source: proiecte/HadoopJUnit/hadoop-0.20.1/docs/api/org/apache/hadoop/util/hash/MurmurHash.html @ 120

Last change on this file since 120 was 120, checked in by (none), 14 years ago

Added the mail files for the Hadoop JUNit Project
  • Property svn:executable set to *
File size: 15.8 KB
Line 
1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
2<!--NewPage-->
3<HTML>
4<HEAD>
5<!-- Generated by javadoc (build 1.6.0_07) on Tue Sep 01 20:56:56 UTC 2009 -->
6<TITLE>
7MurmurHash (Hadoop 0.20.1 API)
8</TITLE>
9
10<META NAME="date" CONTENT="2009-09-01">
11
12<LINK REL ="stylesheet" TYPE="text/css" HREF="../../../../../stylesheet.css" TITLE="Style">
13
14<SCRIPT type="text/javascript">
15function windowTitle()
16{
17    if (location.href.indexOf('is-external=true') == -1) {
18        parent.document.title="MurmurHash (Hadoop 0.20.1 API)";
19    }
20}
21</SCRIPT>
22<NOSCRIPT>
23</NOSCRIPT>
24
25</HEAD>
26
27<BODY BGCOLOR="white" onload="windowTitle();">
28<HR>
29
30
31<!-- ========= START OF TOP NAVBAR ======= -->
32<A NAME="navbar_top"><!-- --></A>
33<A HREF="#skip-navbar_top" title="Skip navigation links"></A>
34<TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY="">
35<TR>
36<TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1">
37<A NAME="navbar_top_firstrow"><!-- --></A>
38<TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY="">
39  <TR ALIGN="center" VALIGN="top">
40  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A>&nbsp;</TD>
41  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A>&nbsp;</TD>
42  <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> &nbsp;<FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT>&nbsp;</TD>
43  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="class-use/MurmurHash.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A>&nbsp;</TD>
44  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A>&nbsp;</TD>
45  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A>&nbsp;</TD>
46  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A>&nbsp;</TD>
47  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A>&nbsp;</TD>
48  </TR>
49</TABLE>
50</TD>
51<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM>
52</EM>
53</TD>
54</TR>
55
56<TR>
57<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
58&nbsp;<A HREF="../../../../../org/apache/hadoop/util/hash/JenkinsHash.html" title="class in org.apache.hadoop.util.hash"><B>PREV CLASS</B></A>&nbsp;
59&nbsp;NEXT CLASS</FONT></TD>
60<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
61  <A HREF="../../../../../index.html?org/apache/hadoop/util/hash/MurmurHash.html" target="_top"><B>FRAMES</B></A>  &nbsp;
62&nbsp;<A HREF="MurmurHash.html" target="_top"><B>NO FRAMES</B></A>  &nbsp;
63&nbsp;<SCRIPT type="text/javascript">
64  <!--
65  if(window==top) {
66    document.writeln('<A HREF="../../../../../allclasses-noframe.html"><B>All Classes</B></A>');
67  }
68  //-->
69</SCRIPT>
70<NOSCRIPT>
71  <A HREF="../../../../../allclasses-noframe.html"><B>All Classes</B></A>
72</NOSCRIPT>
73
74
75</FONT></TD>
76</TR>
77<TR>
78<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
79  SUMMARY:&nbsp;NESTED&nbsp;|&nbsp;<A HREF="#fields_inherited_from_class_org.apache.hadoop.util.hash.Hash">FIELD</A>&nbsp;|&nbsp;<A HREF="#constructor_summary">CONSTR</A>&nbsp;|&nbsp;<A HREF="#method_summary">METHOD</A></FONT></TD>
80<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
81DETAIL:&nbsp;FIELD&nbsp;|&nbsp;<A HREF="#constructor_detail">CONSTR</A>&nbsp;|&nbsp;<A HREF="#method_detail">METHOD</A></FONT></TD>
82</TR>
83</TABLE>
84<A NAME="skip-navbar_top"></A>
85<!-- ========= END OF TOP NAVBAR ========= -->
86
87<HR>
88<!-- ======== START OF CLASS DATA ======== -->
89<H2>
90<FONT SIZE="-1">
91org.apache.hadoop.util.hash</FONT>
92<BR>
93Class MurmurHash</H2>
94<PRE>
95<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">java.lang.Object</A>
96  <IMG SRC="../../../../../resources/inherit.gif" ALT="extended by "><A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html" title="class in org.apache.hadoop.util.hash">org.apache.hadoop.util.hash.Hash</A>
97      <IMG SRC="../../../../../resources/inherit.gif" ALT="extended by "><B>org.apache.hadoop.util.hash.MurmurHash</B>
98</PRE>
99<HR>
100<DL>
101<DT><PRE>public class <B>MurmurHash</B><DT>extends <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html" title="class in org.apache.hadoop.util.hash">Hash</A></DL>
102</PRE>
103
104<P>
105This is a very fast, non-cryptographic hash suitable for general hash-based
106 lookup.  See http://murmurhash.googlepages.com/ for more details.
