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.Set;
  20 import java.util.SortedSet;
  21 import org.opendaylight.controller.config.persist.api.ConfigSnapshotHolder;
  22 import org.opendaylight.controller.config.persist.api.Persister;
  23 import org.opendaylight.controller.config.persist.api.PropertiesProvider;
  24 import org.opendaylight.controller.config.persist.api.StorageAdapter;
  25 import org.opendaylight.controller.config.persist.storage.file.xml.model.Config;
  26 import org.opendaylight.controller.config.persist.storage.file.xml.model.ConfigSnapshot;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 /**
  31  * StorageAdapter that stores configuration in an xml file.
  32  */
  33 public class XmlFileStorageAdapter implements StorageAdapter, Persister {
  34     private static final Logger LOG = LoggerFactory.getLogger(XmlFileStorageAdapter.class);
  35
  36     public static final String FILE_STORAGE_PROP = "fileStorage";
  37     public static final String NUMBER_OF_BACKUPS = "numberOfBackups";
  38
  39     private static Integer numberOfStoredBackups;
  40     private File storage;
  41
  42     private static volatile XmlFileStorageAdapter instance;
  43     private volatile ConfigSnapshot lastCfgSnapshotCache;
  44     private volatile Optional<FeatureListProvider> featuresService = Optional.absent();
  45
  46     @VisibleForTesting
  47     public void reset() {
  48         instance = null;
  49         lastCfgSnapshotCache = null;
  50         featuresService = null;
  51     }
  52
  53     @Override
  54     public Persister instantiate(final PropertiesProvider propertiesProvider) {
  55         if(instance != null) {
  56             return instance;
  57         }
  58
  59         File localStorage = extractStorageFileFromProperties(propertiesProvider);
  60         LOG.debug("Using file {}", localStorage.getAbsolutePath());
  61         // Create file if it does not exist
  62         File parentFile = localStorage.getAbsoluteFile().getParentFile();
  63         if (!parentFile.exists()) {
  64             LOG.debug("Creating parent folders {}", parentFile);
  65             parentFile.mkdirs();
  66         }
  67         if (!localStorage.exists()) {
  68             LOG.debug("Storage file does not exist, creating empty file");
  69             try {
  70                 boolean result = localStorage.createNewFile();
  71                 if (!result) {
  72                     throw new RuntimeException("Unable to create storage file " + localStorage);
  73                 }
  74             } catch (final IOException e) {
  75                 throw new RuntimeException("Unable to create storage file " + localStorage, e);
  76             }
  77         }
  78         if (numberOfStoredBackups == 0) {
  79             throw new RuntimeException(NUMBER_OF_BACKUPS
  80                     + " property should be either set to positive value, or ommited. Can not be set to 0.");
  81         }
  82         setFileStorage(localStorage);
  83
  84         instance = this;
  85         return this;
  86     }
  87
  88     public static Optional<XmlFileStorageAdapter> getInstance() {
  89         return Optional.fromNullable(instance);
  90     }
  91
  92     public Set<String> getPersistedFeatures() {
  93         return lastCfgSnapshotCache == null ? Collections.<String>emptySet() : lastCfgSnapshotCache.getFeatures();
  94     }
  95
  96     public void setFeaturesService(final FeatureListProvider featuresService) {
  97         this.featuresService = Optional.of(featuresService);
  98     }
  99
 100     @VisibleForTesting
 101     public void setFileStorage(final File storage) {
 102         this.storage = storage;
 103     }
 104
 105     @VisibleForTesting
 106     public void setNumberOfBackups(final Integer numberOfBackups) {
 107         numberOfStoredBackups = numberOfBackups;
 108     }
 109
 110     private static File extractStorageFileFromProperties(final PropertiesProvider propertiesProvider) {
 111         String fileStorageProperty = propertiesProvider.getProperty(FILE_STORAGE_PROP);
 112         Preconditions.checkNotNull(fileStorageProperty, "Unable to find " + propertiesProvider.getFullKeyForReporting(FILE_STORAGE_PROP));
 113         File result = new File(fileStorageProperty);
 114         String numberOfBackupsAsString = propertiesProvider.getProperty(NUMBER_OF_BACKUPS);
 115         if (numberOfBackupsAsString != null) {
 116             numberOfStoredBackups = Integer.valueOf(numberOfBackupsAsString);
 117         } else {
 118             numberOfStoredBackups = Integer.MAX_VALUE;
 119         }
 120         LOG.trace("Property {} set to {}", NUMBER_OF_BACKUPS, numberOfStoredBackups);
 121         return result;
 122     }
 123
 124     @Override
 125     public void persistConfig(final ConfigSnapshotHolder holder) throws IOException {
 126         Preconditions.checkNotNull(storage, "Storage file is null");
 127
 128         Set<String> installedFeatureIds = Collections.emptySet();
 129         if(featuresService.isPresent()) {
 130             installedFeatureIds = featuresService.get().listFeatures();
 131         }
 132
 133         Config cfg = Config.fromXml(storage);
 134         cfg.addConfigSnapshot(ConfigSnapshot.fromConfigSnapshot(holder, installedFeatureIds), numberOfStoredBackups);
 135         cfg.toXml(storage);
 136     }
 137
 138     @Override
 139     public List<ConfigSnapshotHolder> loadLastConfigs() throws IOException {
 140         Preconditions.checkNotNull(storage, "Storage file is null");
 141
 142         if (!storage.exists()) {
 143             return Collections.emptyList();
 144         }
 145
 146         Optional<ConfigSnapshot> lastSnapshot = Config.fromXml(storage).getLastSnapshot();
 147
 148         if (lastSnapshot.isPresent()) {
 149             lastCfgSnapshotCache = lastSnapshot.get();
 150             return Lists.newArrayList(toConfigSnapshot(lastCfgSnapshotCache));
 151         } else {
 152             return Collections.emptyList();
 153         }
 154     }
 155
 156
 157     public ConfigSnapshotHolder toConfigSnapshot(final ConfigSnapshot configSnapshot) {
 158         return new ConfigSnapshotHolder() {
 159             @Override
 160             public String getConfigSnapshot() {
 161                 return configSnapshot.getConfigSnapshot();
 162             }
 163
 164             @Override
 165             public SortedSet<String> getCapabilities() {
 166                 return configSnapshot.getCapabilities();
 167             }
 168
 169             @Override
 170             public String toString() {
 171                 return configSnapshot.toString();
 172             }
 173         };
 174     }
 175
 176     @Override
 177     public void close() {
 178
 179     }
 180
 181     @Override
 182     public String toString() {
 183         return "XmlFileStorageAdapter [storage=" + storage + "]";
 184     }
 185
 186 }