liblzf/cs/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>
        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>

                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>
                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
                        //
                }
        }
}

Revision:	1.2
Committed:	Fri Jul 7 15:34:40 2006 UTC (18 years, 3 months ago) by root
Branch:	MAIN
CVS Tags:	rel-3_5, rel-3_4, rel-3_3, rel-3_1, rel-3_0, rel-2_0, rel-2_1, rel-1_7, rel-1_6
Changes since 1.1:	+1 -1 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* Copyright (c) 2005 Oren J. Maurice <oymaurice@hazorea.org.il>
3	*
4	* Redistribution and use in source and binary forms, with or without modifica-
5	* tion, are permitted provided that the following conditions are met:
6	*
7	* 1. Redistributions of source code must retain the above copyright notice,
8	* this list of conditions and the following disclaimer.
9	*
10	* 2. Redistributions in binary form must reproduce the above copyright
11	* notice, this list of conditions and the following disclaimer in the
12	* documentation and/or other materials provided with the distribution.
13	*
14	* 3. The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.
16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19	* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20	* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21	* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23	* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25	* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26	* OF THE POSSIBILITY OF SUCH DAMAGE.
27	*
28	* Alternatively, the contents of this file may be used under the terms of
29	* the GNU General Public License version 2 (the "GPL"), in which case the
30	* provisions of the GPL are applicable instead of the above. If you wish to
31	* allow the use of your version of this file only under the terms of the
32	* GPL and not to allow others to use your version of this file under the
33	* BSD license, indicate your decision by deleting the provisions above and
34	* replace them with the notice and other provisions required by the GPL. If
35	* you do not delete the provisions above, a recipient may use your version
36	* of this file under either the BSD or the GPL.
37	*/
38
39	using System;
40
41	namespace LZF.NET
42	{
43
44	/// <summary>
45	/// Summary description for CLZF.
46	/// </summary>
47	public class CLZF
48	{
49	// CRC32 data & function
50	UInt32 []crc_32_tab = new UInt32[256]
51	{
52	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
53	0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
54	0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
55	0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
56	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
57	0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
58	0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
59	0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
60	0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
61	0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
62	0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
63	0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
64	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
65	0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
66	0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
67	0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
68	0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
69	0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
70	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
71	0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
72	0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
73	0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
74	0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
75	0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
76	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
77	0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
78	0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
79	0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
80	0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
81	0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
82	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
83	0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
84	0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
85	0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
86	0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
87	0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
88	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
89	0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
90	0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
91	0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
92	0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
93	0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
94	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
95	0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
