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140 lines
4.3 KiB
140 lines
4.3 KiB
namespace com.hitrust.util.Zip.Compression.Streams
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{
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using System;
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public class OutputWindow
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{
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private byte[] window = new byte[WINDOW_SIZE];
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private static int WINDOW_MASK = (WINDOW_SIZE - 1);
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private static int WINDOW_SIZE = 0x8000;
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private int windowEnd = 0;
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private int windowFilled = 0;
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public void CopyDict(byte[] dict, int offset, int len)
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{
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if (this.windowFilled > 0)
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{
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throw new InvalidOperationException();
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}
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if (len > WINDOW_SIZE)
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{
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offset += len - WINDOW_SIZE;
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len = WINDOW_SIZE;
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}
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Array.Copy(dict, offset, this.window, 0, len);
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this.windowEnd = len & WINDOW_MASK;
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}
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public int CopyOutput(byte[] output, int offset, int len)
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{
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int windowEnd = this.windowEnd;
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if (len > this.windowFilled)
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{
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len = this.windowFilled;
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}
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else
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{
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windowEnd = ((this.windowEnd - this.windowFilled) + len) & WINDOW_MASK;
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}
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int num2 = len;
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int length = len - windowEnd;
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if (length > 0)
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{
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Array.Copy(this.window, WINDOW_SIZE - length, output, offset, length);
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offset += length;
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len = windowEnd;
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}
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Array.Copy(this.window, windowEnd - len, output, offset, len);
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this.windowFilled -= num2;
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if (this.windowFilled < 0)
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{
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throw new InvalidOperationException();
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}
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return num2;
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}
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public int CopyStored(StreamManipulator input, int len)
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{
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int num;
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len = Math.Min(Math.Min(len, WINDOW_SIZE - this.windowFilled), input.AvailableBytes);
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int length = WINDOW_SIZE - this.windowEnd;
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if (len > length)
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{
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num = input.CopyBytes(this.window, this.windowEnd, length);
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if (num == length)
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{
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num += input.CopyBytes(this.window, 0, len - length);
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}
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}
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else
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{
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num = input.CopyBytes(this.window, this.windowEnd, len);
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}
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this.windowEnd = (this.windowEnd + num) & WINDOW_MASK;
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this.windowFilled += num;
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return num;
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}
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public int GetAvailable()
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{
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return this.windowFilled;
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}
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public int GetFreeSpace()
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{
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return (WINDOW_SIZE - this.windowFilled);
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}
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public void Repeat(int len, int dist)
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{
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if ((this.windowFilled += len) > WINDOW_SIZE)
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{
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throw new InvalidOperationException("Window full");
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}
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int repStart = (this.windowEnd - dist) & WINDOW_MASK;
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int num2 = WINDOW_SIZE - len;
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if ((repStart > num2) || (this.windowEnd >= num2))
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{
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this.SlowRepeat(repStart, len, dist);
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}
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else if (len > dist)
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{
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while (len-- > 0)
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{
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this.window[this.windowEnd++] = this.window[repStart++];
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}
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}
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else
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{
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Array.Copy(this.window, repStart, this.window, this.windowEnd, len);
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this.windowEnd += len;
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}
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}
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public void Reset()
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{
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this.windowFilled = this.windowEnd = 0;
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}
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private void SlowRepeat(int repStart, int len, int dist)
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{
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while (len-- > 0)
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{
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this.window[this.windowEnd++] = this.window[repStart++];
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this.windowEnd &= WINDOW_MASK;
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repStart &= WINDOW_MASK;
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}
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}
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public void Write(int abyte)
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{
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if (this.windowFilled++ == WINDOW_SIZE)
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{
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throw new InvalidOperationException("Window full");
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}
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this.window[this.windowEnd++] = (byte) abyte;
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this.windowEnd &= WINDOW_MASK;
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}
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}
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}
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