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CLZF.cs

/*
 * Copyright (c) 2005 Oren J. Maurice <oymaurice@hazorea.org.il>
 * 
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 * 
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * 
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 *   3.  The name of the author may not be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License version 2 (the "GPL"), in which case the
 * provisions of the GPL are applicable instead of the above. If you wish to
 * allow the use of your version of this file only under the terms of the
 * GPL and not to allow others to use your version of this file under the
 * BSD license, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the GPL. If
 * you do not delete the provisions above, a recipient may use your version
 * of this file under either the BSD or the GPL.
 */

using System;

namespace LZF.NET
{
      
      /// <summary>
      /// Summary description for CLZF.
      /// </summary>
00047       public class CLZF
      {
            // CRC32 data & function
            UInt32 []crc_32_tab = new UInt32[256]
            {
                  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
                  0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
                  0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
                  0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
                  0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
                  0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
                  0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
                  0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
                  0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
                  0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
                  0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
                  0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
                  0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
                  0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
                  0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
                  0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
                  0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
                  0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
                  0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
                  0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
                  0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
                  0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
                  0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
                  0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
                  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
                  0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
                  0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
                  0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
                  0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
                  0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
                  0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
                  0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
                  0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
                  0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
                  0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
                  0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
                  0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
                  0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
                  0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
                  0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
                  0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
                  0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
                  0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
                  0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
                  0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
                  0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
                  0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
                  0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
                  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
                  0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
                  0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
                  0x2d02ef8d
            };

            public UInt32 crc32(UInt32 OldCRC,byte NewData) 
            {
                  return crc_32_tab[(OldCRC & 0xff) ^ NewData] ^ (OldCRC >> 8);
            }


            /// <summary>
            /// LZF Compressor
            /// </summary>

00116             UInt32 HLOG=14;
            UInt32 HSIZE=(1<<14);

            /*
            * don't play with this unless you benchmark!
            * decompression is not dependent on the hash function
            * the hashing function might seem strange, just believe me
            * it works ;)
            */
            UInt32 MAX_LIT=(1 <<  5);
            UInt32 MAX_OFF=(1 << 13);
            UInt32 MAX_REF=((1 <<  8) + (1 << 3));

            UInt32 FRST(byte[] Array,UInt32 ptr) 
            {
                  return (UInt32)(((Array[ptr]) << 8) | Array[ptr+1]);
            }

            UInt32 NEXT(UInt32 v,byte[] Array,UInt32 ptr)
            {
                  return ((v) << 8) | Array[ptr+2];
            }

            UInt32 IDX(UInt32 h) 
            {
                  return ((h ^ (h << 5)) >> (int)(((3*8 - HLOG)) - h*5) & (HSIZE - 1));
            }

            /*
            * compressed format
            *
            * 000LLLLL <L+1>    ; literal
            * LLLOOOOO oooooooo ; backref L
            * 111OOOOO LLLLLLLL oooooooo ; backref L+7
            *
            */

            public int lzf_compress (byte[] in_data, int in_len,byte[] out_data, int out_len)
            {
                  int c;
                  long []htab=new long[1<<14];
                  for (c=0;c<1<<14;c++)
                  {
                        htab[c]=0;
                  }

                  long hslot;
                  UInt32 iidx = 0;
                  UInt32 oidx = 0;
                  //byte *in_end  = ip + in_len;
                  //byte *out_end = op + out_len;
                  long reference;

                  UInt32 hval = FRST (in_data,iidx);
                  long off;
                  int lit = 0;

                  for (;;)
                        {
                        if (iidx < in_len - 2)
                              {
                              hval = NEXT (hval, in_data,iidx);
                              hslot = IDX (hval);
                              reference = htab[hslot]; 
                              htab[hslot] = (long)iidx;

