/*
* Licensed to ElasticSearch and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch 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.elasticsearch.common.lucene.store;
import org.apache.lucene.store.IndexInput;
import java.io.IOException;
import java.io.InputStream;
/**
*
*/
public class InputStreamIndexInput extends InputStream {
private final IndexInput indexInput;
private final long limit;
private final long actualSizeToRead;
private long counter = 0;
private long markPointer;
private long markCounter;
public InputStreamIndexInput(IndexInput indexInput, long limit) {
this.indexInput = indexInput;
this.limit = limit;
if ((indexInput.length() - indexInput.getFilePointer()) > limit) {
actualSizeToRead = limit;
} else {
actualSizeToRead = indexInput.length() - indexInput.getFilePointer();
}
}
public long actualSizeToRead() {
return actualSizeToRead;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (b == null) {
throw new NullPointerException();
} else if (off < 0 || len < 0 || len > b.length - off) {
throw new IndexOutOfBoundsException();
}
if (indexInput.getFilePointer() >= indexInput.length()) {
return -1;
}
if (indexInput.getFilePointer() + len > indexInput.length()) {
len = (int) (indexInput.length() - indexInput.getFilePointer());
}
if (counter + len > limit) {
len = (int) (limit - counter);
}
if (len <= 0) {
return -1;
}
indexInput.readBytes(b, off, len, false);
counter += len;
return len;
}
@Override
public int read() throws IOException {
if (counter++ >= limit) {
return -1;
}
return (indexInput.getFilePointer() < indexInput.length()) ? (indexInput.readByte() & 0xff) : -1;
}
@Override
public boolean markSupported() {
return true;
}
@Override
public synchronized void mark(int readlimit) {
markPointer = indexInput.getFilePointer();
markCounter = counter;
}
@Override
public synchronized void reset() throws IOException {
indexInput.seek(markPointer);
counter = markCounter;
}
}