Leaked source code of windows server 2003
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271 lines
7.4 KiB

// strstreambuf -- strstreambuf basic members
#include <climits>
#include <cstdlib>
#include <cstring>
#include <strstream>
#include <xdebug>
#pragma warning(disable:4244 4097)
_STD_BEGIN
_CRTIMP2 istrstream::~istrstream()
{ // destroy an istrstream
}
_CRTIMP2 ostrstream::ostrstream(char *ptr, streamsize count,
ios_base::openmode mode)
: ostream(&_Mysb),
_Mysb(ptr, count, ptr == 0 || (mode & app) == 0 ? ptr : ptr + strlen(ptr))
{ // construct with [ptr, ptr + count)
}
_CRTIMP2 ostrstream::~ostrstream()
{ // destroy an ostrstream
}
_CRTIMP2 strstream::strstream(char *ptr, streamsize count,
ios_base::openmode mode)
: iostream(&_Mysb),
_Mysb(ptr, count, ptr == 0 || (mode & app) == 0 ? ptr : ptr + strlen(ptr))
{ // construct with [ptr, ptr + count)
}
_CRTIMP2 strstream::~strstream()
{ // destroy a strstream
}
_CRTIMP2 strstreambuf::~strstreambuf()
{ // destroy a strstreambuf
_Tidy();
}
_CRTIMP2 void strstreambuf::freeze(bool freezeit)
{ // freeze or unfreeze writing
if (freezeit && !(_Strmode & _Frozen))
{ // disable writing
_Strmode |= _Frozen;
_Pendsave = epptr();
setp(pbase(), pptr(), eback());
}
else if (!freezeit && _Strmode & _Frozen)
{ // re-enable writing
_Strmode &= ~_Frozen;
setp(pbase(), pptr(), _Pendsave);
}
}
_CRTIMP2 int strstreambuf::overflow(int meta)
{ // try to extend write area
if (meta == EOF)
return (0); // nothing to write
else if (pptr() != 0 && pptr() < epptr())
return ((unsigned char)(*_Pninc() = meta)); // room in buffer
else if (!(_Strmode & _Dynamic)
|| _Strmode & (_Constant | _Frozen))
return (EOF); // can't extend
else
{ // okay to extend
int oldsize = gptr() == 0 ? 0 : epptr() - eback();
int newsize = oldsize;
int inc = newsize / 2 < _Minsize
? _Minsize : newsize / 2; // grow by 50 per cent if possible
_Minsize = _MINSIZE; // back to default for future growth
char *ptr = 0;
while (0 < inc && INT_MAX - inc < newsize)
inc /= 2; // reduce growth increment if too big
if (0 < inc)
{ // room to grow, increase size
newsize += inc;
ptr = _Palloc != 0 ? (char *)(*_Palloc)(newsize)
: _NEW_CRT char[newsize];
}
if (ptr == 0)
return (EOF); // couldn't grow, return failure
if (0 < oldsize)
memcpy(ptr, eback(), oldsize); // copy existing buffer
if (!(_Strmode & _Allocated))
; // no buffer to free
else if (_Pfree != 0)
(*_Pfree)(eback()); // free with function call
else
_DELETE_CRT_VEC(eback()); // free by deleting array
_Strmode |= _Allocated;
if (oldsize == 0)
{ // set up new buffer
_Seekhigh = ptr;
setp(ptr, ptr + newsize);
setg(ptr, ptr, ptr);
}
else
{ // revise old pointers
_Seekhigh = _Seekhigh - eback() + ptr;
setp(pbase() - eback() + ptr, pptr() - eback() + ptr,
ptr + newsize);
setg(ptr, gptr() - eback() + ptr, pptr() + 1);
}
return ((unsigned char)(*_Pninc() = meta));
}
}
_CRTIMP2 int strstreambuf::pbackfail(int meta)
{ // try to putback a character
if (gptr() == 0 || gptr() <= eback() || meta != EOF
&& (unsigned char)meta != (unsigned char)gptr()[-1]
&& _Strmode & _Constant)
return (EOF); // can't put it back
else
{ // safe to back up
gbump(-1);
return (meta == EOF ? 0 : (unsigned char)(*gptr() = meta));
}
}
_CRTIMP2 int strstreambuf::underflow()
{ // read if read position available
if (gptr() == 0)
return (EOF); // no read buffer
else if (gptr() < egptr())
return ((unsigned char)*gptr()); // char in buffer, read it
else if (pptr() == 0 || pptr() <= gptr() && _Seekhigh <= gptr())
return (EOF); // no write buffer to read