107 
108 <p>The C version of MurmurHash 2.0 found at that site was ported
109 to Java by Andrzej Bialecki (ab at getopt org).</p>
110<P>
111
112<P>
113<HR>
114
115<P>
116<!-- =========== FIELD SUMMARY =========== -->
117
118<A NAME="field_summary"><!-- --></A>
119<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
120<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
121<TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
122<B>Field Summary</B></FONT></TH>
123</TR>
124</TABLE>
125&nbsp;<A NAME="fields_inherited_from_class_org.apache.hadoop.util.hash.Hash"><!-- --></A>
126<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
127<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
128<TH ALIGN="left"><B>Fields inherited from class org.apache.hadoop.util.hash.<A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html" title="class in org.apache.hadoop.util.hash">Hash</A></B></TH>
129</TR>
130<TR BGCOLOR="white" CLASS="TableRowColor">
131<TD><CODE><A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#INVALID_HASH">INVALID_HASH</A>, <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#JENKINS_HASH">JENKINS_HASH</A>, <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#MURMUR_HASH">MURMUR_HASH</A></CODE></TD>
132</TR>
133</TABLE>
134&nbsp;
135<!-- ======== CONSTRUCTOR SUMMARY ======== -->
136
137<A NAME="constructor_summary"><!-- --></A>
138<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
139<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
140<TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
141<B>Constructor Summary</B></FONT></TH>
142</TR>
143<TR BGCOLOR="white" CLASS="TableRowColor">
144<TD><CODE><B><A HREF="../../../../../org/apache/hadoop/util/hash/MurmurHash.html#MurmurHash()">MurmurHash</A></B>()</CODE>
145
146<BR>
147&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</TD>
148</TR>
149</TABLE>
150&nbsp;
151<!-- ========== METHOD SUMMARY =========== -->
152
153<A NAME="method_summary"><!-- --></A>
154<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
155<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
156<TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
157<B>Method Summary</B></FONT></TH>
158</TR>
159<TR BGCOLOR="white" CLASS="TableRowColor">
160<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
161<CODE>static&nbsp;<A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html" title="class in org.apache.hadoop.util.hash">Hash</A></CODE></FONT></TD>
162<TD><CODE><B><A HREF="../../../../../org/apache/hadoop/util/hash/MurmurHash.html#getInstance()">getInstance</A></B>()</CODE>
163
164<BR>
165&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</TD>
166</TR>
167<TR BGCOLOR="white" CLASS="TableRowColor">
168<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
169<CODE>&nbsp;int</CODE></FONT></TD>
170<TD><CODE><B><A HREF="../../../../../org/apache/hadoop/util/hash/MurmurHash.html#hash(byte[], int, int)">hash</A></B>(byte[]&nbsp;data,
171     int&nbsp;length,
172     int&nbsp;seed)</CODE>
173
174<BR>
175&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Calculate a hash using bytes from 0 to <code>length</code>, and
176 the provided seed value</TD>
177</TR>
178</TABLE>
179&nbsp;<A NAME="methods_inherited_from_class_org.apache.hadoop.util.hash.Hash"><!-- --></A>
180<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
181<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
182<TH ALIGN="left"><B>Methods inherited from class org.apache.hadoop.util.hash.<A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html" title="class in org.apache.hadoop.util.hash">Hash</A></B></TH>
183</TR>
184<TR BGCOLOR="white" CLASS="TableRowColor">
185<TD><CODE><A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#getHashType(org.apache.hadoop.conf.Configuration)">getHashType</A>, <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#getInstance(org.apache.hadoop.conf.Configuration)">getInstance</A>, <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#getInstance(int)">getInstance</A>, <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#hash(byte[])">hash</A>, <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#hash(byte[], int)">hash</A>, <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#parseHashType(java.lang.String)">parseHashType</A></CODE></TD>
186</TR>
187</TABLE>
188&nbsp;<A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A>
189<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
190<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
191<TH ALIGN="left"><B>Methods inherited from class java.lang.<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></B></TH>
192</TR>
193<TR BGCOLOR="white" CLASS="TableRowColor">
194<TD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#clone()" title="class or interface in java.lang">clone</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#equals(java.lang.Object)" title="class or interface in java.lang">equals</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#finalize()" title="class or interface in java.lang">finalize</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#getClass()" title="class or interface in java.lang">getClass</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#hashCode()" title="class or interface in java.lang">hashCode</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notify()" title="class or interface in java.lang">notify</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notifyAll()" title="class or interface in java.lang">notifyAll</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#toString()" title="class or interface in java.lang">toString</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait()" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long)" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long, int)" title="class or interface in java.lang">wait</A></CODE></TD>
