/********************************************************************************
 * File Name:			MsgQueue.c
 * Function Describe:   共享消息数据缓冲区的消息队列
 * Explain:             
	此消息队列是一个环形数据结构，可以接受消息入队列，并提取消息出队列，队列最多可容纳MSG_QUEUE_NUM_MAX个消息
	每个消息队列使用一个环形结构的消息数据缓冲区，该消息队列内的所有消息将共用此数据缓冲区
	适用于串口接收的数据处理，尤其适用于与模块的串口接收数据处理。
用法：
    先定义消息队列SUT_MSG_QUEUE实例，并定义存放消息数据缓冲区实例
	然后用MsgQueueInit初始化消息队列
	用MsgQueuePost将消息入队列，入队列时将拷贝消息的数据内容到SUT_MSG_QUEUE实例的数据缓冲区中。
	用MsgQueueAccept将从队列中取消息，取消息时将从数据缓冲区中拷贝数据到指定的其他非环形缓冲区，以便处理消息
 * Writer:				ShiLiangWen
 * Date:				2015-7-2
 *******************************************************************************/
#define THIS_FILE_ID 5
/********************************************************************************/
#include "includes.h"

unsigned char msgBuffer[MSG_DATA_BUF_LEN];
SUT_MSG_QUEUE msgQue;

void MsgQueueSet(void)
{
	MsgQueueInit((void *)msgBuffer,MSG_DATA_BUF_LEN);
}
/********************************************************************************************
*
*********************************************************************************************/
void MsgQueueInit(char *pDataBuffer,unsigned short DataBufferLenMax)
{
	int i;
	SUT_MSG_QUEUE *pMsgQueue = &msgQue;
	pMsgQueue->MsgIn=0;
	pMsgQueue->MsgNum=0;
	pMsgQueue->MsgOut=0;
	for(i=0;i<MSG_QUEUE_NUM_MAX;i++){
		pMsgQueue->MsgQueue[i].DataStartIndex=0;
		pMsgQueue->MsgQueue[i].MsgLen=0;
	}
	//
	pMsgQueue->DataBuffer=pDataBuffer;
	for(i=0;i<DataBufferLenMax;i++)pMsgQueue->DataBuffer[i]=0;
	pMsgQueue->DataBufferLenMax=DataBufferLenMax;
	pMsgQueue->DataBufferIn=0;
	pMsgQueue->DataBufferOut=0;
	pMsgQueue->DataBufferLen=0;
}
/********************************************************************************************
*
*********************************************************************************************/
int MsgQueuePost(char *pData,unsigned short DataLen)
{
	SUT_MSG_QUEUE *pMsgQueue = &msgQue;
	unsigned short i;
	//队列满，不允许再入队列
	//SlwTrace(INF, "in MSQ\r\n");
	if(pMsgQueue->MsgNum>=MSG_QUEUE_NUM_MAX){
		//SlwTrace(INF, "MsgQueue full!\r\n");
		return -1;
	}
	//数据缓冲区不够，不允许入队列
	if((DataLen+pMsgQueue->DataBufferLen)>pMsgQueue->DataBufferLenMax){
		//SlwTrace(INF,"DataBuffer full!\r\n");
		return -2;
	}
	//消息入队列
	pMsgQueue->MsgQueue[pMsgQueue->MsgIn].DataStartIndex=pMsgQueue->DataBufferIn;
	pMsgQueue->MsgQueue[pMsgQueue->MsgIn].MsgLen=DataLen;
	//消息数据入缓冲区
	for(i=0;i<DataLen;i++){
		pMsgQueue->DataBuffer[pMsgQueue->DataBufferIn]=pData[i];
		pMsgQueue->DataBufferIn++;
		if(pMsgQueue->DataBufferIn>=MSG_DATA_BUF_LEN)pMsgQueue->DataBufferIn=0;
		pMsgQueue->DataBufferLen++;
	}
	//消息个数增加
	pMsgQueue->MsgIn++;
	if(pMsgQueue->MsgIn>=MSG_QUEUE_NUM_MAX)pMsgQueue->MsgIn=0;
	pMsgQueue->MsgNum++;
	return 0;
}

/********************************************************************************************
提取pMsgQueue消息，并放入pBuf中，给定pBuf空间长度为BufLen
返回r:
r=0   --无消息
r>0   --有消息，并已拷贝消息数据到pData,r为消息数据长度
r<0   --有消息,但接受数据缓冲区长度不够
*********************************************************************************************/

int MsgQueueAccept(char *pBuf,unsigned short BufLen)
{
	SUT_MSG_QUEUE *pMsgQueue = &msgQue;
	unsigned short i,j;
	char data;
	SUT_MESSAGE msg;
	
	if(pMsgQueue->MsgNum==0)return 0;
	//SlwTrace(INF, "out MSQ\r\n");
	msg.MsgLen = pMsgQueue->MsgQueue[pMsgQueue->MsgOut].MsgLen;
	msg.DataStartIndex = pMsgQueue->MsgQueue[pMsgQueue->MsgOut].DataStartIndex;
	j=0;
	for(i=0;i<msg.MsgLen;i++){
		if(0==pMsgQueue->DataBufferLen)break;
		data=pMsgQueue->DataBuffer[pMsgQueue->DataBufferOut];
		pMsgQueue->DataBufferOut++;
		if(pMsgQueue->DataBufferOut>=pMsgQueue->DataBufferLenMax)pMsgQueue->DataBufferOut=0;
		pMsgQueue->DataBufferLen--;
		if(j<BufLen)pBuf[j++]=data;
	}
	pMsgQueue->MsgOut++;
	if(pMsgQueue->MsgOut>=MSG_QUEUE_NUM_MAX)pMsgQueue->MsgOut=0;
	pMsgQueue->MsgNum--;
	
	if(i!=msg.MsgLen){
		return -2;//Databuffer len error!
	}
	
	if(msg.MsgLen>BufLen){
		return -1;
	}else{
		return msg.MsgLen;
	}
}

/********************************************************************************************
*
*********************************************************************************************/