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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>BdbMultipleWorkQueues xref</title><link type="text/css" rel="stylesheet" href="../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../apidocs/org/archive/crawler/frontier/BdbMultipleWorkQueues.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*<em class="comment"> BdbMultipleWorkQueues</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 Dec 24, 2004</em><a name="4" href="#4">4</a> <em class="comment"> *</em><a name="5" href="#5">5</a> <em class="comment"> * Copyright (C) 2004 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/frontier/package-summary.html">org.archive.crawler.frontier</a>;<a name="24" href="#24">24</a> <a name="25" href="#25">25</a> <strong>import</strong> java.io.UnsupportedEncodingException;<a name="26" href="#26">26</a> <strong>import</strong> java.math.BigInteger;<a name="27" href="#27">27</a> <strong>import</strong> java.util.ArrayList;<a name="28" href="#28">28</a> <strong>import</strong> java.util.List;<a name="29" href="#29">29</a> <strong>import</strong> java.util.logging.Level;<a name="30" href="#30">30</a> <strong>import</strong> java.util.logging.Logger;<a name="31" href="#31">31</a> <strong>import</strong> java.util.regex.Pattern;<a name="32" href="#32">32</a> <a name="33" href="#33">33</a> <strong>import</strong> org.archive.crawler.datamodel.CrawlURI;<a name="34" href="#34">34</a> <strong>import</strong> org.archive.crawler.framework.FrontierMarker;<a name="35" href="#35">35</a> <strong>import</strong> org.archive.util.ArchiveUtils;<a name="36" href="#36">36</a> <a name="37" href="#37">37</a> <strong>import</strong> com.sleepycat.bind.serial.StoredClassCatalog;<a name="38" href="#38">38</a> <strong>import</strong> com.sleepycat.je.Cursor;<a name="39" href="#39">39</a> <strong>import</strong> com.sleepycat.je.Database;<a name="40" href="#40">40</a> <strong>import</strong> com.sleepycat.je.DatabaseConfig;<a name="41" href="#41">41</a> <strong>import</strong> com.sleepycat.je.DatabaseEntry;<a name="42" href="#42">42</a> <strong>import</strong> com.sleepycat.je.DatabaseException;<a name="43" href="#43">43</a> <strong>import</strong> com.sleepycat.je.DatabaseNotFoundException;<a name="44" href="#44">44</a> <strong>import</strong> com.sleepycat.je.Environment;<a name="45" href="#45">45</a> <strong>import</strong> com.sleepycat.je.OperationStatus;<a name="46" href="#46">46</a> <strong>import</strong> com.sleepycat.util.RuntimeExceptionWrapper;<a name="47" href="#47">47</a> <a name="48" href="#48">48</a> <a name="49" href="#49">49</a> <em>/**<em>*</em></em><a name="50" href="#50">50</a> <em> * A BerkeleyDB-database-backed structure for holding ordered</em><a name="51" href="#51">51</a> <em> * groupings of CrawlURIs. Reading the groupings from specific</em><a name="52" href="#52">52</a> <em> * per-grouping (per-classKey/per-Host) starting points allows</em><a name="53" href="#53">53</a> <em> * this to act as a collection of independent queues. </em><a name="54" href="#54">54</a> <em> * </em><a name="55" href="#55">55</a> <em> * <p>For how the bdb keys are made, see {@link #calculateInsertKey(CrawlURI)}.</em><a name="56" href="#56">56</a> <em> * </em><a name="57" href="#57">57</a> <em> * <p>TODO: refactor, improve naming.</em><a name="58" href="#58">58</a> <em> * </em><a name="59" href="#59">59</a> <em> * @author gojomo</em><a name="60" href="#60">60</a> <em> */</em><a name="61" href="#61">61</a> <strong>public</strong> <strong>class</strong> <a href="../../../../org/archive/crawler/frontier/BdbMultipleWorkQueues.html">BdbMultipleWorkQueues</a> {<a name="62" href="#62">62</a> <strong>private</strong> <strong>static</strong> <strong>final</strong> <strong>long</strong> serialVersionUID = <a href="../../../../org/archive/util/ArchiveUtils.html">ArchiveUtils</a><a name="63" href="#63">63</a> .<strong>class</strong>nameBasedUID(BdbMultipleWorkQueues.<strong>class</strong>, 1);<a name="64" href="#64">64</a> <a name="65" href="#65">65</a> <strong>private</strong> <strong>static</strong> <strong>final</strong> Logger LOGGER =<a name="66" href="#66">66</a> Logger.getLogger(BdbMultipleWorkQueues.<strong>class</strong>.getName());<a name="67" href="#67">67</a> <a name="68" href="#68">68</a> <em>/**<em>* Database holding all pending URIs, grouped in virtual queues */</em></em><a name="69" href="#69">69</a> <strong>private</strong> Database pendingUrisDB = <strong>null</strong>;<a name="70" href="#70">70</a> <a name="71" href="#71">71</a> <em>/**<em>* Supporting bdb serialization of CrawlURIs */</em></em><a name="72" href="#72">72</a> <strong>private</strong> <a href="../../../../org/archive/crawler/frontier/RecyclingSerialBinding.html">RecyclingSerialBinding</a> crawlUriBinding;<a name="73" href="#73">73</a> <a name="74" href="#74">74</a> <em>/**<em>*</em></em><a name="75" href="#75">75</a> <em> * Create the multi queue in the given environment. </em><a name="76" href="#76">76</a> <em> * </em><a name="77" href="#77">77</a> <em> * @param env bdb environment to use</em><a name="78" href="#78">78</a> <em> * @param classCatalog Class catalog to use.