p7zip-rar/CPP/Common/DynLimBuf.cpp
2017-10-11 12:40:22 +02:00

94 lines
1.5 KiB
C++

// Common/DynLimBuf.cpp
#include "StdAfx.h"
#include "DynLimBuf.h"
#include "MyString.h"
CDynLimBuf::CDynLimBuf(size_t limit) throw()
{
_chars = 0;
_pos = 0;
_size = 0;
_sizeLimit = limit;
_error = true;
unsigned size = 1 << 4;
if (size > limit)
size = (unsigned)limit;
_chars = (Byte *)MyAlloc(size);
if (_chars)
{
_size = size;
_error = false;
}
}
CDynLimBuf & CDynLimBuf::operator+=(char c) throw()
{
if (_error)
return *this;
if (_size == _pos)
{
size_t n = _sizeLimit - _size;
if (n == 0)
{
_error = true;
return *this;
}
if (n > _size)
n = _size;
n += _pos;
Byte *newBuf = (Byte *)MyAlloc(n);
if (!newBuf)
{
_error = true;
return *this;
}
memcpy(newBuf, _chars, _pos);
MyFree(_chars);
_chars = newBuf;
_size = n;
}
_chars[_pos++] = c;
return *this;
}
CDynLimBuf &CDynLimBuf::operator+=(const char *s) throw()
{
if (_error)
return *this;
unsigned len = MyStringLen(s);
size_t rem = _sizeLimit - _pos;
if (rem < len)
{
len = (unsigned)rem;
_error = true;
}
if (_size - _pos < len)
{
size_t n = _pos + len;
if (n - _size < _size)
{
n = _sizeLimit;
if (n - _size > _size)
n = _size * 2;
}
Byte *newBuf = (Byte *)MyAlloc(n);
if (!newBuf)
{
_error = true;
return *this;
}
memcpy(newBuf, _chars, _pos);
MyFree(_chars);
_chars = newBuf;
_size = n;
}
memcpy(_chars + _pos, s, len);
_pos += len;
return *this;
}