queue.cpp

通过用SOCKET发包来实现PING命令

/********************************************************************************
*Copyright:	cchbds Tech .Co
*Filename:	queue.c
*Author        Version           Date:
*Description:	 insert datapack  into loop queue and move away
*Function List
	1	qempty
	2	qoverflow
	3 	qinsert
	4	qmove
*History:
*********************************************************************************/
#include "queue.h"

/********************************************************************************
*Function:	qempty
*Description:	the queue  be empty or not
*Calls:		
*Called By:	get_send_shm
*Input: indata :  front rear 
*Output: 	
*Return: 	1 empty ,0 not empty
*Others:
*********************************************************************************/
int qempty(long front,long rear)
{
	return front==rear;
}
int qfull(long front,long rear,long size)
{
	
	return ((rear+1)%size == front);
}
/********************************************************************************
*Function:	qoverflow
*Description:	the queue will be overflow or not
*Calls:		
*Called By:	shmproducer
*Input: indata : datalen front rear size insertlen
*Output: 	
*Return: 	1 overflow ,0 not overfolw
*Others:
*********************************************************************************/
int qoverflow(long front,long rear,long size,int insertlen)
{
	if((rear<front))
	{
		//队列里的数据是从0到尾和头到size的两段
		if(rear+insertlen>front)
		{
			return 1;
		}
	}
	if((rear>front))
	{
		//队列里的数据是从尾到头的一段
		if(rear+insertlen>front+size)
		{
			return 1;
		}
	}

	return 0;
}
/********************************************************************************
*Function:	qinsert
*Description:	write a datapack to queue tail
*Calls:		
*Called By:	shmproducer
*Input: indata :queue data datalen front rear size
*Output: 	
*Return: 
*Others:
*********************************************************************************/
void qinsert(char *queue,char * data,int datalen,long front,long rear,long size)
{
	if((rear<=front))
	{
		//队列里的数据是从0到尾和头到size的两段
		memcpy(queue+rear,data,datalen);
	}
	else
	{
		//队列里的数据是从尾到头的一段
		if(size-rear>=datalen)
		{
			memcpy(queue+rear,data,datalen);
		}
		else
		{
			int len;
			len=size-rear;
			memcpy(queue+rear,data,len);
			memcpy(queue,data+len,datalen-len);
		}
	}
}
//从队头取
/********************************************************************************
*Function:	qmove
*Description:	get  a datapack from  queue head
*Calls:		
*Called By:	get_send_shm
*Input: indata :queue data datalen front rear size
*Output: 	data
*Return: 
*Others:
*********************************************************************************/
int  qmove(char *queue,char * data,int datalen,long front,long rear,long size)
{
	if(rear==front)
	{
		printf("取数据包时队列为空 %d ==%d \n",rear,front);
		
	}
	if((rear>front))
	{
		//队列里的数据是从0到尾和头到size的两段
		memcpy(data,queue+front,datalen);
	}
	if((rear<front))
	{
		//队列里的数据是从尾到头的一段
		if(size-front>=datalen)
		{
			memcpy(data,queue+front,datalen);
		}
		else
		{
			int len;
			len=size-front;
			memcpy(data,queue+front,len);
			memcpy(data+len,queue,datalen-len);
		}
	}
	return 1;
}