restconf/restconf-openapi/src/main/java/org/opendaylight/restconf/openapi/impl/OpenApiInputStream.java

   1 /*
   2  * Copyright (c) 2023 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.openapi.impl;
   9
  10 import com.fasterxml.jackson.core.JsonFactoryBuilder;
  11 import com.fasterxml.jackson.core.JsonGenerator;
  12 import java.io.ByteArrayInputStream;
  13 import java.io.ByteArrayOutputStream;
  14 import java.io.IOException;
  15 import java.io.InputStream;
  16 import java.io.InputStreamReader;
  17 import java.io.Reader;
  18 import java.nio.charset.StandardCharsets;
  19 import java.util.ArrayDeque;
  20 import java.util.Deque;
  21 import java.util.List;
  22 import java.util.Map;
  23 import org.opendaylight.restconf.openapi.jaxrs.OpenApiBodyWriter;
  24 import org.opendaylight.restconf.openapi.model.Info;
  25 import org.opendaylight.restconf.openapi.model.InfoEntity;
  26 import org.opendaylight.restconf.openapi.model.OpenApiVersionEntity;
  27 import org.opendaylight.restconf.openapi.model.Server;
  28 import org.opendaylight.restconf.openapi.model.ServerEntity;
  29 import org.opendaylight.restconf.openapi.model.ServersEntity;
  30 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  31
  32 public final class OpenApiInputStream extends InputStream {
  33     private final ByteArrayOutputStream stream = new ByteArrayOutputStream();
  34     private final JsonGenerator generator = new JsonFactoryBuilder().build().createGenerator(stream);
  35     private final Deque<InputStream> stack = new ArrayDeque<>();
  36
  37     private Reader reader;
  38
  39     private boolean eof;
  40
  41     public OpenApiInputStream(final EffectiveModelContext context, final String openApiVersion, final Info info,
  42             final List<Server> servers, final List<Map<String, List<String>>> security) throws IOException {
  43         final OpenApiBodyWriter writer = new OpenApiBodyWriter(generator, stream);
  44         stack.add(new OpenApiVersionStream(new OpenApiVersionEntity(), writer));
  45         stack.add(new InfoStream(new InfoEntity(info.version(), info.title(), info.description()), writer));
  46         stack.add(new ServersStream(new ServersEntity(
  47             List.of(new ServerEntity(servers.iterator().next().url()))), writer));
  48         stack.add(new PathsSteam(context, writer, generator, stream));
  49         stack.add(new SchemasStream(context, writer, generator, stream));
  50         stack.add(new SecurityStream(writer));
  51     }
  52
  53     @Override
  54     public int read() throws IOException {
  55         if (eof) {
  56             return -1;
  57         }
  58         if (reader == null) {
  59             generator.writeStartObject();
  60             generator.flush();
  61             reader = new InputStreamReader(new ByteArrayInputStream(stream.toByteArray()), StandardCharsets.UTF_8);
  62             stream.reset();
  63         }
  64
  65         var read = reader.read();
  66         while (read == -1) {
  67             if (stack.isEmpty()) {
  68                 generator.writeEndObject();
  69                 generator.flush();
  70                 reader = new InputStreamReader(new ByteArrayInputStream(stream.toByteArray()), StandardCharsets.UTF_8);
  71                 stream.reset();
  72                 eof = true;
  73                 return reader.read();
  74             }
  75             reader = new InputStreamReader(stack.pop(), StandardCharsets.UTF_8);
  76             read = reader.read();
  77         }
  78
  79         return read;
  80     }
  81
  82     @Override
  83     public int read(final byte[] array, final int off, final int len) throws IOException {
  84         return super.read(array, off, len);
  85     }
  86 }