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 EncodedArrayItemIterator { 43 public static final EncodedArrayItemIterator EMPTY = new EncodedArrayItemIterator() { 44 @Nullable @Override public EncodedValue getNextOrNull() { return null; } 45 @Override public void skipNext() {} 46 @Override public int getReaderOffset() { return 0; } 47 @Override public int getItemCount() { return 0; } 48 }; 49 getNextOrNull()50 @Nullable public abstract EncodedValue getNextOrNull(); skipNext()51 public abstract void skipNext(); getReaderOffset()52 public abstract int getReaderOffset(); getItemCount()53 public abstract int getItemCount(); 54 55 @Nonnull newOrEmpty(@onnull DexBackedDexFile dexFile, int offset)56 public static EncodedArrayItemIterator newOrEmpty(@Nonnull DexBackedDexFile dexFile, int offset) { 57 if (offset == 0) { 58 return EMPTY; 59 } 60 return new EncodedArrayItemIteratorImpl(dexFile, offset); 61 } 62 63 private static class EncodedArrayItemIteratorImpl extends EncodedArrayItemIterator { 64 @Nonnull private final DexReader reader; 65 private final int size; 66 private int index = 0; 67 EncodedArrayItemIteratorImpl(@onnull DexBackedDexFile dexFile, int offset)68 public EncodedArrayItemIteratorImpl(@Nonnull DexBackedDexFile dexFile, int offset) { 69 this.reader = dexFile.readerAt(offset); 70 this.size = reader.readSmallUleb128(); 71 } 72 73 @Nullable getNextOrNull()74 public EncodedValue getNextOrNull() { 75 if (index < size) { 76 index++; 77 return DexBackedEncodedValue.readFrom(reader); 78 } 79 return null; 80 } 81 82 @Override skipNext()83 public void skipNext() { 84 if (index < size) { 85 index++; 86 DexBackedEncodedValue.skipFrom(reader); 87 } 88 } 89 90 @Override getReaderOffset()91 public int getReaderOffset() { 92 return reader.getOffset(); 93 } 94 95 @Override getItemCount()96 public int getItemCount() { 97 return size; 98 } 99 } 100 } 101