CWE-ou-minkata/Sources/Plasma/PubUtilLib/plSockets/plRingBuffer.cpp

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*==LICENSE==*/
#include "hsUtils.h"
#include "plRingBuffer.h"

plRingBuffer::plRingBuffer(int size)
:	plMemBuffer(size)
{            
	fEndPos = 0;
	fStartPos = 0;
}

void plRingBuffer::FullCompress()
{
	if (fStartPos == fEndPos)
	{
		fStartPos = 0;
		fEndPos = 0;
	}
	else 
	{
		ForceWindowSlide();
	}    
}

void plRingBuffer::Compress()
{
	if (fStartPos == fEndPos)
	{
		fStartPos = 0;
		fEndPos = 0;
	}
	else if(fStartPos >= GetBufferSize() / 2) 
	{
		ForceWindowSlide();
	}    
}

bool plRingBuffer::Put(const char * data, int len)
{
	bool ans = false;
	
	if (len > BufferAvailable())
		Compress();
	
	if (len <= BufferAvailable())
	{
		memcpy(GetBufferOpen(), data, len);
		fEndPos += len;
		ans = true;
	}
	return ans;
}

bool plRingBuffer::Get(char * data, int len)
{
	bool ans = false;
	
	if (len < AmountBuffered())
	{
		memcpy(data, GetBufferStart(), len);
		fStartPos += len;
		Compress();
		ans = true;
	}
	return ans;
}

int plRingBuffer::AmountBuffered() 
{ 
	return fEndPos - fStartPos; 
}

int plRingBuffer::BufferAvailable() 
{ 
	return GetBufferSize() - fEndPos; 
}

void plRingBuffer::Reset() 
{ 
	fStartPos = 0; 
	fEndPos = 0; 
}

char * plRingBuffer::GetBufferStart() 
{ 
	return fBuffer+fStartPos;
}

char * plRingBuffer::GetBufferOpen() 
{
	return fBuffer+fEndPos; 
}

void plRingBuffer::ForceWindowSlide()
{
	int len = AmountBuffered();
	if(len > 0 && fStartPos != 0)
	{
		memmove(fBuffer, GetBufferStart(), len);
		fStartPos = 0;
		fEndPos = len;        
	}
}

bool plRingBuffer::PutFast(const char * data, int len)
{
	// no checking be careful
	memcpy(GetBufferOpen(), data, len); // or memmove?
	fEndPos += len;
	return true;
}