opendaylight/config/config-persister-impl/src/main/java/org/opendaylight/controller/config/persist/impl/CapabilityStrippingConfigSnapshotHolder.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.util.Collections;
  13 import java.util.HashSet;
  14 import java.util.Map.Entry;
  15 import java.util.Set;
  16 import java.util.SortedSet;
  17 import java.util.TreeSet;
  18 import org.opendaylight.controller.config.persist.api.ConfigSnapshotHolder;
  19 import org.opendaylight.controller.config.util.xml.XmlElement;
  20 import org.opendaylight.controller.config.util.xml.XmlUtil;
  21 import org.slf4j.Logger;
  22 import org.slf4j.LoggerFactory;
  23 import org.w3c.dom.Attr;
  24 import org.w3c.dom.Element;
  25
  26 /**
  27  * Inspects snapshot xml to be stored, remove all capabilities that are not referenced by it.
  28  * Useful when persisting current configuration.
  29  */
  30 public class CapabilityStrippingConfigSnapshotHolder implements ConfigSnapshotHolder {
  31     private static final Logger LOG = LoggerFactory.getLogger(CapabilityStrippingConfigSnapshotHolder.class);
  32
  33     private final String configSnapshot;
  34     private final StripCapabilitiesResult stripCapabilitiesResult;
  35
  36     public CapabilityStrippingConfigSnapshotHolder(Element snapshot, Set<String> capabilities) {
  37         final XmlElement configElement = XmlElement.fromDomElement(snapshot);
  38         configSnapshot = XmlUtil.toString(configElement.getDomElement());
  39         stripCapabilitiesResult = stripCapabilities(configElement, capabilities);
  40     }
  41
  42     private static class StripCapabilitiesResult {
  43         private final SortedSet<String> requiredCapabilities;
  44         private final SortedSet<String> obsoleteCapabilities;
  45
  46         private StripCapabilitiesResult(SortedSet<String> requiredCapabilities, SortedSet<String> obsoleteCapabilities) {
  47             this.requiredCapabilities = Collections.unmodifiableSortedSet(requiredCapabilities);
  48             this.obsoleteCapabilities = Collections.unmodifiableSortedSet(obsoleteCapabilities);
  49         }
  50     }
  51
  52
  53     @VisibleForTesting
  54     static StripCapabilitiesResult stripCapabilities(XmlElement configElement, Set<String> allCapabilitiesFromHello) {
  55         // collect all namespaces
  56         Set<String> foundNamespacesInXML = getNamespaces(configElement);
  57         LOG.trace("All capabilities {}\nFound namespaces in XML {}", allCapabilitiesFromHello, foundNamespacesInXML);
  58         // required are referenced both in xml and hello
  59         SortedSet<String> requiredCapabilities = new TreeSet<>();
  60         // can be removed
  61         SortedSet<String> obsoleteCapabilities = new TreeSet<>();
  62         for (String capability : allCapabilitiesFromHello) {
  63             String namespace = capability.replaceAll("\\?.*","");
  64             if (foundNamespacesInXML.contains(namespace)) {
  65                 requiredCapabilities.add(capability);
  66             } else {
  67                 obsoleteCapabilities.add(capability);
  68             }
  69         }
  70
  71         LOG.trace("Required capabilities {}, \nObsolete capabilities {}",
  72                 requiredCapabilities, obsoleteCapabilities);
  73
  74         return new StripCapabilitiesResult(requiredCapabilities, obsoleteCapabilities);
  75     }
  76
  77     static Set<String> getNamespaces(XmlElement element){
  78         Set<String> result = new HashSet<>();
  79         for (Entry<String,Attr> attribute : element.getAttributes().entrySet()) {
  80             if  (attribute.getKey().startsWith("xmlns")){
  81                 result.add(attribute.getValue().getValue());
  82             }
  83         }
  84         for(XmlElement child: element.getChildElements()) {
  85             result.addAll(getNamespaces(child));
  86         }
  87         return result;
  88     }
  89
  90     @Override
  91     public SortedSet<String> getCapabilities() {
  92         return stripCapabilitiesResult.requiredCapabilities;
  93     }
  94
  95     @VisibleForTesting
  96     Set<String> getObsoleteCapabilities(){
  97         return stripCapabilitiesResult.obsoleteCapabilities;
  98     }
  99
 100     @Override
 101     public String getConfigSnapshot() {
 102         return configSnapshot;
 103     }
 104 }