InterfaceSorter.java revision db267bc191f906f55eaef21a27110cce2ec57fdf
1/* 2 * ProGuard -- shrinking, optimization, obfuscation, and preverification 3 * of Java bytecode. 4 * 5 * Copyright (c) 2002-2009 Eric Lafortune (eric@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 */ 21package proguard.classfile.editor; 22 23import proguard.classfile.*; 24import proguard.classfile.util.SimplifiedVisitor; 25import proguard.classfile.visitor.ClassVisitor; 26 27import java.util.Arrays; 28 29/** 30 * This ClassVisitor sorts the interfaces of the program classes that it visits. 31 * 32 * @author Eric Lafortune 33 */ 34public class InterfaceSorter 35extends SimplifiedVisitor 36implements 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