/**
* Copyright (c) 2012, University of Konstanz, Distributed Systems Group All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer. * 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. * Neither the name of the University of Konstanz nor the names of its contributors may be used to
* endorse or promote products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 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 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.jscsi.parser.digest;
import java.nio.ByteBuffer;
import java.security.DigestException;
/**
* <h1>CRC32CDigest</h1>
* <p>
* This class implements a Cyclic Redundancy Code (CRC) with the following generator polynom <code>0x11EDC6F41</code>.
* <code>G(x) = x**32 + x**28 + x**27 + x**26 + x**25 + x**23 + x**22 + </code>
* <code>x**20 + x**19 + x**18 + x**14 + x**13 + x**11 + x**10 + x**9 + </code> <code>x**8 + x**6 + 1</code> This
* polynom has a degree of <code>32</code> and is defined in the iSCSI Standard (RFC3720). Further, this class
* implements the algorithm from Intel, which is called Slicing-by-4. This algorithm increases the performance of the
* CRC calculation by a factor of <code>2</code> by using <code>4KB</code> of memory for the look-up tables, in contrast
* to the Sarwate algorithm [2]. It reads <code>32 bytes</code> at a time.
* <p>
* For a detailed description of the Slicing-by-x algorithms look at [1].
* <h3>Lookup Table Generation</h3> A lookup table is easy to create, but needs some knowhow of the internals. So this
* sections should teach you the internal knowhow needed for this process.
* <p>
* There are <code>256</code> different possibilities with <code>8</code> bits. So a table needs <code>256</code>
* entries. Each entry holds the remainder of the polynom division (modulo 2) and the given generator polynom. Thus, an
* entry has to be <code>32</code> bits wide, because the remainder has an degree smaller or equal the degree of the
* generator polynom.
* <p>
* There must be tables for the offsets <code>32</code>, <code>40</code>, <code>48</code>, and <code>56</code> . The
* <code>256</code> possibilities must be left shifted by the offset and divided by the generator polynom. These
* remainders are stored in the tables.
* <p>
* <b>Caution:</b> The bits has to be interpreted in reverse order. So the input bits <code>1 1 0 0 1</code> become to
* <code>1 0 0 1 1</code>.
* <p>
* For an implementation see at the class <code>CRCTables</code>.
* <p>
* An detailed description of this generation process and many more informations can be found in [3].
* <p>
* <h3>References</h3>
* <p>
* [1] Michael E. Kounavis and Frank L. Berry: 'A Systematic Approach to Building High Performance, Software-based, CRC
* Generators', Intel Research and Development, 2005.
* <p>
* [2] Dilip V. Sarwate: 'Computation of Cyclic Redundancy Checks via Table Lookup', Communications of the ACM, 1988.
* <p>
* [3] Ross N. Williams: 'A Painless Guide to CRC Error Detection Algorithms',
* http://www.ross.net/crc/download/crc_v3.txt, 1993
*
* @author Volker Wildi
* @see org.jscsi.digest.CRCTables
*/
final class CRC32CDigest implements IDigest {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Shift a given number by <code>8</code> bits or <code>1</code> byte.
*/
private static final int ONE_BYTE_SHIFT = 8;
/**
* Shift a given number by <code>16</code> bits or <code>2</code> bytes.
*/
private static final int TWO_BYTES_SHIFT = 16;
/** Number of bits in a byte. */
private static final int BITS_PER_BYTE = 8;
/** The java data type int need <code>4</code> bytes. */
public static final int BYTES_PER_INT = Integer.SIZE / BITS_PER_BYTE;
/** Bit mask to extract the fourth byte of a <code>32</code> bit number. */
public static final int FOURTH_BYTE_MASK = 0x000000FF;
/** The flag mask to convert an integer number to a long number. */
private static final long INT_FLAG_MASK_LONG = 0x00000000FFFFFFFFL;
/** The size of the digest number (in bytes) to serialize. */
private static final int DIGEST_SIZE = 4;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* The initial value of the CRC32CDigest algorithm (defined by the iSCSI Standard).
*/
private static final int INITIAL_VALUE = 0xFFFFFFFF;
/** The final remainder after calculating the digest. */
private static final long FINAL_REMAINDER = 0x1C2D19EDL;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* The lookup table for the offset <code>32</code>.following CRC lookup tables were generated by the Octave Script
* <code>crc32c.m</code>.
