
|
|
_ebuf = NULL;
|
|
}
|
|
|
|
#ifdef _MT
|
|
LockFlg = -1; // default is now : locking
|
|
_mtlockinit(lockptr());
|
|
#endif /* _MT */
|
|
|
|
}
|
|
|
|
|
|
/***
|
|
*virtual streambuf::~streambuf() -
|
|
*
|
|
*Purpose:
|
|
* Destructor.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
streambuf::~streambuf()
|
|
{
|
|
#ifdef _MT
|
|
_mtlockterm(lockptr());
|
|
#endif /* _MT */
|
|
|
|
sync(); // make sure buffer empty before possibly destroying it
|
|
if( (_fAlloc) && (_base) )
|
|
delete _base;
|
|
}
|
|
|
|
|
|
/***
|
|
* virtual streambuf * streambuf::setbuf(char * p, int len) -
|
|
*
|
|
*Purpose:
|
|
* Offers the array at p with len bytes to be used as a reserve area.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
streambuf * streambuf::setbuf(char * p, int len)
|
|
{
|
|
if (!_base)
|
|
{
|
|
if ((!p) || (!len))
|
|
_fUnbuf = 1; // mark as unbuffered
|
|
else
|
|
{
|
|
_base = p;
|
|
_ebuf = p + (unsigned)len;
|
|
_fUnbuf = 0;
|
|
}
|
|
return (this);
|
|
}
|
|
return((streambuf *)NULL);
|
|
}
|
|
|
|
|
|
/***
|
|
*virtual int streambuf::xsputn( char* pBuf, int cbBuf ) -
|
|
*
|
|
*Purpose:
|
|
* Tries to output cbBuf characters. Returns number of characters
|
|
* that were outputted.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
int streambuf::xsputn( const char* pBuf, int cbBuf )
|
|
{
|
|
int cbOut;
|
|
|
|
for (cbOut = 0; cbBuf--; cbOut++)
|
|
{
|
|
if ((_fUnbuf) || (_pptr >= _epptr))
|
|
{
|
|
if (overflow((unsigned char)*pBuf)==EOF) // 0-extend 0xFF !=EOF
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
*(_pptr++) = *pBuf;
|
|
}
|
|
pBuf++;
|
|
}
|
|
return cbOut;
|
|
}
|
|
|
|
/***
|
|
*virtual int streambuf::xsgetn( char* pBuf, int cbBuf ) -
|
|
*
|
|
*Purpose:
|
|
* Tries to input cbBuf characters. Returns number of characters
|
|
* that were read from streambuf.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
// #pragma intrinsic(memcpy,__min)
|
|
|
|
int streambuf::xsgetn( char * pBuf, int cbBuf)
|
|
{
|
|
int count;
|
|
int cbIn = 0;
|
|
if (_fUnbuf)
|
|
{
|
|
if (x_lastc==EOF)
|
|
x_lastc=underflow();
|
|
|
|
while (cbBuf--)
|
|
{
|
|
if (x_lastc==EOF)
|
|
break;
|
|
*(pBuf++) = (char)x_lastc;
|
|
cbIn++;
|
|
x_lastc=underflow();
|
|
}
|
|
}
|
|
else
|
|
{
|
|
while (cbBuf)
|
|
{
|
|
if (underflow()==EOF) // make sure something to read
|
|
break;
|
|
count = __min((int)(egptr() - gptr()),cbBuf);
|
|
if (count>0)
|
|
{
|
|
memcpy(pBuf,gptr(),count);
|
|
pBuf += count;
|
|
_gptr += count;
|
|
cbIn += count;
|
|
cbBuf -= count;
|
|
}
|
|
}
|
|
}
|
|
return cbIn;
|
|
}
|
|
|
|
/***
|
|
*virtual int streambuf::sync() -
|
|
*
|
|
*Purpose:
|
|
* Tries to flush all data in put area and give back any data in the
|
|
* get area (if possible), leaving both areas empty on exit.
