/*
* 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.flink.api.common.io;
import org.apache.flink.annotation.Public;
import org.apache.flink.core.fs.FSDataInputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
/**
* This class wraps an {@link java.io.InputStream} and exposes it as {@link org.apache.flink.core.fs.FSDataInputStream}.
* <br>
* <i>NB: {@link #seek(long)} and {@link #getPos()} are currently not supported.</i>
*/
@Public
public class InputStreamFSInputWrapper extends FSDataInputStream {
private final InputStream inStream;
private long pos = 0;
public InputStreamFSInputWrapper(InputStream inStream) {
this.inStream = inStream;
}
@Override
public void close() throws IOException {
this.inStream.close();
}
@Override
public void seek(long desired) throws IOException {
if (desired < this.pos) {
throw new IllegalArgumentException("Wrapped InputStream: cannot search backwards.");
}
while (this.pos < desired) {
long numReadBytes = this.inStream.skip(desired - pos);
if (numReadBytes == -1) {
throw new EOFException("Unexpected EOF during forward seek.");
}
this.pos += numReadBytes;
}
}
@Override
public long getPos() throws IOException {
return this.pos;
}
@Override
public int read() throws IOException {
int read = inStream.read();
if (read != -1) {
this.pos++;
}
return read;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
int numReadBytes = inStream.read(b, off, len);
if (numReadBytes != -1) {
this.pos += numReadBytes;
}
return numReadBytes;
}
@Override
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
}