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<a name="302" href="#302">302</a>     <em>/**<em>* The number of bits in fingerprints generated by</em></em>
<a name="303" href="#303">303</a> <em>        &lt;code>this&lt;/code>. */</em>
<a name="304" href="#304">304</a>     <strong>public</strong> <strong>final</strong> <strong>int</strong> degree;
<a name="305" href="#305">305</a> 
<a name="306" href="#306">306</a>     <em>/**<em>* The polynomial used by &lt;code>this&lt;/code> to generate</em></em>
<a name="307" href="#307">307</a> <em>        fingerprints. */</em>
<a name="308" href="#308">308</a>     <strong>public</strong> <strong>long</strong> polynomial;
<a name="309" href="#309">309</a> 
<a name="310" href="#310">310</a>     <em>/**<em>* Result of reducing certain polynomials.  Specifically, if</em></em>
<a name="311" href="#311">311</a> <em>        &lt;code>f(S)&lt;/code> is bit string &lt;code>S&lt;/code> interpreted as</em>
<a name="312" href="#312">312</a> <em>        a polynomial, &lt;code>f(ByteModTable[i][j])&lt;/code> equals</em>
<a name="313" href="#313">313</a> <em>        &lt;code>mod(x^(127&amp;nbsp;-&amp;nbsp;8*i)&amp;nbsp;*&amp;nbsp;f(j),&amp;nbsp;P)&lt;/code>. */</em>
<a name="314" href="#314">314</a>     <strong>private</strong> <strong>long</strong>[][] ByteModTable;
<a name="315" href="#315">315</a> 
<a name="316" href="#316">316</a>     <em>/**<em>* Create a fingerprint generator.  The fingerprints generated</em></em>
<a name="317" href="#317">317</a> <em>        will have degree &lt;code>degree&lt;/code> and will be generated by</em>
<a name="318" href="#318">318</a> <em>        &lt;code>polynomial&lt;/code>.  Requires that</em>
<a name="319" href="#319">319</a> <em>        &lt;code>polynomial&lt;/code> is an irreducible polynomial of degree</em>
<a name="320" href="#320">320</a> <em>        &lt;code>degree&lt;/code> (the array &lt;code>polynomials&lt;/code></em>
<a name="321" href="#321">321</a> <em>        contains some irreducible polynomials). */</em>
<a name="322" href="#322">322</a>     <strong>private</strong> <a href="../../../st/ata/util/FPGenerator.html">FPGenerator</a>(<strong>long</strong> polynomial, <strong>int</strong> degree) {
<a name="323" href="#323">323</a>         <strong>this</strong>.degree = degree;
<a name="324" href="#324">324</a>         <strong>this</strong>.polynomial = polynomial;
<a name="325" href="#325">325</a>         ByteModTable = <strong>new</strong> <strong>long</strong>[16][256];
<a name="326" href="#326">326</a> 
<a name="327" href="#327">327</a>         <strong>long</strong>[] PowerTable = <strong>new</strong> <strong>long</strong>[128];
<a name="328" href="#328">328</a> 
<a name="329" href="#329">329</a>         <strong>long</strong> x_to_the_i = one;
<a name="330" href="#330">330</a>         <strong>long</strong> x_to_the_degree_minus_one = (one >>> (degree-1));
<a name="331" href="#331">331</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; 128; i++) {
<a name="332" href="#332">332</a>             <em class="comment">// Invariants:</em>
<a name="333" href="#333">333</a>             <em class="comment">//   x_to_the_i = mod(x^i, polynomial)</em>
<a name="334" href="#334">334</a>             <em class="comment">//   forall 0 &lt;= j &lt; i, PowerTable[i] = mod(x^i, polynomial)</em>
<a name="335" href="#335">335</a>             PowerTable[i] = x_to_the_i;
<a name="336" href="#336">336</a>             <strong>boolean</strong> overflow = ((x_to_the_i &amp; x_to_the_degree_minus_one) != 0);