*/
private static final int[] CRC_TABLE_32 = { 0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4, 0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB, 0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B, 0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24, 0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B, 0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384, 0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54, 0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B, 0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A, 0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35, 0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5, 0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA, 0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45, 0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A, 0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A, 0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595, 0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48, 0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957, 0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687, 0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198, 0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927, 0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38, 0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8, 0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7, 0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096, 0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789, 0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859, 0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46, 0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9, 0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6, 0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36, 0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829, 0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C, 0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93, 0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043, 0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C, 0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3, 0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC, 0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C, 0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033, 0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652, 0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D, 0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D, 0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982, 0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D, 0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622, 0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2, 0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED, 0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530, 0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F, 0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF, 0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0, 0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F, 0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540, 0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90, 0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F, 0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE, 0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1, 0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321, 0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E, 0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81, 0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E, 0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E, 0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351 };
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
private static final int[] CRC_TABLE_40 = { 0x00000000, 0x13A29877, 0x274530EE, 0x34E7A899, 0x4E8A61DC, 0x5D28F9AB, 0x69CF5132, 0x7A6DC945, 0x9D14C3B8, 0x8EB65BCF, 0xBA51F356, 0xA9F36B21, 0xD39EA264, 0xC03C3A13, 0xF4DB928A, 0xE7790AFD, 0x3FC5F181, 0x2C6769F6, 0x1880C16F, 0x0B225918, 0x714F905D, 0x62ED082A, 0x560AA0B3, 0x45A838C4, 0xA2D13239, 0xB173AA4E, 0x859402D7, 0x96369AA0, 0xEC5B53E5, 0xFFF9CB92, 0xCB1E630B, 0xD8BCFB7C, 0x7F8BE302, 0x6C297B75, 0x58CED3EC, 0x4B6C4B9B, 0x310182DE, 0x22A31AA9, 0x1644B230, 0x05E62A47, 0xE29F20BA, 0xF13DB8CD, 0xC5DA1054, 0xD6788823, 0xAC154166, 0xBFB7D911, 0x8B507188, 0x98F2E9FF, 0x404E1283, 0x53EC8AF4, 0x670B226D, 0x74A9BA1A, 0x0EC4735F, 0x1D66EB28, 0x298143B1, 0x3A23DBC6, 0xDD5AD13B, 0xCEF8494C, 0xFA1FE1D5, 0xE9BD79A2, 0x93D0B0E7, 0x80722890, 0xB4958009, 0xA737187E, 0xFF17C604, 0xECB55E73, 0xD852F6EA, 0xCBF06E9D, 0xB19DA7D8, 0xA23F3FAF, 0x96D89736, 0x857A0F41, 0x620305BC, 0x71A19DCB, 0x45463552, 0x56E4AD25, 0x2C896460, 0x3F2BFC17, 0x0BCC548E, 0x186ECCF9, 0xC0D23785, 0xD370AFF2, 0xE797076B, 0xF4359F1C, 0x8E585659, 0x9DFACE2E, 0xA91D66B7, 0xBABFFEC0, 0x5DC6F43D, 0x4E646C4A, 0x7A83C4D3, 0x69215CA4, 0x134C95E1, 0x00EE0D96, 0x3409A50F, 0x27AB3D78, 0x809C2506, 0x933EBD71, 0xA7D915E8, 0xB47B8D9F, 0xCE1644DA, 0xDDB4DCAD, 0xE9537434, 0xFAF1EC43, 0x1D88E6BE, 0x0E2A7EC9, 0x3ACDD650, 0x296F4E27, 0x53028762, 0x40A01F15, 0x7447B78C, 0x67E52FFB, 0xBF59D487, 0xACFB4CF0, 0x981CE469, 0x8BBE7C1E, 0xF1D3B55B, 0xE2712D2C, 0xD69685B5, 0xC5341DC2, 0x224D173F, 0x31EF8F48, 0x050827D1, 0x16AABFA6, 0x6CC776E3, 0x7F65EE94, 0x4B82460D, 0x5820DE7A, 0xFBC3FAF9, 0xE861628E, 0xDC86CA17, 0xCF245260, 0xB5499B25, 0xA6EB0352, 0x920CABCB, 0x81AE33BC, 0x66D73941, 0x7575A136, 0x419209AF, 0x523091D8, 0x285D589D, 0x3BFFC0EA, 0x0F186873, 0x1CBAF004, 0xC4060B78, 0xD7A4930F, 0xE3433B96, 0xF0E1A3E1, 0x8A8C6AA4, 0x992EF2D3, 0xADC95A4A, 0xBE6BC23D, 0x5912C8C0, 0x4AB050B7, 0x7E57F82E, 0x6DF56059, 0x1798A91C, 0x043A316B, 0x30DD99F2, 0x237F0185, 0x844819FB, 0x97EA818C, 0xA30D2915, 0xB0AFB162, 0xCAC27827, 0xD960E050, 0xED8748C9, 0xFE25D0BE, 0x195CDA43, 0x0AFE4234, 0x3E19EAAD, 0x2DBB72DA, 0x57D6BB9F, 0x447423E8, 0x70938B71, 0x63311306, 0xBB8DE87A, 0xA82F700D, 0x9CC8D894, 0x8F6A40E3, 0xF50789A6, 0xE6A511D1, 0xD242B948, 0xC1E0213F, 0x26992BC2, 0x353BB3B5, 0x01DC1B2C, 0x127E835B, 0x68134A1E, 0x7BB1D269, 0x4F567AF0, 0x5CF4E287, 0x04D43CFD, 0x1776A48A, 0x23910C13, 0x30339464, 0x4A5E5D21, 0x59FCC556, 0x6D1B6DCF, 0x7EB9F5B8, 0x99C0FF45, 0x8A626732, 0xBE85CFAB, 0xAD2757DC, 0xD74A9E99, 0xC4E806EE, 0xF00FAE77, 0xE3AD3600, 0x3B11CD7C, 0x28B3550B, 0x1C54FD92, 0x0FF665E5, 0x759BACA0, 