зеркало из https://github.com/mozilla/gecko-dev.git
72 строки
1.8 KiB
C++
72 строки
1.8 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* The contents of this file are subject to the Netscape Public License
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* Version 1.0 (the "NPL"); you may not use this file except in
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* compliance with the NPL. You may obtain a copy of the NPL at
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* http://www.mozilla.org/NPL/
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*
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* Software distributed under the NPL is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
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* for the specific language governing rights and limitations under the
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* NPL.
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*
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* The Initial Developer of this code under the NPL is Netscape
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* Communications Corporation. Portions created by Netscape are
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* Copyright (C) 1998 Netscape Communications Corporation. All Rights
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* Reserved.
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*/
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#ifndef _FIFO_H_
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#define _FIFO_H_
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#include "Fundamentals.h"
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template <class N>
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class Fifo
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{
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private:
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N* begin;
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N* limit;
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N* first;
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N* last;
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public:
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Fifo(Uint32 size) {begin = first = last = new N[size]; limit = &begin[size];}
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~Fifo() {delete begin;}
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N& get(); // get at first element inserted.
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void put(N n); // append an element.
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bool empty() const {return (last == first);} // is the fifo empty ?
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Uint32 count() const; // number of elements in the fifo.
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};
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template <class N> inline N&
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Fifo<N>::get()
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{
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assert(last != first);
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N* pos = first++;
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if (first == limit)
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first = begin;
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return *pos;
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}
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template <class N> inline void
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Fifo<N>::put(N n)
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{
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*last++ = n;
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if (last == limit)
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last = begin;
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assert(last != first);
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}
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template <class N> inline Uint32
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Fifo<N>::count() const
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{
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if (last >= first)
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return Uint32(last - first);
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else
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return Uint32(limit - first) + Uint32(last - begin);
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}
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#endif /* _FIFO_H_ */
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