opendaylight/config/config-persister-impl/src/main/java/org/opendaylight/controller/config/persist/impl/PersisterAggregator.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.impl;
  10
  11 import com.google.common.annotations.VisibleForTesting;
  12 import java.io.IOException;
  13 import java.util.ArrayList;
  14 import java.util.Collections;
  15 import java.util.List;
  16 import java.util.ListIterator;
  17 import org.opendaylight.controller.config.persist.api.ConfigSnapshotHolder;
  18 import org.opendaylight.controller.config.persist.api.Persister;
  19 import org.opendaylight.controller.config.persist.api.PropertiesProvider;
  20 import org.opendaylight.controller.config.persist.api.StorageAdapter;
  21 import org.opendaylight.controller.config.persist.impl.osgi.ConfigPersisterActivator;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25 /**
  26  * {@link Persister} implementation that delegates persisting functionality to
  27  * underlying {@link Persister} storages. Each storage has unique id, class, readonly value.
  28  *
  29  * Storage adapters are low level persisters that do the heavy lifting for this
  30  * class. Instances of storage adapters can be injected directly via constructor
  31  * or instantiated from a full name of its class provided in a properties file.
  32  *
  33  * Example configuration:<pre>
  34  netconf.config.persister.active=2,3
  35  # read startup configuration
  36  netconf.config.persister.1.storageAdapterClass=org.opendaylight.controller.config.persist.storage.directory.xml.XmlDirectoryStorageAdapter
  37  netconf.config.persister.1.properties.fileStorage=configuration/initial/
  38
  39  netconf.config.persister.2.storageAdapterClass=org.opendaylight.controller.config.persist.storage.file.xml.XmlFileStorageAdapter
  40  netconf.config.persister.2.readonly=true
  41  netconf.config.persister.2.properties.fileStorage=configuration/current/controller.config.1.xml
  42
  43  netconf.config.persister.3.storageAdapterClass=org.opendaylight.controller.config.persist.storage.file.xml.XmlFileStorageAdapter
  44  netconf.config.persister.3.properties.fileStorage=configuration/current/controller.config.2.xml
  45  netconf.config.persister.3.properties.numberOfBackups=3
  46
  47  </pre>
  48  * During server startup {@link ConfigPersisterNotificationHandler} requests last snapshot from underlying storages.
  49  * Each storage can respond by giving snapshot or absent response.
  50  * The {@link #loadLastConfigs()} will search for first non-absent response from storages ordered backwards as user
  51  * specified (first '3', then '2').
  52  *
  53  * When a commit notification is received, '2' will be omitted because readonly flag is set to true, so
  54  * only '3' will have a chance to persist new configuration. If readonly was false or not specified, both storage adapters
  55  * would be called in order specified by 'netconf.config.persister' property.
  56  *
  57  */
  58 public final class PersisterAggregator implements Persister {
  59     private static final Logger LOG = LoggerFactory.getLogger(PersisterAggregator.class);
  60
  61     public static class PersisterWithConfiguration {
  62
  63         private final Persister storage;
  64         private final boolean readOnly;
  65
  66         public PersisterWithConfiguration(final Persister storage, final boolean readOnly) {
  67             this.storage = storage;
  68             this.readOnly = readOnly;
  69         }
  70
  71         @VisibleForTesting
  72         public Persister getStorage() {
  73             return storage;
  74         }
  75
  76         @VisibleForTesting
  77         public boolean isReadOnly() {
  78             return readOnly;
  79         }
  80
  81         @Override
  82         public String toString() {
  83             return "PersisterWithConfiguration{" +
  84                     "storage=" + storage +
  85                     ", readOnly=" + readOnly +
  86                     '}';
  87         }
  88     }
  89
  90     /**
  91      * Persisters ordered by 'netconf.config.persister' property.