0x663934D7, 0x52DE9C4E, 0x417C0439, 0xA6050EC4, 0xB5A796B3, 0x81403E2A, 0x92E2A65D, 0xE88F6F18, 0xFB2DF76F, 0xCFCA5FF6, 0xDC68C781, 0x7B5FDFFF, 0x68FD4788, 0x5C1AEF11, 0x4FB87766, 0x35D5BE23, 0x26772654, 0x12908ECD, 0x013216BA, 0xE64B1C47, 0xF5E98430, 0xC10E2CA9, 0xD2ACB4DE, 0xA8C17D9B, 0xBB63E5EC, 0x8F844D75, 0x9C26D502, 0x449A2E7E, 0x5738B609, 0x63DF1E90, 0x707D86E7, 0x0A104FA2, 0x19B2D7D5, 0x2D557F4C, 0x3EF7E73B, 0xD98EEDC6, 0xCA2C75B1, 0xFECBDD28, 0xED69455F, 0x97048C1A, 0x84A6146D, 0xB041BCF4, 0xA3E32483 };
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
private static final int[] CRC_TABLE_48 = { 0x00000000, 0xA541927E, 0x4F6F520D, 0xEA2EC073, 0x9EDEA41A, 0x3B9F3664, 0xD1B1F617, 0x74F06469, 0x38513EC5, 0x9D10ACBB, 0x773E6CC8, 0xD27FFEB6, 0xA68F9ADF, 0x03CE08A1, 0xE9E0C8D2, 0x4CA15AAC, 0x70A27D8A, 0xD5E3EFF4, 0x3FCD2F87, 0x9A8CBDF9, 0xEE7CD990, 0x4B3D4BEE, 0xA1138B9D, 0x045219E3, 0x48F3434F, 0xEDB2D131, 0x079C1142, 0xA2DD833C, 0xD62DE755, 0x736C752B, 0x9942B558, 0x3C032726, 0xE144FB14, 0x4405696A, 0xAE2BA919, 0x0B6A3B67, 0x7F9A5F0E, 0xDADBCD70, 0x30F50D03, 0x95B49F7D, 0xD915C5D1, 0x7C5457AF, 0x967A97DC, 0x333B05A2, 0x47CB61CB, 0xE28AF3B5, 0x08A433C6, 0xADE5A1B8, 0x91E6869E, 0x34A714E0, 0xDE89D493, 0x7BC846ED, 0x0F382284, 0xAA79B0FA, 0x40577089, 0xE516E2F7, 0xA9B7B85B, 0x0CF62A25, 0xE6D8EA56, 0x43997828, 0x37691C41, 0x92288E3F, 0x78064E4C, 0xDD47DC32, 0xC76580D9, 0x622412A7, 0x880AD2D4, 0x2D4B40AA, 0x59BB24C3, 0xFCFAB6BD, 0x16D476CE, 0xB395E4B0, 0xFF34BE1C, 0x5A752C62, 0xB05BEC11, 0x151A7E6F, 0x61EA1A06, 0xC4AB8878, 0x2E85480B, 0x8BC4DA75, 0xB7C7FD53, 0x12866F2D, 0xF8A8AF5E, 0x5DE93D20, 0x29195949, 0x8C58CB37, 0x66760B44, 0xC337993A, 0x8F96C396, 0x2AD751E8, 0xC0F9919B, 0x65B803E5, 0x1148678C, 0xB409F5F2, 0x5E273581, 0xFB66A7FF, 0x26217BCD, 0x8360E9B3, 0x694E29C0, 0xCC0FBBBE, 0xB8FFDFD7, 0x1DBE4DA9, 0xF7908DDA, 0x52D11FA4, 0x1E704508, 0xBB31D776, 0x511F1705, 0xF45E857B, 0x80AEE112, 0x25EF736C, 0xCFC1B31F, 0x6A802161, 0x56830647, 0xF3C29439, 0x19EC544A, 0xBCADC634, 0xC85DA25D, 0x6D1C3023, 0x8732F050, 0x2273622E, 0x6ED23882, 0xCB93AAFC, 0x21BD6A8F, 0x84FCF8F1, 0xF00C9C98, 0x554D0EE6, 0xBF63CE95, 0x1A225CEB, 0x8B277743, 0x2E66E53D, 0xC448254E, 0x6109B730, 0x15F9D359, 0xB0B84127, 0x5A968154, 0xFFD7132A, 0xB3764986, 0x1637DBF8, 0xFC191B8B, 0x595889F5, 0x2DA8ED9C, 0x88E97FE2, 0x62C7BF91, 0xC7862DEF, 0xFB850AC9, 0x5EC498B7, 0xB4EA58C4, 0x11ABCABA, 0x655BAED3, 0xC01A3CAD, 0x2A34FCDE, 0x8F756EA0, 0xC3D4340C, 0x6695A672, 0x8CBB6601, 0x29FAF47F, 0x5D0A9016, 0xF84B0268, 0x1265C21B, 0xB7245065, 0x6A638C57, 0xCF221E29, 0x250CDE5A, 0x804D4C24, 0xF4BD284D, 0x51FCBA33, 0xBBD27A40, 0x1E93E83E, 0x5232B292, 0xF77320EC, 0x1D5DE09F, 0xB81C72E1, 0xCCEC1688, 0x69AD84F6, 0x83834485, 0x26C2D6FB, 0x1AC1F1DD, 0xBF8063A3, 0x55AEA3D0, 0xF0EF31AE, 0x841F55C7, 0x215EC7B9, 0xCB7007CA, 0x6E3195B4, 0x2290CF18, 0x87D15D66, 0x6DFF9D15, 0xC8BE0F6B, 0xBC4E6B02, 0x190FF97C, 0xF321390F, 0x5660AB71, 0x4C42F79A, 0xE90365E4, 0x032DA597, 0xA66C37E9, 0xD29C5380, 0x77DDC1FE, 0x9DF3018D, 0x38B293F3, 0x7413C95F, 0xD1525B21, 0x3B7C9B52, 0x9E3D092C, 0xEACD6D45, 0x4F8CFF3B, 0xA5A23F48, 0x00E3AD36, 0x3CE08A10, 0x99A1186E, 0x738FD81D, 0xD6CE4A63, 0xA23E2E0A, 0x077FBC74, 0xED517C07, 