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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><!--NewPage--><HTML><HEAD><!-- Generated by javadoc (build 1.5.0_06) on Wed Sep 27 16:03:10 PDT 2006 --><TITLE>BloomUriUniqFilter (Heritrix 1.10.1)</TITLE><META NAME="keywords" CONTENT="org.archive.crawler.util.BloomUriUniqFilter class"><LINK REL ="stylesheet" TYPE="text/css" HREF="../../../../stylesheet.css" TITLE="Style"><SCRIPT type="text/javascript">function windowTitle(){ parent.document.title="BloomUriUniqFilter (Heritrix 1.10.1)";}</SCRIPT><NOSCRIPT></NOSCRIPT></HEAD><BODY BGCOLOR="white" onload="windowTitle();"><!-- ========= START OF TOP NAVBAR ======= --><A NAME="navbar_top"><!-- --></A><A HREF="#skip-navbar_top" title="Skip navigation links"></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_top_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/BloomUriUniqFilter.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../../../org/archive/crawler/util/BenchmarkUriUniqFilters.html" title="class in org.archive.crawler.util"><B>PREV CLASS</B></A> <A HREF="../../../../org/archive/crawler/util/CheckpointUtils.html" title="class in org.archive.crawler.util"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../../../index.html?org/archive/crawler/util/BloomUriUniqFilter.html" target="_top"><B>FRAMES</B></A> <A HREF="BloomUriUniqFilter.html" target="_top"><B>NO FRAMES</B></A> <SCRIPT type="text/javascript"> <!-- if(window==top) { document.writeln('<A HREF="../../../../allclasses-noframe.html"><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT> <A HREF="../../../../allclasses-noframe.html"><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: NESTED | <A HREF="#field_summary">FIELD</A> | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: <A HREF="#field_detail">FIELD</A> | <A HREF="#constructor_detail">CONSTR</A> | <A HREF="#method_detail">METHOD</A></FONT></TD></TR></TABLE><A NAME="skip-navbar_top"></A><!-- ========= END OF TOP NAVBAR ========= --><HR><!-- ======== START OF CLASS DATA ======== --><H2><FONT SIZE="-1">org.archive.crawler.util</FONT><BR>Class BloomUriUniqFilter</H2><PRE>java.lang.Object <IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><A HREF="../../../../org/archive/crawler/util/SetBasedUriUniqFilter.html" title="class in org.archive.crawler.util">org.archive.crawler.util.SetBasedUriUniqFilter</A> <IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><B>org.archive.crawler.util.BloomUriUniqFilter</B></PRE><DL><DT><B>All Implemented Interfaces:</B> <DD>java.io.Serializable, <A HREF="../../../../org/archive/crawler/datamodel/UriUniqFilter.html" title="interface in org.archive.crawler.datamodel">UriUniqFilter</A></DD></DL><HR><DL><DT><PRE>public class <B>BloomUriUniqFilter</B><DT>extends <A HREF="../../../../org/archive/crawler/util/SetBasedUriUniqFilter.html" title="class in org.archive.crawler.util">SetBasedUriUniqFilter</A><DT>implements java.io.Serializable</DL></PRE><P>A MG4J BloomFilter-based implementation of an AlreadySeen list. This implementation performs adequately without blowing out the heap through to very large numbers of URIs. See <a href="http://crawler.archive.org/cgi-bin/wiki.pl?AlreadySeen">AlreadySeen</a>. It is inherent to Bloom filters that as they get 'saturated', their false-positive rate rises. The default parameters used by this class attempt to maintain a 1-in-4 million (1 in 2^22) false-positive chance through 125 million unique inserts, which creates a filter structure about 495MB in size. You may use the following system properties to tune the size and false-positive rate of the bloom filter structure used by this class: org.archive.crawler.util.BloomUriUniqFilter.expected-size (default 125000000) org.archive.crawler.util.BloomUriUniqFilter.hash-count (default 22) The resulting filter will take up approximately... 1.44 * expected-size * hash-count / 8 ...bytes. The default size is very close to the maximum practical size of the Bloom filter implementation, BloomFilter32bitSplit, created in the initialize() method, due to integer arithmetic limits. If you need a larger filter, you should edit the initialize method to intantiate a BloomFilter64bit instead.<P><P><DL><DT><B>Version:</B></DT> <DD>$Date: 2006/08/17 23:41:59 $, $Revision: 1.8 $</DD><DT><B>Author:</B></DT> <DD>gojomo</DD><DT><B>See Also:</B><DD><A HREF="../../../../serialized-form.html#org.archive.crawler.util.BloomUriUniqFilter">Serialized Form</A></DL><HR><P><!