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      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2009 Eric Lafortune (eric (at) graphics.cornell.edu)
      6  *
      7  * This program is free software; you can redistribute it and/or modify it
      8  * under the terms of the GNU General Public License as published by the Free
      9  * Software Foundation; either version 2 of the License, or (at your option)
     10  * any later version.
     11  *
     12  * This program is distributed in the hope that it will be useful, but WITHOUT
     13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
     15  * more details.
     16  *
     17  * You should have received a copy of the GNU General Public License along
     18  * with this program; if not, write to the Free Software Foundation, Inc.,
     19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
     20  */
     21 package proguard.classfile.editor;
     22 
     23 import proguard.classfile.*;
     24 import proguard.classfile.util.SimplifiedVisitor;
     25 import proguard.classfile.visitor.ClassVisitor;
     26 
     27 import java.util.Arrays;
     28 
     29 /**
     30  * This ClassVisitor sorts the interfaces of the program classes that it visits.
     31  *
     32  * @author Eric Lafortune
     33  */
     34 public class InterfaceSorter
     35 extends      SimplifiedVisitor
     36 implements   ClassVisitor
     37 {
     38     // Implementations for ClassVisitor.
     39 
     40     public void visitProgramClass(ProgramClass programClass)
     41     {
     42         int[] interfaces      = programClass.u2interfaces;
     43         int   interfacesCount = programClass.u2interfacesCount;
     44 
     45         // Sort the interfaces.
     46         Arrays.sort(interfaces, 0, interfacesCount);
     47 
     48         // Remove any duplicate entries.
     49         int newInterfacesCount     = 0;
     50         int previousInterfaceIndex = 0;
     51         for (int index = 0; index < interfacesCount; index++)
     52         {
     53             int interfaceIndex = interfaces[index];
     54 
     55             // Isn't this a duplicate of the previous interface?
     56             if (interfaceIndex != previousInterfaceIndex)
     57             {
     58                 interfaces[newInterfacesCount++] = interfaceIndex;
     59 
     60                 // Remember the interface.
     61                 previousInterfaceIndex = interfaceIndex;
     62             }
     63         }
     64 
     65         programClass.u2interfacesCount = newInterfacesCount;
     66     }
     67 }
     68