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.column.values.reader.value.key;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  
  import org.apache.asterix.column.bytes.stream.in.AbstractBytesInputStream;
  import org.apache.asterix.column.values.IColumnKeyValueReader;
  import org.apache.asterix.column.values.reader.value.AbstractValueReader;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.hyracks.data.std.api.IPointable;
  import org.apache.hyracks.data.std.api.IValueReference;
  import org.apache.hyracks.data.std.primitive.IntegerPointable;
  import org.apache.hyracks.data.std.primitive.UTF8StringPointable;
  import org.apache.hyracks.data.std.primitive.VoidPointable;
  import org.apache.hyracks.util.string.UTF8StringUtil;
  
  public final class StringKeyValueReader extends AbstractValueReader implements IColumnKeyValueReader {
      private final IPointable value;
      private ByteBuffer buffer;
      private int startOffset;
      private int tupleCount;
  
      public StringKeyValueReader() {
          value = new VoidPointable();
      }
  
      @Override
      public void init(AbstractBytesInputStream in, int tupleCount) throws IOException {
          buffer = in.getBuffer();
          startOffset = buffer.position();
          this.tupleCount = tupleCount;
          value.set(null, 0, 0);
      }
  
      @Override
      public int reset(int startIndex, int skipCount) {
          getValue(startIndex);
          return 0;
      }
  
      @Override
      public IValueReference getValue(int index) {
          byte[] bytes = buffer.array();
          int indexOffset = startOffset + index * Integer.BYTES;
          int valueOffset = startOffset + tupleCount * Integer.BYTES + IntegerPointable.getInteger(bytes, indexOffset);
          int valueLength = UTF8StringUtil.getUTFLength(bytes, valueOffset);
          valueLength += UTF8StringUtil.getNumBytesToStoreLength(valueLength);
          value.set(bytes, valueOffset, valueLength);
          return value;
      }
  
      @Override
      public IValueReference getBytes() {
          return value;
      }
  
      @Override
      public void nextValue() {
          if (value.getByteArray() == null) {
              getValue(0);
              return;
          }
          int offset = value.getStartOffset() + value.getLength();
          int length = UTF8StringUtil.getUTFLength(buffer.array(), offset);
          length += UTF8StringUtil.getNumBytesToStoreLength(length);
          value.set(buffer.array(), offset, length);
      }
  
      @Override
      public ATypeTag getTypeTag() {
          return ATypeTag.STRING;
      }
  
      @Override
      public int compareTo(AbstractValueReader o) {
          return UTF8StringPointable.compare(getBytes(), o.getBytes());
      }
  }
  