1/*
2 * Copyright (C) 2010 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 libcore.java.util.zip;
18
19import java.util.zip.DataFormatException;
20import java.util.zip.Deflater;
21import java.util.zip.Inflater;
22import junit.framework.TestCase;
23
24public class DeflaterTest extends TestCase {
25
26    private byte[] compressed = new byte[32];
27    private byte[] decompressed = new byte[20];
28    private Deflater deflater = new Deflater();
29    private Inflater inflater = new Inflater();
30    private int totalDeflated = 0;
31    private int totalInflated = 0;
32
33    public void testDeflate() throws DataFormatException {
34        deflater.setInput(new byte[] { 1, 2, 3 });
35        deflateInflate(Deflater.NO_FLUSH);
36        assertTrue(totalInflated < 3);
37        assertEquals(0, decompressed[2]); // the 3rd byte shouldn't have been flushed yet
38
39        deflater.setInput(new byte[] { 4, 5, 6 });
40        deflateInflate(Deflater.SYNC_FLUSH);
41        assertEquals(6, totalInflated);
42        assertDecompressed(1, 2, 3, 4, 5, 6);
43        assertEquals(0, inflater.inflate(decompressed));
44
45        deflater.setInput(new byte[] { 7, 8, 9 });
46        deflateInflate(Deflater.FULL_FLUSH);
47        assertEquals(9, totalInflated);
48        assertDecompressed(1, 2, 3, 4, 5, 6, 7, 8, 9);
49        assertEquals(0, inflater.inflate(decompressed));
50        inflater = new Inflater(true); // safe because we did a FULL_FLUSH
51
52        deflater.setInput(new byte[] { 10, 11, 12 });
53        deflateInflate(Deflater.SYNC_FLUSH);
54        assertEquals(12, totalInflated);
55        assertDecompressed(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
56        assertEquals(0, inflater.inflate(decompressed));
57    }
58
59    private void deflateInflate(int flush) throws DataFormatException {
60        int lastDeflated = deflater.deflate(compressed, totalDeflated,
61                compressed.length - totalDeflated, flush);
62        assertTrue(inflater.needsInput());
63        inflater.setInput(compressed, totalDeflated, lastDeflated);
64        totalDeflated += lastDeflated;
65        totalInflated += inflater.inflate(decompressed, totalInflated,
66                decompressed.length - totalInflated);
67    }
68
69    private void assertDecompressed(int... expected) {
70        for (int i = 0; i < decompressed.length; i++) {
71            int expectedValue = i < expected.length ? expected[i] : 0;
72            assertEquals(expectedValue, decompressed[i]);
73        }
74    }
75
76    /**
77     * Deflating without calling setInput() is the same as deflating an empty
78     * byte array.
79     */
80    public void testDeflateWithoutSettingInput() throws Exception {
81        deflateInflate(Deflater.FULL_FLUSH);
82        assertTrue(totalDeflated > 0); // the deflated form should be non-empty
83        assertEquals(0, totalInflated);
84    }
85}
86