| <!DOCTYPE html> |
| <!--[if IE]><![endif]--> |
| <html> |
| |
| <head> |
| <meta charset="utf-8"> |
| <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> |
| <title>Interface ICollector |
| | Apache Lucene.NET 4.8.0-beta00011 Documentation </title> |
| <meta name="viewport" content="width=device-width"> |
| <meta name="title" content="Interface ICollector |
| | Apache Lucene.NET 4.8.0-beta00011 Documentation "> |
| <meta name="generator" content="docfx 2.56.0.0"> |
| |
| <link rel="shortcut icon" href="https://lucenenet.apache.org/docs/4.8.0-beta00009/logo/favicon.ico"> |
| <link rel="stylesheet" href="https://lucenenet.apache.org/docs/4.8.0-beta00009/styles/docfx.vendor.css"> |
| <link rel="stylesheet" href="https://lucenenet.apache.org/docs/4.8.0-beta00009/styles/docfx.css"> |
| <link rel="stylesheet" href="https://lucenenet.apache.org/docs/4.8.0-beta00009/styles/main.css"> |
| <meta property="docfx:navrel" content="toc.html"> |
| <meta property="docfx:tocrel" content="core/toc.html"> |
| |
| <meta property="docfx:rel" content="https://lucenenet.apache.org/docs/4.8.0-beta00009/"> |
| |
| </head> |
| <body data-spy="scroll" data-target="#affix" data-offset="120"> |
| <div id="wrapper"> |
| <header> |
| |
| <nav id="autocollapse" class="navbar ng-scope" role="navigation"> |
| <div class="container"> |
| <div class="navbar-header"> |
| <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#navbar"> |
| <span class="sr-only">Toggle navigation</span> |
| <span class="icon-bar"></span> |
| <span class="icon-bar"></span> |
| <span class="icon-bar"></span> |
| </button> |
| |
| <a class="navbar-brand" href="/"> |
| <img id="logo" class="svg" src="https://lucenenet.apache.org/docs/4.8.0-beta00009/logo/lucene-net-color.png" alt=""> |
| </a> |
| </div> |
| <div class="collapse navbar-collapse" id="navbar"> |
| <form class="navbar-form navbar-right" role="search" id="search"> |
| <div class="form-group"> |
| <input type="text" class="form-control" id="search-query" placeholder="Search" autocomplete="off"> |
| </div> |
| </form> |
| </div> |
| </div> |
| </nav> |
| |
| <div class="subnav navbar navbar-default"> |
| <div class="container hide-when-search"> |
| <ul class="level0 breadcrumb"> |
| <li> |
| <a href="https://lucenenet.apache.org/docs/4.8.0-beta00009/">API</a> |
| <span id="breadcrumb"> |
| <ul class="breadcrumb"> |
| <li></li> |
| </ul> |
| </span> |
| </li> |
| </ul> |
| </div> |
| </div> |
| </header> |
| <div class="container body-content"> |
| |
| <div id="search-results"> |
| <div class="search-list"></div> |
| <div class="sr-items"> |
| <p><i class="glyphicon glyphicon-refresh index-loading"></i></p> |
| </div> |
| <ul id="pagination"></ul> |
| </div> |
| </div> |
| <div role="main" class="container body-content hide-when-search"> |
| |
| <div class="sidenav hide-when-search"> |
| <a class="btn toc-toggle collapse" data-toggle="collapse" href="#sidetoggle" aria-expanded="false" aria-controls="sidetoggle">Show / Hide Table of Contents</a> |
| <div class="sidetoggle collapse" id="sidetoggle"> |
| <div id="sidetoc"></div> |
| </div> |
| </div> |
| <div class="article row grid-right"> |
| <div class="col-md-10"> |
| <article class="content wrap" id="_content" data-uid="Lucene.Net.Search.ICollector"> |
| |
| |
| <h1 id="Lucene_Net_Search_ICollector" data-uid="Lucene.Net.Search.ICollector" class="text-break">Interface ICollector |
| </h1> |
