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-rw-r--r--zlib/contrib/dotzlib/DotZLib/CircularBuffer.cs83
1 files changed, 83 insertions, 0 deletions
diff --git a/zlib/contrib/dotzlib/DotZLib/CircularBuffer.cs b/zlib/contrib/dotzlib/DotZLib/CircularBuffer.cs
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+++ b/zlib/contrib/dotzlib/DotZLib/CircularBuffer.cs
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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;
+ }
+
+ }
+}