/*
* Copyright 2010-2017 Amazon.com, Inc. or its affiliates. All Rights
* Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 com.amazonaws.internal;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import org.junit.Test;
/**
* This test demonstrates why we should call mark(Integer.MAX_VALUE) instead of
* mark(-1).
*/
public class BufferedInputStreamResetTest {
@Test
public void testNeatives() throws IOException {
testNegative(-1); // fixed buffer
testNegative(19); // 1 byte short
}
private void testNegative(final int readLimit) throws IOException {
byte[] bytes = new byte[100];
for (int i=0; i < bytes.length; i++)
bytes[i] = (byte)i;
// buffer of 10 bytes
BufferedInputStream bis =
new BufferedInputStream(new ByteArrayInputStream(bytes), 10);
// skip 10 bytes
bis.skip(10);
bis.mark(readLimit); // 1 byte short in buffer size
// read 30 bytes in total, with internal buffer incread to 20
bis.read(new byte[20]);
try {
bis.reset();
fail();
} catch(IOException ex) {
assertEquals("Resetting to invalid mark", ex.getMessage());
}
}
@Test
public void testPositives() throws IOException {
testPositive(20); // just enough
testPositive(Integer.MAX_VALUE);
}
private void testPositive(final int readLimit) throws IOException {
byte[] bytes = new byte[100];
for (int i=0; i < bytes.length; i++)
bytes[i] = (byte)i;
// buffer of 10 bytes
BufferedInputStream bis =
new BufferedInputStream(new ByteArrayInputStream(bytes), 10);
// skip 10 bytes
bis.skip(10);
bis.mark(readLimit); // buffer size would increase up to readLimit
// read 30 bytes in total, with internal buffer increased to 20
bis.read(new byte[20]);
bis.reset();
assert(bis.read() == 10);
}
}