<a name="337" href="#337">337</a>             x_to_the_i >>>= 1;
<a name="338" href="#338">338</a>             <strong>if</strong> (overflow) {
<a name="339" href="#339">339</a>                 x_to_the_i ^= polynomial;
<a name="340" href="#340">340</a>             }
<a name="341" href="#341">341</a>         }
<a name="342" href="#342">342</a>         <strong>this</strong>.empty = PowerTable[64];
<a name="343" href="#343">343</a> 
<a name="344" href="#344">344</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; 16; i++) {
<a name="345" href="#345">345</a>             <em class="comment">// Invariant: forall 0 &lt;= i' &lt; i, forall 0 &lt;= j' &lt; 256,</em>
<a name="346" href="#346">346</a>             <em class="comment">//   ByteModTable[i'][j'] = mod(x^(127 - 8*i') * f(j'), polynomial)</em>
<a name="347" href="#347">347</a>             <strong>for</strong> (<strong>int</strong> j = 0; j &lt; 256; j++) {
<a name="348" href="#348">348</a>                 <em class="comment">// Invariant: forall 0 &lt;= i' &lt; i, forall 0 &lt;= j' &lt; j,</em>
<a name="349" href="#349">349</a>                 <em class="comment">//   ByteModTable[i'][j'] = mod(x^(degree+i')*f(j'),polynomial)</em>
<a name="350" href="#350">350</a>                 <strong>long</strong> v = zero;
<a name="351" href="#351">351</a>                 <strong>for</strong> (<strong>int</strong> k = 0; k &lt; 8; k++) {
<a name="352" href="#352">352</a>                     <em class="comment">// Invariant:</em>
<a name="353" href="#353">353</a>                     <em class="comment">//   v = mod(x^(degree+i) * f(j &amp; ((1&lt;&lt;k)-1)), polynomial)</em>
<a name="354" href="#354">354</a>                     <strong>if</strong> ((j &amp; (1 &lt;&lt; k)) != 0) {
<a name="355" href="#355">355</a>                         v ^= PowerTable[127 - i*8 - k];
<a name="356" href="#356">356</a>                     }
<a name="357" href="#357">357</a>                 }
<a name="358" href="#358">358</a>                 ByteModTable[i][j] = v;
<a name="359" href="#359">359</a>             }
<a name="360" href="#360">360</a>         }
<a name="361" href="#361">361</a>     }
<a name="362" href="#362">362</a> 
<a name="363" href="#363">363</a>     <em>/**<em>* Array of irreducible polynomials.  For each degree</em></em>
<a name="364" href="#364">364</a> <em>        &lt;code>d&lt;/code> between 1 and 64 (inclusive),</em>
<a name="365" href="#365">365</a> <em>        &lt;code>polynomials[d][i]&lt;/code> is an irreducible polynomial of</em>
<a name="366" href="#366">366</a> <em>        degree &lt;code>d&lt;/code>.  There are at least two irreducible</em>
<a name="367" href="#367">367</a> <em>        polynomials for each degree. */</em>
<a name="368" href="#368">368</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> <strong>long</strong> polynomials[][] = {
<a name="369" href="#369">369</a>         <strong>null</strong>,
<a name="370" href="#370">370</a>         {0xC000000000000000L, 0xC000000000000000L},
<a name="371" href="#371">371</a>         {0xE000000000000000L, 0xE000000000000000L},
<a name="372" href="#372">372</a>         {0xD000000000000000L, 0xB000000000000000L},
<a name="373" href="#373">373</a>         {0xF800000000000000L, 0xF800000000000000L},
<a name="374" href="#374">374</a>         {0xEC00000000000000L, 0xBC00000000000000L},
<a name="375" href="#375">375</a>         {0xDA00000000000000L, 0xB600000000000000L},
