1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.dx.util;
18
19import java.io.IOException;
20import java.util.Arrays;
21import junit.framework.TestCase;
22
23public final class Leb128UtilsTest extends TestCase {
24
25    public void testDecodeUnsignedLeb() throws IOException {
26        assertEquals(0, Leb128Utils.readUnsignedLeb128(new ByteArrayByteInput((byte) 0)));
27        assertEquals(1, Leb128Utils.readUnsignedLeb128(new ByteArrayByteInput((byte) 1)));
28        assertEquals(127, Leb128Utils.readUnsignedLeb128(new ByteArrayByteInput((byte) 0x7f)));
29        assertEquals(16256, Leb128Utils.readUnsignedLeb128(
30                new ByteArrayByteInput((byte) 0x80, (byte) 0x7f)));
31    }
32
33    public void testEncodeUnsignedLeb() throws IOException {
34        assertEquals(new byte[] { 0 }, encodeUnsignedLeb(0));
35        assertEquals(new byte[] { 1 }, encodeUnsignedLeb(1));
36        assertEquals(new byte[] { 0x7f }, encodeUnsignedLeb(127));
37        assertEquals(new byte[] { (byte) 0x80, 0x7f }, encodeUnsignedLeb(16256));
38        assertEquals(new byte[] { (byte) 0xb4, 0x07 }, encodeUnsignedLeb(0x3b4));
39        assertEquals(new byte[] { (byte) 0x8c, 0x08 }, encodeUnsignedLeb(0x40c));
40        assertEquals(new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, 0xf },
41                encodeUnsignedLeb(0xffffffff));
42    }
43
44    public void testDecodeSignedLeb() throws IOException {
45        assertEquals(0, Leb128Utils.readSignedLeb128(new ByteArrayByteInput((byte) 0)));
46        assertEquals(1, Leb128Utils.readSignedLeb128(new ByteArrayByteInput((byte) 1)));
47        assertEquals(-1, Leb128Utils.readSignedLeb128(new ByteArrayByteInput((byte) 0x7f)));
48        assertEquals(0x3c, Leb128Utils.readSignedLeb128(new ByteArrayByteInput((byte) 0x3c)));
49        assertEquals(-128, Leb128Utils.readSignedLeb128(
50                new ByteArrayByteInput((byte) 0x80, (byte) 0x7f)));
51    }
52
53    public void testEncodeSignedLeb() throws IOException {
54        assertEquals(new byte[] { 0 }, encodeSignedLeb(0));
55        assertEquals(new byte[] { 1 }, encodeSignedLeb(1));
56        assertEquals(new byte[] { 0x7f }, encodeSignedLeb(-1));
57        assertEquals(new byte[] { (byte) 0x80, 0x7f }, encodeSignedLeb(-128));
58    }
59
60    private byte[] encodeSignedLeb(int value) {
61        ByteArrayAnnotatedOutput out = new ByteArrayAnnotatedOutput(5);
62        Leb128Utils.writeSignedLeb128(out, value);
63        return out.toByteArray();
64    }
65
66    private byte[] encodeUnsignedLeb(int value) {
67        ByteArrayAnnotatedOutput out = new ByteArrayAnnotatedOutput(5);
68        Leb128Utils.writeUnsignedLeb128(out, value);
69        return out.toByteArray();
70    }
71
72    private void assertEquals(byte[] expected, byte[] actual) {
73        assertTrue(Arrays.toString(actual), Arrays.equals(expected, actual));
74    }
75}
76