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.cassandra.index.sasi.analyzer;
  
  import java.nio.CharBuffer;
  import java.nio.ByteBuffer;
  import java.nio.charset.Charset;
  import java.nio.charset.StandardCharsets;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.Map;
  
  import com.google.common.annotations.Beta;
  import com.google.common.base.Preconditions;
  
  import org.apache.cassandra.db.marshal.AbstractType;
  import org.apache.cassandra.db.marshal.AsciiType;
  import org.apache.cassandra.db.marshal.UTF8Type;
  import org.apache.cassandra.utils.AbstractIterator;
  
  @Beta
  public class DelimiterAnalyzer extends AbstractAnalyzer
  {
  
      private static final Map<AbstractType<?>, Charset> VALID_ANALYZABLE_TYPES = new HashMap<AbstractType<?>, Charset>()
      {{
          put(UTF8Type.instance, StandardCharsets.UTF_8);
          put(AsciiType.instance, StandardCharsets.US_ASCII);
      }};
  
      private char delimiter;
      private Charset charset;
      private Iterator<ByteBuffer> iter;
  
      public DelimiterAnalyzer()
      {
      }
  
      @Override
      public ByteBuffer next()
      {
          return iter.next();
      }
  
      public void init(Map<String, String> options, AbstractType<?> validator)
      {
          DelimiterTokenizingOptions tokenizingOptions = DelimiterTokenizingOptions.buildFromMap(options);
          delimiter = tokenizingOptions.getDelimiter();
          charset = VALID_ANALYZABLE_TYPES.get(validator);
      }
  
      public boolean hasNext()
      {
          return iter.hasNext();
      }
  
      public void reset(ByteBuffer input)
      {
          Preconditions.checkNotNull(input);
          final CharBuffer cb = charset.decode(input);
  
          this.iter = new AbstractIterator<ByteBuffer>() {
              protected ByteBuffer computeNext() {
  
                  if (!cb.hasRemaining())
                      return endOfData();
  
                  CharBuffer readahead = cb.duplicate();
                  // loop until we see the next delimiter character, or reach end of data
                  boolean readaheadRemaining;
                  while ((readaheadRemaining = readahead.hasRemaining()) && readahead.get() != delimiter);
  
                  char[] chars = new char[readahead.position() - cb.position() - (readaheadRemaining ? 1 : 0)];
                  cb.get(chars);
                  Preconditions.checkState(!cb.hasRemaining() || cb.get() == delimiter);
  
                  return 0 < chars.length
                          ? charset.encode(CharBuffer.wrap(chars))
                          // blank partition keys not permitted, ref ConcurrentRadixTree.putIfAbsent(..)
                          : computeNext();
              }
          };
      }
  
      @Override
      public boolean isTokenizing()
      {
          return true;
      }
  
      @Override
      public boolean isCompatibleWith(AbstractType<?> validator)
      {
          return VALID_ANALYZABLE_TYPES.containsKey(validator);
      }
  }
  