195</TR>
196</TABLE>
197&nbsp;
198<P>
199
200<!-- ========= CONSTRUCTOR DETAIL ======== -->
201
202<A NAME="constructor_detail"><!-- --></A>
203<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
204<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
205<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
206<B>Constructor Detail</B></FONT></TH>
207</TR>
208</TABLE>
209
210<A NAME="MurmurHash()"><!-- --></A><H3>
211MurmurHash</H3>
212<PRE>
213public <B>MurmurHash</B>()</PRE>
214<DL>
215</DL>
216
217<!-- ============ METHOD DETAIL ========== -->
218
219<A NAME="method_detail"><!-- --></A>
220<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
221<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
222<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
223<B>Method Detail</B></FONT></TH>
224</TR>
225</TABLE>
226
227<A NAME="getInstance()"><!-- --></A><H3>
228getInstance</H3>
229<PRE>
230public static <A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html" title="class in org.apache.hadoop.util.hash">Hash</A> <B>getInstance</B>()</PRE>
231<DL>
232<DD><DL>
233</DL>
234</DD>
235</DL>
236<HR>
237
238<A NAME="hash(byte[], int, int)"><!-- --></A><H3>
239hash</H3>
240<PRE>
241public int <B>hash</B>(byte[]&nbsp;data,
242                int&nbsp;length,
243                int&nbsp;seed)</PRE>
244<DL>
245<DD><B>Description copied from class: <CODE><A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#hash(byte[], int, int)">Hash</A></CODE></B></DD>
246<DD>Calculate a hash using bytes from 0 to <code>length</code>, and
247 the provided seed value
248<P>
249<DD><DL>
250<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html#hash(byte[], int, int)">hash</A></CODE> in class <CODE><A HREF="../../../../../org/apache/hadoop/util/hash/Hash.html" title="class in org.apache.hadoop.util.hash">Hash</A></CODE></DL>
251</DD>
252<DD><DL>
253<DT><B>Parameters:</B><DD><CODE>data</CODE> - input bytes<DD><CODE>length</CODE> - length of the valid bytes to consider<DD><CODE>seed</CODE> - seed value
254<DT><B>Returns:</B><DD>hash value</DL>
255</DD>
256</DL>
257<!-- ========= END OF CLASS DATA ========= -->
258<HR>
259
260
261<!-- ======= START OF BOTTOM NAVBAR ====== -->
262<A NAME="navbar_bottom"><!-- --></A>
263<A HREF="#skip-navbar_bottom" title="Skip navigation links"></A>
264<TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY="">
265<TR>
266<TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1">
267<A NAME="navbar_bottom_firstrow"><!-- --></A>
268<TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY="">
269  <TR ALIGN="center" VALIGN="top">
270  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A>&nbsp;</TD>
271  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A>&nbsp;</TD>
272  <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> &nbsp;<FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT>&nbsp;</TD>
273  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="class-use/MurmurHash.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A>&nbsp;</TD>
274  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A>&nbsp;</TD>
275  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A>&nbsp;</TD>
276  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A>&nbsp;</TD>
277  <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1">    <A HREF="../../../../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A>&nbsp;</TD>
278  </TR>
279</TABLE>
280</TD>
281<TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM>
282</EM>
283</TD>
284</TR>
285
286<TR>
287<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
288&nbsp;<A HREF="../../../../../org/apache/hadoop/util/hash/JenkinsHash.html" title="class in org.apache.hadoop.util.hash"><B>PREV CLASS</B></A>&nbsp;
289&nbsp;NEXT CLASS</FONT></TD>
290<TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2">
291  <A HREF="../../../../../index.html?org/apache/hadoop/util/hash/MurmurHash.html" target="_top"><B>FRAMES</B></A>  &nbsp;
292&nbsp;<A HREF="MurmurHash.html" target="_top"><B>NO FRAMES</B></A>  &nbsp;
293&nbsp;<SCRIPT type="text/javascript">
294  <!--
295  if(window==top) {
296    document.writeln('<A HREF="../../../../../allclasses-noframe.html"><B>All Classes</B></A>');
297  }
298  //-->
299</SCRIPT>
300<NOSCRIPT>
301  <A HREF="../../../../../allclasses-noframe.html"><B>All Classes</B></A>
302</NOSCRIPT>
303
304
305</FONT></TD>
306</TR>
307<TR>
308<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
309  SUMMARY:&nbsp;NESTED&nbsp;|&nbsp;<A HREF="#fields_inherited_from_class_org.apache.hadoop.util.hash.Hash">FIELD</A>&nbsp;|&nbsp;<A HREF="#constructor_summary">CONSTR</A>&nbsp;|&nbsp;<A HREF="#method_summary">METHOD</A></FONT></TD>
310<TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">
311DETAIL:&nbsp;FIELD&nbsp;|&nbsp;<A HREF="#constructor_detail">CONSTR</A>&nbsp;|&nbsp;<A HREF="#method_detail">METHOD</A></FONT></TD>
312</TR>
313</TABLE>
314<A NAME="skip-navbar_bottom"></A>
315<!-- ======== END OF BOTTOM NAVBAR ======= -->
316
317<HR>
318Copyright &copy; 2009 The Apache Software Foundation
319</BODY>
320</HTML>
Note: See TracBrowser for help on using the repository browser.