Java CharsRefBuilder.setLength方法代码示例

import org.apache.lucene.util.CharsRefBuilder; //导入方法依赖的package包/类
/**
 * Wraps a {@link CompletionQuery} with context queries
 *
 * @param query base completion query to wrap
 * @param queryContexts a map of context mapping name and collected query contexts
 * @return a context-enabled query
 */
public ContextQuery toContextQuery(CompletionQuery query, Map<String, List<ContextMapping.InternalQueryContext>> queryContexts) {
    ContextQuery typedContextQuery = new ContextQuery(query);
    if (queryContexts.isEmpty() == false) {
        CharsRefBuilder scratch = new CharsRefBuilder();
        scratch.grow(1);
        for (int typeId = 0; typeId < contextMappings.size(); typeId++) {
            scratch.setCharAt(0, (char) typeId);
            scratch.setLength(1);
            ContextMapping mapping = contextMappings.get(typeId);
            List<ContextMapping.InternalQueryContext> internalQueryContext = queryContexts.get(mapping.name());
            if (internalQueryContext != null) {
                for (ContextMapping.InternalQueryContext context : internalQueryContext) {
                    scratch.append(context.context);
                    typedContextQuery.addContext(scratch.toCharsRef(), context.boost, !context.isPrefix);
                    scratch.setLength(1);
                }
            }
        }
    }
    return typedContextQuery;
}
 

import org.apache.lucene.util.CharsRefBuilder; //导入方法依赖的package包/类
/** Sugar: just joins the provided terms with {@link
 *  SynonymMap#WORD_SEPARATOR}.  reuse and its chars
 *  must not be null. */
public static CharsRef join(String[] words, CharsRefBuilder reuse) {
  int upto = 0;
  char[] buffer = reuse.chars();
  for (String word : words) {
    final int wordLen = word.length();
    final int needed = (0 == upto ? wordLen : 1 + upto + wordLen); // Add 1 for WORD_SEPARATOR
    if (needed > buffer.length) {
      reuse.grow(needed);
      buffer = reuse.chars();
    }
    if (upto > 0) {
      buffer[upto++] = SynonymMap.WORD_SEPARATOR;
    }

    word.getChars(0, wordLen, buffer, upto);
    upto += wordLen;
  }
  reuse.setLength(upto);
  return reuse.get();
}
 

import org.apache.lucene.util.CharsRefBuilder; //导入方法依赖的package包/类
/** Sugar: analyzes the text with the analyzer and
 *  separates by {@link SynonymMap#WORD_SEPARATOR}.
 *  reuse and its chars must not be null. */
public CharsRef analyze(String text, CharsRefBuilder reuse) throws IOException {
  try (TokenStream ts = analyzer.tokenStream("", text)) {
    CharTermAttribute termAtt = ts.addAttribute(CharTermAttribute.class);
    PositionIncrementAttribute posIncAtt = ts.addAttribute(PositionIncrementAttribute.class);
    ts.reset();
    reuse.clear();
    while (ts.incrementToken()) {
      int length = termAtt.length();
      if (length == 0) {
        throw new IllegalArgumentException("term: " + text + " analyzed to a zero-length token");
      }
      if (posIncAtt.getPositionIncrement() != 1) {
        throw new IllegalArgumentException("term: " + text + " analyzed to a token with posinc != 1");
      }
      reuse.grow(reuse.length() + length + 1); /* current + word + separator */
      int end = reuse.length();
      if (reuse.length() > 0) {
        reuse.setCharAt(end++, SynonymMap.WORD_SEPARATOR);
        reuse.setLength(reuse.length() + 1);
      }
      System.arraycopy(termAtt.buffer(), 0, reuse.chars(), end, length);
      reuse.setLength(reuse.length() + length);
    }
    ts.end();
  }
  if (reuse.length() == 0) {
    throw new IllegalArgumentException("term: " + text + " was completely eliminated by analyzer");
  }
  return reuse.get();
}