queue.h

/****************************************************************************
 * modules/include/memutils/s_stl/queue.h
 *
 *   Copyright 2018 Sony Semiconductor Solutions Corporation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    distribution.
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 *    products derived from this software without specific prior written
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 ****************************************************************************/
 
#ifndef QUEUE_H_INCLUDED
#define QUEUE_H_INCLUDED
 
#include "memutils/s_stl/s_stl_config.h"
#include "memutils/s_stl/buffer.h"
 
__STL_BEGIN_NAMESPACE
 
/*-------------------------------------------------------------------*/
template<class T, int N> class Queue{
 
private:
 
    RingBuffer<T, N> data_buf;
    int cnt;
public:
    Queue() : cnt(0){}
 
    bool push(const T& new_data){
        if(cnt>=N){ return FALSE; } else { cnt++; }
        return data_buf.alloc_front(new_data);
    }
 
    bool pop(void){
        if(cnt<=0){ return FALSE; } else { cnt--; }
        return data_buf.free_back();
    }
 
    const T& top(void) const {
        return data_buf.get_back();
    }
 
    T& writable_at(const int n){
        return const_cast<T&>(data_buf.at_back(n));
    }
 
    const T& at(const int n) const {
        return data_buf.at_back(n);
    }
 
    int size(void) const { return cnt; }
    int rest(void) const { return (N-cnt); }
 
    bool empty(void) const { return (cnt==0); }
    bool full(void) const { return (cnt==N); }
 
    void clear(void){
        cnt = 0;
        data_buf.clear();
    }
};
 
__STL_END_NAMESPACE
 
#endif /* QUEUE_H_INCLUDED */