You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
131 lines
5.0 KiB
131 lines
5.0 KiB
<!-------- @HEADER
|
|
!
|
|
! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
|
|
!
|
|
! Zoltan Toolkit for Load-balancing, Partitioning, Ordering and Coloring
|
|
! Copyright 2012 Sandia Corporation
|
|
!
|
|
! Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
|
|
! the U.S. Government retains certain rights in this software.
|
|
!
|
|
! Redistribution and use in source and binary forms, with or without
|
|
! modification, are permitted provided that the following conditions are
|
|
! met:
|
|
!
|
|
! 1. Redistributions of source code must retain the above copyright
|
|
! notice, this list of conditions and the following disclaimer.
|
|
!
|
|
! 2. Redistributions in binary form must reproduce the above copyright
|
|
! notice, this list of conditions and the following disclaimer in the
|
|
! documentation and/or other materials provided with the distribution.
|
|
!
|
|
! 3. Neither the name of the Corporation nor the names of the
|
|
! contributors may be used to endorse or promote products derived from
|
|
! this software without specific prior written permission.
|
|
!
|
|
! THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
|
|
! EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
! PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
|
|
! CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
! EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
! PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
! LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
! NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
! SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
!
|
|
! Questions? Contact Karen Devine kddevin@sandia.gov
|
|
! Erik Boman egboman@sandia.gov
|
|
!
|
|
! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
|
|
!
|
|
! @HEADER
|
|
------->
|
|
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
|
<meta name="GENERATOR" content="Mozilla/4.7 [en] (X11; U; SunOS 5.6 sun4m) [Netscape]">
|
|
<meta name="sandia.approved" content="SAND99-1376">
|
|
<meta name="author" content="karen devine, kddevin@sandia.gov">
|
|
<title> Zoltan Developer's Guide: Hash function</title>
|
|
|
|
</head>
|
|
<body bgcolor="#FFFFFF">
|
|
|
|
<div align=right><b><i><a href="dev.html">Zoltan Developer's Guide</a>
|
|
| <a href="dev_services_time.html">Next</a> | <a href="dev_services_objlist.html">Previous</a></i></b></div>
|
|
|
|
<!------------------------------------------------------------------------->
|
|
|
|
<h2>
|
|
Hash Function</h2>
|
|
Zoltan provides a hash function for global and local IDs. The hash function
|
|
computes a non-negative integer value in a certain range<i> </i>from an
|
|
ID.
|
|
<blockquote><b><a href="#Zoltan_Hash">Zoltan_Hash</a></b> : hash a global
|
|
or local ID into non-negative integers</blockquote>
|
|
|
|
<!------------------------------------------------------------------------->
|
|
<hr>
|
|
<a NAME="Zoltan_Hash"></a>
|
|
<hr>
|
|
unsigned int<b> Zoltan_Hash</b>(
|
|
<b><a href="../ug_html/ug_usage.html#Data Types for Object IDs">ZOLTAN_ID_PTR
|
|
</a></b><i>key</i>,
|
|
int <i>num_id_entries</i>, unsigned int <i>n</i>);
|
|
<hr>
|
|
<b>Zoltan_Hash </b>computes a hash value for a global or local ID. Note
|
|
that this hash function has been optimized for 32-bit integer systems,
|
|
but should work on any machine. The current implementation uses a
|
|
simple multiplicative hash function based on Don Knuth's golden ratio method;
|
|
see <i>The Art of Computer Programming,</i> vol. 3.
|
|
<br>
|
|
<table WIDTH="100%" >
|
|
<tr VALIGN=TOP>
|
|
<td VALIGN=TOP WIDTH="20%"><b>Arguments:</b></td>
|
|
|
|
<td WIDTH="80%"></td>
|
|
</tr>
|
|
|
|
<tr VALIGN=TOP>
|
|
<td VALIGN=TOP> <i>key</i></td>
|
|
|
|
<td>A pointer to the ID to be hashed.</td>
|
|
</tr>
|
|
|
|
<tr VALIGN=TOP>
|
|
<td> <i>num_id_entries</i></td>
|
|
|
|
<td>The length of the ID (as given by <b><a href="../ug_html/ug_param.html#NUM_GID_ENTRIES">NUM_GID_ENTRIES</a></b>
|
|
or <b><a href="../ug_html/ug_param.html#NUM_LID_ENTRIES">NUM_LID_ENTRIES</a></b>).</td>
|
|
</tr>
|
|
|
|
<tr VALIGN=TOP>
|
|
<td VALIGN=TOP> <i>n</i></td>
|
|
|
|
<td>The computed hash value will be between 0 and <i>n</i>-1. </td>
|
|
</tr>
|
|
|
|
<tr VALIGN=TOP>
|
|
<td><b>Return Value:</b></td>
|
|
|
|
<td></td>
|
|
</tr>
|
|
|
|
<tr VALIGN=TOP>
|
|
<td> unsigned int</td>
|
|
|
|
<td>The hash value (between 0<i> </i>and <i>n</i>-1). </td>
|
|
</tr>
|
|
</table>
|
|
|
|
<p>
|
|
<!------------------------------------------------------------------------->
|
|
<hr WIDTH="100%">
|
|
<br>[<a href="dev.html">Table of Contents</a> | <a href="dev_services_time.html">Next:
|
|
Timing Routines</a> | <a href="dev_services_objlist.html">Previous:
|
|
Object List Function</a> | <a href="https://www.sandia.gov/general/privacy-security/index.html">Privacy and Security</a>]
|
|
</body>
|
|
</html>
|
|
|