abstractfrontier.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="133" href="#133">133</a> 
<a name="134" href="#134">134</a>     <em>/**<em>* for retryable problems, seconds to wait before a retry */</em></em>
<a name="135" href="#135">135</a>     <strong>public</strong> <strong>final</strong> <strong>static</strong> String ATTR_RETRY_DELAY = <span class="string">"retry-delay-seconds"</span>;
<a name="136" href="#136">136</a> 
<a name="137" href="#137">137</a>     <em class="comment">// 15 mins</em>
<a name="138" href="#138">138</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> Long DEFAULT_RETRY_DELAY = <strong>new</strong> Long(900);
<a name="139" href="#139">139</a> 
<a name="140" href="#140">140</a>     <em>/**<em>* maximum times to emit a <a href="../../../../org/archive/crawler/datamodel/CrawlURI.html">CrawlURI</a> without final disposition */</em></em>
<a name="141" href="#141">141</a>     <strong>public</strong> <strong>final</strong> <strong>static</strong> String ATTR_MAX_RETRIES = <span class="string">"max-retries"</span>;
<a name="142" href="#142">142</a> 
<a name="143" href="#143">143</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> Integer DEFAULT_MAX_RETRIES = <strong>new</strong> Integer(30);
<a name="144" href="#144">144</a> 
<a name="145" href="#145">145</a>     <strong>public</strong> <strong>final</strong> <strong>static</strong> String ATTR_QUEUE_ASSIGNMENT_POLICY =
<a name="146" href="#146">146</a>         <span class="string">"queue-assignment-policy"</span>;
<a name="147" href="#147">147</a> 
<a name="148" href="#148">148</a>     <em>/**<em>* queue assignment to force onto CrawlURIs; intended to be overridden */</em></em>
<a name="149" href="#149">149</a>     <strong>public</strong> <strong>final</strong> <strong>static</strong> String ATTR_FORCE_QUEUE = <span class="string">"force-queue-assignment"</span>;
<a name="150" href="#150">150</a> 
<a name="151" href="#151">151</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> String DEFAULT_FORCE_QUEUE = <span class="string">""</span>;
<a name="152" href="#152">152</a> 
<a name="153" href="#153">153</a>     <em class="comment">// word chars, dash, period, comma, colon</em>
<a name="154" href="#154">154</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> String ACCEPTABLE_FORCE_QUEUE = <span class="string">"[-&#47;&#47;w&#47;&#47;.,:]*"</span>;
<a name="155" href="#155">155</a>         
<a name="156" href="#156">156</a>     <em>/**<em>* whether pause, rather than finish, when crawl appears done */</em></em>
<a name="157" href="#157">157</a>     <strong>public</strong> <strong>final</strong> <strong>static</strong> String ATTR_PAUSE_AT_FINISH = <span class="string">"pause-at-finish"</span>;
<a name="158" href="#158">158</a>     <em class="comment">// TODO: change default to true once well-tested</em>
<a name="159" href="#159">159</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> Boolean DEFAULT_PAUSE_AT_FINISH = Boolean.FALSE;
<a name="160" href="#160">160</a>     
<a name="161" href="#161">161</a>     <em>/**<em>* whether to pause at crawl start */</em></em>
<a name="162" href="#162">162</a>     <strong>public</strong> <strong>final</strong> <strong>static</strong> String ATTR_PAUSE_AT_START = <span class="string">"pause-at-start"</span>;
<a name="163" href="#163">163</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> Boolean DEFAULT_PAUSE_AT_START = Boolean.FALSE;
<a name="164" href="#164">164</a>     
<a name="165" href="#165">165</a>     <em>/**<em>* whether to pause at crawl start */</em></em>
<a name="166" href="#166">166</a>     <strong>public</strong> <strong>final</strong> <strong>static</strong> String ATTR_SOURCE_TAG_SEEDS = <span class="string">"source-tag-seeds"</span>;
<a name="167" href="#167">167</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> Boolean DEFAULT_SOURCE_TAG_SEEDS = Boolean.FALSE;
<a name="168" href="#168">168</a> 
<a name="169" href="#169">169</a>     <em>/**<em>*</em></em>
<a name="170" href="#170">170</a> <em>     * Recover log on or off attribute.</em>
<a name="171" href="#171">171</a> <em>     */</em>
<a name="172" href="#172">172</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> String ATTR_RECOVERY_ENABLED =
<a name="173" href="#173">173</a>         <span class="string">"recovery-log-enabled"</span>;
<a name="174" href="#174">174</a>     <strong>protected</strong> <strong>final</strong> <strong>static</strong> Boolean DEFAULT_ATTR_RECOVERY_ENABLED =
<a name="175" href="#175">175</a>         Boolean.TRUE;
<a name="176" href="#176">176</a> 
<a name="177" href="#177">177</a>     <em class="comment">// top-level stats</em>
<a name="178" href="#178">178</a>     <strong>protected</strong> <strong>long</strong> queuedUriCount = 0; <em class="comment">// total URIs queued to be visited</em>
<a name="179" href="#179">179</a> 
<a name="180" href="#180">180</a>     <strong>protected</strong> <strong>long</strong> succeededFetchCount = 0;
<a name="181" href="#181">181</a> 
<a name="182" href="#182">182</a>     <strong>protected</strong> <strong>long</strong> failedFetchCount = 0;
<a name="183" href="#183">183</a> 
<a name="184" href="#184">184</a>     <strong>protected</strong> <strong>long</strong> disregardedUriCount = 0; <em class="comment">//URIs that are disregarded (for</em>
<a name="185" href="#185">185</a>                                           <em class="comment">// example because of robot.txt rules)</em>
<a name="186" href="#186">186</a> 
<a name="187" href="#187">187</a>     <em>/**<em>*</em></em>
<a name="188" href="#188">188</a> <em>     * Used when bandwidth constraint are used.</em>
<a name="189" href="#189">189</a> <em>     */</em>
<a name="190" href="#190">190</a>     <strong>protected</strong> <strong>long</strong> totalProcessedBytes = 0;
<a name="191" href="#191">191</a> 
<a name="192" href="#192">192</a>     <strong>private</strong> <strong>transient</strong> <strong>long</strong> nextURIEmitTime = 0;
<a name="193" href="#193">193</a> 
<a name="194" href="#194">194</a>     <strong>protected</strong> <strong>long</strong> processedBytesAfterLastEmittedURI = 0;
<a name="195" href="#195">195</a>     
<a name="196" href="#196">196</a>     <strong>protected</strong> <strong>int</strong> lastMaxBandwidthKB = 0;
<a name="197" href="#197">197</a> 
<a name="198" href="#198">198</a>     <em>/**<em>* Policy for assigning CrawlURIs to named queues */</em></em>
<a name="199" href="#199">199</a>     <strong>protected</strong> <strong>transient</strong> <a href="../../../../org/archive/crawler/frontier/QueueAssignmentPolicy.html">QueueAssignmentPolicy</a> queueAssignmentPolicy = <strong>null</strong>;
<a name="200" href="#200">200</a> 
<a name="201" href="#201">201</a>     <em>/**<em>*</em></em>
<a name="202" href="#202">202</a> <em>     * Crawl replay logger.</em>
<a name="203" href="#203">203</a> <em>     * </em>
<a name="204" href="#204">204</a> <em>     * Currently captures Frontier/URI transitions.</em>
<a name="205" href="#205">205</a> <em>     * Can be null if user chose not to run a recovery.log.</em>
<a name="206" href="#206">206</a> <em>     */</em>
<a name="207" href="#207">207</a>     <strong>private</strong> <strong>transient</strong> <a href="../../../../org/archive/crawler/frontier/FrontierJournal.html">FrontierJournal</a> recover = <strong>null</strong>;
<a name="208" href="#208">208</a> 
<a name="209" href="#209">209</a>     <em>/**<em>* file collecting report of ignored seed-file entries (if any) */</em></em>
<a name="210" href="#210">210</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> String IGNORED_SEEDS_FILENAME = <span class="string">"seeds.ignored"</span>;
<a name="211" href="#211">211</a> 
<a name="212" href="#212">212</a>     <em>/**<em>*</em></em>
<a name="213" href="#213">213</a> <em>     * @param name Name of this frontier.</em>
<a name="214" href="#214">214</a> <em>     * @param description Description for this frontier.</em>
<a name="215" href="#215">215</a> <em>     */</em>
<a name="216" href="#216">216</a>     <strong>public</strong> <a href="../../../../org/archive/crawler/frontier/AbstractFrontier.html">AbstractFrontier</a>(String name, String description) {
<a name="217" href="#217">217</a>         <strong>super</strong>(name, description);
<a name="218" href="#218">218</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_DELAY_FACTOR,
<a name="219" href="#219">219</a>                 <span class="string">"How many multiples of last fetch elapsed time to wait before "</span>
<a name="220" href="#220">220</a>                         + <span class="string">"recontacting same server"</span>, DEFAULT_DELAY_FACTOR));
<a name="221" href="#221">221</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_MAX_DELAY,
<a name="222" href="#222">222</a>                 <span class="string">"Never wait more than this long."</span>, DEFAULT_MAX_DELAY));
<a name="223" href="#223">223</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_MIN_DELAY,
<a name="224" href="#224">224</a>                 <span class="string">"Always wait this long after one completion before recontacting "</span>
<a name="225" href="#225">225</a>                         + <span class="string">"same server."</span>, DEFAULT_MIN_DELAY));
<a name="226" href="#226">226</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_MAX_RETRIES,
<a name="227" href="#227">227</a>                 <span class="string">"How often to retry fetching a URI that failed to be retrieved. "</span>
<a name="228" href="#228">228</a>                         + <span class="string">"If zero, the crawler will get the robots.txt only."</span>,
<a name="229" href="#229">229</a>                 DEFAULT_MAX_RETRIES));
<a name="230" href="#230">230</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_RETRY_DELAY,
<a name="231" href="#231">231</a>                 <span class="string">"How long to wait by default until we retry fetching a"</span>
<a name="232" href="#232">232</a>                         + <span class="string">" URI that failed to be retrieved (seconds). "</span>,
<a name="233" href="#233">233</a>                 DEFAULT_RETRY_DELAY));
<a name="234" href="#234">234</a>         addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(
<a name="235" href="#235">235</a>                 ATTR_PREFERENCE_EMBED_HOPS,
<a name="236" href="#236">236</a>                 <span class="string">"Number of embedded (or redirected) hops up to which "</span>
<a name="237" href="#237">237</a>                 + <span class="string">"a URI has higher priority scheduling. For example, if set "</span>
<a name="238" href="#238">238</a>                 + <span class="string">"to 1 (the default), items such as inline images (1-hop "</span>
<a name="239" href="#239">239</a>                 + <span class="string">"embedded resources) will be scheduled ahead of all regular "</span>
<a name="240" href="#240">240</a>                 + <span class="string">"links (or many-hop resources, like nested frames). If set to "</span>
<a name="241" href="#241">241</a>                 + <span class="string">"zero, no preferencing will occur, and embeds/redirects are "</span>
<a name="242" href="#242">242</a>                 + <span class="string">"scheduled the same as regular links."</span>,
<a name="243" href="#243">243</a>                 DEFAULT_PREFERENCE_EMBED_HOPS));
<a name="244" href="#244">244</a>         <a href="../../../../org/archive/crawler/settings/Type.html">Type</a> t;
<a name="245" href="#245">245</a>         t = addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(
<a name="246" href="#246">246</a>                 ATTR_MAX_OVERALL_BANDWIDTH_USAGE,
<a name="247" href="#247">247</a>                 <span class="string">"The maximum average bandwidth the crawler is allowed to use. "</span>
<a name="248" href="#248">248</a>                 + <span class="string">"The actual read speed is not affected by this setting, it only "</span>
<a name="249" href="#249">249</a>                 + <span class="string">"holds back new URIs from being processed when the bandwidth "</span>
<a name="250" href="#250">250</a>                 + <span class="string">"usage has been to high. 0 means no bandwidth limitation."</span>,
<a name="251" href="#251">251</a>                 DEFAULT_MAX_OVERALL_BANDWIDTH_USAGE));
<a name="252" href="#252">252</a>         t.setOverrideable(false);
<a name="253" href="#253">253</a>         t = addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(
<a name="254" href="#254">254</a>                 ATTR_MAX_HOST_BANDWIDTH_USAGE,
<a name="255" href="#255">255</a>                 <span class="string">"The maximum average bandwidth the crawler is allowed to use per "</span>
<a name="256" href="#256">256</a>                 + <span class="string">"host. The actual read speed is not affected by this setting, "</span>
<a name="257" href="#257">257</a>                 + <span class="string">"it only holds back new URIs from being processed when the "</span>
<a name="258" href="#258">258</a>                 + <span class="string">"bandwidth usage has been to high. 0 means no bandwidth "</span>
<a name="259" href="#259">259</a>                 + <span class="string">"limitation."</span>, DEFAULT_MAX_HOST_BANDWIDTH_USAGE));
<a name="260" href="#260">260</a>         t.setExpertSetting(<strong>true</strong>);
<a name="261" href="#261">261</a> 
<a name="262" href="#262">262</a>         <em class="comment">// Read the list of permissible choices from heritrix.properties.</em>
<a name="263" href="#263">263</a>         <em class="comment">// Its a list of space- or comma-separated values.</em>
<a name="264" href="#264">264</a>         String queueStr = System.getProperty(AbstractFrontier.<strong>class</strong>.getName() +
<a name="265" href="#265">265</a>                 <span class="string">"."</span> + ATTR_QUEUE_ASSIGNMENT_POLICY,
<a name="266" href="#266">266</a>                 HostnameQueueAssignmentPolicy.<strong>class</strong>.getName() + <span class="string">" "</span> +
<a name="267" href="#267">267</a>                 IPQueueAssignmentPolicy.<strong>class</strong>.getName() + <span class="string">" "</span> +
<a name="268" href="#268">268</a>                 BucketQueueAssignmentPolicy.<strong>class</strong>.getName() + <span class="string">" "</span> +
<a name="269" href="#269">269</a>                 SurtAuthorityQueueAssignmentPolicy.<strong>class</strong>.getName());
<a name="270" href="#270">270</a>         Pattern p = Pattern.compile(<span class="string">"&#47;&#47;s*,&#47;&#47;s*|&#47;&#47;s+"</span>);
<a name="271" href="#271">271</a>         String [] queues = p.split(queueStr);
<a name="272" href="#272">272</a>         <strong>if</strong> (queues.length &lt;= 0) {
<a name="273" href="#273">273</a>             <strong>throw</strong> <strong>new</strong> RuntimeException(<span class="string">"Failed parse of "</span> +