#pragma once #include <iostream>
#include <string> class cyclebuffer
{
protected:
volatile int32_t m_nReadIndex;
volatile int32_t m_nWriteIndex;
volatile int32_t m_nDataSize; //有效数据大小
volatile int32_t m_nBufSize; //总buf大小
uint_8 *m_pBuf; public:
cyclebuffer(int nBufSize)
{
Reset();
m_pBuf = (uint8_t *)malloc(nBufSize);
m_nbufSize = nBufSize;
} virtual ~cyclebuffer()
{
if(m_pBuf != NULL)
{
free(m_pBuf);
m_pBuf = NULL;
}
} //剩余空间数
int32_t Space()
{
return m_nBufSize-m_nDataSize;
} //获取buf的总大小
int32_t Capatity()
{
return m_nBufSize;
} //获取有效数据长度
int32_t Size()
{
return m_nDataSize;
} //清空
void Reset()
{
m_nReadIndex = ;
m_nwriteIndex = ;
m_nDataSize = ;
} //增加nSize个字节
int32_t Grow(int32_t nSize)
{
if(nSize<=)
{
return ;
} uint8_t *pMem = (uint8_t *)malloc(nSize + m_nBufSize);
if(pMem == NULL)
{
return ;
} int32_t nWriteIndex = ;
//将旧内存中的数据拷贝到（增大的）新内存中
do
{
int32_t nReadBytes = Read(pMem + nWriteIndex, );
if(nReadBytes <= )
{
break;
}
nWriteIndex += nReadBytes;
}while(m_nDataSize > ); if(m_nDataSize > )
{
return -;
} //释放旧内存块
if(m_pBuf != NULL)
{
free(m_pBuf);
} m_pBuf = pMem;
m_nReadIndex = ;
m_nWriteIndex = nWriteIndex;
m_nDataSize = nWriteIndex;
m_nBufSize += nSize; return nSize;
} //写到写列表的头部---针对新数据
int32_t WriteToHead(const uint8_t *pBuf, int32_t nDataSize)
{
if(nDataSize < || pBuf == NULL)
{
return ;
} //空间不够
if(m_nDataSize + nDataSize > m_nBufsize)
{
if(Grow((m_nDataSize+nDataSize) - m_nDataSize) <= )
{
return ;
}
} if(m_nWriteIndex < m_nReadIndex)
{
memcpy(&m_pBuf[m_nReadIndex-nDataSize], pBuf, nDataSize);
m_nReadIndex -= nDataSize;
}
else if(m_nWriteIndex == m_nReadIndex)
{
return Write(pBuf, nDataSize);
}
else
{
int32_t nLeftDataSize = (nDataSize-m_nReadIndex<)?nDataSize:m_nReadIndex;
if(nLeftDataSize < nDataSize) //此时nLeftDataSize == m_nReadIndex,m_nReadIndex前面的空间不够
{
int32_t nTailDataSize = nDataSize - nLeftDataSize;
int32_t nWriteIndex = m_nBufSize - nTailDatasize;
memcpy(&m_pBuf[nWriteIndex], pBuf, nDataSize-nLeftDataSize); //从内存最后向前写
memcpy(&m_pBuf[], pBuf+nTailDataSize, nLeftDataSize);
m_nReadIndex = nWriteIndex;
}
else
{
if(m_nReadIndex-nDataSize < )
{
return ;
}
memcpy(&m_pBuf[m_nReadIndex-nDataSize], pBuf, nDataSize);
m_nReadIndex -= nDataSize;
}
} m_nDataSize += nDataSize;
return nDataSize;
} //写到列表的尾部
int32_t Write(const uint8_t *pBuf, int32_t nDataSize)
{
if(nDataSize <= || NULL == pBuf)
{
return ;
} if(nDataSize + m_nDataSize > m_nBufSize)
{
if(Grow((nDataSize+nBufSize)-m_nDataSize) <= )
{
return ;
}
} if(m_nWriteIndex < m_nReadIndex)
{
memcpy(&m_pBuf[m_nWriteIndex], pBuf, nDataSize);
m_nWriteIndex += nDataSize;
}
else
{
int32_t nLeftDataSize = m_nBufSize - m_nWriteIndex;
if(nLeftDataSize < nDataSize)
{
memcpy(&m_pBuf[m_nWriteIndex], pBuf, nLeftDataSize);
memcpy(&m_pBuf[], pBuf+nLeftDataSize, nDataSize-nLeftDataSize);
m_nwriteIndex = nDataSize - nLeftDataSize;
}
else
{
memcpy(&m_pBuf[m_nWriteIndex], pBuf, nDataSize);
m_nWriteIndex += nDataSize;
}
}
m_nDataSize += nDataSize;
return nDataSize;
} //读取 读列表的头部内存
int32_t Read(uint8_t *pBuf, const int32_t nWantSize)
{
if(nWantSize <= || NULL == pBuf)
{
return ;
} int32_t nDataSize = ((m_nDataSize < nWantSize)?m_nDataSize : nWantSize);
if(nDataSize<=)
{
return ;
} if(m_nReadIndex < m_nWriteIndex)
{
memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
m_nReadIndex += nDataSize;
}
else
{
int32_t nLeftDataSize = m_nBufSize - m_nReadIndex;
if(nLeftDataSize < nDataSize)
{
memcpy(pBuf, &m_pBuf[m_nReadIndex], nLeftDataSize);
memcpy(pBuf+nLeftDataSize, &m_pBuf[], nDataSize-nLeftDataSize);
m_nReadIndex = nDataSize-nLeftDataSize;
}
else
{
memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
m_nReadIndex += nDataSize;
}
}
m_nDataSize -= nDataSize;
return nDataSize;
} //读取数据但是不修改读索引
int32_t PeekRead(uint8_t *pBuf, const int32_t nWantSize)
{
if(nWantSize <= || pBuf == NULL)
{
return ;
} int32_t nDataSize = ((m_nDataSize < nWantSize) ? m_nDataSize : nWantSize);
if(m_nReadIndex < m_nWriteIndex)
{
memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
}
else if(m_nReadIndex == m_nWriteIndex)
{
return ;
}
else
{
int32_t nLeftDataSize = m_nBufSize - m_nReadIndex;
if(nLeftDataSize < nDataSize)
{
memcpy(pBuf, &m_pBuf[m_nReadIndex], nLeftDataSize);
memcpy(pBuf+nLeftDataSize, &m_pBuf[], nDataSize-nLeftDataSize);
}
else
{
memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
}
}
return nDataSize;
} };