Uploaded image for project: 'Lucene - Core'
  1. Lucene - Core
  2. LUCENE-5897

performance bug ("adversary") in StandardTokenizer

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 4.9.1, 4.10, 6.0
    • Component/s: None
    • Labels:
      None
    • Lucene Fields:
      New

      Description

      There seem to be some conditions (I don't know how rare or what conditions) that cause StandardTokenizer to essentially hang on input: I havent looked hard yet, but as its essentially a DFA I think something wierd might be going on.

      An easy way to reproduce is with 1MB of underscores, it will just hang forever.

        public void testWorthyAdversary() throws Exception {
          char buffer[] = new char[1024 * 1024];
          Arrays.fill(buffer, '_');
          int tokenCount = 0;
          Tokenizer ts = new StandardTokenizer();
          ts.setReader(new StringReader(new String(buffer)));
          ts.reset();
          while (ts.incrementToken()) {
            tokenCount++;
          }
          ts.end();
          ts.close();
          assertEquals(0, tokenCount);
        }
      

        Attachments

          Activity

            People

            • Assignee:
              steve_rowe Steve Rowe
              Reporter:
              rcmuir Robert Muir
            • Votes:
              0 Vote for this issue
              Watchers:
              4 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: