Refactoring in bzip2

3 files changed, 136 insertions, 168 deletions

diff --git a/crypto/bzip2/src/CBZip2InputStream.cs b/crypto/bzip2/src/CBZip2InputStream.cs
index 7144b6d06..09d39d145 100644
--- a/crypto/bzip2/src/CBZip2InputStream.cs
+++ b/crypto/bzip2/src/CBZip2InputStream.cs
@@ -42,20 +42,13 @@ namespace Org.BouncyCastle.Apache.Bzip2
     public class CBZip2InputStream
         : BaseInputStream 
 	{
-        private static void Cadvise() {
-            //System.out.Println("CRC Error");
-            //throw new CCoruptionError();
+        private static void Cadvise()
+        {
+            throw new InvalidOperationException();
         }
 
-//        private static void BadBGLengths() {
-//            Cadvise();
-//        }
-//
-//        private static void BitStreamEOF() {
-//            Cadvise();
-//        }
-
-        private static void CompressedStreamEOF() {
+        private static void CompressedStreamEOF()
+        {
             Cadvise();
         }
 
@@ -135,8 +128,7 @@ namespace Org.BouncyCastle.Apache.Bzip2
 
         private int currentState = START_BLOCK_STATE;
 
-        private int storedBlockCRC, storedCombinedCRC;
-        private int computedBlockCRC, computedCombinedCRC;
+        private int storedBlockCRC, storedCombinedCRC, computedCombinedCRC;
 
         int i2, count, chPrev, ch2;
         int i, tPos;
@@ -281,7 +273,7 @@ namespace Org.BouncyCastle.Apache.Bzip2
 
         private void EndBlock()
         {
-            computedBlockCRC = mCrc.GetFinalCRC();
+            int computedBlockCRC = mCrc.GetFinalCRC();
             /* A bad CRC is considered a fatal error. */
             if (storedBlockCRC != computedBlockCRC)
             {
@@ -813,12 +805,12 @@ namespace Org.BouncyCastle.Apache.Bzip2
                     }
                 }
                 rNToGo--;
-                ch2 ^= (int) ((rNToGo == 1) ? 1 : 0);
+                ch2 ^= (rNToGo == 1) ? 1 : 0;
                 i2++;
 
                 currentChar = ch2;
                 currentState = RAND_PART_B_STATE;
-                mCrc.UpdateCRC(ch2);
+                mCrc.UpdateCRC((byte)ch2);
             } else {
                 EndBlock();
                 InitBlock();
@@ -835,7 +827,7 @@ namespace Org.BouncyCastle.Apache.Bzip2
 
                 currentChar = ch2;
                 currentState = NO_RAND_PART_B_STATE;
-                mCrc.UpdateCRC(ch2);
+                mCrc.UpdateCRC((byte)ch2);
             } else {
                 EndBlock();
                 InitBlock();
@@ -873,9 +865,9 @@ namespace Org.BouncyCastle.Apache.Bzip2
         }
 
         private void SetupRandPartC() {
-            if (j2 < (int) z) {
+            if (j2 < z) {
                 currentChar = ch2;
-                mCrc.UpdateCRC(ch2);
+                mCrc.UpdateCRC((byte)ch2);
                 j2++;
             } else {
                 currentState = RAND_PART_A_STATE;
@@ -906,9 +898,9 @@ namespace Org.BouncyCastle.Apache.Bzip2
         }
 
         private void SetupNoRandPartC() {
-            if (j2 < (int) z) {
+            if (j2 < z) {
                 currentChar = ch2;
-                mCrc.UpdateCRC(ch2);
+                mCrc.UpdateCRC((byte)ch2);
                 j2++;
             } else {
                 currentState = NO_RAND_PART_A_STATE;
diff --git a/crypto/bzip2/src/CBZip2OutputStream.cs b/crypto/bzip2/src/CBZip2OutputStream.cs
index f56ca29b2..307f59cd0 100644
--- a/crypto/bzip2/src/CBZip2OutputStream.cs
+++ b/crypto/bzip2/src/CBZip2OutputStream.cs
@@ -66,8 +66,8 @@ namespace Org.BouncyCastle.Apache.Bzip2
             {
                 if (inUse[i])
                 {
-                    seqToUnseq[nInUse] = (char) i;
-                    unseqToSeq[i] = (char) nInUse;
+                    seqToUnseq[nInUse] = (byte)i;
+                    unseqToSeq[i] = (byte)nInUse;
                     nInUse++;
                 }
             }
@@ -252,8 +252,8 @@ namespace Org.BouncyCastle.Apache.Bzip2
         private bool[] inUse = new bool[256];
         private int nInUse;
 
-        private char[] seqToUnseq = new char[256];
-        private char[] unseqToSeq = new char[256];
+        private byte[] seqToUnseq = new byte[256];
+        private byte[] unseqToSeq = new byte[256];
 
         private char[] selector = new char[BZip2Constants.MAX_SELECTORS];
         private char[] selectorMtf = new char[BZip2Constants.MAX_SELECTORS];
@@ -353,7 +353,7 @@ namespace Org.BouncyCastle.Apache.Bzip2
 
             for (int i = 0; i < runLength; i++)
             {
-                mCrc.UpdateCRC(currentByte);
+                mCrc.UpdateCRC((byte)currentByte);
             }
 
             switch (runLength)
@@ -440,7 +440,7 @@ namespace Org.BouncyCastle.Apache.Bzip2
             bsStream.Flush();
         }
 
-        private int blockCRC, combinedCRC;
+        private int combinedCRC;
 
         private void Initialize()
         {
@@ -469,7 +469,7 @@ namespace Org.BouncyCastle.Apache.Bzip2
 
         private void EndBlock()
         {
-            blockCRC = mCrc.GetFinalCRC();
+            int blockCRC = mCrc.GetFinalCRC();
             combinedCRC = Integers.RotateLeft(combinedCRC, 1) ^ blockCRC;
 
             /* sort the block and establish posn of original string */
@@ -1592,10 +1592,8 @@ namespace Org.BouncyCastle.Apache.Bzip2
 
         private void GenerateMTFValues()
         {
-            char[] yy = new char[256];
-            int  i, j;
-            char tmp;
-            char tmp2;
+            byte[] yy = new byte[256];
+            int i, j;
             int zPend;
             int wr;
             int EOB;
@@ -1612,59 +1610,51 @@ namespace Org.BouncyCastle.Apache.Bzip2
             zPend = 0;
             for (i = 0; i < nInUse; i++)
             {
-                yy[i] = (char) i;
+                yy[i] = (byte)i;
             }
 
             for (i = 0; i < count; i++)
             {
-                char ll_i;
-
-                ll_i = unseqToSeq[blockBytes[zptr[i]]];
+                byte ll_i = unseqToSeq[blockBytes[zptr[i]]];
 
                 j = 0;
-                tmp = yy[j];
-                while (ll_i != tmp)
                 {
-                    j++;
-                    tmp2 = tmp;
-                    tmp = yy[j];
-                    yy[j] = tmp2;
+                    byte tmp = yy[j];
+                    while (ll_i != tmp)
+                    {
+                        j++;
+                        byte tmp2 = tmp;
+                        tmp = yy[j];
+                        yy[j] = tmp2;
+                    }
+                    yy[0] = tmp;
                 }
-                yy[0] = tmp;
 
                 if (j == 0)
                 {
                     zPend++;
+                    continue;
                 }
-                else
+
+                if (zPend > 0)
                 {
-                    if (zPend > 0)
+                    zPend--;
+                    while (true)
                     {
-                        zPend--;
-                        while (true)
-                        {
-                            switch (zPend % 2)
-                            {
-                            case 0:
-                                szptr[wr++] = BZip2Constants.RUNA;
-                                mtfFreq[BZip2Constants.RUNA]++;
-                                break;
-                            case 1:
-                                szptr[wr++] = BZip2Constants.RUNB;
-                                mtfFreq[BZip2Constants.RUNB]++;
-                                break;
-                            }
+                        // BZip2Constants.RUNA or BZip2Constants.RUNB
+                        int run = zPend & 1;
+                        szptr[wr++] = run;
+                        mtfFreq[run]++;
 
-                            if (zPend < 2)
-                                break;
+                        if (zPend < 2)
+                            break;
 
-                            zPend = (zPend - 2) / 2;
-                        }
-                        zPend = 0;
+                        zPend = (zPend - 2) / 2;
                     }
-                    szptr[wr++] = j + 1;
-                    mtfFreq[j + 1]++;
+                    zPend = 0;
                 }
+                szptr[wr++] = j + 1;
+                mtfFreq[j + 1]++;
             }
 
             if (zPend > 0)
@@ -1672,17 +1662,10 @@ namespace Org.BouncyCastle.Apache.Bzip2
                 zPend--;
                 while (true)
                 {
-                    switch (zPend % 2)
-                    {
-                    case 0:
-                        szptr[wr++] = BZip2Constants.RUNA;
-                        mtfFreq[BZip2Constants.RUNA]++;
-                        break;
-                    case 1:
-                        szptr[wr++] = BZip2Constants.RUNB;
-                        mtfFreq[BZip2Constants.RUNB]++;
-                        break;
-                    }
+                    // BZip2Constants.RUNA or BZip2Constants.RUNB
+                    int run = zPend & 1;
+                    szptr[wr++] = run;
+                    mtfFreq[run]++;
 
                     if (zPend < 2)
                         break;
diff --git a/crypto/bzip2/src/CRC.cs b/crypto/bzip2/src/CRC.cs
index 278a9f336..ac2db776a 100644
--- a/crypto/bzip2/src/CRC.cs
+++ b/crypto/bzip2/src/CRC.cs
@@ -26,109 +26,102 @@ using System;
 
 namespace Org.BouncyCastle.Apache.Bzip2
 {
-	/**
+    /**
     * A simple class the hold and calculate the CRC for sanity checking
     * of the data.
     *
     * @author <a href="mailto:keiron@aftexsw.com">Keiron Liddle</a>
     */
-    internal class CRC 
-	{
-        public static readonly int[] crc32Table = {
-            unchecked((int)0x00000000), unchecked((int)0x04c11db7), unchecked((int)0x09823b6e), unchecked((int)0x0d4326d9),
-            unchecked((int)0x130476dc), unchecked((int)0x17c56b6b), unchecked((int)0x1a864db2), unchecked((int)0x1e475005),
-            unchecked((int)0x2608edb8), unchecked((int)0x22c9f00f), unchecked((int)0x2f8ad6d6), unchecked((int)0x2b4bcb61),
-            unchecked((int)0x350c9b64), unchecked((int)0x31cd86d3), unchecked((int)0x3c8ea00a), unchecked((int)0x384fbdbd),
-            unchecked((int)0x4c11db70), unchecked((int)0x48d0c6c7), unchecked((int)0x4593e01e), unchecked((int)0x4152fda9),
-            unchecked((int)0x5f15adac), unchecked((int)0x5bd4b01b), unchecked((int)0x569796c2), unchecked((int)0x52568b75),
-            unchecked((int)0x6a1936c8), unchecked((int)0x6ed82b7f), unchecked((int)0x639b0da6), unchecked((int)0x675a1011),
-            unchecked((int)0x791d4014), unchecked((int)0x7ddc5da3), unchecked((int)0x709f7b7a), unchecked((int)0x745e66cd),
-            unchecked((int)0x9823b6e0), unchecked((int)0x9ce2ab57), unchecked((int)0x91a18d8e), unchecked((int)0x95609039),
-            unchecked((int)0x8b27c03c), unchecked((int)0x8fe6dd8b), unchecked((int)0x82a5fb52), unchecked((int)0x8664e6e5),
-            unchecked((int)0xbe2b5b58), unchecked((int)0xbaea46ef), unchecked((int)0xb7a96036), unchecked((int)0xb3687d81),
-            unchecked((int)0xad2f2d84), unchecked((int)0xa9ee3033), unchecked((int)0xa4ad16ea), unchecked((int)0xa06c0b5d),
-            unchecked((int)0xd4326d90), unchecked((int)0xd0f37027), unchecked((int)0xddb056fe), unchecked((int)0xd9714b49),
-            unchecked((int)0xc7361b4c), unchecked((int)0xc3f706fb), unchecked((int)0xceb42022), unchecked((int)0xca753d95),
-            unchecked((int)0xf23a8028), unchecked((int)0xf6fb9d9f), unchecked((int)0xfbb8bb46), unchecked((int)0xff79a6f1),
-            unchecked((int)0xe13ef6f4), unchecked((int)0xe5ffeb43), unchecked((int)0xe8bccd9a), unchecked((int)0xec7dd02d),
-            unchecked((int)0x34867077), unchecked((int)0x30476dc0), unchecked((int)0x3d044b19), unchecked((int)0x39c556ae),
-            unchecked((int)0x278206ab), unchecked((int)0x23431b1c), unchecked((int)0x2e003dc5), unchecked((int)0x2ac12072),
-            unchecked((int)0x128e9dcf), unchecked((int)0x164f8078), unchecked((int)0x1b0ca6a1), unchecked((int)0x1fcdbb16),
-            unchecked((int)0x018aeb13), unchecked((int)0x054bf6a4), unchecked((int)0x0808d07d), unchecked((int)0x0cc9cdca),
-            unchecked((int)0x7897ab07), unchecked((int)0x7c56b6b0), unchecked((int)0x71159069), unchecked((int)0x75d48dde),
-            unchecked((int)0x6b93dddb), unchecked((int)0x6f52c06c), unchecked((int)0x6211e6b5), unchecked((int)0x66d0fb02),
-            unchecked((int)0x5e9f46bf), unchecked((int)0x5a5e5b08), unchecked((int)0x571d7dd1), unchecked((int)0x53dc6066),
-            unchecked((int)0x4d9b3063), unchecked((int)0x495a2dd4), unchecked((int)0x44190b0d), unchecked((int)0x40d816ba),
-            unchecked((int)0xaca5c697), unchecked((int)0xa864db20), unchecked((int)0xa527fdf9), unchecked((int)0xa1e6e04e),
-            unchecked((int)0xbfa1b04b), unchecked((int)0xbb60adfc), unchecked((int)0xb6238b25), unchecked((int)0xb2e29692),
-            unchecked((int)0x8aad2b2f), unchecked((int)0x8e6c3698), unchecked((int)0x832f1041), unchecked((int)0x87ee0df6),
-            unchecked((int)0x99a95df3), unchecked((int)0x9d684044), unchecked((int)0x902b669d), unchecked((int)0x94ea7b2a),
-            unchecked((int)0xe0b41de7), unchecked((int)0xe4750050), unchecked((int)0xe9362689), unchecked((int)0xedf73b3e),
-            unchecked((int)0xf3b06b3b), unchecked((int)0xf771768c), unchecked((int)0xfa325055), unchecked((int)0xfef34de2),
-            unchecked((int)0xc6bcf05f), unchecked((int)0xc27dede8), unchecked((int)0xcf3ecb31), unchecked((int)0xcbffd686),
-            unchecked((int)0xd5b88683), unchecked((int)0xd1799b34), unchecked((int)0xdc3abded), unchecked((int)0xd8fba05a),
-            unchecked((int)0x690ce0ee), unchecked((int)0x6dcdfd59), unchecked((int)0x608edb80), unchecked((int)0x644fc637),
-            unchecked((int)0x7a089632), unchecked((int)0x7ec98b85), unchecked((int)0x738aad5c), unchecked((int)0x774bb0eb),
-            unchecked((int)0x4f040d56), unchecked((int)0x4bc510e1), unchecked((int)0x46863638), unchecked((int)0x42472b8f),
-            unchecked((int)0x5c007b8a), unchecked((int)0x58c1663d), unchecked((int)0x558240e4), unchecked((int)0x51435d53),
-            unchecked((int)0x251d3b9e), unchecked((int)0x21dc2629), unchecked((int)0x2c9f00f0), unchecked((int)0x285e1d47),
-            unchecked((int)0x36194d42), unchecked((int)0x32d850f5), unchecked((int)0x3f9b762c), unchecked((int)0x3b5a6b9b),
-            unchecked((int)0x0315d626), unchecked((int)0x07d4cb91), unchecked((int)0x0a97ed48), unchecked((int)0x0e56f0ff),
-            unchecked((int)0x1011a0fa), unchecked((int)0x14d0bd4d), unchecked((int)0x19939b94), unchecked((int)0x1d528623),
-            unchecked((int)0xf12f560e), unchecked((int)0xf5ee4bb9), unchecked((int)0xf8ad6d60), unchecked((int)0xfc6c70d7),
-            unchecked((int)0xe22b20d2), unchecked((int)0xe6ea3d65), unchecked((int)0xeba91bbc), unchecked((int)0xef68060b),
-            unchecked((int)0xd727bbb6), unchecked((int)0xd3e6a601), unchecked((int)0xdea580d8), unchecked((int)0xda649d6f),
-            unchecked((int)0xc423cd6a), unchecked((int)0xc0e2d0dd), unchecked((int)0xcda1f604), unchecked((int)0xc960ebb3),
-            unchecked((int)0xbd3e8d7e), unchecked((int)0xb9ff90c9), unchecked((int)0xb4bcb610), unchecked((int)0xb07daba7),
-            unchecked((int)0xae3afba2), unchecked((int)0xaafbe615), unchecked((int)0xa7b8c0cc), unchecked((int)0xa379dd7b),
-            unchecked((int)0x9b3660c6), unchecked((int)0x9ff77d71), unchecked((int)0x92b45ba8), unchecked((int)0x9675461f),
