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kqueue.hh
#pragma once
/*
Copyright (c) 2003-2021 Tommi Junttila
Released under the GNU Lesser General Public License version 3.
This file is part of bliss.
bliss is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, version 3 of the License.
bliss is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with bliss. If not, see <http://www.gnu.org/licenses/>.
*/
#include <new>
#include <cassert>
namespace bliss {
template <class Type>
class KQueue
{
public:
KQueue();
~KQueue();
void init(const unsigned int N);
bool is_empty() const;
unsigned int size() const;
void clear();
Type front() const;
Type pop_front();
void push_front(Type e);
Type pop_back();
void push_back(Type e);
private:
Type *entries, *end;
Type *head, *tail;
};
template <class Type>
KQueue<Type>::KQueue()
{
entries = nullptr;
end = nullptr;
head = nullptr;
tail = nullptr;
}
template <class Type>
KQueue<Type>::~KQueue()
{
delete[] entries;
entries = nullptr;
end = nullptr;
head = nullptr;
tail = nullptr;
}
template <class Type>
void KQueue<Type>::init(const unsigned int k)
{
assert(k > 0);
delete[] entries;
entries = new Type[k+1];
end = entries + k + 1;
head = entries;
tail = head;
}
template <class Type>
void KQueue<Type>::clear()
{
head = entries;
tail = head;
}
template <class Type>
bool KQueue<Type>::is_empty() const
{
return head == tail;
}
template <class Type>
unsigned int KQueue<Type>::size() const
{
if(tail >= head)
return(tail - head);
return (end - head) + (tail - entries);
}
template <class Type>
Type KQueue<Type>::front() const
{
assert(head != tail);
return *head;
}
template <class Type>
Type KQueue<Type>::pop_front()
{
assert(head != tail);
Type *old_head = head;
head++;
if(head == end)
head = entries;
return *old_head;
}
template <class Type>
void KQueue<Type>::push_front(Type e)
{
if(head == entries)
head = end - 1;
else
head--;
assert(head != tail);
*head = e;
}
template <class Type>
void KQueue<Type>::push_back(Type e)
{
*tail = e;
tail++;
if(tail == end)
tail = entries;
assert(head != tail);
}
} // namespace bliss
bliss::KQueue::init
void init(const unsigned int N)
Definition kqueue.hh:95
bliss::KQueue::push_front
void push_front(Type e)
Definition kqueue.hh:145
bliss::KQueue::is_empty
bool is_empty() const
Definition kqueue.hh:113
bliss::KQueue::size
unsigned int size() const
Definition kqueue.hh:119
bliss::KQueue::push_back
void push_back(Type e)
Definition kqueue.hh:156
bliss::KQueue::pop_back
Type pop_back()
bliss::KQueue::pop_front
Type pop_front()
Definition kqueue.hh:134
bliss::KQueue::clear
void clear()
Definition kqueue.hh:106
bliss::KQueue::KQueue
KQueue()
Definition kqueue.hh:76
bliss::KQueue::front
Type front() const
Definition kqueue.hh:127
bliss
Definition abstractgraph.cc:35