96	0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
97	0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
98	0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
99	0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
100	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
101	0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
102	0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
103	0x2d02ef8d
104	};
105
106	public UInt32 crc32(UInt32 OldCRC,byte NewData)
107	{
108	return crc_32_tab[(OldCRC & 0xff) ^ NewData] ^ (OldCRC >> 8);
109	}
110
111
112	/// <summary>
113	/// LZF Compressor
114	/// </summary>
115
116	UInt32 HLOG=14;
117	UInt32 HSIZE=(1<<14);
118
119	/*
120	* don't play with this unless you benchmark!
121	* decompression is not dependent on the hash function
122	* the hashing function might seem strange, just believe me
123	* it works ;)
124	*/
125	UInt32 MAX_LIT=(1 << 5);
126	UInt32 MAX_OFF=(1 << 13);
127	UInt32 MAX_REF=((1 << 8) + (1 << 3));
128
129	UInt32 FRST(byte[] Array,UInt32 ptr)
130	{
131	return (UInt32)(((Array[ptr]) << 8) \| Array[ptr+1]);
132	}
133
134	UInt32 NEXT(UInt32 v,byte[] Array,UInt32 ptr)
135	{
136	return ((v) << 8) \| Array[ptr+2];
137	}
138
139	UInt32 IDX(UInt32 h)
140	{
141	return ((h ^ (h << 5)) >> (int)(((38 - HLOG)) - h5) & (HSIZE - 1));
142	}
143
144	/*
145	* compressed format
146	*
147	* 000LLLLL <L+1> ; literal
148	* LLLOOOOO oooooooo ; backref L
149	* 111OOOOO LLLLLLLL oooooooo ; backref L+7
150	*
151	*/
152
153	public int lzf_compress (byte[] in_data, int in_len,byte[] out_data, int out_len)
154	{
155	int c;
156	long []htab=new long[1<<14];
157	for (c=0;c<1<<14;c++)
158	{
159	htab[c]=0;
160	}
161
162	long hslot;
163	UInt32 iidx = 0;
164	UInt32 oidx = 0;
165	//byte *in_end = ip + in_len;
166	//byte *out_end = op + out_len;
167	long reference;
168
169	UInt32 hval = FRST (in_data,iidx);
170	long off;
171	int lit = 0;
172
173	for (;;)
174	{
175	if (iidx < in_len - 2)
176	{
177	hval = NEXT (hval, in_data,iidx);
178	hslot = IDX (hval);
179	reference = htab[hslot];
180	htab[hslot] = (long)iidx;
181
182	if ((off = iidx - reference - 1) < MAX_OFF
183	&& iidx + 4 < in_len
184	&& reference > 0
185	&& in_data[reference+0] == in_data[iidx+0]
186	&& in_data[reference+1] == in_data[iidx+1]
187	&& in_data[reference+2] == in_data[iidx+2]
188	)
189	{
190	/* match found at reference++ /
191	UInt32 len = 2;
192	UInt32 maxlen = (UInt32)in_len - iidx - len;
193	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
194
195	if (oidx + lit + 1 + 3 >= out_len)
196	return 0;
197
198	do
199	len++;
200	while (len < maxlen && in_data[reference+len] == in_data[iidx+len]);
201
202	if (lit!=0)
203	{
204	out_data[oidx++] = (byte)(lit - 1);
205	lit = -lit;
206	do
207	out_data[oidx++] = in_data[iidx+lit];
208	while ((++lit)!=0);
209	}
210
211	len -= 2;
212	iidx++;
213
214	if (len < 7)
215	{
216	out_data[oidx++] = (byte)((off >> 8) + (len << 5));
217	}
218	else
219	{
220	out_data[oidx++] = (byte)((off >> 8) + ( 7 << 5));
221	out_data[oidx++] = (byte)(len - 7);
222	}
223
224	out_data[oidx++] = (byte)off;
225
226	iidx += len-1;
227	hval = FRST (in_data,iidx);
228
229	hval = NEXT (hval,in_data, iidx);
230	htab[IDX (hval)] = iidx;
231	iidx++;
232
233	hval = NEXT (hval, in_data,iidx);
234	htab[IDX (hval)] = iidx;
235	iidx++;
236	continue;
237	}
238	}
239	else if (iidx == in_len)
240	break;
241
242	/* one more literal byte we must copy */
243	lit++;
244	iidx++;
245
246	if (lit == MAX_LIT)
247	{
248	if (oidx + 1 + MAX_LIT >= out_len)
249	return 0;
250
251	out_data[oidx++] = (byte)(MAX_LIT - 1);
252	lit = -lit;
253	do
254	out_data[oidx++] = in_data[iidx+lit];
255	while ((++lit)!=0);
256	}
257	}
258
259	if (lit!=0)
260	{
261	if (oidx + lit + 1 >= out_len)
262	return 0;
263
264	out_data[oidx++] = (byte)(lit - 1);
265	lit = -lit;
266	do
267	out_data[oidx++] = in_data[iidx+lit];
268	while ((++lit)!=0);
269	}
270
271	return (int)oidx;
272	}
273
274	/// <summary>
275	/// LZF Decompressor
276	/// </summary>
277	public int lzf_decompress ( byte[] in_data, int in_len, byte[] out_data, int out_len)
278	{
279	UInt32 iidx=0;
280	UInt32 oidx=0;
281
282	do
283	{
284	UInt32 ctrl = in_data[iidx++];
285
286	if (ctrl < (1 << 5)) /* literal run */
287	{
288	ctrl++;
289
290	if (oidx + ctrl > out_len)
291	{
292	//SET_ERRNO (E2BIG);
293	return 0;
294	}
295
296	do
297	out_data[oidx++] = in_data[iidx++];
298	while ((--ctrl)!=0);
299	}
300	else /* back reference */
301	{
302	UInt32 len = ctrl >> 5;
303
304	int reference = (int)(oidx - ((ctrl & 0x1f) << 8) - 1);
305
306	if (len == 7)
307	len += in_data[iidx++];
308
309	reference -= in_data[iidx++];
310
311	if (oidx + len + 2 > out_len)
312	{
313	//SET_ERRNO (E2BIG);
314	return 0;
315	}
316
317	if (reference < 0)
318	{
319	//SET_ERRNO (EINVAL);
320	return 0;
321	}
322
323	out_data[oidx++]=out_data[reference++];
324	out_data[oidx++]=out_data[reference++];
325
326	do
327	out_data[oidx++]=out_data[reference++];
328	while ((--len)!=0);
329	}
330	}
331	while (iidx < in_len);
332
333	return (int)oidx;
334	}
335
336	public CLZF()
337	{
338	//
339	// TODO: Add ructor logic here
340	//
341	}
342	}
343	}
344