fpgenerator.html

用JAVA编写的,在做实验的时候留下来的,本来想删的,但是传上来,大家分享吧

<a name="147" href="#147">147</a>     <strong>public</strong> <strong>long</strong> fp(<strong>char</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="148" href="#148">148</a>         <strong>return</strong> extend(empty, buf, start, n);
<a name="149" href="#149">149</a>     }
<a name="150" href="#150">150</a> 
<a name="151" href="#151">151</a> <em class="comment">// COMMENTED OUT TO REMOVE Dependency on st.ata.util.Text</em>
<a name="152" href="#152">152</a> <em class="comment">//    </em><em>/**<em>* Compute fingerprint of (all bits of) &lt;code>t&lt;/code> */</em></em>
<a name="153" href="#153">153</a> <em class="comment">//    public long fp(Text t) {</em>
<a name="154" href="#154">154</a> <em class="comment">//        return extend(empty, t);</em>
<a name="155" href="#155">155</a> <em class="comment">//    }</em>
<a name="156" href="#156">156</a>     <em>/**<em>* Compute fingerprint of (all bits of) the characters of "s". */</em></em>
<a name="157" href="#157">157</a>     <strong>public</strong> <strong>long</strong> fp(CharSequence s) {
<a name="158" href="#158">158</a>         <strong>return</strong> extend(empty, s);
<a name="159" href="#159">159</a>     }
<a name="160" href="#160">160</a> 
<a name="161" href="#161">161</a>     <em>/**<em>* Compute fingerprint of (all bits of) "n" characters of "buf"</em></em>
<a name="162" href="#162">162</a> <em>        starting from "buf[i]".  Requires "[i, i+n)" is in bounds. */</em>
<a name="163" href="#163">163</a>     <strong>public</strong> <strong>long</strong> fp(<strong>int</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="164" href="#164">164</a>         <strong>return</strong> extend(empty, buf, start, n);
<a name="165" href="#165">165</a>     }
<a name="166" href="#166">166</a> 
<a name="167" href="#167">167</a>     <em>/**<em>* Compute fingerprint of (all bits of) "n" characters of "buf"</em></em>
<a name="168" href="#168">168</a> <em>        starting from "buf[i]".  Requires "[i, i+n)" is in bounds. */</em>
<a name="169" href="#169">169</a>     <strong>public</strong> <strong>long</strong> fp(<strong>long</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="170" href="#170">170</a>         <strong>return</strong> extend(empty, buf, start, n);
<a name="171" href="#171">171</a>     }
<a name="172" href="#172">172</a> 
<a name="173" href="#173">173</a>     <em>/**<em>* Compute fingerprint of the lower eight bits of the characters</em></em>
<a name="174" href="#174">174</a> <em>        of "s". */</em>
<a name="175" href="#175">175</a>     <strong>public</strong> <strong>long</strong> fp8(String s) {
<a name="176" href="#176">176</a>         <strong>return</strong> extend8(empty, s);
<a name="177" href="#177">177</a>     }
<a name="178" href="#178">178</a> 
<a name="179" href="#179">179</a>     <em>/**<em>* Compute fingerprint of the lower eight bits of "n" characters</em></em>
<a name="180" href="#180">180</a> <em>        of "buf" starting from "buf[i]".  Requires "[i, i+n)" is in</em>
<a name="181" href="#181">181</a> <em>        bounds. */</em>
<a name="182" href="#182">182</a>     <strong>public</strong> <strong>long</strong> fp8(<strong>char</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="183" href="#183">183</a>         <strong>return</strong> extend8(empty, buf, start, n);
<a name="184" href="#184">184</a>     }
<a name="185" href="#185">185</a> 
<a name="186" href="#186">186</a> 
<a name="187" href="#187">187</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding the low eight</em></em>
<a name="188" href="#188">188</a> <em>        bits of "b". */</em>
<a name="189" href="#189">189</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, byte v) {
<a name="190" href="#190">190</a>         <strong>return</strong> reduce(extend_byte(f, v));
<a name="191" href="#191">191</a>     }
<a name="192" href="#192">192</a> 
<a name="193" href="#193">193</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of)</em></em>
<a name="194" href="#194">194</a> <em>        "v". */</em>
<a name="195" href="#195">195</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, <strong>char</strong> v) {
