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53 lines
899 B
53 lines
899 B
// SevenZip/CRC.java
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package SevenZip;
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public class CRC
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{
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static public int[] Table = new int[256];
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static
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{
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for (int i = 0; i < 256; i++)
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{
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int r = i;
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for (int j = 0; j < 8; j++)
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if ((r & 1) != 0)
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r = (r >>> 1) ^ 0xEDB88320;
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else
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r >>>= 1;
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Table[i] = r;
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}
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}
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int _value = -1;
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public void Init()
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{
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_value = -1;
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}
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public void Update(byte[] data, int offset, int size)
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{
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for (int i = 0; i < size; i++)
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_value = Table[(_value ^ data[offset + i]) & 0xFF] ^ (_value >>> 8);
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}
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public void Update(byte[] data)
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{
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int size = data.length;
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for (int i = 0; i < size; i++)
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_value = Table[(_value ^ data[i]) & 0xFF] ^ (_value >>> 8);
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}
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public void UpdateByte(int b)
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{
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_value = Table[(_value ^ b) & 0xFF] ^ (_value >>> 8);
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}
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public int GetDigest()
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{
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return _value ^ (-1);
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}
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}
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