| <div class="markdown level0 summary"><p>Expert: Collectors are primarily meant to be used to |
| gather raw results from a search, and implement sorting |
| or custom result filtering, collation, etc. </p> |
| |
| <p>Lucene's core collectors are derived from Collector. |
| Likely your application can use one of these classes, or |
| subclass <a class="xref" href="Lucene.Net.Search.TopDocsCollector-1.html">TopDocsCollector<T></a>, instead of |
| implementing <a class="xref" href="Lucene.Net.Search.ICollector.html">ICollector</a> directly: |
| |
| <ul><li><a class="xref" href="Lucene.Net.Search.TopDocsCollector-1.html">TopDocsCollector<T></a> is an abstract base class |
| that assumes you will retrieve the top N docs, |
| according to some criteria, after collection is |
| done. </li><li><a class="xref" href="Lucene.Net.Search.TopScoreDocCollector.html">TopScoreDocCollector</a> is a concrete subclass |
| <a class="xref" href="Lucene.Net.Search.TopDocsCollector-1.html">TopDocsCollector<T></a> and sorts according to score + |
| docID. This is used internally by the |
| <a class="xref" href="Lucene.Net.Search.IndexSearcher.html">IndexSearcher</a> search methods that do not take an |
| explicit <a class="xref" href="Lucene.Net.Search.Sort.html">Sort</a>. It is likely the most frequently |
| used collector.</li><li><a class="xref" href="Lucene.Net.Search.TopFieldCollector.html">TopFieldCollector</a> subclasses |
| <a class="xref" href="Lucene.Net.Search.TopDocsCollector-1.html">TopDocsCollector<T></a> and sorts according to a specified |
| <a class="xref" href="Lucene.Net.Search.Sort.html">Sort</a> object (sort by field). This is used |
| internally by the <a class="xref" href="Lucene.Net.Search.IndexSearcher.html">IndexSearcher</a> search methods |
| that take an explicit <a class="xref" href="Lucene.Net.Search.Sort.html">Sort</a>.</li><li><a class="xref" href="Lucene.Net.Search.TimeLimitingCollector.html">TimeLimitingCollector</a>, which wraps any other |
| Collector and aborts the search if it's taken too much |
| time.</li><li><a class="xref" href="Lucene.Net.Search.PositiveScoresOnlyCollector.html">PositiveScoresOnlyCollector</a> wraps any other |
| <a class="xref" href="Lucene.Net.Search.ICollector.html">ICollector</a> and prevents collection of hits whose score |
| is <= 0.0</li></ul> |
| </p> |
| |
| <p><a class="xref" href="Lucene.Net.Search.ICollector.html">ICollector</a> decouples the score from the collected doc: |
| the score computation is skipped entirely if it's not |
| needed. Collectors that do need the score should |
| implement the <a class="xref" href="Lucene.Net.Search.ICollector.html#Lucene_Net_Search_ICollector_SetScorer_Lucene_Net_Search_Scorer_">SetScorer(Scorer)</a> method, to hold onto the |
| passed <a class="xref" href="Lucene.Net.Search.Scorer.html">Scorer</a> instance, and call |
| <a class="xref" href="Lucene.Net.Search.Scorer.html#Lucene_Net_Search_Scorer_GetScore">GetScore()</a> within the collect method to compute the |
| current hit's score. If your collector may request the |
| score for a single hit multiple times, you should use |
| <a class="xref" href="Lucene.Net.Search.ScoreCachingWrappingScorer.html">ScoreCachingWrappingScorer</a>. </p> |
| |
| <p><strong>NOTE:</strong> The doc that is passed to the collect |
| method is relative to the current reader. If your |
| collector needs to resolve this to the docID space of the |
| Multi*Reader, you must re-base it by recording the |
