Java tutorial
/* * Copyright 2016-present Open Networking Foundation * * Licensed 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.onlab.util; import com.google.common.testing.EqualsTester; import org.apache.commons.lang3.RandomUtils; import org.junit.Assert; import org.junit.Rule; import org.junit.Test; import org.junit.rules.ExpectedException; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.util.Random; import static java.lang.Integer.max; import static java.lang.String.format; import static org.hamcrest.MatcherAssert.assertThat; import static org.hamcrest.Matchers.equalTo; import static org.hamcrest.Matchers.is; public class ImmutableByteSequenceTest { public static final int MIN_RAND_FIT_VALUE = 0xf; public static final int MAX_RAND_FIT_VALUE = 0x7fffffff; @Rule public ExpectedException thrown = ExpectedException.none(); @Test public void testCopy() throws Exception { byte byteValue = (byte) 1; short shortValue = byteValue; int intValue = byteValue; long longValue = byteValue; byte[] arrayValue = new byte[64]; arrayValue[63] = byteValue; ByteBuffer bufferValue = ByteBuffer.allocate(64).put(arrayValue); ImmutableByteSequence bsByte = ImmutableByteSequence.copyFrom(byteValue); ImmutableByteSequence bsShort = ImmutableByteSequence.copyFrom(shortValue); ImmutableByteSequence bsInt = ImmutableByteSequence.copyFrom(intValue); ImmutableByteSequence bsLong = ImmutableByteSequence.copyFrom(longValue); ImmutableByteSequence bsArray = ImmutableByteSequence.copyFrom(arrayValue); ImmutableByteSequence bsBuffer = ImmutableByteSequence.copyFrom(bufferValue); assertThat("byte sequence of a byte value must have size 1", bsByte.size(), is(equalTo(1))); assertThat("byte sequence of a short value must have size 2", bsShort.size(), is(equalTo(2))); assertThat("byte sequence of an int value must have size 4", bsInt.size(), is(equalTo(4))); assertThat("byte sequence of a long value must have size 8", bsLong.size(), is(equalTo(8))); assertThat("byte sequence of a byte array value must have same size of the array", bsArray.size(), is(equalTo(arrayValue.length))); assertThat("byte sequence of a byte buffer value must have same size of the buffer", bsBuffer.size(), is(equalTo(bufferValue.capacity()))); String errStr = "incorrect byte sequence value"; assertThat(errStr, bsByte.asArray()[0], is(equalTo(byteValue))); assertThat(errStr, bsShort.asArray()[1], is(equalTo(byteValue))); assertThat(errStr, bsInt.asArray()[3], is(equalTo(byteValue))); assertThat(errStr, bsLong.asArray()[7], is(equalTo(byteValue))); assertThat(errStr, bsArray.asArray()[63], is(equalTo(byteValue))); assertThat(errStr, bsBuffer.asArray()[63], is(equalTo(byteValue))); } @Test public void testEndianness() throws Exception { long longValue = RandomUtils.nextLong(); // creates a new sequence from a big-endian buffer ByteBuffer bbBigEndian = ByteBuffer.allocate(8).order(ByteOrder.BIG_ENDIAN).putLong(longValue); ImmutableByteSequence bsBufferCopyBigEndian = ImmutableByteSequence.copyFrom(bbBigEndian); // creates a new sequence from a little-endian buffer ByteBuffer bbLittleEndian = ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN).putLong(longValue); ImmutableByteSequence bsBufferCopyLittleEndian = ImmutableByteSequence.copyFrom(bbLittleEndian); // creates a new sequence from primitive type ImmutableByteSequence bsLongCopy = ImmutableByteSequence.copyFrom(longValue); new EqualsTester() // big-endian byte array cannot be equal to little-endian array .addEqualityGroup(bbBigEndian.array()).addEqualityGroup(bbLittleEndian.array()) // all byte sequences must be equal .addEqualityGroup(bsBufferCopyBigEndian, bsBufferCopyLittleEndian, bsLongCopy) // byte buffer views of all sequences must be equal .addEqualityGroup(bsBufferCopyBigEndian.asReadOnlyBuffer(), bsBufferCopyLittleEndian.asReadOnlyBuffer(), bsLongCopy.asReadOnlyBuffer()) // byte buffer orders of all sequences must be ByteOrder.BIG_ENDIAN .addEqualityGroup(bsBufferCopyBigEndian.asReadOnlyBuffer().order(), bsBufferCopyLittleEndian.asReadOnlyBuffer().order(), bsLongCopy.asReadOnlyBuffer().order(), ByteOrder.BIG_ENDIAN) .testEquals(); } @Test public void testBitSetMethods() throws Exception { // All zeros tests assertThat("3 bytes, all 0's", ImmutableByteSequence.ofZeros(3), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { 0, 0, 0 })))); assertThat("3 bytes, all 0's via prefix", ImmutableByteSequence.prefixZeros(3, 3 * Byte.SIZE), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { 0, 0, 0 })))); // All ones tests assertThat("3 bytes, all 1's", ImmutableByteSequence.ofZeros(3), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { 0, 0, 0 })))); assertThat("3 bytes, all 1's