165 lines
2.6 KiB
C++
165 lines
2.6 KiB
C++
#include "StdAfx.h"
|
|
#include "Buffer.h"
|
|
#include <math.h>
|
|
|
|
|
|
#define U_PAGE_ALIGNMENT 3
|
|
#define F_PAGE_ALIGNMENT 3.0
|
|
|
|
CBuffer::CBuffer()
|
|
{
|
|
m_ulMaxLength = 0;
|
|
|
|
m_Ptr = m_Base = NULL;
|
|
}
|
|
|
|
|
|
CBuffer::~CBuffer(void)
|
|
{
|
|
if (m_Base)
|
|
{
|
|
VirtualFree(m_Base, 0, MEM_RELEASE);
|
|
m_Base = NULL;
|
|
}
|
|
|
|
m_Base = m_Ptr = NULL;
|
|
m_ulMaxLength = 0;
|
|
}
|
|
|
|
|
|
|
|
ULONG CBuffer::ReadBuffer(PBYTE Buffer, ULONG ulLength)
|
|
{
|
|
if (ulLength > GetBufferMaxLength())
|
|
{
|
|
return 0;
|
|
}
|
|
if (ulLength > GetBufferLength())
|
|
{
|
|
ulLength = GetBufferLength();
|
|
}
|
|
|
|
if (ulLength)
|
|
{
|
|
CopyMemory(Buffer,m_Base,ulLength);
|
|
|
|
MoveMemory(m_Base,m_Base+ulLength,GetBufferMaxLength() - ulLength);
|
|
m_Ptr -= ulLength;
|
|
}
|
|
|
|
DeAllocateBuffer(GetBufferLength());
|
|
|
|
return ulLength;
|
|
}
|
|
|
|
|
|
|
|
ULONG CBuffer::DeAllocateBuffer(ULONG ulLength)
|
|
{
|
|
if (ulLength < GetBufferLength())
|
|
return 0;
|
|
|
|
ULONG ulNewMaxLength = (ULONG)ceil(ulLength / F_PAGE_ALIGNMENT) * U_PAGE_ALIGNMENT;
|
|
|
|
if (GetBufferMaxLength() <= ulNewMaxLength)
|
|
{
|
|
return 0;
|
|
}
|
|
PBYTE NewBase = (PBYTE) VirtualAlloc(NULL,ulNewMaxLength,MEM_COMMIT,PAGE_READWRITE);
|
|
if (NewBase == NULL)
|
|
return 0;
|
|
ULONG ulv1 = GetBufferLength(); //算原先内存的有效长度
|
|
CopyMemory(NewBase,m_Base,ulv1);
|
|
|
|
VirtualFree(m_Base,0,MEM_RELEASE);
|
|
|
|
m_Base = NewBase;
|
|
|
|
m_Ptr = m_Base + ulv1;
|
|
|
|
m_ulMaxLength = ulNewMaxLength;
|
|
|
|
return m_ulMaxLength;
|
|
}
|
|
|
|
|
|
BOOL CBuffer::WriteBuffer(PBYTE Buffer, ULONG ulLength)
|
|
{
|
|
if (ReAllocateBuffer(ulLength + GetBufferLength()) == -1)//10 +1 1024
|
|
{
|
|
return false;
|
|
}
|
|
|
|
CopyMemory(m_Ptr,Buffer,ulLength);//Hello 5
|
|
|
|
m_Ptr+=ulLength;
|
|
return TRUE;
|
|
}
|
|
|
|
|
|
|
|
ULONG CBuffer::ReAllocateBuffer(ULONG ulLength)
|
|
{
|
|
if (ulLength < GetBufferMaxLength())
|
|
return 0;
|
|
|
|
ULONG ulNewMaxLength = (ULONG)ceil(ulLength / F_PAGE_ALIGNMENT) * U_PAGE_ALIGNMENT;
|
|
PBYTE NewBase = (PBYTE) VirtualAlloc(NULL,ulNewMaxLength,MEM_COMMIT,PAGE_READWRITE);
|
|
if (NewBase == NULL)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
ULONG ulv1 = GetBufferLength(); //原先的有效数据长度
|
|
CopyMemory(NewBase,m_Base,ulv1);
|
|
|
|
if (m_Base)
|
|
{
|
|
VirtualFree(m_Base,0,MEM_RELEASE);
|
|
}
|
|
m_Base = NewBase;
|
|
m_Ptr = m_Base + ulv1; //1024
|
|
|
|
m_ulMaxLength = ulNewMaxLength; //2048
|
|
|
|
return m_ulMaxLength;
|
|
}
|
|
|
|
|
|
|
|
VOID CBuffer::ClearBuffer()
|
|
{
|
|
m_Ptr = m_Base;
|
|
|
|
DeAllocateBuffer(1024);
|
|
}
|
|
|
|
|
|
|
|
ULONG CBuffer::GetBufferLength() const //获得有效数据长度
|
|
{
|
|
if (m_Base == NULL)
|
|
return 0;
|
|
|
|
return (ULONG)m_Ptr - (ULONG)m_Base;
|
|
}
|
|
|
|
|
|
ULONG CBuffer::GetBufferMaxLength() const
|
|
{
|
|
return m_ulMaxLength;
|
|
}
|
|
|
|
PBYTE CBuffer::GetBuffer(ULONG ulPos) const
|
|
{
|
|
if (m_Base==NULL)
|
|
{
|
|
return NULL;
|
|
}
|
|
if (ulPos>=GetBufferLength())
|
|
{
|
|
return NULL;
|
|
}
|
|
return m_Base+ulPos;
|
|
}
|