content: package org.apache.lucene.index;
  
  /**
   * 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.
   */
  
  import java.io.Reader;
  
  /** Used by DocumentsWriter to implemented a StringReader
   *  that can be reset to a new string; we use this when
   *  tokenizing the string value from a Field. */
  final class ReusableStringReader extends Reader {
    int upto;
    int left;
    String s;
    void init(String s) {
      this.s = s;
      left = s.length();
      this.upto = 0;
    }
    @Override
    public int read(char[] c) {
      return read(c, 0, c.length);
    }
    @Override
    public int read(char[] c, int off, int len) {
      if (left > len) {
        s.getChars(upto, upto+len, c, off);
        upto += len;
        left -= len;
        return len;
      } else if (0 == left) {
        // don't keep a reference (s could have been very large)
        s = null;
        return -1;
      } else {
        s.getChars(upto, upto+left, c, off);
        int r = left;
        left = 0;
        upto = s.length();
        return r;
      }
    }
    @Override
    public void close() {}
  }
  
  