los_cir_buf.c 文件参考

浏览源代码.

函数
UINT32	LOS_CirBufUsedSize (CirBuf *cirbufCB)
	返回循环buf已使用的大小 更多...
STATIC UINT32	OsCirBufWriteLinear (CirBuf *cirbufCB, const CHAR *buf, UINT32 size)
STATIC UINT32	OsCirBufWriteLoop (CirBuf *cirbufCB, const CHAR *buf, UINT32 size)
UINT32	LOS_CirBufWrite (CirBuf *cirbufCB, const CHAR *buf, UINT32 size)
	写入数据到循环buf区 更多...
STATIC UINT32	OsCirBufReadLinear (CirBuf *cirbufCB, CHAR *buf, UINT32 size)
STATIC UINT32	OsCirBufReadLoop (CirBuf *cirbufCB, CHAR *buf, UINT32 size)
UINT32	LOS_CirBufRead (CirBuf *cirbufCB, CHAR *buf, UINT32 size)
	读取循环buf的数据 更多...
UINT32	LOS_CirBufInit (CirBuf *cirbufCB, CHAR *fifo, UINT32 size)
	初始化循环buf 更多...
VOID	LOS_CirBufDeinit (CirBuf *cirbufCB)
	删除初始化操作，其实就是清0 更多...

函数说明

LOS_CirBufDeinit()

VOID LOS_CirBufDeinit

(

CirBuf *

cirbufCB

)

删除初始化操作，其实就是清0

在文件 los_cir_buf.c 第 241 行定义.

{
    (VOID)memset_s(cirbufCB, sizeof(CirBuf), 0, sizeof(CirBuf));
}

这是这个函数的调用关系图:

LOS_CirBufInit()

UINT32 LOS_CirBufInit	(	CirBuf *	cirbufCB,
		CHAR *	fifo,
		UINT32	size
	)

初始化循环buf

在文件 los_cir_buf.c 第 225 行定义.

{
    if ((cirbufCB == NULL) || (fifo == NULL)) {
        return LOS_NOK;
    }
 
    (VOID)memset_s(cirbufCB, sizeof(CirBuf), 0, sizeof(CirBuf));//清0
    LOS_SpinInit(&cirbufCB->lock);//自旋锁初始化
    cirbufCB->size = size;  //记录size
    cirbufCB->remain = size;//剩余size
    cirbufCB->status = CBUF_USED;//标记为已使用
    cirbufCB->fifo = fifo;  //顺序buf ,这1K buf 是循环利用
 
    return LOS_OK;
}

函数调用图:

这是这个函数的调用关系图:

LOS_CirBufRead()

UINT32 LOS_CirBufRead	(	CirBuf *	cirbufCB,
		CHAR *	buf,
		UINT32	size
	)

读取循环buf的数据

在文件 los_cir_buf.c 第 199 行定义.

{
    UINT32 cpSize = 0;
    UINT32 intSave;
 
    if ((cirbufCB == NULL) || (buf == NULL) || (size == 0) || (cirbufCB->status != CBUF_USED)) {
        return 0;
    }
 
    LOS_SpinLockSave(&cirbufCB->lock, &intSave);
 
    if ((cirbufCB->fifo == NULL) || (cirbufCB->remain == cirbufCB->size)) {
        goto EXIT;
    }
 
    if (cirbufCB->startIdx >= cirbufCB->endIdx) {//开始位置大于结束位置的情况怎么读
        cpSize = OsCirBufReadLoop(cirbufCB, buf, size);//循环读取buf
    } else {//开始位置小于结束位置的情况怎么读
        cpSize = OsCirBufReadLinear(cirbufCB, buf, size);//线性读取，读取 endIdx - startIdx 部分就行了，所以是线性读取 
    }
 
EXIT:
    LOS_SpinUnlockRestore(&cirbufCB->lock, intSave);
    return cpSize;
}

函数调用图:

这是这个函数的调用关系图:

LOS_CirBufUsedSize()

UINT32 LOS_CirBufUsedSize

(

CirBuf *

cirbufCB

)

返回循环buf已使用的大小

在文件 los_cir_buf.c 第 37 行定义.

{
    UINT32 size;
    UINT32 intSave;
 
    LOS_SpinLockSave(&cirbufCB->lock, &intSave);
    size = cirbufCB->size - cirbufCB->remain; //得到已使用大小
    LOS_SpinUnlockRestore(&cirbufCB->lock, intSave);
 
    return size;
}

函数调用图:

这是这个函数的调用关系图:

LOS_CirBufWrite()

UINT32 LOS_CirBufWrite	(	CirBuf *	cirbufCB,
		const CHAR *	buf,
		UINT32	size
	)

写入数据到循环buf区

在文件 los_cir_buf.c 第 112 行定义.

