opendaylight/config/config-persister-file-xml-adapter/src/main/java/org/opendaylight/controller/config/persist/storage/file/xml/XmlFileStorageAdapter.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.config.persist.storage.file.xml;
  10
  11 import com.google.common.annotations.VisibleForTesting;
  12 import com.google.common.base.Optional;
  13 import com.google.common.base.Preconditions;
  14 import com.google.common.collect.Lists;
  15 import java.io.File;
  16 import java.io.IOException;
  17 import java.util.Collections;
  18 import java.util.List;
  19 import java.util.SortedSet;
  20 import org.opendaylight.controller.config.persist.api.ConfigSnapshotHolder;
  21 import org.opendaylight.controller.config.persist.api.Persister;
  22 import org.opendaylight.controller.config.persist.api.PropertiesProvider;
  23 import org.opendaylight.controller.config.persist.api.StorageAdapter;
  24 import org.opendaylight.controller.config.persist.storage.file.xml.model.Config;
  25 import org.opendaylight.controller.config.persist.storage.file.xml.model.ConfigSnapshot;
  26 import org.slf4j.Logger;
  27 import org.slf4j.LoggerFactory;
  28
  29 /**
  30  * StorageAdapter that stores configuration in an xml file.
  31  */
  32 public class XmlFileStorageAdapter implements StorageAdapter, Persister {
  33     private static final Logger LOG = LoggerFactory.getLogger(XmlFileStorageAdapter.class);
  34
  35     public static final String FILE_STORAGE_PROP = "fileStorage";
  36     public static final String NUMBER_OF_BACKUPS = "numberOfBackups";
  37
  38     private static Integer numberOfStoredBackups;
  39     private File storage;
  40
  41     @Override
  42     public Persister instantiate(PropertiesProvider propertiesProvider) {
  43         File storage = extractStorageFileFromProperties(propertiesProvider);
  44         LOG.debug("Using file {}", storage.getAbsolutePath());
  45         // Create file if it does not exist
  46         File parentFile = storage.getAbsoluteFile().getParentFile();
  47         if (parentFile.exists() == false) {
  48             LOG.debug("Creating parent folders {}", parentFile);
  49             parentFile.mkdirs();
  50         }
  51         if (storage.exists() == false) {
  52             LOG.debug("Storage file does not exist, creating empty file");
  53             try {
  54                 boolean result = storage.createNewFile();
  55                 if (result == false)
  56                     throw new RuntimeException("Unable to create storage file " + storage);
  57             } catch (IOException e) {
  58                 throw new RuntimeException("Unable to create storage file " + storage, e);
  59             }
  60         }
  61         if (numberOfStoredBackups == 0) {
  62             throw new RuntimeException(NUMBER_OF_BACKUPS
  63                     + " property should be either set to positive value, or ommited. Can not be set to 0.");
  64         }
  65         setFileStorage(storage);
  66         return this;
  67     }
  68
  69     @VisibleForTesting
  70     public void setFileStorage(File storage) {
  71         this.storage = storage;
  72     }
  73
  74     @VisibleForTesting
  75     public void setNumberOfBackups(Integer numberOfBackups) {
  76         numberOfStoredBackups = numberOfBackups;
  77     }
  78
  79     private static File extractStorageFileFromProperties(PropertiesProvider propertiesProvider) {
  80         String fileStorageProperty = propertiesProvider.getProperty(FILE_STORAGE_PROP);
  81         Preconditions.checkNotNull(fileStorageProperty, "Unable to find " + propertiesProvider.getFullKeyForReporting(FILE_STORAGE_PROP));
  82         File result = new File(fileStorageProperty);
  83         String numberOfBackupsAsString = propertiesProvider.getProperty(NUMBER_OF_BACKUPS);
  84         if (numberOfBackupsAsString != null) {
  85             numberOfStoredBackups = Integer.valueOf(numberOfBackupsAsString);
  86         } else {
  87             numberOfStoredBackups = Integer.MAX_VALUE;
  88         }
  89         LOG.trace("Property {} set to {}", NUMBER_OF_BACKUPS, numberOfStoredBackups);
  90         return result;
  91     }
  92
  93     @Override
  94     public void persistConfig(ConfigSnapshotHolder holder) throws IOException {
  95         Preconditions.checkNotNull(storage, "Storage file is null");
  96
  97         Config cfg = Config.fromXml(storage);
  98         cfg.addConfigSnapshot(ConfigSnapshot.fromConfigSnapshot(holder), numberOfStoredBackups);
  99         cfg.toXml(storage);
 100     }
 101
 102     @Override
 103     public List<ConfigSnapshotHolder> loadLastConfigs() throws IOException {
 104         Preconditions.checkNotNull(storage, "Storage file is null");
 105
 106         if (!storage.exists()) {
 107             return Collections.emptyList();
 108         }
 109
 110         Optional<ConfigSnapshot> lastSnapshot = Config.fromXml(storage).getLastSnapshot();
 111
 112         if (lastSnapshot.isPresent()) {
 113             return Lists.newArrayList(toConfigSnapshot(lastSnapshot.get()));
 114         } else {
 115             return Collections.emptyList();
 116         }
 117     }
 118
 119
 120     public ConfigSnapshotHolder toConfigSnapshot(final ConfigSnapshot configSnapshot) {
 121         return new ConfigSnapshotHolder() {
 122             @Override
 123             public String getConfigSnapshot() {
 124                 return configSnapshot.getConfigSnapshot();
 125             }
 126
 127             @Override
 128             public SortedSet<String> getCapabilities() {
 129                 return configSnapshot.getCapabilities();
 130             }
 131
 132             @Override
 133             public String toString() {
 134                 return configSnapshot.toString();
 135             }
 136         };
 137     }
 138
 139     @Override
 140     public void close() {
 141
 142     }
 143
 144     @Override
 145     public String toString() {
 146         return "XmlFileStorageAdapter [storage=" + storage + "]";
 147     }
 148
 149 }