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, obsoleteCapabilities;
  44
  45         private StripCapabilitiesResult(SortedSet<String> requiredCapabilities, SortedSet<String> obsoleteCapabilities) {
  46             this.requiredCapabilities = Collections.unmodifiableSortedSet(requiredCapabilities);
  47             this.obsoleteCapabilities = Collections.unmodifiableSortedSet(obsoleteCapabilities);
  48         }
  49     }
  50
  51
  52     @VisibleForTesting
  53     static StripCapabilitiesResult stripCapabilities(XmlElement configElement, Set<String> allCapabilitiesFromHello) {
  54         // collect all namespaces
  55         Set<String> foundNamespacesInXML = getNamespaces(configElement);
  56         LOG.trace("All capabilities {}\nFound namespaces in XML {}", allCapabilitiesFromHello, foundNamespacesInXML);
  57         // required are referenced both in xml and hello
  58         SortedSet<String> requiredCapabilities = new TreeSet<>();
  59         // can be removed
  60         SortedSet<String> obsoleteCapabilities = new TreeSet<>();
  61         for (String capability : allCapabilitiesFromHello) {
  62             String namespace = capability.replaceAll("\\?.*","");
  63             if (foundNamespacesInXML.contains(namespace)) {
  64                 requiredCapabilities.add(capability);
  65             } else {
  66                 obsoleteCapabilities.add(capability);
  67             }
  68         }
  69
  70         LOG.trace("Required capabilities {}, \nObsolete capabilities {}",
  71                 requiredCapabilities, obsoleteCapabilities);
  72
  73         return new StripCapabilitiesResult(requiredCapabilities, obsoleteCapabilities);
  74     }
  75
  76     static Set<String> getNamespaces(XmlElement element){
  77         Set<String> result = new HashSet<>();
  78         for (Entry<String,Attr> attribute : element.getAttributes().entrySet()) {
  79             if  (attribute.getKey().startsWith("xmlns")){
  80                 result.add(attribute.getValue().getValue());
  81             }
  82         }
  83         for(XmlElement child: element.getChildElements()) {
  84             result.addAll(getNamespaces(child));
  85         }
  86         return result;
  87     }
  88
  89     @Override
  90     public SortedSet<String> getCapabilities() {
  91         return stripCapabilitiesResult.requiredCapabilities;
  92     }
  93
  94     @VisibleForTesting
  95     Set<String> getObsoleteCapabilities(){
  96         return stripCapabilitiesResult.obsoleteCapabilities;
  97     }
  98
  99     @Override
 100     public String getConfigSnapshot() {
 101         return configSnapshot;
 102     }
 103 }