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