package org.apache.lucene.store; /** * 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. */ import java.io.IOException; import java.util.zip.CRC32; import java.util.zip.Checksum; /** Writes bytes through to a primary IndexOutput, computing * checksum as it goes. Note that you cannot use seek(). */ public class ChecksumIndexInput extends IndexInput { IndexInput main; Checksum digest; public ChecksumIndexInput(IndexInput main) { this.main = main; digest = new CRC32(); } public byte readByte() throws IOException { final byte b = main.readByte(); digest.update(b); return b; } public void readBytes(byte[] b, int offset, int len) throws IOException { main.readBytes(b, offset, len); digest.update(b, offset, len); } public long getChecksum() { return digest.getValue(); } public void close() throws IOException { main.close(); } public long getFilePointer() { return main.getFilePointer(); } public void seek(long pos) { throw new RuntimeException("not allowed"); } public long length() { return main.length(); } }