netconf/netconf-netty-util/src/main/java/org/opendaylight/netconf/nettyutil/handler/exi/EXIParameters.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 package org.opendaylight.netconf.nettyutil.handler.exi;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.base.Preconditions;
  12 import com.siemens.ct.exi.CodingMode;
  13 import com.siemens.ct.exi.EXIFactory;
  14 import com.siemens.ct.exi.EncodingOptions;
  15 import com.siemens.ct.exi.FidelityOptions;
  16 import com.siemens.ct.exi.exceptions.UnsupportedOption;
  17 import com.siemens.ct.exi.helpers.DefaultEXIFactory;
  18 import java.util.Objects;
  19 import org.opendaylight.netconf.api.xml.XmlElement;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22 import org.w3c.dom.Element;
  23 import org.w3c.dom.NodeList;
  24
  25 public final class EXIParameters {
  26     private static final Logger LOG = LoggerFactory.getLogger(EXIParameters.class);
  27
  28     static final String EXI_PARAMETER_ALIGNMENT = "alignment";
  29     private static final String EXI_PARAMETER_BYTE_ALIGNED = "byte-aligned";
  30     private static final String EXI_PARAMETER_BIT_PACKED = "bit-packed";
  31     private static final String EXI_PARAMETER_COMPRESSED = "compressed";
  32     private static final String EXI_PARAMETER_PRE_COMPRESSION = "pre-compression";
  33
  34     static final String EXI_PARAMETER_FIDELITY = "fidelity";
  35     private static final String EXI_FIDELITY_DTD = "dtd";
  36     private static final String EXI_FIDELITY_LEXICAL_VALUES = "lexical-values";
  37     private static final String EXI_FIDELITY_COMMENTS = "comments";
  38     private static final String EXI_FIDELITY_PIS = "pis";
  39     private static final String EXI_FIDELITY_PREFIXES = "prefixes";
  40
  41     private static final EncodingOptions ENCODING_OPTIONS;
  42
  43     static {
  44         final EncodingOptions opts = EncodingOptions.createDefault();
  45         try {
  46             opts.setOption(EncodingOptions.RETAIN_ENTITY_REFERENCE);
  47             opts.setOption(EncodingOptions.INCLUDE_OPTIONS);
  48
  49             /**
  50              * NETCONF is XML environment, so the use of EXI cookie is not really needed. Adding it
  51              * decreases efficiency of encoding by adding human-readable 4 bytes "EXI$" to the head
  52              * of the stream. This is really useful, so let's output it now.
  53              */
  54             opts.setOption(EncodingOptions.INCLUDE_COOKIE);
  55         } catch (final UnsupportedOption e) {
  56             throw new ExceptionInInitializerError(e);
  57         }
  58
  59         ENCODING_OPTIONS = opts;
  60     }
  61
  62     private final FidelityOptions fidelityOptions;
  63     private final CodingMode codingMode;
  64
  65     public EXIParameters(final CodingMode codingMode, final FidelityOptions fidelityOptions) {
  66         this.fidelityOptions = Preconditions.checkNotNull(fidelityOptions);
  67         this.codingMode = Preconditions.checkNotNull(codingMode);
  68     }
  69
  70     @VisibleForTesting
  71     public static EXIParameters empty() {
  72         return new EXIParameters(CodingMode.BIT_PACKED, FidelityOptions.createDefault());
  73     }
  74
  75     public static EXIParameters fromXmlElement(final XmlElement root) throws UnsupportedOption {
  76         final CodingMode coding;
  77         final NodeList alignmentElements = root.getElementsByTagName(EXI_PARAMETER_ALIGNMENT);
  78         if (alignmentElements.getLength() > 0) {
  79             final Element alignmentElement = (Element) alignmentElements.item(0);
  80             final String alignmentTextContent = alignmentElement.getTextContent().trim();
  81
  82             switch (alignmentTextContent) {
  83                 case EXI_PARAMETER_BYTE_ALIGNED:
  84                     coding = CodingMode.BYTE_PACKED;
  85                     break;
  86                 case EXI_PARAMETER_COMPRESSED:
  87                     coding = CodingMode.COMPRESSION;
  88                     break;
  89                 case EXI_PARAMETER_PRE_COMPRESSION:
  90                     coding = CodingMode.PRE_COMPRESSION;