| docBase from the most recent <a class="xref" href="Lucene.Net.Search.ICollector.html#Lucene_Net_Search_ICollector_SetNextReader_Lucene_Net_Index_AtomicReaderContext_">SetNextReader(AtomicReaderContext)</a> call. Here's |
| a simple example showing how to collect docIDs into an |
| <a class="xref" href="Lucene.Net.Util.OpenBitSet.html">OpenBitSet</a>:</p> |
| |
| <pre><code>private class MySearchCollector : ICollector |
| { |
| private readonly OpenBitSet bits; |
| private int docBase; |
| |
| public MySearchCollector(OpenBitSet bits) |
| { |
| if (bits == null) throw new ArgumentNullException("bits"); |
| this.bits = bits; |
| } |
| |
| // ignore scorer |
| public void SetScorer(Scorer scorer) |
| { |
| } |
| |
| // accept docs out of order (for a BitSet it doesn't matter) |
| public bool AcceptDocsOutOfOrder |
| { |
| get { return true; } |
| } |
| |
| public void Collect(int doc) |
| { |
| bits.Set(doc + docBase); |
| } |
| |
| public void SetNextReader(AtomicReaderContext context) |
| { |
| this.docBase = context.DocBase; |
| } |
| } |
| |
| IndexSearcher searcher = new IndexSearcher(indexReader); |
| OpenBitSet bits = new OpenBitSet(indexReader.MaxDoc); |
| searcher.Search(query, new MySearchCollector(bits));</code></pre> |
| |
| <p>Not all collectors will need to rebase the docID. For |
| example, a collector that simply counts the total number |
| of hits would skip it.</p> |
| |
| <p><strong>NOTE:</strong> Prior to 2.9, Lucene silently filtered |
| out hits with score <= 0. As of 2.9, the core <a class="xref" href="Lucene.Net.Search.ICollector.html">ICollector</a>s |
| no longer do that. It's very unusual to have such hits |
| (a negative query boost, or function query returning |
| negative custom scores, could cause it to happen). If |
| you need that behavior, use |
| <a class="xref" href="Lucene.Net.Search.PositiveScoresOnlyCollector.html">PositiveScoresOnlyCollector</a>.</p> |
| |
| <div class="lucene-block lucene-experimental">This is a Lucene.NET EXPERIMENTAL API, use at your own risk</div><p><p> |
| @since 2.9</p> |
| </div> |
| <div class="markdown level0 conceptual"></div> |
| <h6><strong>Namespace</strong>: <a class="xref" href="Lucene.Net.Search.html">Lucene.Net.Search</a></h6> |
| <h6><strong>Assembly</strong>: Lucene.Net.dll</h6> |
| <h5 id="Lucene_Net_Search_ICollector_syntax">Syntax</h5> |
| <div class="codewrapper"> |
| <pre><code class="lang-csharp hljs">public interface ICollector</code></pre> |
| </div> |
| <h3 id="properties">Properties |
| </h3> |
| <span class="small pull-right mobile-hide"> |
| <span class="divider">|</span> |
| <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00011/websites/apidocs/apiSpec/new?filename=Lucene_Net_Search_ICollector_AcceptsDocsOutOfOrder.md&value=---%0Auid%3A%20Lucene.Net.Search.ICollector.AcceptsDocsOutOfOrder%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a> |
| </span> |
| <span class="small pull-right mobile-hide"> |
| <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00011/src/Lucene.Net/Search/Collector.cs/#L189">View Source</a> |
| </span> |
| <a id="Lucene_Net_Search_ICollector_AcceptsDocsOutOfOrder_" data-uid="Lucene.Net.Search.ICollector.AcceptsDocsOutOfOrder*"></a> |
| <h4 id="Lucene_Net_Search_ICollector_AcceptsDocsOutOfOrder" data-uid="Lucene.Net.Search.ICollector.AcceptsDocsOutOfOrder">AcceptsDocsOutOfOrder</h4> |
| <div class="markdown level1 summary"><p>Return <code>true</code> if this collector does not |
| require the matching docIDs to be delivered in int sort |
| order (smallest to largest) to <a class="xref" href="Lucene.Net.Search.ICollector.html#Lucene_Net_Search_ICollector_Collect_System_Int32_">Collect(Int32)</a>.</p> |
| <p> Most Lucene Query implementations will visit |
| matching docIDs in order. However, some queries |
| (currently limited to certain cases of <a class="xref" href="Lucene.Net.Search.BooleanQuery.html">BooleanQuery</a>) |
| can achieve faster searching if the |
| <a class="xref" href="Lucene.Net.Search.ICollector.html">ICollector</a> allows them to deliver the |
| docIDs out of order.</p> |
| |
| <p> Many collectors don't mind getting docIDs out of |
| order, so it's important to return <code>true</code> |
| here.</p> |
| </div> |
| <div class="markdown level1 conceptual"></div> |
| <h5 class="decalaration">Declaration</h5> |
| <div class="codewrapper"> |
| <pre><code class="lang-csharp hljs">bool AcceptsDocsOutOfOrder { get; }</code></pre> |
| </div> |
| <h5 class="propertyValue">Property Value</h5> |
| <table class="table table-bordered table-striped table-condensed"> |
| <thead> |
| <tr> |
| <th>Type</th> |
| <th>Description</th> |
| </tr> |
| </thead> |
| <tbody> |
| <tr> |
| <td><span class="xref">System.Boolean</span></td> |
| <td></td> |
| </tr> |
| </tbody> |
| </table> |
| <h3 id="methods">Methods |
| </h3> |
| <span class="small pull-right mobile-hide"> |
| <span class="divider">|</span> |
| <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00011/websites/apidocs/apiSpec/new?filename=Lucene_Net_Search_ICollector_Collect_System_Int32_.md&value=---%0Auid%3A%20Lucene.Net.Search.ICollector.Collect(System.Int32)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a> |
| </span> |
| <span class="small pull-right mobile-hide"> |
| <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00011/src/Lucene.Net/Search/Collector.cs/#L161">View Source</a> |
| </span> |
| <a id="Lucene_Net_Search_ICollector_Collect_" data-uid="Lucene.Net.Search.ICollector.Collect*"></a> |
| <h4 id="Lucene_Net_Search_ICollector_Collect_System_Int32_" data-uid="Lucene.Net.Search.ICollector.Collect(System.Int32)">Collect(Int32)</h4> |
| <div class="markdown level1 summary"><p>Called once for every document matching a query, with the unbased document |
| number. |
| <p>Note: The collection of the current segment can be terminated by throwing |
| a <a class="xref" href="Lucene.Net.Search.CollectionTerminatedException.html">CollectionTerminatedException</a>. In this case, the last docs of the |
| current <a class="xref" href="Lucene.Net.Index.AtomicReaderContext.html">AtomicReaderContext</a> will be skipped and <a class="xref" href="Lucene.Net.Search.IndexSearcher.html">IndexSearcher</a> |
| will swallow the exception and continue collection with the next leaf. |
| <p> |
| Note: this is called in an inner search loop. For good search performance, |
| implementations of this method should not call <a class="xref" href="Lucene.Net.Search.IndexSearcher.html#Lucene_Net_Search_IndexSearcher_Doc_System_Int32_">Doc(Int32)</a> or |
| <a class="xref" href="Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_Document_System_Int32_">Document(Int32)</a> on every hit. |
| Doing so can slow searches by an order of magnitude or more.</p> |
| </div> |
| <div class="markdown level1 conceptual"></div> |
| <h5 class="decalaration">Declaration</h5> |
| <div class="codewrapper"> |
| <pre><code class="lang-csharp hljs">void Collect(int doc)</code></pre> |