<a name="196" href="#196">196</a>         <strong>return</strong> reduce(extend_<strong>char</strong>(f, v));
<a name="197" href="#197">197</a>     }
<a name="198" href="#198">198</a> 
<a name="199" href="#199">199</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of)</em></em>
<a name="200" href="#200">200</a> <em>        "v". */</em>
<a name="201" href="#201">201</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, <strong>int</strong> v) {
<a name="202" href="#202">202</a>         <strong>return</strong> reduce(extend_<strong>int</strong>(f, v));
<a name="203" href="#203">203</a>     }
<a name="204" href="#204">204</a> 
<a name="205" href="#205">205</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of)</em></em>
<a name="206" href="#206">206</a> <em>        "v". */</em>
<a name="207" href="#207">207</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, <strong>long</strong> v) {
<a name="208" href="#208">208</a>         <strong>return</strong> reduce(extend_<strong>long</strong>(f, v));
<a name="209" href="#209">209</a>     }
<a name="210" href="#210">210</a> 
<a name="211" href="#211">211</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding "n" bytes of</em></em>
<a name="212" href="#212">212</a> <em>        "buf" starting from "buf[start]".</em>
<a name="213" href="#213">213</a> <em>        Result is reduced.</em>
<a name="214" href="#214">214</a> <em>        Requires "[i,&amp;nbsp;i+n)" is in bounds. */</em>
<a name="215" href="#215">215</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, byte[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="216" href="#216">216</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; n; i++) {
<a name="217" href="#217">217</a>             f = extend_byte(f, buf[start+i]);
<a name="218" href="#218">218</a>         }
<a name="219" href="#219">219</a>         <strong>return</strong> reduce(f);
<a name="220" href="#220">220</a>     }
<a name="221" href="#221">221</a> 
<a name="222" href="#222">222</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of) "n"</em></em>
<a name="223" href="#223">223</a> <em>        characters of "buf" starting from "buf[i]".</em>
<a name="224" href="#224">224</a> <em>        Result is reduced.</em>
<a name="225" href="#225">225</a> <em>        Requires "[i,&amp;nbsp;i+n)" is in bounds. */</em>
<a name="226" href="#226">226</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, <strong>char</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="227" href="#227">227</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; n; i++) {
<a name="228" href="#228">228</a>             f = extend_<strong>char</strong>(f, buf[start+i]);
<a name="229" href="#229">229</a>         }
<a name="230" href="#230">230</a>         <strong>return</strong> reduce(f);
<a name="231" href="#231">231</a>     }
<a name="232" href="#232">232</a> 
<a name="233" href="#233">233</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of)</em></em>
<a name="234" href="#234">234</a> <em>        the characters of "s".</em>
<a name="235" href="#235">235</a> <em>        Result is reduced. */</em>
<a name="236" href="#236">236</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, CharSequence s) {
<a name="237" href="#237">237</a>         <strong>int</strong> n = s.length();
<a name="238" href="#238">238</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; n; i++) {
<a name="239" href="#239">239</a>             <strong>int</strong> v = (<strong>int</strong>) s.charAt(i);
<a name="240" href="#240">240</a>             f = extend_<strong>char</strong>(f, v);
<a name="241" href="#241">241</a>         }
<a name="242" href="#242">242</a>         <strong>return</strong> reduce(f);
<a name="243" href="#243">243</a>     }
<a name="244" href="#244">244</a> 
<a name="245" href="#245">245</a> <em class="comment">//  COMMENTED OUT TO REMOVE Dependency on st.ata.util.Text</em>
<a name="246" href="#246">246</a> <em class="comment">//    </em><em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of)</em></em>
<a name="247" href="#247">247</a> <em>//     *  &lt;code>t&lt;/code> */</em>
<a name="248" href="#248">248</a> <em class="comment">//    public long extend(long f, Text t) {</em>
<a name="249" href="#249">249</a> <em class="comment">//        return extend(f, t.buf, t.start, t.length());</em>