0x4810EE79, 0x04B1B4D5, 0xA1F026AB, 0x4BDEE6D8, 0xEE9F74A6, 0x9A6F10CF, 0x3F2E82B1, 0xD50042C2, 0x7041D0BC, 0xAD060C8E, 0x08479EF0, 0xE2695E83, 0x4728CCFD, 0x33D8A894, 0x96993AEA, 0x7CB7FA99, 0xD9F668E7, 0x9557324B, 0x3016A035, 0xDA386046, 0x7F79F238, 0x0B899651, 0xAEC8042F, 0x44E6C45C, 0xE1A75622, 0xDDA47104, 0x78E5E37A, 0x92CB2309, 0x378AB177, 0x437AD51E, 0xE63B4760, 0x0C158713, 0xA954156D, 0xE5F54FC1, 0x40B4DDBF, 0xAA9A1DCC, 0x0FDB8FB2, 0x7B2BEBDB, 0xDE6A79A5, 0x3444B9D6, 0x91052BA8 };
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
private static final int[] CRC_TABLE_56 = { 0x00000000, 0xDD45AAB8, 0xBF672381, 0x62228939, 0x7B2231F3, 0xA6679B4B, 0xC4451272, 0x1900B8CA, 0xF64463E6, 0x2B01C95E, 0x49234067, 0x9466EADF, 0x8D665215, 0x5023F8AD, 0x32017194, 0xEF44DB2C, 0xE964B13D, 0x34211B85, 0x560392BC, 0x8B463804, 0x924680CE, 0x4F032A76, 0x2D21A34F, 0xF06409F7, 0x1F20D2DB, 0xC2657863, 0xA047F15A, 0x7D025BE2, 0x6402E328, 0xB9474990, 0xDB65C0A9, 0x06206A11, 0xD725148B, 0x0A60BE33, 0x6842370A, 0xB5079DB2, 0xAC072578, 0x71428FC0, 0x136006F9, 0xCE25AC41, 0x2161776D, 0xFC24DDD5, 0x9E0654EC, 0x4343FE54, 0x5A43469E, 0x8706EC26, 0xE524651F, 0x3861CFA7, 0x3E41A5B6, 0xE3040F0E, 0x81268637, 0x5C632C8F, 0x45639445, 0x98263EFD, 0xFA04B7C4, 0x27411D7C, 0xC805C650, 0x15406CE8, 0x7762E5D1, 0xAA274F69, 0xB327F7A3, 0x6E625D1B, 0x0C40D422, 0xD1057E9A, 0xABA65FE7, 0x76E3F55F, 0x14C17C66, 0xC984D6DE, 0xD0846E14, 0x0DC1C4AC, 0x6FE34D95, 0xB2A6E72D, 0x5DE23C01, 0x80A796B9, 0xE2851F80, 0x3FC0B538, 0x26C00DF2, 0xFB85A74A, 0x99A72E73, 0x44E284CB, 0x42C2EEDA, 0x9F874462, 0xFDA5CD5B, 0x20E067E3, 0x39E0DF29, 0xE4A57591, 0x8687FCA8, 0x5BC25610, 0xB4868D3C, 0x69C32784, 0x0BE1AEBD, 0xD6A40405, 0xCFA4BCCF, 0x12E11677, 0x70C39F4E, 0xAD8635F6, 0x7C834B6C, 0xA1C6E1D4, 0xC3E468ED, 0x1EA1C255, 0x07A17A9F, 0xDAE4D027, 0xB8C6591E, 0x6583F3A6, 0x8AC7288A, 0x57828232, 0x35A00B0B, 0xE8E5A1B3, 0xF1E51979, 0x2CA0B3C1, 0x4E823AF8, 0x93C79040, 0x95E7FA51, 0x48A250E9, 0x2A80D9D0, 0xF7C57368, 0xEEC5CBA2, 0x3380611A, 0x51A2E823, 0x8CE7429B, 0x63A399B7, 0xBEE6330F, 0xDCC4BA36, 0x0181108E, 0x1881A844, 0xC5C402FC, 0xA7E68BC5, 0x7AA3217D, 0x52A0C93F, 0x8FE56387, 0xEDC7EABE, 0x30824006, 0x2982F8CC, 0xF4C75274, 0x96E5DB4D, 0x4BA071F5, 0xA4E4AAD9, 0x79A10061, 0x1B838958, 0xC6C623E0, 0xDFC69B2A, 0x02833192, 0x60A1B8AB, 0xBDE41213, 0xBBC47802, 0x6681D2BA, 0x04A35B83, 0xD9E6F13B, 0xC0E649F1, 0x1DA3E349, 0x7F816A70, 0xA2C4C0C8, 0x4D801BE4, 0x90C5B15C, 0xF2E73865, 0x2FA292DD, 0x36A22A17, 0xEBE780AF, 0x89C50996, 0x5480A32E, 0x8585DDB4, 0x58C0770C, 0x3AE2FE35, 0xE7A7548D, 0xFEA7EC47, 0x23E246FF, 0x41C0CFC6, 0x9C85657E, 0x73C1BE52, 0xAE8414EA, 0xCCA69DD3, 0x11E3376B, 0x08E38FA1, 0xD5A62519, 0xB784AC20, 0x6AC10698, 0x6CE16C89, 0xB1A4C631, 0xD3864F08, 0x0EC3E5B0, 0x17C35D7A, 0xCA86F7C2, 0xA8A47EFB, 0x75E1D443, 0x9AA50F6F, 0x47E0A5D7, 0x25C22CEE, 0xF8878656, 0xE1873E9C, 0x3CC29424, 0x5EE01D1D, 0x83A5B7A5, 0xF90696D8, 0x24433C60, 0x4661B559, 0x9B241FE1, 0x8224A72B, 0x5F610D93, 0x3D4384AA, 0xE0062E12, 0x0F42F53E, 0xD2075F86, 0xB025D6BF, 0x6D607C07, 0x7460C4CD, 0xA9256E75, 0xCB07E74C, 0x16424DF4, 0x106227E5, 0xCD278D5D, 0xAF050464, 0x7240AEDC, 0x6B401616, 0xB605BCAE, 0xD4273597, 0x09629F2F, 0xE6264403, 0x3B63EEBB, 0x59416782, 0x8404CD3A, 0x9D0475F0, 0x4041DF48, 0x22635671, 0xFF26FCC9, 0x2E238253, 0xF36628EB, 0x9144A1D2, 0x4C010B6A, 0x5501B3A0, 0x88441918, 0xEA669021, 0x37233A99, 0xD867E1B5, 0x05224B0D, 0x6700C234, 0xBA45688C, 0xA345D046, 0x7E007AFE, 0x1C22F3C7, 0xC167597F, 0xC747336E, 0x1A0299D6, 0x782010EF, 0xA565BA57, 0xBC65029D, 0x6120A825, 0x0302211C, 0xDE478BA4, 0x31035088, 0xEC46FA30, 0x8E647309, 0x5321D9B1, 0x4A21617B, 0x9764CBC3, 0xF54642FA, 0x2803E842 };
