restconf/restconf-nb/src/main/java/org/opendaylight/restconf/server/spi/NormalizedFormattableBody.java

   1 /*
   2  * Copyright (c) 2024 PANTHEON.tech, s.r.o. 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.restconf.server.spi;
   9
  10 import static com.google.common.base.Verify.verify;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import com.google.common.base.MoreObjects.ToStringHelper;
  14 import java.io.IOException;
  15 import java.io.OutputStream;
  16 import javax.xml.stream.XMLStreamException;
  17 import org.eclipse.jdt.annotation.NonNullByDefault;
  18 import org.opendaylight.restconf.api.FormattableBody;
  19 import org.opendaylight.restconf.api.query.PrettyPrintParam;
  20 import org.opendaylight.restconf.server.api.DatabindContext;
  21 import org.opendaylight.restconf.server.api.DatabindFormattableBody;
  22 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
  23 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  24 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  25 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  26 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  27 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  28 import org.opendaylight.yangtools.yang.data.codec.xml.XMLStreamNormalizedNodeStreamWriter;
  29 import org.opendaylight.yangtools.yang.model.api.stmt.DataTreeEffectiveStatement;
  30 import org.opendaylight.yangtools.yang.model.api.stmt.LeafListEffectiveStatement;
  31 import org.opendaylight.yangtools.yang.model.api.stmt.ListEffectiveStatement;
  32 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack.Inference;
  33
  34 /**
  35  * A {@link FormattableBody} representing a data resource.
  36  */
  37 @NonNullByDefault
  38 public final class NormalizedFormattableBody<N extends NormalizedNode> extends DatabindFormattableBody {
  39     private final Inference parent;
  40     private final N data;
  41
  42     public NormalizedFormattableBody(final DatabindContext databind, final Inference parent, final N data) {
  43         super(databind);
  44         this.parent = requireNonNull(parent);
  45         this.data = requireNonNull(data);
  46         // RESTCONF allows returning one list item. We need to wrap it in map node in order to serialize it properly,
  47         // which is where the notion of "parent Inference" may be confusing. We mean
  48         // 'inference to the parent NormalizedNode', which for *EntryNode ends up the corresponding statement
  49         if (data instanceof MapEntryNode) {
  50             verifyParent(parent, ListEffectiveStatement.class, data);
  51         } else if (data instanceof LeafSetEntryNode) {
  52             verifyParent(parent, LeafListEffectiveStatement.class, data);
  53         }
  54     }
  55
  56     private static void verifyParent(final Inference inference,
  57             final Class<? extends DataTreeEffectiveStatement<?>> expectedStmt, final NormalizedNode data) {
  58         // Let's not bother with niceties of error report -- if we trip here, the caller is doing the wrong
  59         final var qname = expectedStmt.cast(inference.toSchemaInferenceStack().currentStatement()).argument();
  60         verify(qname.equals(data.name().getNodeType()));
  61     }
  62
  63     @Override
  64     protected void formatToJSON(final DatabindContext databind, final PrettyPrintParam prettyPrint,
  65             final OutputStream out) throws IOException {
  66         writeTo(JSONNormalizedNodeStreamWriter.createExclusiveWriter(databind.jsonCodecs(), parent, null,
  67             FormattableBodySupport.createJsonWriter(out, prettyPrint)));
  68     }
  69
  70     @Override
  71     protected void formatToXML(final DatabindContext databind, final PrettyPrintParam prettyPrint,
  72             final OutputStream out) throws IOException {
  73         final var xmlWriter = FormattableBodySupport.createXmlWriter(out, prettyPrint);
  74         writeTo(XMLStreamNormalizedNodeStreamWriter.create(xmlWriter, parent));
  75         try {
  76             xmlWriter.close();
  77         } catch (XMLStreamException e) {
  78             throw new IOException("Failed to write data", e);
  79         }
  80     }
  81
  82     @Override
  83     protected ToStringHelper addToStringAttributes(final ToStringHelper helper) {
  84         return helper.add("body", data.prettyTree());
  85     }
  86
  87     private void writeTo(final NormalizedNodeStreamWriter streamWriter) throws IOException {
  88         try (var writer = NormalizedNodeWriter.forStreamWriter(streamWriter)) {
  89             writer.write(data);
  90         }
  91     }
  92 }