-            unchecked((int)0x8832161a), unchecked((int)0x8cf30bad), unchecked((int)0x81b02d74), unchecked((int)0x857130c3),
-            unchecked((int)0x5d8a9099), unchecked((int)0x594b8d2e), unchecked((int)0x5408abf7), unchecked((int)0x50c9b640),
-            unchecked((int)0x4e8ee645), unchecked((int)0x4a4ffbf2), unchecked((int)0x470cdd2b), unchecked((int)0x43cdc09c),
-            unchecked((int)0x7b827d21), unchecked((int)0x7f436096), unchecked((int)0x7200464f), unchecked((int)0x76c15bf8),
-            unchecked((int)0x68860bfd), unchecked((int)0x6c47164a), unchecked((int)0x61043093), unchecked((int)0x65c52d24),
-            unchecked((int)0x119b4be9), unchecked((int)0x155a565e), unchecked((int)0x18197087), unchecked((int)0x1cd86d30),
-            unchecked((int)0x029f3d35), unchecked((int)0x065e2082), unchecked((int)0x0b1d065b), unchecked((int)0x0fdc1bec),
-            unchecked((int)0x3793a651), unchecked((int)0x3352bbe6), unchecked((int)0x3e119d3f), unchecked((int)0x3ad08088),
-            unchecked((int)0x2497d08d), unchecked((int)0x2056cd3a), unchecked((int)0x2d15ebe3), unchecked((int)0x29d4f654),
-            unchecked((int)0xc5a92679), unchecked((int)0xc1683bce), unchecked((int)0xcc2b1d17), unchecked((int)0xc8ea00a0),
-            unchecked((int)0xd6ad50a5), unchecked((int)0xd26c4d12), unchecked((int)0xdf2f6bcb), unchecked((int)0xdbee767c),
-            unchecked((int)0xe3a1cbc1), unchecked((int)0xe760d676), unchecked((int)0xea23f0af), unchecked((int)0xeee2ed18),
-            unchecked((int)0xf0a5bd1d), unchecked((int)0xf464a0aa), unchecked((int)0xf9278673), unchecked((int)0xfde69bc4),
-            unchecked((int)0x89b8fd09), unchecked((int)0x8d79e0be), unchecked((int)0x803ac667), unchecked((int)0x84fbdbd0),
-            unchecked((int)0x9abc8bd5), unchecked((int)0x9e7d9662), unchecked((int)0x933eb0bb), unchecked((int)0x97ffad0c),
-            unchecked((int)0xafb010b1), unchecked((int)0xab710d06), unchecked((int)0xa6322bdf), unchecked((int)0xa2f33668),
-            unchecked((int)0xbcb4666d), unchecked((int)0xb8757bda), unchecked((int)0xb5365d03), unchecked((int)0xb1f740b4)
+    internal class CRC
+    {
+        private static readonly uint[] Crc32Table = {
+            0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
+            0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
+            0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
+            0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
+            0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
+            0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
+            0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
+            0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
+            0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
+            0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
+            0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
+            0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
+            0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
+            0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
+            0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
+            0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
+            0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
+            0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
+            0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
+            0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
+            0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
+            0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
+            0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
+            0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
+            0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
+            0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
+            0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
+            0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
+            0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
+            0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
+            0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
+            0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
+            0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
+            0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
+            0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
+            0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
+            0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
+            0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
+            0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
+            0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
+            0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
+            0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
+            0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
+            0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
+            0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
+            0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
+            0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
+            0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
+            0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
+            0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
+            0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
+            0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
+            0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
+            0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
+            0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
+            0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
+            0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
+            0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
+            0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
+            0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
+            0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
+            0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
+            0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
+            0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
         };
 