<a name="376" href="#376">376</a>         {0xE500000000000000L, 0xE500000000000000L},
<a name="377" href="#377">377</a>         {0x9680000000000000L, 0xD480000000000000L},
<a name="378" href="#378">378</a>         {0x80C0000000000000L, 0x8840000000000000L},
<a name="379" href="#379">379</a>         {0xB0A0000000000000L, 0xE9A0000000000000L},
<a name="380" href="#380">380</a>         {0xD9F0000000000000L, 0xC9B0000000000000L},
<a name="381" href="#381">381</a>         {0xE758000000000000L, 0xDE98000000000000L},
<a name="382" href="#382">382</a>         {0xE42C000000000000L, 0x94E4000000000000L},
<a name="383" href="#383">383</a>         {0xD4CE000000000000L, 0xB892000000000000L},
<a name="384" href="#384">384</a>         {0xE2AB000000000000L, 0x9E39000000000000L},
<a name="385" href="#385">385</a>         {0xCCE4800000000000L, 0x9783800000000000L},
<a name="386" href="#386">386</a>         {0xD8F8C00000000000L, 0xA9CDC00000000000L},
<a name="387" href="#387">387</a>         {0x9A28200000000000L, 0xFD79E00000000000L},
<a name="388" href="#388">388</a>         {0xC782500000000000L, 0x96CD300000000000L},
<a name="389" href="#389">389</a>         {0xBEE6880000000000L, 0xE902C80000000000L},
<a name="390" href="#390">390</a>         {0x86D7E40000000000L, 0xF066340000000000L},
<a name="391" href="#391">391</a>         {0x9888060000000000L, 0x910ABE0000000000L},
<a name="392" href="#392">392</a>         {0xFF30E30000000000L, 0xB27EFB0000000000L},
<a name="393" href="#393">393</a>         {0x8E375B8000000000L, 0xA03D948000000000L},
<a name="394" href="#394">394</a>         {0xD1415C4000000000L, 0xF5357CC000000000L},
<a name="395" href="#395">395</a>         {0x91A916E000000000L, 0xB6CE66E000000000L},
<a name="396" href="#396">396</a>         {0xE6D2FC5000000000L, 0xD55882B000000000L},
<a name="397" href="#397">397</a>         {0x9A3BA0B800000000L, 0xFBD654E800000000L},
<a name="398" href="#398">398</a>         {0xAEA5D2E400000000L, 0xF0E533AC00000000L},
<a name="399" href="#399">399</a>         {0xDA88B7BE00000000L, 0xAA3AAEDE00000000L},
<a name="400" href="#400">400</a>         {0xBA75BB4300000000L, 0xF5A811C500000000L},
<a name="401" href="#401">401</a>         {0x9B6C9A2F80000000L, 0x9603CCED80000000L},
<a name="402" href="#402">402</a>         {0xFABB538840000000L, 0xE2747090C0000000L},
<a name="403" href="#403">403</a>         {0x8358898EA0000000L, 0x8C698D3D20000000L},
<a name="404" href="#404">404</a>         {0xDA8ABD5BF0000000L, 0xF6DF3A0AF0000000L},
<a name="405" href="#405">405</a>         {0xB090C3F758000000L, 0xD3B4D3D298000000L},
<a name="406" href="#406">406</a>         {0xAD9882F5BC000000L, 0x88DA4FB544000000L},
<a name="407" href="#407">407</a>         {0xC3C366272A000000L, 0xDCCF2A2262000000L},
<a name="408" href="#408">408</a>         {0x9BC0224A97000000L, 0xAF5D96F273000000L},
<a name="409" href="#409">409</a>         {0x8643FFF621800000L, 0x8E390C6EDC800000L},
<a name="410" href="#410">410</a>         {0xE45C01919BC00000L, 0xCBB34C8945C00000L},
<a name="411" href="#411">411</a>         {0x80D8141BC2E00000L, 0x886AFC3912200000L},
<a name="412" href="#412">412</a>         {0xF605807C26500000L, 0xA3B92D28F6300000L},
<a name="413" href="#413">413</a>         {0xCE9A2CFC76280000L, 0x98400C1921280000L},
<a name="414" href="#414">414</a>         {0xF61894904C040000L, 0xC8BE6DBCEC8C0000L},
<a name="415" href="#415">415</a>         {0xE3A44C104D160000L, 0xCA84A59443760000L},