  92      */
  93     private final List<PersisterWithConfiguration> persisterWithConfigurations;
  94
  95     public PersisterAggregator(final List<PersisterWithConfiguration> persisterWithConfigurations) {
  96         this.persisterWithConfigurations = persisterWithConfigurations;
  97     }
  98
  99     private static PersisterWithConfiguration loadConfiguration(final String index, final PropertiesProvider propertiesProvider) {
 100
 101         String classKey = index + "." + ConfigPersisterActivator.STORAGE_ADAPTER_CLASS_PROP_SUFFIX;
 102         String storageAdapterClass = propertiesProvider.getProperty(classKey);
 103         StorageAdapter storageAdapter;
 104         if (storageAdapterClass == null || storageAdapterClass.isEmpty()) {
 105             throw new IllegalStateException("No persister is defined in " +
 106                     propertiesProvider.getFullKeyForReporting(classKey)
 107                     + " property. Persister is not operational");
 108         }
 109
 110         try {
 111             Class<?> clazz = Class.forName(storageAdapterClass);
 112             boolean implementsCorrectIfc = StorageAdapter.class.isAssignableFrom(clazz);
 113             if (!implementsCorrectIfc) {
 114                 throw new IllegalArgumentException("Storage adapter " + clazz + " does not implement " + StorageAdapter.class);
 115             }
 116             storageAdapter = StorageAdapter.class.cast(clazz.newInstance());
 117
 118             String readOnlyProperty = propertiesProvider.getProperty(index + "." + "readonly");
 119             boolean readOnly = Boolean.parseBoolean(readOnlyProperty);
 120
 121             PropertiesProviderAdapterImpl innerProvider = new PropertiesProviderAdapterImpl(propertiesProvider, index);
 122             Persister storage = storageAdapter.instantiate(innerProvider);
 123             return new PersisterWithConfiguration(storage, readOnly);
 124         } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
 125             throw new IllegalArgumentException("Unable to instantiate storage adapter from " + storageAdapterClass, e);
 126         }
 127     }
 128
 129     public static PersisterAggregator createFromProperties(final PropertiesProvider propertiesProvider) {
 130         List<PersisterWithConfiguration> persisterWithConfigurations = new ArrayList<>();
 131         String prefixes = propertiesProvider.getProperty("active");
 132         if (prefixes!=null && !prefixes.isEmpty()) {
 133             String [] keys = prefixes.split(",");
 134             for (String index: keys) {
 135                 persisterWithConfigurations.add(PersisterAggregator.loadConfiguration(index, propertiesProvider));
 136             }
 137         }
 138         LOG.debug("Initialized persister with following adapters {}", persisterWithConfigurations);
 139         return new PersisterAggregator(persisterWithConfigurations);
 140     }
 141
 142     @Override
 143     public void persistConfig(final ConfigSnapshotHolder holder) throws IOException {
 144         for (PersisterWithConfiguration persisterWithConfiguration: persisterWithConfigurations){
 145             if (!persisterWithConfiguration.readOnly){
 146                 LOG.debug("Calling {}.persistConfig", persisterWithConfiguration.getStorage());
 147                 persisterWithConfiguration.getStorage().persistConfig(holder);
 148             }
 149         }
 150     }
 151
 152     /**
 153      * @return last non-empty result from input persisters
 154      */
 155     @Override
 156     public List<ConfigSnapshotHolder> loadLastConfigs()  {
 157         // iterate in reverse order
 158         ListIterator<PersisterWithConfiguration> li = persisterWithConfigurations.listIterator(persisterWithConfigurations.size());
 159         while(li.hasPrevious()) {
 160             PersisterWithConfiguration persisterWithConfiguration = li.previous();
 161             List<ConfigSnapshotHolder> configs = null;
 162             try {
 163                 configs = persisterWithConfiguration.storage.loadLastConfigs();
 164             } catch (final IOException e) {
 165                 throw new RuntimeException("Error while calling loadLastConfig on " +  persisterWithConfiguration, e);
 166             }
 167             if (!configs.isEmpty()) {
 168                 LOG.debug("Found non empty configs using {}:{}", persisterWithConfiguration, configs);
 169                 return configs;
 170             }
 171         }
 172         // no storage had an answer
 173         LOG.debug("No non-empty list of configuration snapshots found");
 174         return Collections.emptyList();
 175     }
 176
 177     @VisibleForTesting
 178     List<PersisterWithConfiguration> getPersisterWithConfigurations() {
 179         return persisterWithConfigurations;
 180     }
 181
 182     @Override
 183     public void close() {
 184         RuntimeException lastException = null;
 185         for (PersisterWithConfiguration persisterWithConfiguration: persisterWithConfigurations){
 186             try{
 187                 persisterWithConfiguration.storage.close();
 188             }catch(final RuntimeException e) {
 189                 LOG.error("Error while closing {}", persisterWithConfiguration.storage, e);
 190                 if (lastException == null){
 191                     lastException = e;
 192                 } else {
 193                     lastException.addSuppressed(e);
 194                 }
 195             }
 196         }
 197         if (lastException != null){
 198             throw lastException;
 199         }
 200     }
 201
 202     @Override
 203     public String toString() {
 204         return "PersisterAggregator{" +
 205                 "persisterWithConfigurations=" + persisterWithConfigurations +
 206                 '}';
 207     }
 208 }