-- ======== NESTED CLASS SUMMARY ======== --><A NAME="nested_class_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"><B>Nested Class Summary</B></FONT></TH></TR></TABLE> <A NAME="nested_classes_inherited_from_class_org.archive.crawler.datamodel.UriUniqFilter"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor"><TH ALIGN="left"><B>Nested classes/interfaces inherited from interface org.archive.crawler.datamodel.<A HREF="../../../../org/archive/crawler/datamodel/UriUniqFilter.html" title="interface in org.archive.crawler.datamodel">UriUniqFilter</A></B></TH></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><A HREF="../../../../org/archive/crawler/datamodel/UriUniqFilter.HasUriReceiver.html" title="interface in org.archive.crawler.datamodel">UriUniqFilter.HasUriReceiver</A></CODE></TD></TR></TABLE> <!-- =========== FIELD SUMMARY =========== --><A NAME="field_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"><B>Field Summary</B></FONT></TH></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>(package private) <A HREF="../../../../org/archive/util/BloomFilter.html" title="interface in org.archive.util">BloomFilter</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#bloom">bloom</A></B></CODE><BR> </TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>protected int</CODE></FONT></TD><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#expected_n">expected_n</A></B></CODE><BR> </TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>protected static java.lang.String</CODE></FONT></TD><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#EXPECTED_SIZE_KEY">EXPECTED_SIZE_KEY</A></B></CODE><BR> </TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>protected static java.lang.String</CODE></FONT></TD><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#HASH_COUNT_KEY">HASH_COUNT_KEY</A></B></CODE><BR> </TD></TR></TABLE> <A NAME="fields_inherited_from_class_org.archive.crawler.util.SetBasedUriUniqFilter"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor"><TH ALIGN="left"><B>Fields inherited from class org.archive.crawler.util.<A HREF="../../../../org/archive/crawler/util/SetBasedUriUniqFilter.html" title="class in org.archive.crawler.util">SetBasedUriUniqFilter</A></B></TH></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><A HREF="../../../../org/archive/crawler/util/SetBasedUriUniqFilter.html#duplicateCount">duplicateCount</A>, <A HREF="../../../../org/archive/crawler/util/SetBasedUriUniqFilter.html#duplicatesAtLastSample">duplicatesAtLastSample</A>, <A HREF="../../../../org/archive/crawler/util/SetBasedUriUniqFilter.html#profileLog">profileLog</A>, <A HREF="../../../../org/archive/crawler/util/SetBasedUriUniqFilter.html#receiver">receiver</A></CODE></TD></TR></TABLE> <!-- ======== CONSTRUCTOR SUMMARY ======== --><A NAME="constructor_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"><B>Constructor Summary</B></FONT></TH></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#BloomUriUniqFilter()">BloomUriUniqFilter</A></B>()</CODE><BR> Default constructor</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#BloomUriUniqFilter(int, int)">BloomUriUniqFilter</A></B>(int n, int d)</CODE><BR> Constructor.</TD></TR></TABLE> <!-- ========== METHOD SUMMARY =========== --><A NAME="method_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"><B>Method Summary</B></FONT></TH></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> void</CODE></FONT></TD><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#forget(java.lang.String, org.archive.crawler.datamodel.CandidateURI)">forget</A></B>(java.lang.String canonical, <A HREF="../../../../org/archive/crawler/datamodel/CandidateURI.html" title="class in org.archive.crawler.datamodel">CandidateURI</A> item)</CODE><BR> Forget item was seen</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>protected void</CODE></FONT></TD><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#initialize(int, int)">initialize</A></B>(int n, int d)</CODE><BR> Initializer shared by constructors.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>protected boolean</CODE></FONT></TD><TD><CODE><B><A HREF="../../../../org/archive/crawler/util/BloomUriUniqFilter.html#setAdd(java.lang.CharSequence)">setAdd</A></B>(java.lang.CharSequence uri)</CODE><BR> </TD></TR><TR BGCOLOR="white" CLASS="TableRowColor">⌨️ 快捷键说明
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