1 /* 2 * Copyright 2012, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 package org.jf.dexlib2.dexbacked.util; 33 34 import org.jf.dexlib2.dexbacked.DexBackedDexFile; 35 import org.jf.dexlib2.dexbacked.DexReader; 36 import org.jf.dexlib2.dexbacked.value.DexBackedEncodedValue; 37 import org.jf.dexlib2.iface.value.EncodedValue; 38 39 import javax.annotation.Nonnull; 40 import javax.annotation.Nullable; 41 42 public abstract class StaticInitialValueIterator { 43 public static final StaticInitialValueIterator EMPTY = new StaticInitialValueIterator() { 44 @Nullable @Override public EncodedValue getNextOrNull() { return null; } 45 @Override public void skipNext() {} 46 }; 47 getNextOrNull()48 @Nullable public abstract EncodedValue getNextOrNull(); skipNext()49 public abstract void skipNext(); 50 51 @Nonnull newOrEmpty(@onnull DexBackedDexFile dexFile, int offset)52 public static StaticInitialValueIterator newOrEmpty(@Nonnull DexBackedDexFile dexFile, int offset) { 53 if (offset == 0) { 54 return EMPTY; 55 } 56 return new StaticInitialValueIteratorImpl(dexFile, offset); 57 } 58 59 private static class StaticInitialValueIteratorImpl extends StaticInitialValueIterator { 60 @Nonnull private final DexReader reader; 61 private final int size; 62 private int index = 0; 63 StaticInitialValueIteratorImpl(@onnull DexBackedDexFile dexFile, int offset)64 public StaticInitialValueIteratorImpl(@Nonnull DexBackedDexFile dexFile, int offset) { 65 this.reader = dexFile.readerAt(offset); 66 this.size = reader.readSmallUleb128(); 67 } 68 69 @Nullable getNextOrNull()70 public EncodedValue getNextOrNull() { 71 if (index < size) { 72 index++; 73 return DexBackedEncodedValue.readFrom(reader); 74 } 75 return null; 76 } 77 skipNext()78 public void skipNext() { 79 if (index < size) { 80 index++; 81 DexBackedEncodedValue.skipFrom(reader); 82 } 83 } 84 } 85 } 86