| </div> |
| <h5 class="parameters">Parameters</h5> |
| <table class="table table-bordered table-striped table-condensed"> |
| <thead> |
| <tr> |
| <th>Type</th> |
| <th>Name</th> |
| <th>Description</th> |
| </tr> |
| </thead> |
| <tbody> |
| <tr> |
| <td><span class="xref">System.Int32</span></td> |
| <td><span class="parametername">doc</span></td> |
| <td></td> |
| </tr> |
| </tbody> |
| </table> |
| <span class="small pull-right mobile-hide"> |
| <span class="divider">|</span> |
| <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00011/websites/apidocs/apiSpec/new?filename=Lucene_Net_Search_ICollector_SetNextReader_Lucene_Net_Index_AtomicReaderContext_.md&value=---%0Auid%3A%20Lucene.Net.Search.ICollector.SetNextReader(Lucene.Net.Index.AtomicReaderContext)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a> |
| </span> |
| <span class="small pull-right mobile-hide"> |
| <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00011/src/Lucene.Net/Search/Collector.cs/#L171">View Source</a> |
| </span> |
| <a id="Lucene_Net_Search_ICollector_SetNextReader_" data-uid="Lucene.Net.Search.ICollector.SetNextReader*"></a> |
| <h4 id="Lucene_Net_Search_ICollector_SetNextReader_Lucene_Net_Index_AtomicReaderContext_" data-uid="Lucene.Net.Search.ICollector.SetNextReader(Lucene.Net.Index.AtomicReaderContext)">SetNextReader(AtomicReaderContext)</h4> |
| <div class="markdown level1 summary"><p>Called before collecting from each <a class="xref" href="Lucene.Net.Index.AtomicReaderContext.html">AtomicReaderContext</a>. All doc ids in |
| <a class="xref" href="Lucene.Net.Search.ICollector.html#Lucene_Net_Search_ICollector_Collect_System_Int32_">Collect(Int32)</a> will correspond to <a class="xref" href="Lucene.Net.Index.IndexReaderContext.html#Lucene_Net_Index_IndexReaderContext_Reader">Reader</a>. |
| <p> |
| Add <a class="xref" href="Lucene.Net.Index.AtomicReaderContext.html#Lucene_Net_Index_AtomicReaderContext_DocBase">DocBase</a> to the current <a class="xref" href="Lucene.Net.Index.IndexReaderContext.html#Lucene_Net_Index_IndexReaderContext_Reader">Reader</a>'s |
| internal document id to re-base ids in <a class="xref" href="Lucene.Net.Search.ICollector.html#Lucene_Net_Search_ICollector_Collect_System_Int32_">Collect(Int32)</a>.</p> |
| </div> |
| <div class="markdown level1 conceptual"></div> |
| <h5 class="decalaration">Declaration</h5> |
| <div class="codewrapper"> |
| <pre><code class="lang-csharp hljs">void SetNextReader(AtomicReaderContext context)</code></pre> |
| </div> |
| <h5 class="parameters">Parameters</h5> |
| <table class="table table-bordered table-striped table-condensed"> |
| <thead> |
| <tr> |
| <th>Type</th> |
| <th>Name</th> |
| <th>Description</th> |
| </tr> |
| </thead> |
| <tbody> |
| <tr> |
| <td><a class="xref" href="Lucene.Net.Index.AtomicReaderContext.html">AtomicReaderContext</a></td> |
| <td><span class="parametername">context</span></td> |
| <td><p>next atomic reader context </p> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| <span class="small pull-right mobile-hide"> |
| <span class="divider">|</span> |
| <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00011/websites/apidocs/apiSpec/new?filename=Lucene_Net_Search_ICollector_SetScorer_Lucene_Net_Search_Scorer_.md&value=---%0Auid%3A%20Lucene.Net.Search.ICollector.SetScorer(Lucene.Net.Search.Scorer)%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A">Improve this Doc</a> |
