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.dataflow.data.common;
  
  import org.apache.asterix.dataflow.data.nontagged.serde.AOrderedListSerializerDeserializer;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.EnumDeserializer;
  import org.apache.asterix.om.utils.NonTaggedFormatUtil;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.storage.am.lsm.invertedindex.fulltext.TokenizerCategory;
  import org.apache.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizer;
  import org.apache.hyracks.storage.am.lsm.invertedindex.tokenizers.IToken;
  import org.apache.hyracks.storage.am.lsm.invertedindex.tokenizers.ITokenFactory;
  import org.apache.hyracks.storage.am.lsm.invertedindex.tokenizers.TokenizerInfo.TokenizerType;
  
  public class AOrderedListBinaryTokenizer implements IBinaryTokenizer {
  
      protected byte[] data;
      protected int start;
      protected int length;
      protected int listLength;
      protected int itemIndex;
  
      protected final IToken token;
  
      public AOrderedListBinaryTokenizer(ITokenFactory tokenFactory) {
          token = tokenFactory.createToken();
      }
  
      @Override
      public IToken getToken() {
          return token;
      }
  
      @Override
      public boolean hasNext() {
          return itemIndex < listLength;
      }
  
      @Override
      public void next() {
          int itemOffset = -1;
          int length = -1;
          try {
              itemOffset = getItemOffset(data, start, itemIndex);
              // Assuming homogeneous list.
              ATypeTag typeTag = EnumDeserializer.ATYPETAGDESERIALIZER.deserialize(data[start + 1]);
              // ? Can we handle the non-string type ?
              length = NonTaggedFormatUtil.getFieldValueLength(data, itemOffset, typeTag, false);
              // Last param is a hack to pass the type tag.
              token.reset(data, itemOffset, itemOffset + length, length, data[start + 1]);
          } catch (HyracksDataException e) {
              throw new IllegalStateException(e);
          }
          itemIndex++;
      }
  
      @Override
      public void reset(byte[] data, int start, int length) {
          this.data = data;
          this.start = start;
          this.length = length;
          this.listLength = getNumberOfItems(data, start);
          this.itemIndex = 0;
      }
  
      protected int getItemOffset(byte[] data, int start, int itemIndex) throws HyracksDataException {
          return AOrderedListSerializerDeserializer.getItemOffset(data, start, itemIndex);
      }
  
      protected int getNumberOfItems(byte[] data, int start) {
          return AOrderedListSerializerDeserializer.getNumberOfItems(data, start);
      }
  
      @Override
      public short getTokensCount() {
          return (short) listLength;
      }
  
      @Override
      public TokenizerType getTokenizerType() {
          return TokenizerType.LIST;
      }
  
      @Override
      public TokenizerCategory getTokenizerCategory() {
          // Currently, the AOrderedListBinaryTokenizer is used in ftcontains() function only,
          // which means it is used to tokenize WORD only
          //
          // The functions that utilize NGRAM index are edit_distance(), edit_distance_check() and so on,
          // which don't take a list as input (string only).
          // e.g. edit_distance(u.name, "Suzanna Tilson")
          return TokenizerCategory.WORD;
      }
  }
  