package org.apache.lucene.util;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import org.junit.Test;
import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util.Vint8;
/*
* 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.
*/
/**
* Tests the {@link Vint8} class.
*/
public class Vint8Test extends LuceneTestCase {
/**
* Tests the position wrapper.
* @throws Exception For any reason.
*/
@Test
public void testPosition() throws Exception {
Vint8.Position pos = new Vint8.Position();
assertEquals(0, pos.pos);
pos = new Vint8.Position(12345);
assertEquals(12345, pos.pos);
}
private static int[] testValues = {
-1000000000,
-1, 0, (1 << 7) - 1, 1 << 7, (1 << 14) - 1, 1 << 14,
(1 << 21) - 1, 1 << 21, (1 << 28) - 1, 1 << 28
};
private static int[] bytesNeededTestValues = {
5, 5, 1, 1, 2, 2, 3, 3, 4, 4, 5
};
/**
* Tests the {@code bytesNeeded} method.
*/
@Test
public void testBytesNeeded() {
assertEquals(5, Vint8.MAXIMUM_BYTES_NEEDED);
for (int j = 0; j < testValues.length; j++) {
assertEquals(bytesNeededTestValues[j], Vint8.bytesNeeded(testValues[j]));
}
}
/**
* Tests encoding and decoding to and from a stream.
*/
@Test
public void testStreamEncodingAndDecoding() throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream(256);
int expectedSize = 0;
for (int j = 0; j < testValues.length; j++) {
Vint8.encode(testValues[j], baos);
expectedSize += bytesNeededTestValues[j];
}
assertEquals(expectedSize, baos.size());
ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
for (int j = 0; j < testValues.length; j++) {
assertEquals(testValues[j], Vint8.decode(bais));
}
assertEquals(0, bais.available());
}
/**
* Tests encoding and decoding to and from an array.
*/
@Test
public void testArrayEncodingAndDecoding() throws IOException {
byte[] byteArray = new byte[256];
int position = 0, expectedSize = 0;
for (int j = 0; j < testValues.length; j++) {
position += Vint8.encode(testValues[j], byteArray, position);
expectedSize += bytesNeededTestValues[j];
}
assertEquals(expectedSize, position);
Vint8.Position pos = new Vint8.Position();
for (int j = 0; j < testValues.length; j++) {
assertEquals(testValues[j], Vint8.decode(byteArray, pos));
}
assertEquals(expectedSize, pos.pos);
}
/**
* The result of encoding the test values with the current algorithm. If these
* values are changed to match an algorithm change, compatibility with legacy
* data will be broken.
*/
private static final byte[] encodedTestValues = {
-4, -93, -108, -20, 0, -1, -1, -1, -1, 127, 0, 127, -127, 0, -1, 127,
-127, -128, 0, -1, -1, 127, -127, -128, -128, 0, -1, -1, -1, 127, -127,
-128, -128, -128, 0
};
/**
* Tests algorithm.
*/
@Test
public void testLegacyCompatibility() throws IOException {
/* To generate the encoded test values:
byte[] byteArray = new byte[256];
int position = 0, expectedSize = 0;
for (int j = 0; j < testValues.length; j++) {
position += Vint8.encode(testValues[j], byteArray, position);
expectedSize += bytesNeededTestValues[j];
}
assertEquals(expectedSize, position);
Vint8.Position pos = new Vint8.Position();
for (int j = 0; j < expectedSize; j++) {
System.out.print(byteArray[j] + ", ");
}
System.out.flush();
pos.pos = 0;
*/
Vint8.Position pos = new Vint8.Position();
for (int j = 0; j < testValues.length; j++) {
assertEquals(testValues[j], Vint8.decode(encodedTestValues, pos));
}
}
} // end class Vint8Test