| </span> |
| <span class="small pull-right mobile-hide"> |
| <a href="https://github.com/NightOwl888/lucenenet/blob/release/Lucene.Net_4_8_0_beta00011/src/Lucene.Net/Search/Collector.cs/#L146">View Source</a> |
| </span> |
| <a id="Lucene_Net_Search_ICollector_SetScorer_" data-uid="Lucene.Net.Search.ICollector.SetScorer*"></a> |
| <h4 id="Lucene_Net_Search_ICollector_SetScorer_Lucene_Net_Search_Scorer_" data-uid="Lucene.Net.Search.ICollector.SetScorer(Lucene.Net.Search.Scorer)">SetScorer(Scorer)</h4> |
| <div class="markdown level1 summary"><p>Called before successive calls to <a class="xref" href="Lucene.Net.Search.ICollector.html#Lucene_Net_Search_ICollector_Collect_System_Int32_">Collect(Int32)</a>. Implementations |
| that need the score of the current document (passed-in to |
| <a class="xref" href="Lucene.Net.Search.ICollector.html#Lucene_Net_Search_ICollector_Collect_System_Int32_">Collect(Int32)</a>), should save the passed-in <a class="xref" href="Lucene.Net.Search.Scorer.html">Scorer</a> and call |
| <code>scorer.GetScore()</code> when needed.</p> |
| </div> |
| <div class="markdown level1 conceptual"></div> |
| <h5 class="decalaration">Declaration</h5> |
| <div class="codewrapper"> |
| <pre><code class="lang-csharp hljs">void SetScorer(Scorer scorer)</code></pre> |
| </div> |
| <h5 class="parameters">Parameters</h5> |
| <table class="table table-bordered table-striped table-condensed"> |
| <thead> |
| <tr> |
| <th>Type</th> |
| <th>Name</th> |
| <th>Description</th> |
| </tr> |
| </thead> |
| <tbody> |
| <tr> |
| <td><a class="xref" href="Lucene.Net.Search.Scorer.html">Scorer</a></td> |
| <td><span class="parametername">scorer</span></td> |
| <td></td> |
| </tr> |
| </tbody> |
| </table> |
| </article> |
| </div> |
| |
| <div class="hidden-sm col-md-2" role="complementary"> |
| <div class="sideaffix"> |
| <div class="contribution"> |
| <ul class="nav"> |
| <li> |
| <a href="https://github.com/apache/lucenenet/new/docs/4.8.0-beta00011/websites/apidocs/apiSpec/new?filename=Lucene_Net_Search_ICollector.md&value=---%0Auid%3A%20Lucene.Net.Search.ICollector%0Asummary%3A%20'*You%20can%20override%20summary%20for%20the%20API%20here%20using%20*MARKDOWN*%20syntax'%0A---%0A%0A*Please%20type%20below%20more%20information%20about%20this%20API%3A*%0A%0A" class="contribution-link">Improve this Doc</a> |
| </li> |
| <li> |
| <a href="https://github.com/apache/lucenenet/blob/release/Lucene.Net_4_8_0_beta00011/src/Lucene.Net/Search/Collector.cs/#L138" class="contribution-link">View Source</a> |
| </li> |
| </ul> |
| </div> |
| <nav class="bs-docs-sidebar hidden-print hidden-xs hidden-sm affix" id="affix"> |
| <!-- <p><a class="back-to-top" href="#top">Back to top</a><p> --> |
| </nav> |
| </div> |
| </div> |
| </div> |
| </div> |
| |
| <footer> |
| <div class="grad-bottom"></div> |
| <div class="footer"> |
| <div class="container"> |
| <span class="pull-right"> |
| <a href="#top">Back to top</a> |
| </span> |
| Copyright © 2020 Licensed to the Apache Software Foundation (ASF) |
| |
| </div> |
| </div> |
| </footer> |
| </div> |
| |
| <script type="text/javascript" src="https://lucenenet.apache.org/docs/4.8.0-beta00009/styles/docfx.vendor.js"></script> |
| <script type="text/javascript" src="https://lucenenet.apache.org/docs/4.8.0-beta00009/styles/docfx.js"></script> |
| <script type="text/javascript" src="https://lucenenet.apache.org/docs/4.8.0-beta00009/styles/main.js"></script> |
| </body> |
| </html> |
