| /* HashFinder.java -- finds the hash character. |
| Copyright (C) 2006 Free Software Foundation |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| */ |
| |
| |
| package gnu.classpath.tools.giop.grmic; |
| |
| import java.util.HashSet; |
| |
| /** |
| * This class finds the hash character (the most different character in |
| * the passed array of strings). This character is used to accelerate the |
| * method invocation by name. |
| * |
| * @author Audrius Meskauskas (AudriusA@Bioinformatics.org) |
| */ |
| public class HashFinder |
| { |
| /** |
| * Find the hash char position in the given collection of strings. |
| * |
| * @param strings the string collection |
| * |
| * @return the optimal hash character position, always less then the |
| * length of the shortest string. |
| */ |
| public int findHashCharPosition(String[] strings) |
| { |
| // Find the length of the shortest string: |
| |
| int l = strings[0].length(); |
| for (int i = 1; i < strings.length; i++) |
| { |
| if (strings[i].length() < l) |
| l = strings[i].length(); |
| } |
| |
| // Find the position with the smallest number of the matching characters: |
| HashSet[] charLists = new HashSet[l]; |
| |
| for (int i = 0; i < charLists.length; i++) |
| { |
| charLists[i] = new HashSet(strings.length); |
| } |
| |
| for (int i = 0; i < strings.length; i++) |
| for (int p = 0; p < l; p++) |
| { |
| charLists[p].add(new Integer(strings[i].charAt(p))); |
| } |
| |
| int m = 0; |
| int v = charLists[0].size(); |
| |
| for (int i = 1; i < charLists.length; i++) |
| { |
| // Replace on equality also, seeking the hash char closer to the end |
| // of line. |
| if (charLists[i].size()>=v) |
| { |
| m = i; |
| v = charLists[i].size(); |
| } |
| } |
| return m; |
| } |
| } |