| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.commons.compress.utils; |
| |
| import static org.junit.Assert.assertEquals; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.IOException; |
| import java.nio.ByteOrder; |
| |
| import org.junit.Test; |
| |
| public class BitInputStreamTest { |
| |
| @Test(expected = IllegalArgumentException.class) |
| public void shouldNotAllowReadingOfANegativeAmountOfBits() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| bis.readBits(-1); |
| } |
| } |
| |
| @Test(expected = IllegalArgumentException.class) |
| public void shouldNotAllowReadingOfMoreThan63BitsAtATime() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| bis.readBits(64); |
| } |
| } |
| |
| @Test |
| public void testReading24BitsInLittleEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x000140f8, bis.readBits(24)); |
| } |
| } |
| |
| @Test |
| public void testReading24BitsInBigEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.BIG_ENDIAN)) { |
| assertEquals(0x00f84001, bis.readBits(24)); |
| } |
| } |
| |
| @Test |
| public void testReading17BitsInLittleEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x000140f8, bis.readBits(17)); |
| } |
| } |
| |
| @Test |
| public void testReading17BitsInBigEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.BIG_ENDIAN)) { |
| // 1-11110000-10000000 |
| assertEquals(0x0001f080, bis.readBits(17)); |
| } |
| } |
| |
| @Test |
| public void testReading30BitsInLittleEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x2f0140f8, bis.readBits(30)); |
| } |
| } |
| |
| @Test |
| public void testReading30BitsInBigEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.BIG_ENDIAN)) { |
| // 111110-00010000-00000000-01001011 |
| assertEquals(0x3e10004b, bis.readBits(30)); |
| } |
| } |
| |
| @Test |
| public void testReading31BitsInLittleEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x2f0140f8, bis.readBits(31)); |
| } |
| } |
| |
| @Test |
| public void testReading31BitsInBigEndian() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.BIG_ENDIAN)) { |
| // 1111100-00100000-00000000-10010111 |
| assertEquals(0x7c200097, bis.readBits(31)); |
| } |
| } |
| |
| @Test |
| public void testClearBitCache() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x08, bis.readBits(4)); |
| bis.clearBitCache(); |
| assertEquals(0, bis.readBits(1)); |
| } |
| } |
| |
| @Test |
| public void testEOF() throws IOException { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x2f0140f8, bis.readBits(30)); |
| assertEquals(-1, bis.readBits(3)); |
| } |
| } |
| |
| /** |
| * @see "https://issues.apache.org/jira/browse/COMPRESS-363" |
| */ |
| @Test |
| public void littleEndianWithOverflow() throws Exception { |
| ByteArrayInputStream in = new ByteArrayInputStream(new byte[] { |
| 87, // 01010111 |
| 45, // 00101101 |
| 66, // 01000010 |
| 15, // 00001111 |
| 90, // 01011010 |
| 29, // 00011101 |
| 88, // 01011000 |
| 61, // 00111101 |
| 33, // 00100001 |
| 74 // 01001010 |
| }); |
| try (final BitInputStream bin = new BitInputStream(in, ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(23, // 10111 |
| bin.readBits(5)); |
| assertEquals(714595605644185962l, // 0001-00111101-01011000-00011101-01011010-00001111-01000010-00101101-010 |
| bin.readBits(63)); |
| assertEquals(1186, // 01001010-0010 |
| bin.readBits(12)); |
| assertEquals(-1 , bin.readBits(1)); |
| } |
| } |
| |
| @Test |
| public void bigEndianWithOverflow() throws Exception { |
| ByteArrayInputStream in = new ByteArrayInputStream(new byte[] { |
| 87, // 01010111 |
| 45, // 00101101 |
| 66, // 01000010 |
| 15, // 00001111 |
| 90, // 01011010 |
| 29, // 00011101 |
| 88, // 01011000 |
| 61, // 00111101 |
| 33, // 00100001 |
| 74 // 01001010 |
| }); |
| try (final BitInputStream bin = new BitInputStream(in, ByteOrder.BIG_ENDIAN)) { |
| assertEquals(10, // 01010 |
| bin.readBits(5)); |
| assertEquals(8274274654740644818l, //111-00101101-01000010-00001111-01011010-00011101-01011000-00111101-0010 |
| bin.readBits(63)); |
| assertEquals(330, // 0001-01001010 |
| bin.readBits(12)); |
| assertEquals(-1 , bin.readBits(1)); |
| } |
| } |
| |
| @Test |
| public void alignWithByteBoundaryWhenAtBoundary() throws Exception { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0xF8, bis.readBits(8)); |
| bis.alignWithByteBoundary(); |
| assertEquals(0, bis.readBits(4)); |
| } |
| } |
| |
| @Test |
| public void alignWithByteBoundaryWhenNotAtBoundary() throws Exception { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x08, bis.readBits(4)); |
| assertEquals(4, bis.bitsCached()); |
| bis.alignWithByteBoundary(); |
| assertEquals(0, bis.bitsCached()); |
| assertEquals(0, bis.readBits(4)); |
| } |
| } |
| |
| @Test |
| public void availableWithoutCache() throws Exception { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(32, bis.bitsAvailable()); |
| } |
| } |
| |
| @Test |
| public void availableWithCache() throws Exception { |
| try (final BitInputStream bis = new BitInputStream(getStream(), ByteOrder.LITTLE_ENDIAN)) { |
| assertEquals(0x08, bis.readBits(4)); |
| assertEquals(28, bis.bitsAvailable()); |
| } |
| } |
| |
| private ByteArrayInputStream getStream() { |
| return new ByteArrayInputStream(new byte[] { |
| (byte) 0xF8, // 11111000 |
| 0x40, // 01000000 |
| 0x01, // 00000001 |
| 0x2F }); // 00101111 |
| } |
| |
| } |