</em><a name="79" href="#79">79</a> <em> * @param recycle True if we are to reuse db content if any.</em><a name="80" href="#80">80</a> <em> * @throws DatabaseException</em><a name="81" href="#81">81</a> <em> */</em><a name="82" href="#82">82</a> <strong>public</strong> <a href="../../../../org/archive/crawler/frontier/BdbMultipleWorkQueues.html">BdbMultipleWorkQueues</a>(Environment env,<a name="83" href="#83">83</a> StoredClassCatalog classCatalog, <strong>final</strong> <strong>boolean</strong> recycle)<a name="84" href="#84">84</a> throws DatabaseException {<a name="85" href="#85">85</a> <em class="comment">// Open the database. Create it if it does not already exist. </em><a name="86" href="#86">86</a> DatabaseConfig dbConfig = <strong>new</strong> DatabaseConfig();<a name="87" href="#87">87</a> dbConfig.setAllowCreate(<strong>true</strong>);<a name="88" href="#88">88</a> <strong>if</strong> (!recycle) {<a name="89" href="#89">89</a> <strong>try</strong> {<a name="90" href="#90">90</a> env.truncateDatabase(<strong>null</strong>, <span class="string">"pending"</span>, false);<a name="91" href="#91">91</a> } <strong>catch</strong> (DatabaseNotFoundException e) {<a name="92" href="#92">92</a> <em class="comment">// Ignored</em><a name="93" href="#93">93</a> }<a name="94" href="#94">94</a> }<a name="95" href="#95">95</a> <em class="comment">// Make database deferred write: URLs that are added then removed </em><a name="96" href="#96">96</a> <em class="comment">// before a page-out is required need never cause disk IO.</em><a name="97" href="#97">97</a> dbConfig.setDeferredWrite(<strong>true</strong>);<a name="98" href="#98">98</a> <a name="99" href="#99">99</a> <strong>this</strong>.pendingUrisDB = env.openDatabase(<strong>null</strong>, <span class="string">"pending"</span>, dbConfig);<a name="100" href="#100">100</a> crawlUriBinding =<a name="101" href="#101">101</a> <strong>new</strong> <a href="../../../../org/archive/crawler/frontier/RecyclingSerialBinding.html">RecyclingSerialBinding</a>(<strong>class</strong>Catalog, CrawlURI.<strong>class</strong>);<a name="102" href="#102">102</a> }<a name="103" href="#103">103</a> <a name="104" href="#104">104</a> <em>/**<em>*</em></em><a name="105" href="#105">105</a> <em> * Delete all CrawlURIs matching the given expression.</em><a name="106" href="#106">106</a> <em> * </em><a name="107" href="#107">107</a> <em> * @param match</em><a name="108" href="#108">108</a> <em> * @param queue</em><a name="109" href="#109">109</a> <em> * @param headKey</em><a name="110" href="#110">110</a> <em> * @return count of deleted items</em><a name="111" href="#111">111</a> <em> * @throws DatabaseException</em><a name="112" href="#112">112</a> <em> * @throws DatabaseException</em><a name="113" href="#113">113</a> <em> */</em><a name="114" href="#114">114</a> <strong>public</strong> <strong>long</strong> deleteMatchingFromQueue(String match, String queue,<a name="115" href="#115">115</a> DatabaseEntry headKey) throws DatabaseException {<a name="116" href="#116">116</a> <strong>long</strong> deletedCount = 0;<a name="117" href="#117">117</a> Pattern pattern = Pattern.compile(match);<a name="118" href="#118">118</a> DatabaseEntry key = headKey;<a name="119" href="#119">119</a> DatabaseEntry value = <strong>new</strong> DatabaseEntry();<a name="120" href="#120">120</a> Cursor cursor = <strong>null</strong>;<a name="121" href="#121">121</a> <strong>try</strong> {<a name="122" href="#122">122</a> cursor = pendingUrisDB.openCursor(<strong>null</strong>, <strong>null</strong>);<a name="123" href="#123">123</a> OperationStatus result = cursor.getSearchKeyRange(headKey,<a name="124" href="#124">124</a> value, <strong>null</strong>);<a name="125" href="#125">125</a> <a name="126" href="#126">126</a> <strong>while</strong> (result == OperationStatus.SUCCESS) {<a name="127" href="#127">127</a> <strong>if</strong>(value.getData().length>0) {<a name="128" href="#128">128</a> <a href="../../../../org/archive/crawler/datamodel/CrawlURI.html">CrawlURI</a> curi = (CrawlURI) crawlUriBinding<a name="129" href="#129">129</a> .entryToObject(value);<a name="130" href="#130">130</a> <strong>if</strong> (!curi.getClassKey().equals(queue)) {<a name="131" href="#131">131</a> <em class="comment">// rolled into next queue; finished with this queue</em><a name="132" href="#132">132</a> <strong>break</strong>;<a name="133" href="#133">133</a> }<a name="134" href="#134">134</a> <strong>if</strong> (pattern.matcher(curi.toString()).matches()) {<a name="135" href="#135">135</a> cursor.delete();<a name="136" href="#136">136</a> deletedCount++;?? 快捷鍵說明
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