| /* |
| * 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.sling.nosql.couchbase.client; |
| |
| import java.io.UnsupportedEncodingException; |
| import java.security.MessageDigest; |
| import java.security.NoSuchAlgorithmException; |
| |
| import aQute.bnd.annotation.ProviderType; |
| |
| /** |
| * Builds couchbase keys. Cuts them off and replaces the remaining part with a hash if too long. |
| */ |
| @ProviderType |
| public final class CouchbaseKey { |
| |
| static final int MAX_KEY_LENGTH = 250; |
| |
| private CouchbaseKey() { |
| // static methods only |
| } |
| |
| /** |
| * Builds a key for a couchbase document with the given prefix that does not |
| * exceed the max. length for couchbase keys. |
| * @param key Full key |
| * @param keyPrefix Prefix to add before the key |
| * @return Valid key for couchbase |
| */ |
| public static String build(String key, String keyPrefix) { |
| String cacheKey = keyPrefix + key; |
| |
| if (cacheKey.length() < MAX_KEY_LENGTH) { |
| return cacheKey; |
| } |
| |
| int charactersToKeep = MAX_KEY_LENGTH - keyPrefix.length() - 41; |
| |
| String toKeep = key.substring(0, charactersToKeep); |
| String toHash = key.substring(charactersToKeep); |
| |
| String hash = calculateHash(toHash); |
| |
| return keyPrefix + toKeep + "#" + hash; |
| } |
| |
| private static String calculateHash(String message) { |
| try { |
| MessageDigest digest = MessageDigest.getInstance("SHA-1"); |
| digest.update(message.getBytes("UTF-8")); |
| byte[] digestBytes = digest.digest(); |
| |
| return javax.xml.bind.DatatypeConverter.printHexBinary(digestBytes).toLowerCase(); |
| } |
| catch (NoSuchAlgorithmException ex) { |
| throw new RuntimeException("Failed to create sha1 Hash from " + message, ex); |
| } |
| catch (UnsupportedEncodingException ex) { |
| throw new RuntimeException("Failed to create sha1 Hash from " + message, ex); |
| } |
| } |
| |
| } |