|
|
* Default behavior is to fail unless buffers empty.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
int streambuf::sync()
|
|
{
|
|
if ((gptr() <_egptr) || (_pptr > _pbase))
|
|
{
|
|
return EOF;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/***
|
|
*int streambuf::allocate() -
|
|
*
|
|
*Purpose:
|
|
* Tries to set up a Reserve Area. If one already exists, or if
|
|
* unbuffered, just returns 0.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
int streambuf::allocate()
|
|
{
|
|
if ((_fUnbuf) || (_base))
|
|
return 0;
|
|
if (doallocate()==EOF) return EOF;
|
|
|
|
return(1);
|
|
}
|
|
|
|
/***
|
|
*virtual int streambuf::doallocate() -
|
|
*
|
|
*Purpose:
|
|
* Tries to set up a Reserve Area. Returns EOF if unsuccessful.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
int streambuf::doallocate()
|
|
{
|
|
char * tptr;
|
|
if (!( tptr = _new_crt char[BUFSIZ]))
|
|
return(EOF);
|
|
setb(tptr, tptr + BUFSIZ, 1);
|
|
return(1);
|
|
}
|
|
|
|
/***
|
|
*void streambuf::setb(char * b, char * eb, int a = 0) -
|
|
*
|
|
*Purpose:
|
|
* Sets up reserve area.
|
|
*
|
|
*Entry:
|
|
*
|
|
*Exit:
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
void streambuf::setb(char * b, char * eb, int a )
|
|
{
|
|
if ((_fAlloc) && (_base))
|
|
delete _base;
|
|
_base = b;
|
|
_fAlloc = a;
|
|
_ebuf = eb;
|
|
}
|
|
|
|
/***
|
|
*virtual streampos streambuf::seekoff(streamoff off, ios::seekdir dir, int mode)
|
|
*
|
|
*Purpose:
|
|
* seekoff member function. seek forward or backward in the stream.
|
|
* Default behavior: returns EOF.
|
|
*
|
|
*Entry:
|
|
* off = offset (+ or -) to seek by
|
|
* dir = one of ios::beg, ios::end, or ios::cur.
|
|
* mode = ios::in or ios::out.
|
|
*
|
|
*Exit:
|
|
* Returns new file position or EOF if error or seeking not supported.
|
|
*
|
|
*Exceptions:
|
|
* Returns EOF if error.
|
|
*
|
|
*******************************************************************************/
|
|
streampos streambuf::seekoff(streamoff,ios::seek_dir,int)
|
|
{
|
|
return EOF;
|
|
}
|
|
|
|
/***
|
|
*virtual streampos streambuf::seekpos(streampos pos, int mode) -
|
|
*
|
|
*Purpose:
|
|
* seekoff member function. seek to absolute file position.
|
|
* Default behavior: returns seekoff(streamoff(pos), ios::beg, mode).
|
|
*
|
|
*Entry:
|
|
* pos = absolute offset to seek to
|
|
* mode = ios::in or ios::out.
|
|
*
|
|
*Exit:
|
|
* Returns new file position or EOF if error or seeking not supported.
|
|
*
|
|
*Exceptions:
|
|
* Returns EOF if error.
|
|
*
|
|
*******************************************************************************/
|
|
streampos streambuf::seekpos(streampos pos,int mode)
|
|
{
|
|
return seekoff(streamoff(pos), ios::beg, mode);
|
|
}
|
|
|
|
/***
|
|
*virtual int streambuf::pbackfail(int c) - handle failure of putback
|
|
*
|
|
*Purpose:
|
|
* pbackfail member function. Handle exception of pback function.
|
|
* Default behavior: returns EOF. See spec. for details.
|
|
*
|
|
* Note: the following implementation gives default behavior, thanks
|
|
* to the default seekoff, but also supports derived classes properly:
|
|
*
|
|
*Entry:
|
|
* c = character to put back
|
|
*
|
|
*Exit:
|
|
* Returns c if successful or EOF on error.
|
|
*
|
|
*Exceptions:
|
|
* Returns EOF if error. Behavior is undefined if c was not the
|
|
* previous character in the stream.
|
|
*
|
|
*******************************************************************************/
|
|
int streambuf::pbackfail(int c)
|
|
{
|
|
if (eback()<gptr()) return sputbackc((char)c);
|
|
|
|
if (seekoff( -1, ios::cur, ios::in)==EOF) // always EOF for streambufs
|
|
return EOF;
|
|
if (!unbuffered() && egptr())
|
|
{
|
|
memmove((gptr()+1),gptr(),(int)(egptr()-(gptr()+1)));
|
|
*gptr()=(char)c;
|
|
}
|
|
return(c);
|
|
}
|