via prefix", ImmutableByteSequence.prefixOnes(3, 3 * Byte.SIZE), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xff })))); // Zero prefix tests assertThat("2 bytes, prefixed with 5 0's", ImmutableByteSequence.prefix(2, 5, (byte) 0), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { (byte) 0x7, (byte) 0xff })))); assertThat("4 bytes, prefixed with 16 0's", ImmutableByteSequence.prefix(4, 16, (byte) 0), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { 0, 0, (byte) 0xff, (byte) 0xff })))); assertThat("4 bytes, prefixed with 20 0's", ImmutableByteSequence.prefix(4, 20, (byte) 0), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { 0, 0, (byte) 0x0f, (byte) 0xff })))); assertThat("8 bytes, prefixed with 36 0's", ImmutableByteSequence.prefixZeros(8, 38), is(equalTo(ImmutableByteSequence .copyFrom(new byte[] { 0, 0, 0, 0, (byte) 0x03, (byte) 0xff, (byte) 0xff, (byte) 0xff })))); // Ones prefix tests assertThat("2 bytes, prefixed with 5 1's", ImmutableByteSequence.prefix(2, 5, (byte) 0xff), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { (byte) 0xf8, 0 })))); assertThat("4 bytes, prefixed with 16 1's", ImmutableByteSequence.prefix(4, 16, (byte) 0xff), is(equalTo(ImmutableByteSequence.copyFrom(new byte[] { (byte) 0xff, (byte) 0xff, 0, 0 })))); assertThat("4 bytes, prefixed with 20 1's", ImmutableByteSequence.prefix(4, 20, (byte) 0xff), is( equalTo(ImmutableByteSequence.copyFrom(new byte[] { (byte) 0xff, (byte) 0xff, (byte) 0xf0, 0 })))); assertThat("8 bytes, prefixed with 10 1's", ImmutableByteSequence.prefixOnes(8, 10), is(equalTo( ImmutableByteSequence.copyFrom(new byte[] { (byte) 0xff, (byte) 0xc0, 0, 0, 0, 0, 0, 0 })))); } @Test public void testBadPrefixVal() { thrown.expect(IllegalArgumentException.class); thrown.reportMissingExceptionWithMessage("Expect IllegalArgumentException due to val = 0x7"); ImmutableByteSequence.prefix(5, 10, (byte) 0x7); } @Test public void testMsbIndex() { assertThat("Value 0 should have MSB index -1", ImmutableByteSequence.copyFrom(0).msbIndex(), is(-1)); for (int i = 0; i < 63; i++) { long value = (long) Math.pow(2, i); assertThat(format("Value %d should have MSB index %d", value, i), ImmutableByteSequence.copyFrom(value).msbIndex(), is(i)); } } private void checkIllegalFit(ImmutableByteSequence bytes, int bitWidth) { try { bytes.fit(bitWidth); Assert.fail(format("Except ByteSequenceTrimException due to value = %s and bitWidth %d", bytes.toString(), bitWidth)); } catch (ImmutableByteSequence.ByteSequenceTrimException e) { // We expect this. } } private void checkLegalFit(ImmutableByteSequence bytes, int bitWidth) throws ImmutableByteSequence.ByteSequenceTrimException { ImmutableByteSequence fitBytes = bytes.fit(bitWidth); ImmutableByteSequence sameBytes = fitBytes.fit(bytes.size() * 8); assertThat(format("Fitted value %s (re-extended to %s) not equal to original value %s", fitBytes, sameBytes, bytes), sameBytes, is(equalTo(bytes))); } @Test public void testFit() throws ImmutableByteSequence.ByteSequenceTrimException { // Test fit by forcing a given MSB index. for (int msbIndex = 0; msbIndex < 32; msbIndex++) { long value = (long) Math.pow(2, msbIndex); ImmutableByteSequence bytes = ImmutableByteSequence.copyFrom(value); checkLegalFit(bytes, msbIndex + 1); if (msbIndex != 0) { checkIllegalFit(bytes, msbIndex); } } } @Test public void testRandomFit() throws ImmutableByteSequence.ByteSequenceTrimException { // Test fit against the computed MSB index. Random random = new Random(); for (int i = 0; i < 1000; i++) { int randValue = random.nextInt((MAX_RAND_FIT_VALUE - MIN_RAND_FIT_VALUE) + 1) + MIN_RAND_FIT_VALUE; ImmutableByteSequence bytes = ImmutableByteSequence.copyFrom((long) randValue); int msbIndex = bytes.msbIndex(); // Truncate. checkIllegalFit(bytes, max(msbIndex - random.nextInt(16), 1)); // Expand. checkLegalFit(bytes, msbIndex + 2 + random.nextInt(128)); // Fit to same bit-width of original value. checkLegalFit(bytes, msbIndex + 1); } } @Test public void testBitwiseOperations() { Random random = new Random(); long long1 = random.nextLong(); long long2 = random.nextLong(); ImmutableByteSequence bs1 = ImmutableByteSequence.copyFrom(long1); ImmutableByteSequence bs2 = ImmutableByteSequence.copyFrom(long2); ImmutableByteSequence andBs = bs1.bitwiseAnd(bs2); ImmutableByteSequence orBs = bs1.bitwiseOr(bs2); ImmutableByteSequence xorBs = bs1.bitwiseXor(bs2); assertThat("Invalid bitwise AND result", andBs.asReadOnlyBuffer().getLong(), is(long1 & long2)); assertThat("Invalid bitwise OR result", orBs.asReadOnlyBuffer().getLong(), is(long1 | long2)); assertThat("Invalid bitwise XOR result", xorBs.asReadOnlyBuffer().getLong(), is(long1 ^ long2)); } }