                              if ((off = iidx - reference - 1) < MAX_OFF 
                                    && iidx + 4 < in_len 
                                    && reference > 0
                                    && in_data[reference+0] == in_data[iidx+0]
                                    && in_data[reference+1] == in_data[iidx+1]
                                    && in_data[reference+2] == in_data[iidx+2]
                                    )
                                    {
                                    /* match found at *reference++ */
                                    UInt32 len = 2;
                                    UInt32 maxlen = (UInt32)in_len - iidx - len;
                                    maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;

                                    if (oidx + lit + 1 + 3 >= out_len)
                                          return 0;

                                    do
                                          len++;
                                    while (len < maxlen && in_data[reference+len] == in_data[iidx+len]);

                                    if (lit!=0)
                                          {
                                          out_data[oidx++] = (byte)(lit - 1);
                                          lit = -lit;
                                          do
                                                out_data[oidx++] = in_data[iidx+lit];
                                          while ((++lit)!=0);
                                          }

                                    len -= 2;
                                    iidx++;

                                    if (len < 7)
                                          {
                                          out_data[oidx++] = (byte)((off >> 8) + (len << 5));
                                          }
                                    else
                                          {
                                          out_data[oidx++] = (byte)((off >> 8) + (  7 << 5));
                                          out_data[oidx++] = (byte)(len - 7);
                                          }

                                    out_data[oidx++] = (byte)off;

                                    iidx += len-1;
                                    hval = FRST (in_data,iidx);

                                    hval = NEXT (hval,in_data, iidx);
                                    htab[IDX (hval)] = iidx;
                                    iidx++;

                                    hval = NEXT (hval, in_data,iidx);
                                    htab[IDX (hval)] = iidx;
                                    iidx++;
                                    continue;
                                    }
                              }
                        else if (iidx == in_len)
                              break;

                        /* one more literal byte we must copy */
                        lit++;
                        iidx++;

                        if (lit == MAX_LIT)
                              {
                              if (oidx + 1 + MAX_LIT >= out_len)
                                    return 0;

                              out_data[oidx++] = (byte)(MAX_LIT - 1);
                              lit = -lit;
                              do
                                    out_data[oidx++] = in_data[iidx+lit];
                              while ((++lit)!=0);
                              }
                        }

                  if (lit!=0)
                        {
                        if (oidx + lit + 1 >= out_len)
                              return 0;

                        out_data[oidx++] = (byte)(lit - 1);
                        lit = -lit;
                        do
                              out_data[oidx++] = in_data[iidx+lit];
                        while ((++lit)!=0);
                        }

                  return (int)oidx;
            }

            /// <summary>
            /// LZF Decompressor
            /// </summary>
00277             public int lzf_decompress ( byte[] in_data, int in_len, byte[] out_data, int out_len)
            {
                  UInt32 iidx=0;
                  UInt32 oidx=0;

                  do
                        {
                        UInt32 ctrl = in_data[iidx++];

                        if (ctrl < (1 << 5)) /* literal run */
                              {
                              ctrl++;

                              if (oidx + ctrl > out_len)
                                    {
                                    //SET_ERRNO (E2BIG);
                                    return 0;
                                    }

                              do
                                    out_data[oidx++] = in_data[iidx++];
                              while ((--ctrl)!=0);
                              }
                        else /* back reference */
                              {
                              UInt32 len = ctrl >> 5;

                              int reference = (int)(oidx - ((ctrl & 0x1f) << 8) - 1);

                              if (len == 7)
                                    len += in_data[iidx++];
                            
                              reference -= in_data[iidx++];

                              if (oidx + len + 2 > out_len)
                                    {
                                    //SET_ERRNO (E2BIG);
                                    return 0;
                                    }

                              if (reference < 0)
                                    {
                                    //SET_ERRNO (EINVAL);
                                    return 0;
                                    }

                              out_data[oidx++]=out_data[reference++];
                              out_data[oidx++]=out_data[reference++];

                              do
                                    out_data[oidx++]=out_data[reference++];
                              while ((--len)!=0);
                              }
                        }
                  while (iidx < in_len);

                  return (int)oidx;
            }

            public CLZF()
            {
                  //
                  // TODO: Add ructor logic here
                  //
            }
      }
}


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