[LUCENE-6033] Add CachingTokenFilter.isCached and switch LinkedList to ArrayList

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 5.0, 6.0
• Lucene Fields: New
• Assignee: David Smiley
• Reporter: David Smiley
• Created: 29/Oct/14 20:36
• Updated: 28/Aug/22 14:18
• Resolved: 12/Nov/14 14:12

Description

CachingTokenFilter could use a simple boolean isCached() method implemented as-such:

  /** If the underlying token stream was consumed and cached */
  public boolean isCached() {
    return cache != null;
  }

It's useful for the highlighting code to remove its wrapping of CachingTokenFilter if after handing-off to parts of its framework it turns out that it wasn't used.

Furthermore, use an ArrayList, not a LinkedList. ArrayList is leaner when the token count is high, and this class doesn't manipulate the list in a way that might favor LL.

A separate patch will come that actually uses this method.

Issue Links

• duplicates: LUCENE-5861 CachingTokenFilter should use ArrayList not LinkedList
• is related to: LUCENE-6121 Fix CachingTokenFilter to propagate reset() the first time
• is required by: SOLR-6680 DefaultSolrHighlighter can sometimes avoid CachingTokenFilter
• relates to: LUCENE-937 Make CachingTokenFilter faster