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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>AdaptiveRevisitHostQueue xref</title><link type="text/css" rel="stylesheet" href="../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../apidocs/org/archive/crawler/frontier/AdaptiveRevisitHostQueue.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*<em class="comment"> AdaptiveRevisitHostQueue</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 13, 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 Kristinn Sigur?sson.</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.IOException;<a name="26" href="#26">26</a> <strong>import</strong> java.util.logging.Level;<a name="27" href="#27">27</a> <strong>import</strong> java.util.logging.Logger;<a name="28" href="#28">28</a> <a name="29" href="#29">29</a> <strong>import</strong> org.archive.crawler.datamodel.CandidateURI;<a name="30" href="#30">30</a> <strong>import</strong> org.archive.crawler.datamodel.CrawlSubstats;<a name="31" href="#31">31</a> <strong>import</strong> org.archive.crawler.datamodel.CrawlURI;<a name="32" href="#32">32</a> <strong>import</strong> org.archive.crawler.framework.Frontier.FrontierGroup;<a name="33" href="#33">33</a> <strong>import</strong> org.archive.util.ArchiveUtils;<a name="34" href="#34">34</a> <a name="35" href="#35">35</a> <strong>import</strong> com.sleepycat.bind.EntryBinding;<a name="36" href="#36">36</a> <strong>import</strong> com.sleepycat.bind.serial.ClassCatalog;<a name="37" href="#37">37</a> <strong>import</strong> com.sleepycat.bind.serial.SerialBinding;<a name="38" href="#38">38</a> <strong>import</strong> com.sleepycat.bind.serial.StoredClassCatalog;<a name="39" href="#39">39</a> <strong>import</strong> com.sleepycat.bind.serial.TupleSerialKeyCreator;<a name="40" href="#40">40</a> <strong>import</strong> com.sleepycat.bind.tuple.StringBinding;<a name="41" href="#41">41</a> <strong>import</strong> com.sleepycat.bind.tuple.TupleBinding;<a name="42" href="#42">42</a> <strong>import</strong> com.sleepycat.bind.tuple.TupleInput;<a name="43" href="#43">43</a> <strong>import</strong> com.sleepycat.bind.tuple.TupleOutput;<a name="44" href="#44">44</a> <strong>import</strong> com.sleepycat.je.Cursor;<a name="45" href="#45">45</a> <strong>import</strong> com.sleepycat.je.Database;<a name="46" href="#46">46</a> <strong>import</strong> com.sleepycat.je.DatabaseConfig;<a name="47" href="#47">47</a> <strong>import</strong> com.sleepycat.je.DatabaseEntry;<a name="48" href="#48">48</a> <strong>import</strong> com.sleepycat.je.DatabaseException;<a name="49" href="#49">49</a> <strong>import</strong> com.sleepycat.je.Environment;<a name="50" href="#50">50</a> <strong>import</strong> com.sleepycat.je.LockMode;<a name="51" href="#51">51</a> <strong>import</strong> com.sleepycat.je.OperationStatus;<a name="52" href="#52">52</a> <strong>import</strong> com.sleepycat.je.SecondaryConfig;<a name="53" href="#53">53</a> <strong>import</strong> com.sleepycat.je.SecondaryDatabase;<a name="54" href="#54">54</a> <a name="55" href="#55">55</a> <em>/**<em>*</em></em><a name="56" href="#56">56</a> <em> * A priority based queue of CrawlURIs. Each queue should represent</em><a name="57" href="#57">57</a> <em> * one host (although this is not enforced in this class). Items are ordered</em><a name="58" href="#58">58</a> <em> * by the scheduling directive and time of next processing (in that order) </em><a name="59" href="#59">59</a> <em> * and also indexed by the URI.</em><a name="60" href="#60">60</a> <em> * <p></em><a name="61" href="#61">61</a> <em> * The HQ does no calculations on the 'time of next processing.' It always </em><a name="62" href="#62">62</a> <em> * relies on values already set on the CrawlURI.</em><a name="63" href="#63">63</a> <em> * <p></em><a name="64" href="#64">64</a> <em> * Note: Class is not 'thread safe.' In multi threaded environment the caller</em><a name="65" href="#65">65</a> <em> * must ensure that two threads do not make overlapping calls.</em><a name="66" href="#66">66</a> <em> * <p></em><a name="67" href="#67">67</a> <em> * Any BDB DatabaseException will be converted to an IOException by public </em><a name="68" href="#68">68</a> <em> * methods. This includes preserving the original stacktrace, in favor of the</em><a name="69" href="#69">69</a> <em> * one created for the IOException, so that the true source of the exception</em><a name="70" href="#70">70</a> <em> * is not lost. </em><a name="71" href="#71">71</a> <em> *</em><a name="72" href="#72">72</a> <em> * @author Kristinn Sigurdsson</em><a name="73" href="#73">73</a> <em> */</em><a name="74" href="#74">74</a> <strong>public</strong> <strong>class</strong> <a href="../../../../org/archive/crawler/frontier/AdaptiveRevisitHostQueue.html">AdaptiveRevisitHostQueue</a><a name="75" href="#75">75</a> implements AdaptiveRevisitAttributeConstants, FrontierGroup {<a name="76" href="#76">76</a> <a name="77" href="#77">77</a> <em class="comment">// TODO: Need to be able to remove URIs, both by name and reg.expr.