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 static com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import com.google.common.annotations.VisibleForTesting;
  14 import java.util.Objects;
  15 import org.opendaylight.netconf.api.xml.XmlElement;
  16 import org.opendaylight.netconf.shaded.exificient.core.CodingMode;
  17 import org.opendaylight.netconf.shaded.exificient.core.EXIFactory;
  18 import org.opendaylight.netconf.shaded.exificient.core.EncodingOptions;
  19 import org.opendaylight.netconf.shaded.exificient.core.FidelityOptions;
  20 import org.opendaylight.netconf.shaded.exificient.core.SchemaIdResolver;
  21 import org.opendaylight.netconf.shaded.exificient.core.exceptions.EXIException;
  22 import org.opendaylight.netconf.shaded.exificient.core.exceptions.UnsupportedOption;
  23 import org.opendaylight.netconf.shaded.exificient.core.grammars.Grammars;
  24 import org.opendaylight.netconf.shaded.exificient.core.helpers.DefaultEXIFactory;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27 import org.w3c.dom.Element;
  28 import org.w3c.dom.NodeList;
  29
  30 public final class EXIParameters {
  31     private static final Logger LOG = LoggerFactory.getLogger(EXIParameters.class);
  32
  33     static final String EXI_PARAMETER_ALIGNMENT = "alignment";
  34     private static final String EXI_PARAMETER_BYTE_ALIGNED = "byte-aligned";
  35     private static final String EXI_PARAMETER_BIT_PACKED = "bit-packed";
  36     private static final String EXI_PARAMETER_COMPRESSED = "compressed";
  37     private static final String EXI_PARAMETER_PRE_COMPRESSION = "pre-compression";
  38
  39     static final String EXI_PARAMETER_FIDELITY = "fidelity";
  40     private static final String EXI_FIDELITY_DTD = "dtd";
  41     private static final String EXI_FIDELITY_LEXICAL_VALUES = "lexical-values";
  42     private static final String EXI_FIDELITY_COMMENTS = "comments";
  43     private static final String EXI_FIDELITY_PIS = "pis";
  44     private static final String EXI_FIDELITY_PREFIXES = "prefixes";
  45
  46     static final String EXI_PARAMETER_SCHEMAS = "schemas";
  47
  48     private static final SchemaIdResolver SCHEMA_RESOLVER = schemaId -> {
  49         if (schemaId == null) {
  50             return null;
  51         }
  52         if (schemaId.isEmpty()) {
  53             return EXISchema.BUILTIN.getGrammar();
  54         }
  55
  56         final Grammars g = EXISchema.BASE_1_1.getGrammar();
  57         if (g.getSchemaId().equals(schemaId)) {
  58             return g;
  59         }
  60
  61         throw new EXIException("Cannot resolve schema " + schemaId);
  62     };
  63
  64     private static final EncodingOptions ENCODING_OPTIONS;
  65
  66     static {
  67         final EncodingOptions opts = EncodingOptions.createDefault();
  68         try {
  69             opts.setOption(EncodingOptions.RETAIN_ENTITY_REFERENCE);
  70             opts.setOption(EncodingOptions.INCLUDE_OPTIONS);
  71
  72             /**
  73              * NETCONF is XML environment, so the use of EXI cookie is not really needed. Adding it
  74              * decreases efficiency of encoding by adding human-readable 4 bytes "EXI$" to the head
  75              * of the stream. This is really useful, so let's output it now.
  76              */
  77             opts.setOption(EncodingOptions.INCLUDE_COOKIE);
  78         } catch (final UnsupportedOption e) {
  79             throw new ExceptionInInitializerError(e);
  80         }
  81
  82         ENCODING_OPTIONS = opts;
  83     }
  84
  85     private final FidelityOptions fidelityOptions;
  86     private final CodingMode codingMode;
  87     private final EXISchema schema;
  88
  89     public EXIParameters(final CodingMode codingMode, final FidelityOptions fidelityOptions) {
  90         this(codingMode, fidelityOptions, EXISchema.NONE);
  91     }
  92
  93     public EXIParameters(final CodingMode codingMode, final FidelityOptions fidelityOptions, final EXISchema schema) {
  94         this.fidelityOptions = requireNonNull(fidelityOptions);
  95         this.codingMode = requireNonNull(codingMode);
  96         this.schema = requireNonNull(schema);
  97     }
  98
  99     @VisibleForTesting
 100     public static EXIParameters empty() {
 101         return new EXIParameters(CodingMode.BIT_PACKED, FidelityOptions.createDefault());
 102     }
 103
 104     public static EXIParameters fromXmlElement(final XmlElement root) throws UnsupportedOption {
 105         final CodingMode coding;
 106         final NodeList alignmentElements = root.getElementsByTagName(EXI_PARAMETER_ALIGNMENT);
 107         if (alignmentElements.getLength() > 0) {
 108             final Element alignmentElement = (Element) alignmentElements.item(0);
 109             final String alignmentTextContent = alignmentElement.getTextContent().trim();
 110
 111             switch (alignmentTextContent) {
 112                 case EXI_PARAMETER_BYTE_ALIGNED:
 113                     coding = CodingMode.BYTE_PACKED;
 114                     break;
 115                 case EXI_PARAMETER_COMPRESSED:
 116                     coding = CodingMode.COMPRESSION;
