queue.c

基于UNIX的中间件编程,只能运行于UNIX操作系统

/*********************************************************
**	queue.cpp:the queue manage functions				**
**
**						zhoushijie						**
**
**						2000/3							**
*********************************************************/

#include "queue.h"
/*
** -------------------------------------------------------
** CreateQueue():Create a new queue
** -------------------------------------------------------
*/
void CreateQueue(Queue *q)
{
	q->count=0;	
	q->front=q->rear=NULL;
}

/*
**--------------------------------------------------------
** AppendNode():append Node to the end of a queue
**--------------------------------------------------------
*/
void AppendNode(QueueNode *p,Queue *q)
{
	if(p==NULL)
	{
		Error("attempt to append the null node to the queue");
		return ;
	}	
	if(QueueEmpty(q))
	{
		q->front =q->rear =p;
		
	}
	else if (q->count==1)
	{
		q->rear=p ;
		q->front->next =p ;		
		
	}
	else
	{
		q->rear->next=p; 
		q->rear =p;				
		
	}
	q->count ++;
}

/*
**---------------------------------------------------------
**ServerNode():pop a node from a queue
**---------------------------------------------------------
*/
void ServeNode(QueueNode **p,Queue *q)
{
	if(QueueEmpty(q))
		Error("attempt to server the empty queue");
	else
	{
		q->count--;
		(*p)=q->front ;
		if(QueueEmpty(q))
			q->front=q->rear=NULL;		
		else
		{
			q->front=q->front->next;			
		}
	}
}

/*
**-------------------------------------------------------
** QueueEmpty():where a queue ois empty
**-------------------------------------------------------
*/
int QueueEmpty(Queue *q)
{
	return  q->count==0;
		
}

/*
**------------------------------------------------------
** ClearQueue():clear the  queue 
**------------------------------------------------------
*/
void ClearQueue(Queue *q)
{
	if(QueueEmpty(q))
		return;
	q->count =0;
	q->front =q->rear =NULL;	

}

/*
**------------------------------------------------------
** DestroyQueue():free the  queue 
**------------------------------------------------------
*/
void DestroyQueue(Queue *q)
{
	QueueNode *t;

	if(QueueEmpty(q))
		return;
	t=q->front;	
	while(q->count)
	{
		t=q->front;
		q->front=t->next ;
		free(t);
		q->count--;
	}

}

/*
-----------------------------------------
QueueSize():return the size of a queue
-----------------------------------------
*/
int QueueSize(Queue *q)
{
	return q->count;
}

/*
-------------------------------------
QueueFull():where a queueu is full
-------------------------------------
*/
int QueueFull(Queue *q,MAXQUEUE max)
{
	return q->count>=max;
}

/*
------------------------------------------
QueueFront():return the pointer of the front 
of a queue
------------------------------------------
*/
void QueueFront(QueueEntry *x,Queue *q)
{
	if(QueueEmpty(q))
		x=NULL;
	else
		x=&q->front->entry ;
}

/*
------------------------------------------
QueueFrontnode():return the node of the front 
of a queue
------------------------------------------
*/
void QueueFrontNode(QueueNode *x,Queue *q)
{
	if(QueueEmpty(q))
		x->next =NULL;
	else
	{
		x->next =q->front->next ;
		x->entry =q->front->entry ;
	}
}

/*
---------------------------------------------------
TraverseQueue():Traverse a queue and take a actionof
every node in a queue
---------------------------------------------------
*/
void TraverseQueue(Queue *q,int(*Visit)(QueueEntry x))
{
	int count=0;
	int i;
	QueueNode *p;

	if(QueueEmpty(q))
		return;
	count=q->count;
	/************************************************************** 
	**	the Queue size will increase dynamic ,so define a const to
	**	restore its size
	**	2000/3/29
	**  for(int i=0;i<q->count;i++)
	***************************************************************
	

	***************************************************************
	** Loop the queue to send the queuenode.If the visit fanction
	** return 1,then some node be delete from queue.avoid resend
	** the queuenode,break the loop if visit return 1.Otherwise 
	** continue loop the queue
	***************************************************************/
	p=q->front;
	
	while((count--)>0)
	{
		if(Visit(p->entry)==1)
			break;
		else 
			p=p->next ;				
	}
}

/*
-------------------------------------------------------------
DeleteQueueNode():delete a queue node from a queue
-------------------------------------------------------------
*/
int  DeleteQueueNode(QueueNode *node,Queue *q,QueueNode **ReturnNode)
{
	int flag;
	QueueNode *p;
	QueueNode *t;

	if(QueueEmpty(q))
		return 1;
	flag=0;	
	p=q->front;
	t=p;
	while(p!=NULL)
	{
		if(!strcmp(node->entry.MessageQueue.source,p->entry.MessageQueue.source) && \
			!strcmp(node->entry.MessageQueue.sn,p->entry.MessageQueue.sn))		   
		{
			q->count--;
			if(QueueEmpty(q))
			{
				q->front =q->rear =NULL;				
			}
			else if(flag==0)
			{
				q->front =p->next;				
			}
			else
			{
				t->next =p->next;				
			}
			
			*ReturnNode=p;
			(*ReturnNode)->next =NULL;			
			return 0;
		}		
		t=p;
		p=p->next ;		
		flag++;

	}

return 1;
}

/*
------------------------------------------------------
MakeQueueNode():form  a queue node
------------------------------------------------------
*/
QueueNode *MakeQueueNode(QueueEntry x)
{
	QueueNode *p=(QueueNode *)malloc(sizeof(QueueNode));
	if(p)
	{
		p->entry =x;
		p->next =NULL;
	}
	else
		Error("no memery to  make the QueueNode");
	return p;
}

/*
------------------------------------------------------------
AllocateNode():allocate a blank queue node
------------------------------------------------------------
*/
int AllocateNode(Queue *Source,Queue *Destination,MESSAGESTRUCTURE m_struct)
{
	QueueNode *newnode;
	
	if(QueueEmpty(Source))
		Error("There is no room for allocate");
	else 
	{
		ServeNode(&newnode,Source);		
		SetNodeEntryContent(newnode,m_struct);
		AppendNode(newnode,Destination);
	}

	return 0;		
}

/*
-----------------------------------------------------
SetNodeEntryContent():set the content of a queue node
-----------------------------------------------------
*/
void SetNodeEntryContent(QueueNode *node,MESSAGESTRUCTURE m_struct)
{
	node->entry.flag =1;
	node->entry.MessageQueue=m_struct;
}

/*
---------------------------------------------------------
CopyQueue():copy the content of a queu to another queue
---------------------------------------------------------
*/
Queue *CopyQueue(Queue *destination,Queue *source)
{
	if (QueueEmpty(source))
		return destination;
	destination->count=source->count ;
	destination->front =source->front ;
	destination->rear =source->rear ;
	destination->rear->next= NULL;
	return destination;
}

int  Error(char *message)
{
	vfprintf(stdout,"error:%s",message);
	return 1;
}

void Warning(char *message)
{
	vfprintf(stdout,"error:%s",message);
}