</em><a name="78" href="#78">78</a> <a name="79" href="#79">79</a> <em class="comment">// Constants declerations</em><a name="80" href="#80">80</a> <em>/**<em>* HQ contains no queued CrawlURIs elements. This state only occurs after </em></em><a name="81" href="#81">81</a> <em> * queue creation before the first add. After the first item is added the </em><a name="82" href="#82">82</a> <em> * state can never become empty again. */</em><a name="83" href="#83">83</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> <strong>int</strong> HQSTATE_EMPTY = 0;<a name="84" href="#84">84</a> <em>/**<em>* HQ has a <a href="../../../../org/archive/crawler/datamodel/CrawlURI.html">CrawlURI</a> ready for processing */</em></em><a name="85" href="#85">85</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> <strong>int</strong> HQSTATE_READY = 1;<a name="86" href="#86">86</a> <em>/**<em>* HQ has maximum number of CrawlURI currently being processed. This number</em></em><a name="87" href="#87">87</a> <em> * is either equal to the 'valence' (maximum number of simultanious </em><a name="88" href="#88">88</a> <em> * connections to a host) or (if smaller) the total number of CrawlURIs </em><a name="89" href="#89">89</a> <em> * in the HQ. */</em><a name="90" href="#90">90</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> <strong>int</strong> HQSTATE_BUSY = 2; <a name="91" href="#91">91</a> <em>/**<em>* HQ is in a suspended state until it can be woken back up */</em></em><a name="92" href="#92">92</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> <strong>int</strong> HQSTATE_SNOOZED = 3;<a name="93" href="#93">93</a> <a name="94" href="#94">94</a> <em class="comment">// Internal class variables</em><a name="95" href="#95">95</a> <em>/**<em>* Name of the host that this <a href="../../../../org/archive/crawler/frontier/AdaptiveRevisitHostQueue.html">AdaptiveRevisitHostQueue</a> represents */</em></em><a name="96" href="#96">96</a> <strong>final</strong> String hostName;<a name="97" href="#97">97</a> <em>/**<em>* Last known state of HQ -- ALL methods should use getState() to read</em></em><a name="98" href="#98">98</a> <em> * this value, never read it directly. */</em><a name="99" href="#99">99</a> <strong>int</strong> state;<a name="100" href="#100">100</a> <em>/**<em>* Time (in milliseconds) when the HQ will next be ready to issue a URI</em></em><a name="101" href="#101">101</a> <em> * for processing. When setting this value, methods should use the </em><a name="102" href="#102">102</a> <em> * setter method {@link #setNextReadyTime(long) setNextReadyTime()}</em><a name="103" href="#103">103</a> <em> */</em><a name="104" href="#104">104</a> <strong>long</strong> nextReadyTime;<a name="105" href="#105">105</a> <em>/**<em>* Time (in milliseconds) when each URI 'slot' becomes available again.<p></em></em><a name="106" href="#106">106</a> <em> * Any positive value larger then the current time signifies a taken slot </em><a name="107" href="#107">107</a> <em> * where the URI has completed processing but the politness wait has not</em><a name="108" href="#108">108</a> <em> * ended. <p></em><a name="109" href="#109">109</a> <em> * A zero or positive value smaller then the current time in milliseconds</em><a name="110" href="#110">110</a> <em> * signifies an empty slot.<p> </em><a name="111" href="#111">111</a> <em> * Any negative value signifies a slot for a URI that is being processed.</em><a name="112" href="#112">112</a> <em> * <p></em><a name="113" href="#113">113</a> <em> * Methods should never write directly to this, rather use the </em><a name="114" href="#114">114</a> <em> * {@link #updateWakeUpTimeSlot(long) updateWakeUpTimeSlot()} and</em><a name="115" href="#115">115</a> <em> * {@link #useWakeUpTimeSlot() useWakeUpTimeSlot()} methods as needed.</em><a name="116" href="#116">116</a> <em> */</em><a name="117" href="#117">117</a> <strong>long</strong>[] wakeUpTime;<a name="118" href="#118">118</a> <em>/**<em>* Number of simultanious connections permitted to this host. I.e. this </em></em><a name="119" href="#119">119</a> <em> * many URIs can be issued before state of HQ becomes busy until one of </em><a name="120" href="#120">120</a> <em> * them is returned via the update method. */</em><a name="121" href="#121">121</a> <strong>int</strong> valence;<a name="122" href="#122">122</a> <em>/**<em>*</em></em><a name="123" href="#123">123</a> <em> * Size of queue. That is, the number of CrawlURIs that have been added to</em><a name="124" href="#124">124</a> <em> * it, including any that are currently being processed.</em><a name="125" href="#125">125</a> <em> */</em><a name="126" href="#126">126</a> <strong>long</strong> size;<a name="127" href="#127">127</a> <em>/**<em>* Number of URIs belonging to this queue that are being processed at the</em></em><a name="128" href="#128">128</a> <em> * moment. This number will always be in the range of 0 - valence </em><a name="129" href="#129">129</a> <em> */</em><a name="130" href="#130">130</a> <strong>long</strong> inProcessing;<a name="131" href="#131">131</a> <em>/**<em>* The AdaptiveRevisitHostQueueList that contains this class. This</em></em><a name="132" href="#132">132</a> <em> * reference is </em><a name="133" href="#133">133</a> <em> * maintained to inform the owning class of changes to the sort order</em><a name="134" href="#134">134</a> <em> * value. Value may be null, in which case no notices are made.*/</em><a name="135" href="#135">135</a> <strong>private</strong> <a href="../../../../org/archive/crawler/frontier/AdaptiveRevisitQueueList.html">AdaptiveRevisitQueueList</a> owner;?? 快捷鍵說明
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