68 lines
2.0 KiB
C#
68 lines
2.0 KiB
C#
//
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// Copyright (c) 2008-2011, Kenneth Bell
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//
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// Permission is hereby granted, free of charge, to any person obtaining a
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// copy of this software and associated documentation files (the "Software"),
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// to deal in the Software without restriction, including without limitation
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// the rights to use, copy, modify, merge, publish, distribute, sublicense,
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// and/or sell copies of the Software, and to permit persons to whom the
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// Software is furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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// DEALINGS IN THE SOFTWARE.
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//
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namespace DiscUtils.Compression
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{
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internal class MoveToFront
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{
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private readonly byte[] _buffer;
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public MoveToFront()
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: this(256, false) {}
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public MoveToFront(int size, bool autoInit)
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{
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_buffer = new byte[size];
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if (autoInit)
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{
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for (byte i = 0; i < size; ++i)
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{
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_buffer[i] = i;
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}
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}
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}
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public byte Head
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{
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get { return _buffer[0]; }
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}
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public void Set(int pos, byte val)
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{
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_buffer[pos] = val;
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}
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public byte GetAndMove(int pos)
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{
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byte val = _buffer[pos];
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for (int i = pos; i > 0; --i)
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{
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_buffer[i] = _buffer[i - 1];
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}
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_buffer[0] = val;
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return val;
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}
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}
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} |