waitevaluator.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="145" href="#145">145</a>                 DEFAULT_DEFAULT_WAIT_INTERVAL));
<a name="146" href="#146">146</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_UNCHANGED_FACTOR,
<a name="147" href="#147">147</a>                 <span class="string">"The factor by which a URIs wait time is increased when a "</span> +
<a name="148" href="#148">148</a>                 <span class="string">"revisit reveals an unchanged document. A value of 1 will "</span> +
<a name="149" href="#149">149</a>                 <span class="string">"leave it unchanged, a value of 2 will double it etc."</span>,
<a name="150" href="#150">150</a>                 <strong>default</strong>_unchanged_factor));
<a name="151" href="#151">151</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_CHANGED_FACTOR,
<a name="152" href="#152">152</a>                 <span class="string">"The factor by which a URIs wait time is decreased when a "</span> +
<a name="153" href="#153">153</a>                 <span class="string">"revisit reveals a changed document. A value of 1 will leave "</span> +
<a name="154" href="#154">154</a>                 <span class="string">"it unchanged, a value of two will half it etc."</span>,
<a name="155" href="#155">155</a>                 <strong>default</strong>_changed_factor));
<a name="156" href="#156">156</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_USE_OVERDUE_TIME,
<a name="157" href="#157">157</a>                 <span class="string">"Indicates if the amount of time the URI was overdue should "</span> +
<a name="158" href="#158">158</a>                 <span class="string">"be added to the wait time before the new wait time is "</span> +
<a name="159" href="#159">159</a>                 <span class="string">"calculated."</span>,
<a name="160" href="#160">160</a>                 DEFAULT_USE_OVERDUE_TIME));
<a name="161" href="#161">161</a> 
<a name="162" href="#162">162</a>         <em class="comment">// Register persistent CrawlURI items </em>
<a name="163" href="#163">163</a>         CrawlURI.addAlistPersistentMember(A_WAIT_INTERVAL);
<a name="164" href="#164">164</a>     }
<a name="165" href="#165">165</a> 
<a name="166" href="#166">166</a>     <strong>protected</strong> <strong>void</strong> innerProcess(<a href="../../../../org/archive/crawler/datamodel/CrawlURI.html">CrawlURI</a> curi) throws InterruptedException {
<a name="167" href="#167">167</a>         
<a name="168" href="#168">168</a>         <strong>if</strong>(curi.isSuccess()==false){
<a name="169" href="#169">169</a>             <em class="comment">// If the URI was not crawled successfully, we can not reevaluate</em>
<a name="170" href="#170">170</a>             <em class="comment">// the wait interval.</em>
<a name="171" href="#171">171</a>             <strong>return</strong>;
<a name="172" href="#172">172</a>         }
<a name="173" href="#173">173</a>         
<a name="174" href="#174">174</a>         <strong>if</strong>(curi.containsKey(A_WAIT_REEVALUATED) &amp;&amp; 
<a name="175" href="#175">175</a>                 ((Boolean)curi.getObject(A_WAIT_REEVALUATED)).booleanValue()){
<a name="176" href="#176">176</a>             <em class="comment">// This CrawlURIs wait interval has already been reevaluted during</em>
<a name="177" href="#177">177</a>             <em class="comment">// this processing round.</em>
<a name="178" href="#178">178</a>             <strong>return</strong>;
<a name="179" href="#179">179</a>         }
<a name="180" href="#180">180</a>             
<a name="181" href="#181">181</a>         <strong>long</strong> min;
<a name="182" href="#182">182</a>         <strong>try</strong> {
<a name="183" href="#183">183</a>             min = ((Long)getAttribute(curi, ATTR_MIN_WAIT_INTERVAL)).
<a name="184" href="#184">184</a>                 longValue() * 1000;
<a name="185" href="#185">185</a>         } <strong>catch</strong> (AttributeNotFoundException e1) {
<a name="186" href="#186">186</a>             min = DEFAULT_MIN_WAIT_INTERVAL.longValue();
<a name="187" href="#187">187</a>             logger.fine(<span class="string">"Unable to load minimum wait interval for "</span> + 
<a name="188" href="#188">188</a>                     curi.toString());
<a name="189" href="#189">189</a>         }
<a name="190" href="#190">190</a> 
<a name="191" href="#191">191</a>         <strong>long</strong> max;
<a name="192" href="#192">192</a>         <strong>try</strong> {
<a name="193" href="#193">193</a>             max = ((Long)getAttribute(curi, ATTR_MAX_WAIT_INTERVAL)).
<a name="194" href="#194">194</a>                 longValue() * 1000;
<a name="195" href="#195">195</a>         } <strong>catch</strong> (AttributeNotFoundException e1) {
<a name="196" href="#196">196</a>             max = DEFAULT_MAX_WAIT_INTERVAL.longValue();
<a name="197" href="#197">197</a>             logger.fine(<span class="string">"Unable to load maximum wait interval for "</span> + 
<a name="198" href="#198">198</a>                     curi.toString());
<a name="199" href="#199">199</a>         }
<a name="200" href="#200">200</a> 
<a name="201" href="#201">201</a>         
<a name="202" href="#202">202</a>         <strong>long</strong> waitInterval;
<a name="203" href="#203">203</a>         <strong>if</strong> (!curi.containsKey(A_CONTENT_STATE_KEY) ||
<a name="204" href="#204">204</a>                 curi.getInt(A_CONTENT_STATE_KEY) == CONTENT_UNKNOWN) {
<a name="205" href="#205">205</a>             <strong>try</strong> {
<a name="206" href="#206">206</a>                 waitInterval = ((Long)getAttribute(curi,
<a name="207" href="#207">207</a>                         ATTR_DEFAULT_WAIT_INTERVAL)).longValue() * 1000;
<a name="208" href="#208">208</a>             } <strong>catch</strong> (AttributeNotFoundException e1) {
<a name="209" href="#209">209</a>                 waitInterval = DEFAULT_DEFAULT_WAIT_INTERVAL.longValue();
<a name="210" href="#210">210</a>                 logger.fine(<span class="string">"Unable to load default wait interval for "</span>
<a name="211" href="#211">211</a>                         + curi.toString());
<a name="212" href="#212">212</a>             }
<a name="213" href="#213">213</a>         } <strong>else</strong> {
<a name="214" href="#214">214</a>             <em class="comment">/*<em class="comment"> Calculate curi's time of next processing */</em> </em>
<a name="215" href="#215">215</a>             waitInterval = DEFAULT_INITIAL_WAIT_INTERVAL.longValue()*1000;
<a name="216" href="#216">216</a> 
<a name="217" href="#217">217</a>             <em class="comment">// Retrieve wait interval</em>
<a name="218" href="#218">218</a>             <strong>if</strong>(curi.containsKey(A_WAIT_INTERVAL)){
<a name="219" href="#219">219</a>                 waitInterval =  curi.getLong(A_WAIT_INTERVAL); 
<a name="220" href="#220">220</a> 
<a name="221" href="#221">221</a>                 <em class="comment">// Should override time be taken into account?</em>
<a name="222" href="#222">222</a>                 <strong>boolean</strong> useOverrideTime = DEFAULT_USE_OVERDUE_TIME.<strong>boolean</strong>Value();
<a name="223" href="#223">223</a>                 <strong>try</strong> {
<a name="224" href="#224">224</a>                     useOverrideTime = ((Boolean)getAttribute(
<a name="225" href="#225">225</a>                             curi,ATTR_USE_OVERDUE_TIME)).booleanValue();
<a name="226" href="#226">226</a>                 } <strong>catch</strong> (AttributeNotFoundException e1) {
<a name="227" href="#227">227</a>                     useOverrideTime = DEFAULT_USE_OVERDUE_TIME.booleanValue();
<a name="228" href="#228">228</a>                     logger.fine(<span class="string">"Unable to load use-overdue-time for "</span> + 
<a name="229" href="#229">229</a>                             curi.toString());
<a name="230" href="#230">230</a>                 }
<a name="231" href="#231">231</a>                 
<a name="232" href="#232">232</a>                 <strong>if</strong>(useOverrideTime){
<a name="233" href="#233">233</a>                     waitInterval += curi.getLong(A_FETCH_OVERDUE);
<a name="234" href="#234">234</a>                 }
<a name="235" href="#235">235</a> 
<a name="236" href="#236">236</a>                 <em class="comment">// Revise the wait interval</em>
<a name="237" href="#237">237</a>                 <strong>if</strong>(curi.getInt(A_CONTENT_STATE_KEY) == CONTENT_CHANGED){
<a name="238" href="#238">238</a>                     <em class="comment">// Had changed. Decrease wait interval time.</em>
<a name="239" href="#239">239</a>                     <strong>double</strong> factor;
<a name="240" href="#240">240</a>                     <strong>try</strong> {
<a name="241" href="#241">241</a>                         factor = ((Double)getAttribute(
<a name="242" href="#242">242</a>                                 curi,ATTR_CHANGED_FACTOR)).doubleValue();
<a name="243" href="#243">243</a>                     } <strong>catch</strong> (AttributeNotFoundException e2) {
<a name="244" href="#244">244</a>                         factor = DEFAULT_CHANGED_FACTOR.doubleValue();
<a name="245" href="#245">245</a>                         logger.fine(<span class="string">"Unable to load changed factor for "</span> + 
<a name="246" href="#246">246</a>                                 curi.toString());
<a name="247" href="#247">247</a>                     }
<a name="248" href="#248">248</a>                     waitInterval = (<strong>long</strong>)(waitInterval / factor);
<a name="249" href="#249">249</a>                 } <strong>else</strong> <strong>if</strong>(curi.getInt(A_CONTENT_STATE_KEY) ==
<a name="250" href="#250">250</a>                         CONTENT_UNCHANGED) {
<a name="251" href="#251">251</a>                     <em class="comment">// Had not changed. Increase wait interval time</em>
<a name="252" href="#252">252</a>                     <strong>double</strong> factor;
<a name="253" href="#253">253</a>                     <strong>try</strong> {
<a name="254" href="#254">254</a>                         factor = ((Double)getAttribute(
<a name="255" href="#255">255</a>                                 curi,ATTR_UNCHANGED_FACTOR)).doubleValue();
<a name="256" href="#256">256</a>                     } <strong>catch</strong> (AttributeNotFoundException e2) {
<a name="257" href="#257">257</a>                         factor = DEFAULT_UNCHANGED_FACTOR.doubleValue();
<a name="258" href="#258">258</a>                         logger.fine(<span class="string">"Unable to load unchanged factor for "</span> + 
<a name="259" href="#259">259</a>                                 curi.toString());
<a name="260" href="#260">260</a>                     }
<a name="261" href="#261">261</a>                     waitInterval = (<strong>long</strong>)(waitInterval*factor);
<a name="262" href="#262">262</a>                 }
<a name="263" href="#263">263</a>             } <strong>else</strong> {
<a name="264" href="#264">264</a>                 <em class="comment">// If wait element not found, use initial wait interval </em>
<a name="265" href="#265">265</a>                 <strong>try</strong> {
<a name="266" href="#266">266</a>                     waitInterval = ((Long)getAttribute(
<a name="267" href="#267">267</a>                             curi,ATTR_INITIAL_WAIT_INTERVAL)).longValue()*1000;
<a name="268" href="#268">268</a>                 } <strong>catch</strong> (AttributeNotFoundException e1) {
<a name="269" href="#269">269</a>                     <em class="comment">// If this fails use default (already set) and log error.</em>
<a name="270" href="#270">270</a>                     logger.fine(<span class="string">"Unable to load initial wait interval for "</span> + 
<a name="271" href="#271">271</a>                             curi.toString());
<a name="272" href="#272">272</a>                 }        
<a name="273" href="#273">273</a>             }
<a name="274" href="#274">274</a>         }
<a name="275" href="#275">275</a>         
<a name="276" href="#276">276</a>         <strong>if</strong>(waitInterval &lt; min){
<a name="277" href="#277">277</a>             waitInterval = min;
<a name="278" href="#278">278</a>         } <strong>else</strong> <strong>if</strong>(waitInterval > max){
<a name="279" href="#279">279</a>             waitInterval = max;
<a name="280" href="#280">280</a>         }
<a name="281" href="#281">281</a>         
<a name="282" href="#282">282</a>         <strong>if</strong> (logger.isLoggable(Level.FINE)) {
<a name="283" href="#283">283</a>             logger.fine(<span class="string">"URI "</span> + curi.toString() + <span class="string">", change: "</span>
<a name="284" href="#284">284</a>                     + curi.getInt(A_CONTENT_STATE_KEY) + <span class="string">" new wait interval: "</span>
<a name="285" href="#285">285</a>                     + waitInterval);
<a name="286" href="#286">286</a>         }
<a name="287" href="#287">287</a>         <em class="comment">// Update wait interval</em>
<a name="288" href="#288">288</a>         curi.putLong(A_WAIT_INTERVAL,waitInterval);
<a name="289" href="#289">289</a>         curi.putObject(A_WAIT_REEVALUATED,<strong>new</strong> Boolean(<strong>true</strong>));
<a name="290" href="#290">290</a>     }
<a name="291" href="#291">291</a> }
</pre>
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