<a name="416" href="#416">416</a>         {0xC7E84953A11B0000L, 0xD9D4F6AA02CB0000L},
<a name="417" href="#417">417</a>         {0xC26CDD1C9A358000L, 0x8BE8478434328000L},
<a name="418" href="#418">418</a>         {0xAE125DBEB198C000L, 0xFCC5DBFD5AAAC000L},
<a name="419" href="#419">419</a>         {0x86DE52A079A6A000L, 0xC5F16BD883816000L},
<a name="420" href="#420">420</a>         {0xDF82486AAFE37000L, 0xA293EC735692D000L},
<a name="421" href="#421">421</a>         {0xE91ABA275C272800L, 0xD686192874E3C800L},
<a name="422" href="#422">422</a>         {0x963D0960DAB3FC00L, 0xBA9DE62072621400L},
<a name="423" href="#423">423</a>         {0xA2188C4E8A46CE00L, 0xD31F75BCB4977E00L},
<a name="424" href="#424">424</a>         {0xC43A416020A6CB00L, 0x99F57FECA12B3900L},
<a name="425" href="#425">425</a>         {0xA4F72EF82A58AE80L, 0xCECE4391B81DA380L},
<a name="426" href="#426">426</a>         {0xB39F119264BC0940L, 0x80A277D20DABB9C0L},
<a name="427" href="#427">427</a>         {0xFD6616C0CBFA0B20L, 0xED16E64117DC11A0L},
<a name="428" href="#428">428</a>         {0xFFA8BC44327B5390L, 0xEDFB13DB3B66C210L},
<a name="429" href="#429">429</a>         {0xCAE8EB99E73AB548L, 0xC86135B6EA2F0B98L},
<a name="430" href="#430">430</a>         {0xBA49BADCDD19B16CL, 0x8F1944AFB18564C4L},
<a name="431" href="#431">431</a>         {0xECFC86D765EABBEEL, 0x9190E1C46CC13702L},
<a name="432" href="#432">432</a>         {0xE1F8D6B3195D6D97L, 0xDF70267FF5E4C979L},
<a name="433" href="#433">433</a>         {0xD74307D3FD3382DBL, 0x9999B3FFDC769B48L}
<a name="434" href="#434">434</a>     };
<a name="435" href="#435">435</a> 
<a name="436" href="#436">436</a>     <em>/**<em>* The standard 64-bit fingerprint generator using</em></em>
<a name="437" href="#437">437</a> <em>        &lt;code>polynomials[0][64]&lt;/code>. */</em>
<a name="438" href="#438">438</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> <a href="../../../st/ata/util/FPGenerator.html">FPGenerator</a> std64 = make(polynomials[64][0], 64);
<a name="439" href="#439">439</a> 
<a name="440" href="#440">440</a>     <em>/**<em>* A standard 32-bit fingerprint generator using</em></em>
<a name="441" href="#441">441</a> <em>        &lt;code>polynomials[0][32]&lt;/code>. */</em>
<a name="442" href="#442">442</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> <a href="../../../st/ata/util/FPGenerator.html">FPGenerator</a> std32 = make(polynomials[32][0], 32);
<a name="443" href="#443">443</a>     
<a name="444" href="#444">444</a>     <em class="comment">// Below added by St.Ack on 09/30/2004.</em>
<a name="445" href="#445">445</a>     <em>/**<em>* A standard 40-bit fingerprint generator using</em></em>
<a name="446" href="#446">446</a> <em>        &lt;code>polynomials[0][40]&lt;/code>. */</em>
<a name="447" href="#447">447</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> <a href="../../../st/ata/util/FPGenerator.html">FPGenerator</a> std40 = make(polynomials[40][0], 40);
<a name="448" href="#448">448</a>     <em>/**<em>* A standard 24-bit fingerprint generator using</em></em>
<a name="449" href="#449">449</a> <em>        &lt;code>polynomials[0][24]&lt;/code>. */</em>
<a name="450" href="#450">450</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> <a href="../../../st/ata/util/FPGenerator.html">FPGenerator</a> std24 = make(polynomials[24][0], 24);
<a name="451" href="#451">451</a> }
</pre>
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