/**
* 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.drill.common.util;
import java.io.DataInput;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.lang3.exception.ExceptionUtils;
public class DataInputInputStream extends InputStream {
private final DataInput in;
private boolean closed = false;
/**
* Construct an InputStream from the given DataInput. If 'in'
* is already an InputStream, simply returns it. Otherwise, wraps
* it in an InputStream.
* @param in the DataInput to wrap
* @return an InputStream instance that inputs to 'in'
*/
public static InputStream constructInputStream(DataInput in) {
if (in instanceof InputStream) {
return (InputStream)in;
} else {
return new DataInputInputStream(in);
}
}
private DataInputInputStream(DataInput in) {
this.in = in;
}
@Override
public void close() {
this.closed = true;
}
@Override
public int available() {
return this.closed ? 0 : 1;
}
@Override
public int read() throws IOException {
return in.readByte();
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
for (int i = off; i < off + len; i++) {
try {
b[i] = in.readByte();
} catch(Exception e) {
if (ExceptionUtils.getRootCause(e) instanceof EOFException) {
return i - off;
} else {
throw e;
}
}
}
return len;
}
@Override
public int read(byte[] b) throws IOException {
for (int i = 0; i < b.length; i++) {
try {
b[i] = in.readByte();
} catch (EOFException e) {
close();
return i;
}
}
return b.length;
}
}