001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.parser;
018
019import java.io.*;
020
021/**
022 * Input stream meant to be used as input for stream-based parsers.
023 *
024 * <p>
025 * Keeps track of current byte position.
026 *
027 * <h5 class='section'>Notes:</h5><ul>
028 *    <li class='warn'>This class is not thread safe.
029 * </ul>
030 *
031 * <h5 class='section'>See Also:</h5><ul>
032 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/SerializersAndParsers">Serializers and Parsers</a>
033 * </ul>
034 */
035public class ParserInputStream extends InputStream implements Positionable {
036
037   private final InputStream is;
038   int pos = 0;
039
040   /**
041    * Constructor.
042    *
043    * @param pipe The parser input.
044    * @throws IOException Thrown by underlying stream.
045    */
046   protected ParserInputStream(ParserPipe pipe) throws IOException {
047      this.is = pipe.getInputStream();
048      pipe.setPositionable(this);
049   }
050
051   @Override /* InputStream */
052   public int read() throws IOException {
053      int i = is.read();
054      if (i > 0)
055         pos++;
056      return i;
057   }
058
059   @Override /* Positionable */
060   public Position getPosition() {
061      return new Position(pos);
062   }
063}