Package org.pentaho.di.core.xml

Class XMLHandlerCache

java.lang.Object
org.pentaho.di.core.xml.XMLHandlerCache
public class XMLHandlerCache extends Object
Singleton to help speed up lookups in an XML DOM tree.
The theory is that you often loop over occurrences of a certain tag in a Node.
If there are 20 occurrences, you go from index 0..19.
Every time we do the following
- found node 0
- found node 0, 1
- found node 0, 1, 2
- ...
So the time to search node index 19 is 20 times larger on average then index 0.

We can solve this by caching the position of index 18 and by starting back at that position.

This class is a singleton to keep everyting 100% compatible with the rest of the codebase.
Since:
22-Apr-2006
Author:
Matt

  • Method Details

    • getInstance

      public static XMLHandlerCache getInstance()

    • storeCache

      public void storeCache(XMLHandlerCacheEntry entry, int lastChildNr)
      Store a cache entry
      Parameters:
      entry - The cache entry to store

    • getLastChildNr

      public int getLastChildNr(XMLHandlerCacheEntry entry)
      Retrieve the last child were we left off...
      Parameters:
      entry - The cache entry to look for.
      Returns:
      the last child position or -1 if nothing was found.

    • getCacheHits

      public int getCacheHits()
      Returns:
      the number of cache hits for your statistical pleasure.

    • setCacheHits

      public void setCacheHits(int cacheHits)
      Allows you to (re-)set the number of cache hits
      Parameters:
      cacheHits - the number of cache hits.

    • clear

      public void clear()
      Clears the cache