+++ /dev/null
-package org.apache.lucene.util;
-
-/**
- * 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 org.apache.lucene.store.DataInput;
-import org.apache.lucene.store.DataOutput;
-import org.apache.lucene.index.CorruptIndexException;
-import org.apache.lucene.index.IndexFormatTooNewException;
-import org.apache.lucene.index.IndexFormatTooOldException;
-
-import java.io.IOException;
-
-/**
- * @lucene.experimental
- */
-
-public final class CodecUtil {
- private CodecUtil() {} // no instance
-
- private final static int CODEC_MAGIC = 0x3fd76c17;
-
- public static DataOutput writeHeader(DataOutput out, String codec, int version)
- throws IOException {
- BytesRef bytes = new BytesRef(codec);
- if (bytes.length != codec.length() || bytes.length >= 128) {
- throw new IllegalArgumentException("codec must be simple ASCII, less than 128 characters in length [got " + codec + "]");
- }
- out.writeInt(CODEC_MAGIC);
- out.writeString(codec);
- out.writeInt(version);
-
- return out;
- }
-
- public static int headerLength(String codec) {
- return 9+codec.length();
- }
-
- public static int checkHeader(DataInput in, String codec, int minVersion, int maxVersion)
- throws IOException {
-
- // Safety to guard against reading a bogus string:
- final int actualHeader = in.readInt();
- if (actualHeader != CODEC_MAGIC) {
- throw new CorruptIndexException("codec header mismatch: actual header=" + actualHeader + " vs expected header=" + CODEC_MAGIC);
- }
-
- final String actualCodec = in.readString();
- if (!actualCodec.equals(codec)) {
- throw new CorruptIndexException("codec mismatch: actual codec=" + actualCodec + " vs expected codec=" + codec);
- }
-
- final int actualVersion = in.readInt();
- if (actualVersion < minVersion) {
- throw new IndexFormatTooOldException(null, actualVersion, minVersion, maxVersion);
- }
- if (actualVersion > maxVersion) {
- throw new IndexFormatTooNewException(null, actualVersion, minVersion, maxVersion);
- }
-
- return actualVersion;
- }
-}