com.hazelcast.internal.util.BufferingInputStream Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2017, Hazelcast, Inc. 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.
* 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 com.hazelcast.internal.util;
import java.io.IOException;
import java.io.InputStream;
import static java.lang.System.arraycopy;
/**
* {@link InputStream} implementation with a configurable buffer.
*/
public class BufferingInputStream extends InputStream {
private static final int BYTE_MASK = 0xff;
private final InputStream in;
private final byte[] buf;
private int position;
private int limit;
public BufferingInputStream(InputStream in, int bufferSize) {
this.in = in;
this.buf = new byte[bufferSize];
}
@Override
public int read() throws IOException {
if (!ensureDataInBuffer()) {
return -1;
}
return buf[position++] & BYTE_MASK;
}
@Override
@SuppressWarnings("NullableProblems")
public int read(byte[] destBuf, int off, int len) throws IOException {
if (!ensureDataInBuffer()) {
return -1;
}
int transferredCount = Math.min(limit - position, len);
arraycopy(buf, position, destBuf, off, transferredCount);
position += transferredCount;
return transferredCount;
}
@Override
public void close() throws IOException {
in.close();
}
private boolean ensureDataInBuffer() throws IOException {
if (position != limit) {
return true;
}
position = 0;
final int newLimit = in.read(buf);
if (newLimit == -1) {
limit = 0;
return false;
} else {
limit = newLimit;
return true;
}
}
}