package org.apache.lucene.util.encoding;
import java.io.IOException;
import java.io.StreamCorruptedException;
/*
* 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.
*/
/**
* A simple stream decoder which can decode values encoded with
* {@link SimpleIntEncoder}.
*
* @lucene.experimental
*/
public class SimpleIntDecoder extends IntDecoder {
/**
* reusable buffer - allocated only once as this is not a thread-safe object
*/
private byte[] buffer = new byte[4];
@Override
public long decode() throws IOException {
// we need exactly 4 bytes to decode an int in this decoder impl, otherwise, throw an exception
int offset = 0;
while (offset < 4) {
int nRead = in.read(buffer, offset, 4 - offset);
if (nRead == -1) {
if (offset > 0) {
throw new StreamCorruptedException(
"Need 4 bytes for decoding an int, got only " + offset);
}
return EOS;
}
offset += nRead;
}
int v = buffer[3] & 0xff;
v |= (buffer[2] << 8) & 0xff00;
v |= (buffer[1] << 16) & 0xff0000;
v |= (buffer[0] << 24) & 0xff000000;
return v;
}
@Override
public String toString() {
return "Simple";
}
}