org.apache.hudi.org.apache.commons.io.input.CircularInputStream Maven / Gradle / Ivy
/*
* 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.io.input;
import java.io.IOException;
import java.io.InputStream;
import java.util.Objects;
import org.apache.commons.io.IOUtils;
/**
*
* An {@link InputStream} that repeats provided bytes for given target byte count.
*
* Closing this input stream has no effect. The methods in this class can be called after the stream has been closed
* without generating an {@link IOException}.
*
*
* @see InfiniteCircularInputStream
* @since 2.8.0
*/
public class CircularInputStream extends InputStream {
/**
* Throws an {@link IllegalArgumentException} if the input contains -1.
*
* @param repeatContent input to validate.
* @return the input.
*/
private static byte[] validate(final byte[] repeatContent) {
Objects.requireNonNull(repeatContent, "repeatContent");
for (final byte b : repeatContent) {
if (b == IOUtils.EOF) {
throw new IllegalArgumentException("repeatContent contains the end-of-stream marker " + IOUtils.EOF);
}
}
return repeatContent;
}
private long byteCount;
private int position = -1;
private final byte[] repeatedContent;
private final long targetByteCount;
/**
* Creates an instance from the specified array of bytes.
*
* @param repeatContent Input buffer to be repeated this buffer is not copied.
* @param targetByteCount How many bytes the read. A negative number means an infinite target count.
*/
public CircularInputStream(final byte[] repeatContent, final long targetByteCount) {
this.repeatedContent = validate(repeatContent);
if (repeatContent.length == 0) {
throw new IllegalArgumentException("repeatContent is empty.");
}
this.targetByteCount = targetByteCount;
}
@Override
public int read() {
if (targetByteCount >= 0) {
if (byteCount == targetByteCount) {
return IOUtils.EOF;
}
byteCount++;
}
position = (position + 1) % repeatedContent.length;
return repeatedContent[position] & 0xff;
}
}