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Flag to indicate, if the crc has changed but the last XOR operation was not invoked.
*/
private boolean dirty;
/** The currenct CRC. */
private int crc = INITIAL_VALUE;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** Creates a new CRC32CDigest (slicing-by-8) object. */
public CRC32CDigest () {
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
public final void update (final byte[] b, final int off, final int len) {
if (len % BYTES_PER_INT != 0) { throw new IllegalArgumentException("Length must be a multiple of 32 bits (4 Byte)."); }
update(ByteBuffer.wrap(b), off, len);
}
/** {@inheritDoc} */
public final void update (final int b) {
slicingBy4(b);
dirty = true;
}
/** {@inheritDoc} */
public final void update (final ByteBuffer data, final int off, final int len) {
if (len % BYTES_PER_INT != 0) { throw new IllegalArgumentException("Length must be a multiple of 32 bits (4 Byte)."); }
data.position(off);
for (int i = 0; i < len && data.hasRemaining(); i++) {
slicingBy4(data.getInt());
}
}
/** {@inheritDoc} */
public final void reset () {
crc = INITIAL_VALUE;
}
/** {@inheritDoc} */
public final long getValue () {
if (dirty) {
crc ^= INT_FLAG_MASK_LONG;
}
return Integer.reverseBytes((int) (crc & INT_FLAG_MASK_LONG));
}
/** {@inheritDoc} */
public final void validate () throws DigestException {
if (getValue() != FINAL_REMAINDER) { throw new DigestException("Invalid CRC32CDigest Digest: " + getValue()); }
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
public final int getSize () {
return DIGEST_SIZE;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
public boolean equals (Object o) {
if (o instanceof CRC32CDigest == false) return false;
CRC32CDigest oCrc = (CRC32CDigest) o;
if (oCrc.getValue() == this.getValue()) return true;
return false;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* This method calculates the CRC with Slicing-by-4 algorithm.
*
* @param data An integer data value, which is added to the CRC.
*/
protected final void slicingBy4 (final int data) {
crc ^= Integer.reverseBytes(data);
final int term1 = CRC_TABLE_56[crc & FOURTH_BYTE_MASK] ^ CRC_TABLE_48[(crc >>> ONE_BYTE_SHIFT) & FOURTH_BYTE_MASK];
final int term2 = crc >>> TWO_BYTES_SHIFT;
crc = term1 ^ CRC_TABLE_40[term2 & FOURTH_BYTE_MASK] ^ CRC_TABLE_32[(term2 >>> ONE_BYTE_SHIFT) & FOURTH_BYTE_MASK];
}
/**
* This method calculates the CRC with Slicing-by-4 algorithm.
*
* @param data An integer array, which elements all are added to the CRC.
*/
protected final void slicingBy4 (final int[] data) {
final int n = data.length;
for (int i = 0; i < n; i++) {
slicingBy4(data[i]);
}
crc ^= INT_FLAG_MASK_LONG;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
}