-        public CRC() {
-            InitialiseCRC();
-        }
-
-        internal void InitialiseCRC() {
-            globalCrc = unchecked((int)0xffffffff);
-        }
+        private uint m_globalCrc;
 
-        internal int GetFinalCRC() {
-            return ~globalCrc;
+        internal CRC()
+        {
+            InitialiseCRC();
         }
 
-        internal int GetGlobalCRC() {
-            return globalCrc;
+        internal void InitialiseCRC()
+        {
+            m_globalCrc = 0xffffffff;
         }
 
-        internal void SetGlobalCRC(int newCrc) {
-            globalCrc = newCrc;
+        internal int GetFinalCRC()
+        {
+            return (int)~m_globalCrc;
         }
 
-        internal void UpdateCRC(int inCh) {
-            int temp = (globalCrc >> 24) ^ inCh;
-            if (temp < 0) {
-                temp = 256 + temp;
-            }
-            globalCrc = (globalCrc << 8) ^ CRC.crc32Table[temp];
+        internal void UpdateCRC(byte inCh)
+        {
+            uint index = (m_globalCrc >> 24) ^ inCh;
+            m_globalCrc = (m_globalCrc << 8) ^ Crc32Table[index];
         }
-
-        internal int globalCrc;
     }
-}
\ No newline at end of file
+}