{
    UINT32 cpSize = 0;
    UINT32 intSave;
 
    if ((cirbufCB == NULL) || (buf == NULL) || (size == 0) || (cirbufCB->status != CBUF_USED)) {
        return 0;
    }
 
    LOS_SpinLockSave(&cirbufCB->lock, &intSave);
 
    if ((cirbufCB->fifo == NULL) || (cirbufCB->remain == 0))  {
        goto EXIT;;
    }
 
    if (cirbufCB->startIdx <= cirbufCB->endIdx) {//开始位置在前面
        cpSize = OsCirBufWriteLoop(cirbufCB, buf, size);//循环方式写入，分两次拷贝
    } else {
        cpSize = OsCirBufWriteLinear(cirbufCB, buf, size);//线性方式写入，分一次拷贝
    }
 
EXIT:
    LOS_SpinUnlockRestore(&cirbufCB->lock, intSave);
    return cpSize;
}

函数调用图:

这是这个函数的调用关系图:

OsCirBufReadLinear()

STATIC UINT32 OsCirBufReadLinear	(	CirBuf *	cirbufCB,
		CHAR *	buf,
		UINT32	size
	)

在文件 los_cir_buf.c 第 144 行定义.

{
    UINT32 cpSize, remain;
    errno_t err;
 
    remain = cirbufCB->endIdx - cirbufCB->startIdx;//这里表示剩余可读区
    cpSize = (remain < size) ? remain : size;
 
    if (cpSize == 0) {
        return 0;
    }
 
    err = memcpy_s(buf, size, cirbufCB->fifo + cirbufCB->startIdx, cpSize);//完成拷贝
    if (err != EOK) {
        return 0;
    }
 
    cirbufCB->remain += cpSize;//读完了那总剩余size肯定是要增加的
    cirbufCB->startIdx += cpSize;//startIdx也要往前移动
 
    return cpSize;
}

这是这个函数的调用关系图:

OsCirBufReadLoop()

STATIC UINT32 OsCirBufReadLoop	(	CirBuf *	cirbufCB,
		CHAR *	buf,
		UINT32	size
	)

在文件 los_cir_buf.c 第 173 行定义.

{
    UINT32 right, cpSize;
    errno_t err;
 
    right = cirbufCB->size - cirbufCB->startIdx;//先算出要读取的部分
    cpSize = (right < size) ? right : size;
 
    err = memcpy_s(buf, size, cirbufCB->fifo + cirbufCB->startIdx, cpSize);//先读第一部分数据
    if (err != EOK) {
        return 0;
    }
 
    cirbufCB->remain += cpSize;//读完了那总剩余size肯定是要增加的
    cirbufCB->startIdx += cpSize;//startIdx也要往前移动
    if (cirbufCB->startIdx == cirbufCB->size) {//如果移动到头了
        cirbufCB->startIdx = 0;//循环buf的关键,新的循环开始了
    }
 
    if (cpSize < size) {
        cpSize += OsCirBufReadLinear(cirbufCB, buf + cpSize, size - cpSize);//剩余的就交给线性方式读取了
    }
 
    return cpSize;
}

函数调用图:

这是这个函数的调用关系图:

OsCirBufWriteLinear()

STATIC UINT32 OsCirBufWriteLinear	(	CirBuf *	cirbufCB,
		const CHAR *	buf,
		UINT32	size
	)

在文件 los_cir_buf.c 第 56 行定义.

{
    UINT32 cpSize;
    errno_t err;
 
    cpSize = (cirbufCB->remain < size) ? cirbufCB->remain : size;//得到cp的大小
 
    if (cpSize == 0) {
        return 0;
    }
 
    err = memcpy_s(cirbufCB->fifo + cirbufCB->endIdx, cirbufCB->remain, buf, cpSize);//完成拷贝
    if (err != EOK) {
        return 0;
    }
 
    cirbufCB->remain -= cpSize;//写完了那总剩余size肯定是要减少的
    cirbufCB->endIdx += cpSize;//结尾变大
 
    return cpSize;
}

函数调用图:

这是这个函数的调用关系图:

OsCirBufWriteLoop()

STATIC UINT32 OsCirBufWriteLoop	(	CirBuf *	cirbufCB,
		const CHAR *	buf,
		UINT32	size
	)

在文件 los_cir_buf.c 第 84 行定义.

{
    UINT32 right, cpSize;
    errno_t err;
 
    right = cirbufCB->size - cirbufCB->endIdx;//先计算右边部分
    cpSize = (right < size) ? right : size;//算出cpSize，很可能要分两次
 
    err = memcpy_s(cirbufCB->fifo + cirbufCB->endIdx, right, buf, cpSize);//先拷贝一部分
    if (err != EOK) {
        return 0;
    }
 
    cirbufCB->remain -= cpSize;//写完了那总剩余size肯定是要减少的
    cirbufCB->endIdx += cpSize;//endIdx 增加，一直往后移
    if (cirbufCB->endIdx == cirbufCB->size) {//这个相当于移到最后一个了
        cirbufCB->endIdx = 0;//循环从这里开始
    }
 
    if (cpSize == size) {//拷贝完了的情况
        return size;//返回size
    } else {
        cpSize += OsCirBufWriteLinear(cirbufCB, buf + cpSize, size - cpSize);//需第二次拷贝
    }
 
    return cpSize;
}

函数调用图:

这是这个函数的调用关系图: