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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><meta http-equiv="content-type" content="text/html; charset=UTF-8" /><title>HashCrawlMapper xref</title><link type="text/css" rel="stylesheet" href="../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../apidocs/org/archive/crawler/processor/HashCrawlMapper.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*<em class="comment"> HashCrawlMapper</em></em><a name="2" href="#2">2</a> <em class="comment"> * </em><a name="3" href="#3">3</a> <em class="comment"> * Created on Sep 30, 2005</em><a name="4" href="#4">4</a> <em class="comment"> *</em><a name="5" href="#5">5</a> <em class="comment"> * Copyright (C) 2005 Internet Archive.</em><a name="6" href="#6">6</a> <em class="comment"> * </em><a name="7" href="#7">7</a> <em class="comment"> * This file is part of the Heritrix web crawler (crawler.archive.org).</em><a name="8" href="#8">8</a> <em class="comment"> * </em><a name="9" href="#9">9</a> <em class="comment"> * Heritrix is free software; you can redistribute it and/or modify</em><a name="10" href="#10">10</a> <em class="comment"> * it under the terms of the GNU Lesser Public License as published by</em><a name="11" href="#11">11</a> <em class="comment"> * the Free Software Foundation; either version 2.1 of the License, or</em><a name="12" href="#12">12</a> <em class="comment"> * any later version.</em><a name="13" href="#13">13</a> <em class="comment"> * </em><a name="14" href="#14">14</a> <em class="comment"> * Heritrix is distributed in the hope that it will be useful, </em><a name="15" href="#15">15</a> <em class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</em><a name="16" href="#16">16</a> <em class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</em><a name="17" href="#17">17</a> <em class="comment"> * GNU Lesser Public License for more details.</em><a name="18" href="#18">18</a> <em class="comment"> * </em><a name="19" href="#19">19</a> <em class="comment"> * You should have received a copy of the GNU Lesser Public License</em><a name="20" href="#20">20</a> <em class="comment"> * along with Heritrix; if not, write to the Free Software</em><a name="21" href="#21">21</a> <em class="comment"> * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA</em><a name="22" href="#22">22</a> <em class="comment"> */</em><a name="23" href="#23">23</a> <strong>package</strong> <a href="../../../../org/archive/crawler/processor/package-summary.html">org.archive.crawler.processor</a>;<a name="24" href="#24">24</a> <a name="25" href="#25">25</a> <strong>import</strong> java.util.regex.Matcher;<a name="26" href="#26">26</a> <a name="27" href="#27">27</a> <strong>import</strong> org.archive.crawler.datamodel.CandidateURI;<a name="28" href="#28">28</a> <strong>import</strong> org.archive.crawler.settings.SimpleType;<a name="29" href="#29">29</a> <strong>import</strong> org.archive.util.TextUtils;<a name="30" href="#30">30</a> <a name="31" href="#31">31</a> <strong>import</strong> st.ata.util.FPGenerator;<a name="32" href="#32">32</a> <a name="33" href="#33">33</a> <em>/**<em>*</em></em><a name="34" href="#34">34</a> <em> * Maps URIs to one of N crawler names by applying a hash to the</em><a name="35" href="#35">35</a> <em> * URI's (possibly-transformed) classKey. </em><a name="36" href="#36">36</a> <em> * </em><a name="37" href="#37">37</a> <em> * @author gojomo</em><a name="38" href="#38">38</a> <em> * @version $Date: 2006-09-25 20:19:54 +0000 (Mon, 25 Sep 2006) $, $Revision: 4654 $</em><a name="39" href="#39">39</a> <em> */</em><a name="40" href="#40">40</a> <strong>public</strong> <strong>class</strong> <a href="../../../../org/archive/crawler/processor/HashCrawlMapper.html">HashCrawlMapper</a> <strong>extends</strong> <a href="../../../../org/archive/crawler/processor/CrawlMapper.html">CrawlMapper</a> {<a name="41" href="#41">41</a> <strong>private</strong> <strong>static</strong> <strong>final</strong> <strong>long</strong> serialVersionUID = 1L;<a name="42" href="#42">42</a> <a name="43" href="#43">43</a> <em>/**<em>* count of crawlers */</em></em><a name="44" href="#44">44</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> String ATTR_CRAWLER_COUNT = <span class="string">"crawler-count"</span>;<a name="45" href="#45">45</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> Long DEFAULT_CRAWLER_COUNT = <strong>new</strong> Long(1);<a name="46" href="#46">46</a> <a name="47" href="#47">47</a> <em>/**<em>* regex pattern for reducing classKey */</em></em><a name="48" href="#48">48</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> String ATTR_REDUCE_PATTERN = <span class="string">"reduce-prefix-pattern"</span>;<a name="49" href="#49">49</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> String DEFAULT_REDUCE_PATTERN = <span class="string">""</span>;<a name="50" href="#50">50</a> <a name="51" href="#51">51</a> <em class="comment">// </em><em>/**<em>* replace pattern for reducing classKey */</em></em><a name="52" href="#52">52</a> <em class="comment">// public static final String ATTR_REPLACE_PATTERN = "replace-pattern";</em><a name="53" href="#53">53</a> <em class="comment">// public static final String DEFAULT_REPLACE_PATTERN = "";</em><a name="54" href="#54">54</a> <a name="55" href="#55">55</a> <strong>long</strong> bucketCount = 1;<a name="56" href="#56">56</a> String reducePattern = <strong>null</strong>;<a name="57" href="#57">57</a> <em class="comment">// String replacePattern = null;</em><a name="58" href="#58">58</a> <a name="59" href="#59">59</a> <em>/**<em>*</em></em><a name="60" href="#60">60</a> <em> * Constructor.</em><a name="61" href="#61">61</a> <em> * @param name Name of this processor.</em><a name="62" href="#62">62</a> <em> */</em><a name="63" href="#63">63</a> <strong>public</strong> <a href="../../../../org/archive/crawler/processor/HashCrawlMapper.html">HashCrawlMapper</a>(String name) {<a name="64" href="#64">64</a> <strong>super</strong>(name, <span class="string">"HashCrawlMapper. Maps URIs to a numerically named "</span> +<a name="65" href="#65">65</a> <span class="string">"crawler by hashing the URI's (possibly transfored) "</span> +<a name="66" href="#66">66</a> <span class="string">"classKey to one of the specified number of buckets."</span>);<a name="67" href="#67">67</a> addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_CRAWLER_COUNT,<a name="68" href="#68">68</a> <span class="string">"Number of crawlers among which to split up the URIs. "</span> +<a name="69" href="#69">69</a> <span class="string">"Their names are assumed to be 0..N-1."</span>,<a name="70" href="#70">70</a> DEFAULT_CRAWLER_COUNT));<a name="71" href="#71">71</a> addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_REDUCE_PATTERN,<a name="72" href="#72">72</a> <span class="string">"A regex pattern to apply to the classKey, using "</span> +<a name="73" href="#73">73</a> <span class="string">"the first match as the mapping key. If empty (the"</span> +<a name="74" href="#74">74</a> <span class="string">"default), use the full classKey."</span>,<a name="75" href="#75">75</a> DEFAULT_REDUCE_PATTERN));<a name="76" href="#76">76</a> }<a name="77" href="#77">77</a> <a name="78" href="#78">78</a> <em>/**<em>*</em></em><a name="79" href="#79">79</a> <em> * Look up the crawler node name to which the given CandidateURI </em><a name="80" href="#80">80</a> <em> * should be mapped. </em><a name="81" href="#81">81</a> <em> * </em><a name="82" href="#82">82</a> <em> * @param cauri CandidateURI to consider</em><a name="83" href="#83">83</a> <em> * @return String node name which should handle URI</em><a name="84" href="#84">84</a> <em> */</em><a name="85" href="#85">85</a> <strong>protected</strong> String map(<a href="../../../../org/archive/crawler/datamodel/CandidateURI.html">CandidateURI</a> cauri) {<a name="86" href="#86">86</a> <em class="comment">// get classKey, via frontier to generate if necessary</em><a name="87" href="#87">87</a> String key = getController().getFrontier().getClassKey(cauri);<a name="88" href="#88">88</a> <strong>return</strong> mapString(key, reducePattern, bucketCount); <a name="89" href="#89">89</a> }<a name="90" href="#90">90</a> <a name="91" href="#91">91</a> <strong>protected</strong> <strong>void</strong> initialTasks() {<a name="92" href="#92">92</a> <strong>super</strong>.initialTasks();<a name="93" href="#93">93</a> bucketCount = (Long) getUncheckedAttribute(<strong>null</strong>,ATTR_CRAWLER_COUNT);<a name="94" href="#94">94</a> kickUpdate();<a name="95" href="#95">95</a> }<a name="96" href="#96">96</a> <a name="97" href="#97">97</a> @Override<a name="98" href="#98">98</a> <strong>public</strong> <strong>void</strong> kickUpdate() {<a name="99" href="#99">99</a> <strong>super</strong>.kickUpdate();<a name="100" href="#100">100</a> reducePattern = (String)getUncheckedAttribute(<strong>null</strong>, ATTR_REDUCE_PATTERN);<a name="101" href="#101">101</a> }<a name="102" href="#102">102</a> <a name="103" href="#103">103</a> <strong>public</strong> <strong>static</strong> String mapString(String key, String reducePattern, <strong>long</strong> bucketCount) {<a name="104" href="#104">104</a> <strong>if</strong>(reducePattern!=<strong>null</strong> && reducePattern.length()>0) {<a name="105" href="#105">105</a> Matcher matcher = TextUtils.getMatcher(reducePattern,key);<a name="106" href="#106">106</a> <strong>if</strong>(matcher.find()) {<a name="107" href="#107">107</a> key = matcher.group();<a name="108" href="#108">108</a> }<a name="109" href="#109">109</a> TextUtils.recycleMatcher(matcher);<a name="110" href="#110">110</a> }<a name="111" href="#111">111</a> <strong>long</strong> fp = FPGenerator.std64.fp(key);<a name="112" href="#112">112</a> <strong>long</strong> bucket = fp % bucketCount;<a name="113" href="#113">113</a> <strong>return</strong> Long.toString(bucket >= 0 ? bucket : -bucket);<a name="114" href="#114">114</a> }<a name="115" href="#115">115</a> }</pre><hr/><div id="footer">This page was automatically generated by <a href="http://maven.apache.org/">Maven</a></div></body></html>?? 快捷鍵說明
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