golang 用数组实现的循环队列

const maxSize = 100

//SqQueue 结构体定义
type SqQueue struct {
    data  [maxSize]interface{}
    front int
    rear  int
}

//New 新建空队列
func New() *SqQueue {
    return &SqQueue{
        front: 0,
        rear:  0,
    }
}

// Length 队列长度
func (q *SqQueue) Length() interface{} {
    return (q.rear - q.front + maxSize) % maxSize
}

// Enqueue 入队
func (q *SqQueue) Enqueue(e interface{}) error {
    if (q.rear+1)%maxSize == q.front {
        return fmt.Errorf("quque is full")
    }
    q.data[q.rear] = e
    q.rear = (q.rear + 1) % maxSize
    return nil
}

// Dequeue 出队
func (q *SqQueue) Dequeue() (e interface{}, err error) {
    if q.rear == q.front {
        return e, fmt.Errorf("quque is empty")
    }
    e = q.data[q.front]
    q.front = (q.front + 1) % maxSize
    return e, nil
}