  91                     break;
  92                 case EXI_PARAMETER_BIT_PACKED:
  93                     coding = CodingMode.BIT_PACKED;
  94                     break;
  95                 default:
  96                     LOG.warn("Unexpected value in alignmentTextContent: {} , using default value",
  97                             alignmentTextContent);
  98                     coding = CodingMode.BIT_PACKED;
  99                     break;
 100             }
 101         } else {
 102             coding = CodingMode.BIT_PACKED;
 103         }
 104
 105         final FidelityOptions fidelity = FidelityOptions.createDefault();
 106         final NodeList fidelityElements = root.getElementsByTagName(EXI_PARAMETER_FIDELITY);
 107         if (fidelityElements.getLength() > 0) {
 108             final Element fidelityElement = (Element) fidelityElements.item(0);
 109
 110             fidelity.setFidelity(FidelityOptions.FEATURE_DTD,
 111                 fidelityElement.getElementsByTagName(EXI_FIDELITY_DTD).getLength() > 0);
 112             fidelity.setFidelity(FidelityOptions.FEATURE_LEXICAL_VALUE,
 113                 fidelityElement.getElementsByTagName(EXI_FIDELITY_LEXICAL_VALUES).getLength() > 0);
 114             fidelity.setFidelity(FidelityOptions.FEATURE_COMMENT,
 115                 fidelityElement.getElementsByTagName(EXI_FIDELITY_COMMENTS).getLength() > 0);
 116             fidelity.setFidelity(FidelityOptions.FEATURE_PI,
 117                 fidelityElement.getElementsByTagName(EXI_FIDELITY_PIS).getLength() > 0);
 118             fidelity.setFidelity(FidelityOptions.FEATURE_PREFIX,
 119                 fidelityElement.getElementsByTagName(EXI_FIDELITY_PREFIXES).getLength() > 0);
 120         }
 121
 122         return new EXIParameters(coding, fidelity);
 123     }
 124
 125     public EXIFactory getFactory() {
 126         final EXIFactory factory = DefaultEXIFactory.newInstance();
 127         factory.setCodingMode(codingMode);
 128         factory.setEncodingOptions(ENCODING_OPTIONS);
 129         factory.setFidelityOptions(fidelityOptions);
 130         return factory;
 131     }
 132
 133     @Override
 134     public int hashCode() {
 135         return Objects.hash(fidelityOptions, codingMode);
 136     }
 137
 138     @Override
 139     public boolean equals(final Object obj) {
 140         if (this == obj) {
 141             return true;
 142         }
 143         if (!(obj instanceof EXIParameters)) {
 144             return false;
 145         }
 146         final EXIParameters other = (EXIParameters) obj;
 147         return codingMode == other.codingMode && fidelityOptions.equals(other.fidelityOptions);
 148     }
 149
 150     String getAlignment() {
 151         switch (codingMode) {
 152             case BIT_PACKED:
 153                 return EXI_PARAMETER_BIT_PACKED;
 154             case BYTE_PACKED:
 155                 return EXI_PARAMETER_BYTE_ALIGNED;
 156             case COMPRESSION:
 157                 return EXI_PARAMETER_COMPRESSED;
 158             case PRE_COMPRESSION:
 159                 return EXI_PARAMETER_PRE_COMPRESSION;
 160             default:
 161                 throw new IllegalStateException("Unhandled coding mode " + codingMode);
 162         }
 163     }
 164
 165     private String fidelityString(final String feature, final String string) {
 166         return fidelityOptions.isFidelityEnabled(feature) ? string : null;
 167     }
 168
 169     String getPreserveComments() {
 170         return fidelityString(FidelityOptions.FEATURE_COMMENT, EXI_FIDELITY_COMMENTS);
 171     }
 172
 173     String getPreserveDTD() {
 174         return fidelityString(FidelityOptions.FEATURE_DTD, EXI_FIDELITY_DTD);
 175     }
 176
 177     String getPreserveLexicalValues() {
 178         return fidelityString(FidelityOptions.FEATURE_LEXICAL_VALUE, EXI_FIDELITY_LEXICAL_VALUES);
 179     }
 180
 181     String getPreservePIs() {
 182         return fidelityString(FidelityOptions.FEATURE_PI, EXI_FIDELITY_PIS);
 183     }
 184
 185     String getPreservePrefixes() {
 186         return fidelityString(FidelityOptions.FEATURE_PREFIX, EXI_FIDELITY_PREFIXES);
 187     }
 188 }