content: /*
   * 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.asterix.external.util;
  
  import java.io.IOException;
  import java.io.StringWriter;
  import java.security.MessageDigest;
  import java.util.List;
  import java.util.Map;
  import java.util.TreeMap;
  
  import org.apache.asterix.common.library.ILibraryManager;
  import org.apache.asterix.common.metadata.Namespace;
  import org.apache.hyracks.algebricks.common.utils.Pair;
  import org.apache.hyracks.util.bytes.HexPrinter;
  
  public class ExternalLibraryUtils {
  
      private ExternalLibraryUtils() {
      }
  
      public static String digestToHexString(MessageDigest digest) throws IOException {
          byte[] hashBytes = digest.digest();
          StringWriter hashBuilder = new StringWriter();
          HexPrinter.printHexString(hashBytes, 0, hashBytes.length, hashBuilder);
          return hashBuilder.toString();
      }
  
      public static Map<Namespace, Map<String, String>> produceLibraryListing(ILibraryManager libraryManager)
              throws IOException {
          List<Pair<Namespace, String>> libs = libraryManager.getLibraryListing();
          Map<Namespace, Map<String, String>> dvToLibHashes = new TreeMap<>();
          for (Pair<Namespace, String> lib : libs) {
              dvToLibHashes.computeIfAbsent(lib.first, h -> new TreeMap<>()).put(lib.getSecond(),
                      libraryManager.getLibraryHash(lib.first, lib.second));
          }
          return dvToLibHashes;
      }
  }
  