#include "stdafx.h"
#include "MyCircularBuf.h"
//CMyCircularBuf
CMyCircularBuf::CMyCircularBuf()
{
	pBuffer=NULL;
	nDataSize=0;
	bIsEmpty=true;
	bIsFull=false;
}
CMyCircularBuf::CMyCircularBuf(int nCapicity)
{
	Alloc(nCapicity);
}
CMyCircularBuf::~CMyCircularBuf()
{
	if (pBuffer!=NULL) {delete [] pBuffer;pBuffer=NULL;}	
}
int CMyCircularBuf::Alloc(int nCapicity)
{
	if (pBuffer!=NULL) {delete [] pBuffer;pBuffer=NULL;}
	pBuffer=new char[nCapicity]; 
	nmCapacity=nCapicity;
	nDataSize=0;
	ReadP=0;WriteP=0;
	bIsEmpty=true;
	bIsFull=false;
	return nCapicity;
}
int CMyCircularBuf::GetCapicity()
{
	return nmCapacity;
}
int CMyCircularBuf::GetNextWriteP(int nOffset)
{
	int nextip=WriteP+nOffset;
	if (nextip>=nmCapacity) {nextip-=nmCapacity;}
	return nextip;
}
int CMyCircularBuf::GetNextReadP(int nOffset)
{
	int nextop=ReadP+nOffset;
	if (nextop>=nmCapacity) {nextop-=nmCapacity;}
	return nextop;
}
int CMyCircularBuf::GetTailRoomSize()
{
	int nTailLeftSize;
	if (bIsFull) {nTailLeftSize=0; return nTailLeftSize;}
	if (WriteP<ReadP) {nTailLeftSize=ReadP-WriteP;}
	else {nTailLeftSize=nmCapacity-WriteP;}
	return nTailLeftSize;
}
int CMyCircularBuf::GetTailDataSize()
{
	int nTailLeftDataSize;
	if (bIsEmpty) return 0;
	if (WriteP>ReadP) nTailLeftDataSize=WriteP-ReadP;
	else {nTailLeftDataSize=nmCapacity-ReadP;}
	return nTailLeftDataSize;
}
int CMyCircularBuf::GetLeftRoomSize()
{
	int nLeftSize=nmCapacity-nDataSize;
	return nLeftSize;
}
int CMyCircularBuf::GetDataSize()
{
	return nDataSize;
}
char * CMyCircularBuf::GetWriteBuffer(int * LeftRoomSize)
{
	int nTailLeftRoomSize=GetTailRoomSize();
	*LeftRoomSize=nTailLeftRoomSize;
	return pBuffer+WriteP;
}
int CMyCircularBuf::ReleaseWriteBuffer(int AddSize)
{
	WriteP=GetNextWriteP(AddSize);
	nDataSize+=AddSize;
	bIsEmpty=false;
	if (nDataSize>=nmCapacity) bIsFull=true;

	return AddSize;
}
char * CMyCircularBuf::GetReadBuffer(int * DataSize)
{
	int nTailLeftDataSize=GetTailDataSize();
	*DataSize=nTailLeftDataSize;
	return pBuffer+ReadP;
}
int CMyCircularBuf::ReleaseReadBuffer(int DelSize)
{
	DelData(DelSize);
	return DelSize;
}

int CMyCircularBuf::PushIn(void * pData,int Size)
{
	if (GetLeftRoomSize()<Size) {return -1;}
	int nTailLeftSize=GetTailRoomSize();
	if (nTailLeftSize>=Size)
	{
		memcpy_s(pBuffer+WriteP,nTailLeftSize,pData,Size);
		WriteP=GetNextWriteP(Size);
	}else
	{
		memcpy_s(pBuffer+WriteP,nTailLeftSize,pData,nTailLeftSize);
		memcpy_s(pBuffer,Size-nTailLeftSize,(char *)pData+nTailLeftSize,Size-nTailLeftSize);
		WriteP=GetNextWriteP(Size);
	}
	bIsEmpty=false;
	nDataSize+=Size;
	if (nDataSize==nmCapacity) {bIsFull=true;}
	return Size;
}
int CMyCircularBuf::CopyData(void * pData,int Size)
{
	if (GetDataSize()<Size) {return -1;}
	int nTailLeftSize=GetTailDataSize(); //»·Ðλº³åβ²¿Ê£ÓàÊý¾ÝÁ¿
	if (nTailLeftSize<Size)	////Ê£Óà¿Õ¼äС£¬½«Êý¾ÝתÒƵ½Ò»Æð
	{
		memcpy_s(pData,Size,pBuffer+ReadP,nTailLeftSize);
		memcpy_s((char *)pData+nTailLeftSize,Size-nTailLeftSize,pBuffer,Size-nTailLeftSize);
	}else
	{
		memcpy_s(pData,Size,pBuffer+ReadP,Size);
	}
	return Size;
}
int CMyCircularBuf::DelData(int Size)
{
	if (GetDataSize()<Size) {return -1;}
	bIsFull=false;
	ReadP=GetNextReadP(Size);
	nDataSize-=Size;
	if (nDataSize==0) {bIsEmpty=true;}
	return Size;
}

int CMyCircularBuf::PopOut(void * pData,int Size)
{
	CopyData(pData,Size);
	DelData(Size);
	return Size;
}