 117                     break;
 118                 case EXI_PARAMETER_PRE_COMPRESSION:
 119                     coding = CodingMode.PRE_COMPRESSION;
 120                     break;
 121                 case EXI_PARAMETER_BIT_PACKED:
 122                     coding = CodingMode.BIT_PACKED;
 123                     break;
 124                 default:
 125                     LOG.warn("Unexpected value in alignmentTextContent: {} , using default value",
 126                             alignmentTextContent);
 127                     coding = CodingMode.BIT_PACKED;
 128                     break;
 129             }
 130         } else {
 131             coding = CodingMode.BIT_PACKED;
 132         }
 133
 134         final FidelityOptions fidelity = FidelityOptions.createDefault();
 135         final NodeList fidelityElements = root.getElementsByTagName(EXI_PARAMETER_FIDELITY);
 136         if (fidelityElements.getLength() > 0) {
 137             final Element fidelityElement = (Element) fidelityElements.item(0);
 138
 139             fidelity.setFidelity(FidelityOptions.FEATURE_DTD,
 140                 fidelityElement.getElementsByTagName(EXI_FIDELITY_DTD).getLength() > 0);
 141             fidelity.setFidelity(FidelityOptions.FEATURE_LEXICAL_VALUE,
 142                 fidelityElement.getElementsByTagName(EXI_FIDELITY_LEXICAL_VALUES).getLength() > 0);
 143             fidelity.setFidelity(FidelityOptions.FEATURE_COMMENT,
 144                 fidelityElement.getElementsByTagName(EXI_FIDELITY_COMMENTS).getLength() > 0);
 145             fidelity.setFidelity(FidelityOptions.FEATURE_PI,
 146                 fidelityElement.getElementsByTagName(EXI_FIDELITY_PIS).getLength() > 0);
 147             fidelity.setFidelity(FidelityOptions.FEATURE_PREFIX,
 148                 fidelityElement.getElementsByTagName(EXI_FIDELITY_PREFIXES).getLength() > 0);
 149         }
 150
 151         final EXISchema schema;
 152         final NodeList schemaElements = root.getElementsByTagName(EXI_PARAMETER_SCHEMAS);
 153         if (schemaElements.getLength() > 0) {
 154             final Element schemaElement = (Element) schemaElements.item(0);
 155             final String schemaName = schemaElement.getTextContent().trim();
 156             schema = EXISchema.forOption(schemaName);
 157             checkArgument(schema != null, "Unsupported schema name %s", schemaName);
 158         } else {
 159             schema = EXISchema.NONE;
 160         }
 161
 162         return new EXIParameters(coding, fidelity, schema);
 163     }
 164
 165     public EXIFactory getFactory() {
 166         final EXIFactory factory = DefaultEXIFactory.newInstance();
 167         factory.setCodingMode(codingMode);
 168         factory.setEncodingOptions(ENCODING_OPTIONS);
 169         factory.setFidelityOptions(fidelityOptions);
 170         factory.setGrammars(schema.getGrammar());
 171         factory.setSchemaIdResolver(SCHEMA_RESOLVER);
 172         return factory;
 173     }
 174
 175     @Override
 176     public int hashCode() {
 177         return Objects.hash(fidelityOptions, codingMode, schema);
 178     }
 179
 180     @Override
 181     public boolean equals(final Object obj) {
 182         if (this == obj) {
 183             return true;
 184         }
 185         if (!(obj instanceof EXIParameters)) {
 186             return false;
 187         }
 188         final EXIParameters other = (EXIParameters) obj;
 189         return codingMode == other.codingMode && schema == other.schema
 190                 && fidelityOptions.equals(other.fidelityOptions);
 191     }
 192
 193     String getAlignment() {
 194         switch (codingMode) {
 195             case BIT_PACKED:
 196                 return EXI_PARAMETER_BIT_PACKED;
 197             case BYTE_PACKED:
 198                 return EXI_PARAMETER_BYTE_ALIGNED;
 199             case COMPRESSION:
 200                 return EXI_PARAMETER_COMPRESSED;
 201             case PRE_COMPRESSION:
 202                 return EXI_PARAMETER_PRE_COMPRESSION;
 203             default:
 204                 throw new IllegalStateException("Unhandled coding mode " + codingMode);
 205         }
 206     }
 207
 208     private String fidelityString(final String feature, final String string) {
 209         return fidelityOptions.isFidelityEnabled(feature) ? string : null;
 210     }
 211
 212     String getPreserveComments() {
 213         return fidelityString(FidelityOptions.FEATURE_COMMENT, EXI_FIDELITY_COMMENTS);
 214     }
 215
 216     String getPreserveDTD() {
 217         return fidelityString(FidelityOptions.FEATURE_DTD, EXI_FIDELITY_DTD);
 218     }
 219
 220     String getPreserveLexicalValues() {
 221         return fidelityString(FidelityOptions.FEATURE_LEXICAL_VALUE, EXI_FIDELITY_LEXICAL_VALUES);
 222     }
 223
 224     String getPreservePIs() {
 225         return fidelityString(FidelityOptions.FEATURE_PI, EXI_FIDELITY_PIS);
 226     }
 227
 228     String getPreservePrefixes() {
 229         return fidelityString(FidelityOptions.FEATURE_PREFIX, EXI_FIDELITY_PREFIXES);
 230     }
 231
 232     String getSchema() {
 233         return schema == EXISchema.NONE ? null : schema.name();
 234     }
 235 }