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//
// © Copyright Henrik Ravn 2004
//
// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
using System;
using System.Diagnostics;
namespace DotZLib
{
/// <summary>
/// This class implements a circular buffer
/// </summary>
internal class CircularBuffer
{
#region Private data
private int _capacity;
private int _head;
private int _tail;
private int _size;
private byte[] _buffer;
#endregion
public CircularBuffer(int capacity)
{
Debug.Assert( capacity > 0 );
_buffer = new byte[capacity];
_capacity = capacity;
_head = 0;
_tail = 0;
_size = 0;
}
public int Size { get { return _size; } }
public int Put(byte[] source, int offset, int count)
{
Debug.Assert( count > 0 );
int trueCount = Math.Min(count, _capacity - Size);
for (int i = 0; i < trueCount; ++i)
_buffer[(_tail+i) % _capacity] = source[offset+i];
_tail += trueCount;
_tail %= _capacity;
_size += trueCount;
return trueCount;
}
public bool Put(byte b)
{
if (Size == _capacity) // no room
return false;
_buffer[_tail++] = b;
_tail %= _capacity;
++_size;
return true;
}
public int Get(byte[] destination, int offset, int count)
{
int trueCount = Math.Min(count,Size);
for (int i = 0; i < trueCount; ++i)
destination[offset + i] = _buffer[(_head+i) % _capacity];
_head += trueCount;
_head %= _capacity;
_size -= trueCount;
return trueCount;
}
public int Get()
{
if (Size == 0)
return -1;
int result = (int)_buffer[_head++ % _capacity];
--_size;
return result;
}
}
}