| /* |
| * 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.vxquery.runtime.functions.index.updateIndex; |
| |
| import org.apache.log4j.Level; |
| import org.apache.log4j.Logger; |
| |
| import javax.xml.bind.DatatypeConverter; |
| import javax.xml.bind.JAXBContext; |
| import javax.xml.bind.JAXBException; |
| import javax.xml.bind.Marshaller; |
| import javax.xml.bind.Unmarshaller; |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.nio.file.Files; |
| import java.nio.file.Paths; |
| import java.security.MessageDigest; |
| import java.security.NoSuchAlgorithmException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| /** |
| * Utility class for writing, reading metadata file and generating checksum. |
| */ |
| public class MetaFileUtil { |
| |
| private File metaFile; |
| private Logger LOGGER = Logger.getLogger("MetadataFileUtil"); |
| private String index; |
| private String collection; |
| private ConcurrentHashMap<String, XmlMetadata> indexMap = new ConcurrentHashMap<>(); |
| |
| public MetaFileUtil(String indexFolder) { |
| this.metaFile = new File(indexFolder + "/" + Constants.META_FILE_NAME); |
| } |
| |
| /** |
| * Checks for existing metadata file. |
| * |
| * @return true if the metadata file is present |
| */ |
| public boolean isMetaFilePresent() { |
| return metaFile.exists(); |
| } |
| |
| /** |
| * Update the content of the metadata map. |
| * If the current collection data is present, replace it. |
| * Otherwise insert new. |
| * @param metadataMap : Set of XmlMetaData objects. |
| * @param index : The path to index location. |
| */ |
| public void updateMetadataMap(ConcurrentHashMap<String, XmlMetadata> metadataMap, String index) { |
| this.indexMap = metadataMap; |
| this.index = index; |
| |
| } |
| |
| /** |
| * Method to get the set of xml metadata for a given collection |
| * |
| * @return : Map containing the set of XmlMetadata objects.\ |
| */ |
| public ConcurrentHashMap<String, XmlMetadata> getMetadata() { |
| return this.indexMap; |
| } |
| |
| /** |
| * Read the metadata file and create an in-memory map containing collection paths and xml files. |
| */ |
| public void readMetadataFile() { |
| try { |
| JAXBContext jaxbContext = JAXBContext.newInstance(VXQueryIndex.class); |
| Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller(); |
| XmlMetadataCollection indexes = (XmlMetadataCollection) jaxbUnmarshaller.unmarshal(metaFile); |
| |
| this.collection = indexes.getCollection(); |
| this.index = indexes.getIndexLocation(); |
| |
| for (XmlMetadata metadata : indexes.getMetadataList()) { |
| this.indexMap.put(index, metadata); |
| } |
| } catch (JAXBException e) { |
| if (LOGGER.isTraceEnabled()) { |
| LOGGER.log(Level.ERROR, "Could not read the XML file due to " + e); |
| } |
| } |
| } |
| |
| /** |
| * Write the content of the ConcurrentHashMap to the xml metadata file. |
| */ |
| public void writeMetadataToFile() { |
| XmlMetadataCollection collection = new XmlMetadataCollection(); |
| List<XmlMetadata> metadataList = new ArrayList<>(); |
| |
| for (Map.Entry<String, XmlMetadata> entry : this.indexMap.entrySet()) { |
| metadataList.add(entry.getValue()); |
| } |
| |
| collection.setMetadataList(metadataList); |
| collection.setCollection(this.collection); |
| collection.setIndexLocation(this.index); |
| try{ |
| FileOutputStream fileOutputStream = new FileOutputStream(this.metaFile); |
| JAXBContext jaxbContext = JAXBContext.newInstance(VXQueryIndex.class); |
| Marshaller jaxbMarshaller = jaxbContext.createMarshaller(); |
| jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); |
| jaxbMarshaller.marshal(collection, fileOutputStream); |
| |
| if (LOGGER.isDebugEnabled()) { |
| LOGGER.log(Level.DEBUG, "Writing metadata file completed successfully!"); |
| } |
| } catch (JAXBException | FileNotFoundException e) { |
| if (LOGGER.isTraceEnabled()) { |
| LOGGER.log(Level.ERROR, "Could not read the XML file due to " + e); |
| } |
| } |
| |
| |
| } |
| |
| |
| /** |
| * Generate MD5 checksum string for a given file. |
| * |
| * @param file : File which the checksum should be generated. |
| * @return : Checksum String |
| * @throws IOException : The file is not available |
| */ |
| public String generateMD5(File file) throws IOException { |
| try { |
| MessageDigest md = MessageDigest.getInstance("MD5"); |
| md.update(Files.readAllBytes(file.toPath())); |
| byte[] md5 = md.digest(); |
| return DatatypeConverter.printHexBinary(md5); |
| } catch (NoSuchAlgorithmException e) { |
| if (LOGGER.isTraceEnabled()) { |
| LOGGER.log(Level.ERROR, "No Such Algorithm Error " + e.getMessage()); |
| } |
| return null; |
| } |
| } |
| |
| /** |
| * Delete the existing Metadata file. |
| * |
| * @return True if deleted, false otherwise. |
| */ |
| public boolean deleteMetaDataFile() { |
| try { |
| Files.delete(Paths.get(metaFile.getCanonicalPath())); |
| if (LOGGER.isDebugEnabled()){ |
| LOGGER.log(Level.DEBUG, "Metadata file deleted!"); |
| } |
| return true; |
| } catch (IOException e) { |
| if (LOGGER.isTraceEnabled()){ |
| LOGGER.log(Level.ERROR, "Metadata file could not be deleted!"); |
| } |
| return false; |
| } |
| } |
| |
| /** |
| * Get the collection for a given index location. |
| * @return collection folder for a given index. |
| */ |
| public String getCollection() { |
| return this.collection; |
| } |
| |
| /** |
| * Set the entry for given index and collection. |
| * @param collection : path to corresponding collection |
| */ |
| public void setCollection(String collection) { |
| this.collection = collection; |
| } |
| } |