else
{ // update _Seekhigh and expand read region
if (_Seekhigh < pptr())
_Seekhigh = pptr();
setg(eback(), gptr(), _Seekhigh);
return ((unsigned char)*gptr());
}
}
_CRTIMP2 streampos strstreambuf::seekoff(streamoff off,
ios_base::seekdir way, ios_base::openmode which)
{ // seek by specified offset
if (pptr() != 0 && _Seekhigh < pptr())
_Seekhigh = pptr(); // update high water mark
if (which & ios_base::in && gptr() != 0)
{ // set input (and maybe output) pointer
if (way == ios_base::end)
off += _Seekhigh - eback(); // seek from end
else if (way == ios_base::cur
&& !(which & ios_base::out))
off += gptr() - eback(); // seek from current position
else if (way != ios_base::beg || off == _BADOFF)
off = _BADOFF; // invalid seek
if (0 <= off && off <= _Seekhigh - eback())
{ // seek from beginning, set one or two pointers
gbump(eback() - gptr() + off);
if (which & ios_base::out && pptr() != 0)
setp(pbase(), gptr(), epptr());
}
else
off = _BADOFF; // invalid seek from beginning
}
else if (which & ios_base::out && pptr() != 0)
{ // set only output pointer
if (way == ios_base::end)
off += _Seekhigh - eback(); // seek from end
else if (way == ios_base::cur)
off += pptr() - eback(); // seek from current position
else if (way != ios_base::beg || off == _BADOFF)
off = _BADOFF; // invalid seek
if (0 <= off && off <= _Seekhigh - eback())
pbump(eback() - pptr() + off); // seek from beginning
else
off = _BADOFF; // invalid seek from beginning
}
else // nothing to set
off = _BADOFF;
return (streampos(off));
}
_CRTIMP2 streampos strstreambuf::seekpos(streampos sp,
ios_base::openmode which)
{ // seek to memorized position
streamoff off = (streamoff)sp;
if (pptr() != 0 && _Seekhigh < pptr())
_Seekhigh = pptr(); // update high water mark
if (off == _BADOFF)
; // invalid seek
else if (which & ios_base::in && gptr() != 0)
{ // set input (and maybe output) pointer
if (0 <= off && off <= _Seekhigh - eback())
{ // set valid offset
gbump(eback() - gptr() + off);
if (which & ios_base::out && pptr() != 0)
setp(pbase(), gptr(), epptr());
}
else
off = _BADOFF; // offset invalid, don't seek
}
else if (which & ios_base::out && pptr() != 0)
{ // set output pointer
if (0 <= off && off <= _Seekhigh - eback())
pbump(eback() - pptr() + off);
else
off = _BADOFF; // offset invalid, don't seek
}
else // nothing to set
off = _BADOFF;
return (streampos(off));
}
_CRTIMP2 void strstreambuf::_Init(streamsize count, char *gp, char *pp,
_Strstate mode)
{ // initialize with possibly static buffer
streambuf::_Init();
_Minsize = _MINSIZE;
_Pendsave = 0;
_Seekhigh = 0;
_Palloc = 0;
_Pfree = 0;
_Strmode = mode;
if (gp == 0)
{ // make dynamic
_Strmode |= _Dynamic;
if (_Minsize < count)
_Minsize = count;
}
else
{ // make static
int size = count < 0 ? INT_MAX : count == 0 ? (int)strlen(gp) : count;
_Seekhigh = gp + size;
if (pp == 0)
setg(gp, gp, gp + size); // set read pointers only
else
{ // make writable too
if (pp < gp)
pp = gp;
else if (gp + size < pp)
pp = gp + size;
setp(pp, gp + size);
setg(gp, gp, pp);
}
}
}
_CRTIMP2 void strstreambuf::_Tidy()
{ // free any allocated storage
if ((_Strmode & (_Allocated | _Frozen)) != _Allocated)
; // no buffer to free
else if (_Pfree != 0)
(*_Pfree)(eback()); // free with function call
else
_DELETE_CRT_VEC(eback()); // free by deleting array
_Seekhigh = 0;
_Strmode &= ~(_Allocated | _Frozen);
}
_STD_END
/*
* Copyright (c) 1992-2001 by P.J. Plauger. ALL RIGHTS RESERVED.
* Consult your license regarding permissions and restrictions.
V3.10:0009 */