<a name="250" href="#250">250</a> <em class="comment">//    }</em>
<a name="251" href="#251">251</a> 
<a name="252" href="#252">252</a> 
<a name="253" href="#253">253</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of) "n"</em></em>
<a name="254" href="#254">254</a> <em>        characters of "buf" starting from "buf[i]".</em>
<a name="255" href="#255">255</a> <em>        Result is reduced.</em>
<a name="256" href="#256">256</a> <em>        Requires "[i,&amp;nbsp;i+n)" is in bounds. */</em>
<a name="257" href="#257">257</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, <strong>int</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="258" href="#258">258</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; n; i++) {
<a name="259" href="#259">259</a>             f = extend_<strong>int</strong>(f, buf[start+i]);
<a name="260" href="#260">260</a>         }
<a name="261" href="#261">261</a>         <strong>return</strong> reduce(f);
<a name="262" href="#262">262</a>     }
<a name="263" href="#263">263</a> 
<a name="264" href="#264">264</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding (all bits of) "n"</em></em>
<a name="265" href="#265">265</a> <em>        characters of "buf" starting from "buf[i]".</em>
<a name="266" href="#266">266</a> <em>        Result is reduced.</em>
<a name="267" href="#267">267</a> <em>        Requires "[i,&amp;nbsp;i+n)" is in bounds. */</em>
<a name="268" href="#268">268</a>     <strong>public</strong> <strong>long</strong> extend(<strong>long</strong> f, <strong>long</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="269" href="#269">269</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; n; i++) {
<a name="270" href="#270">270</a>             f = extend_<strong>long</strong>(f, buf[start+i]);
<a name="271" href="#271">271</a>         }
<a name="272" href="#272">272</a>         <strong>return</strong> reduce(f);
<a name="273" href="#273">273</a>     }
<a name="274" href="#274">274</a> 
<a name="275" href="#275">275</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding the lower eight</em></em>
<a name="276" href="#276">276</a> <em>        bits of the characters of "s".</em>
<a name="277" href="#277">277</a> <em>        Result is reduced. */</em>
<a name="278" href="#278">278</a>     <strong>public</strong> <strong>long</strong> extend8(<strong>long</strong> f, String s) {
<a name="279" href="#279">279</a>         <strong>int</strong> n = s.length();
<a name="280" href="#280">280</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; n; i++) {
<a name="281" href="#281">281</a>             <strong>int</strong> x = (<strong>int</strong>) s.charAt(i);
<a name="282" href="#282">282</a>             f = extend_byte(f, x);
<a name="283" href="#283">283</a>         }
<a name="284" href="#284">284</a>         <strong>return</strong> reduce(f);
<a name="285" href="#285">285</a>     }
<a name="286" href="#286">286</a> 
<a name="287" href="#287">287</a>     <em>/**<em>* Extends fingerprint &lt;code>f&lt;/code> by adding the lower eight</em></em>
<a name="288" href="#288">288</a> <em>        bits of "n" characters of "buf" starting from "buf[i]".</em>
<a name="289" href="#289">289</a> <em>        Result is reduced.</em>
<a name="290" href="#290">290</a> <em>        Requires "[i, i+n)" is in bounds. */</em>
<a name="291" href="#291">291</a>     <strong>public</strong> <strong>long</strong> extend8(<strong>long</strong> f, <strong>char</strong>[] buf, <strong>int</strong> start, <strong>int</strong> n) {
<a name="292" href="#292">292</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; n; i++) {
<a name="293" href="#293">293</a>             f = extend_byte(f, buf[start+i]);
<a name="294" href="#294">294</a>         }
<a name="295" href="#295">295</a>         <strong>return</strong> reduce(f);
<a name="296" href="#296">296</a>     }
<a name="297" href="#297">297</a> 
<a name="298" href="#298">298</a> 
<a name="299" href="#299">299</a>     <em>/**<em>* Fingerprint of the empty string of bytes. */</em></em>
<a name="300" href="#300">300</a>     <strong>public</strong> <strong>final</strong> <strong>long</strong> empty;
<a name="301" href="#301">301</a>