#include "DataHelper.h"

/**
 * 初始化一个先入先出缓冲
 * 
 * @author lxz (041620 15:15:44)
 * 
 * @param fifo 缓冲对象
 * @param buffer 数据缓冲
 * @param total 总数据大小
 */
void dh_fifo_init(fifo_buffer_t *fifo, unsigned char *buffer, int total) {
    fifo->buffer = buffer;
    fifo->total = total;
    fifo->count = 0;
    fifo->head = 0;
    fifo->tail = 0;
}

/**
 * 缓冲保存一个数据
 * 
 * @author lxz (041620 15:16:14)
 * 
 * @param fifo 缓冲对象
 * @param dat 缓冲数据
 */
void dh_fifo_push(fifo_buffer_t *fifo, unsigned char dat) {
    if (fifo->count + 1 < fifo->total) {
        DH_ENTER_CRITCAL();
        fifo->buffer[fifo->head] = dat;
        if (++fifo->head >= fifo->total) {
            fifo->head = 0;
        }
        fifo->count++;
        DH_EXIT_CRITCAL();
    }
}

/**
 * 
 * 
 * @author lxz (041620 15:16:43)
 * 
 * @param fifo 
 * @param dat 
 * 
 * @return int 
 */
int dh_fifo_pop(fifo_buffer_t *fifo, unsigned char *dat) {

    if (fifo->count > 0) {
        DH_ENTER_CRITCAL();
        *dat = fifo->buffer[fifo->tail];
        if (++fifo->tail >= fifo->total) {
            fifo->tail = 0;
        }
        fifo->count--;
        DH_EXIT_CRITCAL(); 
        return 1;
    }
    return 0;
}