cmpppacketcircle.java

来自「短信网关发送接受平台。」· Java 代码 · 共 96 行

import java.lang.*;
import java.net.*;
import java.io.*;

import CMPPPacket;

public class CMPPPacketCircle
{
	final static int m_nSize = 0x10;
	final static int m_nSizeMask = 0x0f;

	int m_nReadPosition = 0;
	int m_nWritePosition = 0;
	CMPPPacket[] m_packets = null;

	public CMPPPacketCircle()
	{
		m_nReadPosition = 0;
		m_nWritePosition = 0;
		m_packets = new CMPPPacket[m_nSize];
	}
	
	public boolean isReadable()
	{
		if(m_nReadPosition == m_nWritePosition)
		{
			return false;
		}
		
		return true;
	}
	
	public synchronized CMPPPacket read()
	{
		if(isReadable())
		{
			CMPPPacket packet = new CMPPPacket(m_packets[m_nReadPosition]);
			
			m_packets[m_nReadPosition] = null;
			
			m_nReadPosition ++;
			
			m_nReadPosition &= m_nSizeMask;
			
			return packet;
		}
		
		return null;
	}
	
	public synchronized CMPPPacket peer()
	{
		if(isReadable())
		{
			return m_packets[m_nReadPosition];
		}
		
		return null;
	}
	
	public boolean isWritable()
	{
		if(((m_nWritePosition + 1) & m_nSizeMask) == m_nReadPosition)
		{
			return false;
		}
		
		return true;
	}
	
	public synchronized boolean write(CMPPPacket packet)
	{
		if(isWritable() && packet != null)
		{
			m_packets[m_nWritePosition] = new CMPPPacket(packet);
			
			m_nWritePosition ++;
			
			m_nWritePosition &= m_nSizeMask;
			
			return true;
		}
		
		return false;
	}
	
	public boolean isEmpty()
	{
		if(m_nReadPosition == m_nWritePosition)
		{
			return true;
		}
		
		return false;
	}
}