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