content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.asterix.external.input.stream;
  
  import java.io.IOException;
  import java.io.Reader;
  import java.nio.ByteBuffer;
  import java.nio.CharBuffer;
  import java.nio.charset.CharsetDecoder;
  import java.nio.charset.StandardCharsets;
  
  import org.apache.asterix.external.api.AsterixInputStream;
  import org.apache.asterix.external.dataflow.AbstractFeedDataFlowController;
  import org.apache.asterix.external.util.IFeedLogManager;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  
  public class AsterixInputStreamReader extends Reader {
      private final AsterixInputStream in;
      private final CharsetDecoder decoder;
      private byte[] bytes;
      protected final ByteBuffer byteBuffer;
      protected final CharBuffer charBuffer;
      protected boolean done = false;
      protected boolean remaining = false;
  
      public AsterixInputStreamReader(AsterixInputStream in, int bufferSize) {
          this.in = in;
          this.decoder = StandardCharsets.UTF_8.newDecoder();
          this.bytes = new byte[bufferSize];
          this.byteBuffer = ByteBuffer.wrap(bytes);
          this.charBuffer = CharBuffer.allocate(bufferSize);
          this.byteBuffer.flip();
      }
  
      public void stop() throws IOException {
          try {
              in.stop();
          } catch (Exception e) {
              throw new IOException(e);
          }
      }
  
      public void setController(AbstractFeedDataFlowController controller) {
          in.setController(controller);
      }
  
      public void setFeedLogManager(IFeedLogManager feedLogManager) throws HyracksDataException {
          in.setFeedLogManager(feedLogManager);
      }
  
      @Override
      public int read(char cbuf[]) throws IOException {
          return read(cbuf, 0, cbuf.length);
      }
  
      @Override
      public int read(char[] cbuf, int offset, int length) throws IOException {
          if (done) {
              return -1;
          }
          int len = 0;
          charBuffer.clear();
          while (charBuffer.position() == 0) {
              if (byteBuffer.hasRemaining()) {
                  remaining = true;
                  decoder.decode(byteBuffer, charBuffer, false);
                  System.arraycopy(charBuffer.array(), 0, cbuf, offset, charBuffer.position());
                  if (charBuffer.position() > 0) {
                      return charBuffer.position();
                  } else {
                      // need to read more data
                      System.arraycopy(bytes, byteBuffer.position(), bytes, 0, byteBuffer.remaining());
                      len = 0; // reset to read more bytes
                      byteBuffer.position(byteBuffer.remaining());
                      byteBuffer.limit(byteBuffer.capacity()); //set limit to capacity for the new bytes
                      while (len == 0) {
                          len = in.read(bytes, byteBuffer.position(), bytes.length - byteBuffer.position());
                      }
                  }
              } else {
                  byteBuffer.clear();
                  while (len == 0) {
                      len = in.read(bytes, 0, bytes.length);
                  }
              }
              if (len == -1) {
                  done = true;
                  return len;
              }
              if (remaining) {
                  byteBuffer.position(len + byteBuffer.position());
              } else {
                  byteBuffer.position(len);
              }
              byteBuffer.flip();
              remaining = false;
              decoder.decode(byteBuffer, charBuffer, false);
              System.arraycopy(charBuffer.array(), 0, cbuf, offset, charBuffer.position());
          }
          return charBuffer.position();
      }
  
      @Override
      public void close() throws IOException {
          in.close();
      }
  
      public boolean handleException(Throwable th) {
          return in.handleException(th);
      }
  
      @Override
      public void reset() throws IOException {
          byteBuffer.limit(0);
      }
  
      public String getStreamName() {
          return in.getStreamName();
      }
  
      public String getPreviousStreamName() {
          return in.getPreviousStreamName();
      }
  }
  