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 32package org.jf.dexlib2.dexbacked.util; 33 34import org.jf.dexlib2.dexbacked.DexBackedDexFile; 35import org.jf.dexlib2.dexbacked.DexReader; 36 37import javax.annotation.Nonnull; 38import java.util.Iterator; 39import java.util.NoSuchElementException; 40 41public abstract class VariableSizeIterator<T> implements Iterator<T> { 42 @Nonnull private final DexReader reader; 43 protected final int size; 44 45 private int index; 46 47 protected VariableSizeIterator(@Nonnull DexBackedDexFile dexFile, int offset, int size) { 48 this.reader = dexFile.readerAt(offset); 49 this.size = size; 50 } 51 52 protected VariableSizeIterator(@Nonnull DexReader reader, int size) { 53 this.reader = reader; 54 this.size = size; 55 } 56 57 /** 58 * Reads the next item from reader. 59 * 60 * @param reader The {@code DexReader} to read the next item from 61 * @param index The index of the item being read. This is guaranteed to be less than {@code size} 62 * @return The item that was read 63 */ 64 protected abstract T readNextItem(@Nonnull DexReader reader, int index); 65 66 public int getReaderOffset() { 67 return reader.getOffset(); 68 } 69 70 @Override 71 public boolean hasNext() { 72 return index < size; 73 } 74 75 @Override 76 public T next() { 77 if (index >= size) { 78 throw new NoSuchElementException(); 79 } 80 return readNextItem(reader, index++); 81 } 82 83 @Override public void remove() { throw new UnsupportedOperationException(); } 84} 85