workqueuefrontier.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="278" href="#278">278</a>     }
<a name="279" href="#279">279</a> 
<a name="280" href="#280">280</a>     <em>/**<em>*</em></em>
<a name="281" href="#281">281</a> <em>     * Initializes the Frontier, given the supplied CrawlController.</em>
<a name="282" href="#282">282</a> <em>     *</em>
<a name="283" href="#283">283</a> <em>     * @see org.archive.crawler.framework.Frontier#initialize(org.archive.crawler.framework.CrawlController)</em>
<a name="284" href="#284">284</a> <em>     */</em>
<a name="285" href="#285">285</a>     <strong>public</strong> <strong>void</strong> initialize(<a href="../../../../org/archive/crawler/framework/CrawlController.html">CrawlController</a> c)
<a name="286" href="#286">286</a>             throws FatalConfigurationException, IOException {
<a name="287" href="#287">287</a>         <em class="comment">// Call the super method. It sets up frontier journalling.</em>
<a name="288" href="#288">288</a>         <strong>super</strong>.initialize(c);
<a name="289" href="#289">289</a>         <strong>this</strong>.controller = c;
<a name="290" href="#290">290</a>         
<a name="291" href="#291">291</a>         <strong>this</strong>.targetSizeForReadyQueues = (Integer)getUncheckedAttribute(<strong>null</strong>,
<a name="292" href="#292">292</a>             ATTR_TARGET_READY_QUEUES_BACKLOG);
<a name="293" href="#293">293</a>         <strong>if</strong> (<strong>this</strong>.targetSizeForReadyQueues &lt; 1) {
<a name="294" href="#294">294</a>             <strong>this</strong>.targetSizeForReadyQueues = 1;
<a name="295" href="#295">295</a>         }
<a name="296" href="#296">296</a>         <strong>this</strong>.wakeTimer = <strong>new</strong> Timer(<span class="string">"waker for "</span> + c.toString());
<a name="297" href="#297">297</a>         
<a name="298" href="#298">298</a>         <strong>try</strong> {
<a name="299" href="#299">299</a>             <strong>if</strong> (workQueueDataOnDisk()
<a name="300" href="#300">300</a>                     &amp;&amp; queueAssignmentPolicy.maximumNumberOfKeys() >= 0
<a name="301" href="#301">301</a>                     &amp;&amp; queueAssignmentPolicy.maximumNumberOfKeys() &lt;= 
<a name="302" href="#302">302</a>                         MAX_QUEUES_TO_HOLD_ALLQUEUES_IN_MEMORY) {
<a name="303" href="#303">303</a>                 <strong>this</strong>.allQueues = Collections.synchronizedMap(<strong>new</strong> HashMap());
<a name="304" href="#304">304</a>             } <strong>else</strong> {
<a name="305" href="#305">305</a>                 <strong>this</strong>.allQueues = c.getBigMap(<span class="string">"allqueues"</span>,
<a name="306" href="#306">306</a>                         String.<strong>class</strong>, WorkQueue.<strong>class</strong>);
<a name="307" href="#307">307</a>                 <strong>if</strong> (logger.isLoggable(Level.FINE)) {
<a name="308" href="#308">308</a>                     Iterator i = <strong>this</strong>.allQueues.keySet().iterator();
<a name="309" href="#309">309</a>                     <strong>try</strong> {
<a name="310" href="#310">310</a>                         <strong>for</strong> (; i.hasNext();) {
<a name="311" href="#311">311</a>                             logger.fine((String) i.next());
<a name="312" href="#312">312</a>                         }
<a name="313" href="#313">313</a>                     } <strong>finally</strong> {
<a name="314" href="#314">314</a>                         StoredIterator.close(i);
<a name="315" href="#315">315</a>                     }
<a name="316" href="#316">316</a>                 }
<a name="317" href="#317">317</a>             }
<a name="318" href="#318">318</a>             <strong>this</strong>.alreadyIncluded = createAlreadyIncluded();
<a name="319" href="#319">319</a>             initQueue();
<a name="320" href="#320">320</a>         } <strong>catch</strong> (IOException e) {
<a name="321" href="#321">321</a>             e.printStackTrace();
<a name="322" href="#322">322</a>             <strong>throw</strong> (FatalConfigurationException)
<a name="323" href="#323">323</a>                 <strong>new</strong> <a href="../../../../org/archive/crawler/framework/exceptions/FatalConfigurationException.html">FatalConfigurationException</a>(e.getMessage()).initCause(e);
<a name="324" href="#324">324</a>         } <strong>catch</strong> (Exception e) {
<a name="325" href="#325">325</a>             e.printStackTrace();
<a name="326" href="#326">326</a>             <strong>throw</strong> (FatalConfigurationException)
<a name="327" href="#327">327</a>                 <strong>new</strong> <a href="../../../../org/archive/crawler/framework/exceptions/FatalConfigurationException.html">FatalConfigurationException</a>(e.getMessage()).initCause(e);
<a name="328" href="#328">328</a>         }
<a name="329" href="#329">329</a>         
<a name="330" href="#330">330</a>         initCostPolicy();
<a name="331" href="#331">331</a>         
<a name="332" href="#332">332</a>         loadSeeds();
<a name="333" href="#333">333</a>     }
<a name="334" href="#334">334</a>     
<a name="335" href="#335">335</a>     <em>/**<em>*</em></em>
<a name="336" href="#336">336</a> <em>     * Set (or reset after configuration change) the cost policy in effect.</em>
<a name="337" href="#337">337</a> <em>     * </em>
<a name="338" href="#338">338</a> <em>     * @throws FatalConfigurationException</em>
<a name="339" href="#339">339</a> <em>     */</em>
<a name="340" href="#340">340</a>     <strong>private</strong> <strong>void</strong> initCostPolicy() throws FatalConfigurationException {
<a name="341" href="#341">341</a>         <strong>try</strong> {
<a name="342" href="#342">342</a>             costAssignmentPolicy = (CostAssignmentPolicy) Class.forName(
<a name="343" href="#343">343</a>                     (String) getUncheckedAttribute(<strong>null</strong>, ATTR_COST_POLICY))
<a name="344" href="#344">344</a>                     .newInstance();
<a name="345" href="#345">345</a>         } <strong>catch</strong> (Exception e) {
<a name="346" href="#346">346</a>             e.printStackTrace();
<a name="347" href="#347">347</a>             <strong>throw</strong> <strong>new</strong> <a href="../../../../org/archive/crawler/framework/exceptions/FatalConfigurationException.html">FatalConfigurationException</a>(e.getMessage());
<a name="348" href="#348">348</a>         }
<a name="349" href="#349">349</a>     }
<a name="350" href="#350">350</a> 
<a name="351" href="#351">351</a>     <em class="comment">/*<em class="comment"> (non-Javadoc)</em></em>
<a name="352" href="#352">352</a> <em class="comment">     * @see org.archive.crawler.frontier.AbstractFrontier#crawlEnded(java.lang.String)</em>
<a name="353" href="#353">353</a> <em class="comment">     */</em>
<a name="354" href="#354">354</a>     <strong>public</strong> <strong>void</strong> crawlEnded(String sExitMessage) {
<a name="355" href="#355">355</a>         <em class="comment">// Cleanup.  CrawlJobs persist after crawl has finished so undo any</em>
<a name="356" href="#356">356</a>         <em class="comment">// references.</em>
<a name="357" href="#357">357</a>         <strong>if</strong> (<strong>this</strong>.alreadyIncluded != <strong>null</strong>) {
<a name="358" href="#358">358</a>             <strong>this</strong>.alreadyIncluded.close();
<a name="359" href="#359">359</a>             <strong>this</strong>.alreadyIncluded = <strong>null</strong>;
<a name="360" href="#360">360</a>         }
<a name="361" href="#361">361</a> 
<a name="362" href="#362">362</a>         <strong>this</strong>.queueAssignmentPolicy = <strong>null</strong>;
<a name="363" href="#363">363</a>         
<a name="364" href="#364">364</a>         <strong>try</strong> {
<a name="365" href="#365">365</a>             closeQueue();
<a name="366" href="#366">366</a>         } <strong>catch</strong> (IOException e) {
<a name="367" href="#367">367</a>             <em class="comment">// FIXME exception handling</em>
<a name="368" href="#368">368</a>             e.printStackTrace();
<a name="369" href="#369">369</a>         }
<a name="370" href="#370">370</a>         <strong>this</strong>.wakeTimer.cancel();
<a name="371" href="#371">371</a>         
<a name="372" href="#372">372</a>         <strong>this</strong>.allQueues.clear();
<a name="373" href="#373">373</a>         <strong>this</strong>.allQueues = <strong>null</strong>;
<a name="374" href="#374">374</a>         <strong>this</strong>.inProcessQueues = <strong>null</strong>;
<a name="375" href="#375">375</a>         <strong>this</strong>.readyClassQueues = <strong>null</strong>;
<a name="376" href="#376">376</a>         <strong>this</strong>.snoozedClassQueues = <strong>null</strong>;
<a name="377" href="#377">377</a>         <strong>this</strong>.inactiveQueues = <strong>null</strong>;
<a name="378" href="#378">378</a>         <strong>this</strong>.retiredQueues = <strong>null</strong>;
<a name="379" href="#379">379</a>         
<a name="380" href="#380">380</a>         <strong>this</strong>.costAssignmentPolicy = <strong>null</strong>;
<a name="381" href="#381">381</a>         
<a name="382" href="#382">382</a>         <em class="comment">// Clearing controller is a problem. We get NPEs in #preNext.</em>
<a name="383" href="#383">383</a>         <strong>super</strong>.crawlEnded(sExitMessage);
<a name="384" href="#384">384</a>         <strong>this</strong>.controller = <strong>null</strong>;
<a name="385" href="#385">385</a>     }
<a name="386" href="#386">386</a> 
<a name="387" href="#387">387</a>     <em>/**<em>*</em></em>
<a name="388" href="#388">388</a> <em>     * Create a UriUniqFilter that will serve as record </em>
<a name="389" href="#389">389</a> <em>     * of already seen URIs.</em>
<a name="390" href="#390">390</a> <em>     *</em>
<a name="391" href="#391">391</a> <em>     * @return A UURISet that will serve as a record of already seen URIs</em>
<a name="392" href="#392">392</a> <em>     * @throws IOException</em>
<a name="393" href="#393">393</a> <em>     */</em>
<a name="394" href="#394">394</a>     <strong>protected</strong> <strong>abstract</strong> <a href="../../../../org/archive/crawler/datamodel/UriUniqFilter.html">UriUniqFilter</a> createAlreadyIncluded() throws IOException;
<a name="395" href="#395">395</a> 
<a name="396" href="#396">396</a>     <em>/**<em>*</em></em>
<a name="397" href="#397">397</a> <em>     * Arrange for the given CandidateURI to be visited, if it is not</em>
<a name="398" href="#398">398</a> <em>     * already scheduled/completed.</em>
<a name="399" href="#399">399</a> <em>     *</em>
<a name="400" href="#400">400</a> <em>     * @see org.archive.crawler.framework.Frontier#schedule(org.archive.crawler.datamodel.CandidateURI)</em>
<a name="401" href="#401">401</a> <em>     */</em>
<a name="402" href="#402">402</a>     <strong>public</strong> <strong>void</strong> schedule(<a href="../../../../org/archive/crawler/datamodel/CandidateURI.html">CandidateURI</a> caUri) {
<a name="403" href="#403">403</a>         <em class="comment">// Canonicalization may set forceFetch flag.  See</em>
<a name="404" href="#404">404</a>         <em class="comment">// #canonicalization(CandidateURI) javadoc for circumstance.</em>
<a name="405" href="#405">405</a>         String canon = canonicalize(caUri);
<a name="406" href="#406">406</a>         <strong>if</strong> (caUri.forceFetch()) {
<a name="407" href="#407">407</a>             alreadyIncluded.addForce(canon, caUri);
<a name="408" href="#408">408</a>         } <strong>else</strong> {
<a name="409" href="#409">409</a>             alreadyIncluded.add(canon, caUri);
<a name="410" href="#410">410</a>         }
<a name="411" href="#411">411</a>     }
<a name="412" href="#412">412</a> 
<a name="413" href="#413">413</a>     <em>/**<em>*</em></em>
<a name="414" href="#414">414</a> <em>     * Accept the given CandidateURI for scheduling, as it has</em>
<a name="415" href="#415">415</a> <em>     * passed the alreadyIncluded filter. </em>
<a name="416" href="#416">416</a> <em>     * </em>
<a name="417" href="#417">417</a> <em>     * Choose a per-classKey queue and enqueue it. If this</em>
<a name="418" href="#418">418</a> <em>     * item has made an unready queue ready, place that </em>
<a name="419" href="#419">419</a> <em>     * queue on the readyClassQueues queue. </em>
<a name="420" href="#420">420</a> <em>     * @param caUri CandidateURI.</em>