Package mondrian.rolap.cache

Class MemorySegmentCache

java.lang.Object
mondrian.rolap.cache.MemorySegmentCache
All Implemented Interfaces:
SegmentCache
public class MemorySegmentCache extends Object implements SegmentCache
Implementation of SegmentCache that stores segments in memory.

Segments are held via soft references, so the garbage collector can remove them if it sees fit.

Author:
Julian Hyde

  • Constructor Details

    • MemorySegmentCache

      public MemorySegmentCache()

  • Method Details

    • get

      public SegmentBody get(SegmentHeader header)
      Description copied from interface: SegmentCache
      Returns a SegmentBody once the cache has returned any results, or null if no segment corresponding to the header could be found.

      Cache implementations are at liberty to 'forget' segments. Therefore it is allowable for this method to return null at any time

      Specified by:
      get in interface SegmentCache
      Parameters:
      header - The header of the segment to find. Consider this as a key.
      Returns:
      A SegmentBody, or null if no corresponding segment could be found in cache.

    • contains

      public boolean contains(SegmentHeader header)

    • getSegmentHeaders

      public List<SegmentHeader> getSegmentHeaders()
      Description copied from interface: SegmentCache
      Returns a list of all segments present in the cache.
      Specified by:
      getSegmentHeaders in interface SegmentCache
      Returns:
      A List of segment headers describing the contents of the cache.

    • put

      public boolean put(SegmentHeader header, SegmentBody body)
      Description copied from interface: SegmentCache
      Stores a segment data in the cache.
      Specified by:
      put in interface SegmentCache
      Parameters:
      header - The header of the segment.
      body - The segment body to cache.
      Returns:
      Whether the cache write succeeded

    • remove

      public boolean remove(SegmentHeader header)
      Description copied from interface: SegmentCache
      Removes a segment from the cache.
      Specified by:
      remove in interface SegmentCache
      Parameters:
      header - The header of the segment we want to remove.
      Returns:
      True if the segment was found and removed, false otherwise.

    • tearDown

      public void tearDown()
      Description copied from interface: SegmentCache
      Tear down and clean up the cache.
      Specified by:
      tearDown in interface SegmentCache

    • addListener

      public void addListener(SegmentCache.SegmentCacheListener listener)
      Description copied from interface: SegmentCache
      Adds a listener to this segment cache implementation. The listener will get notified via SegmentCache.SegmentCacheListener.SegmentCacheEvent instances.
      Specified by:
      addListener in interface SegmentCache
      Parameters:
      listener - The listener to attach to this cache.

    • removeListener

      public void removeListener(SegmentCache.SegmentCacheListener listener)
      Description copied from interface: SegmentCache
      Unregisters a listener from this segment cache implementation.
      Specified by:
      removeListener in interface SegmentCache
      Parameters:
      listener - The listener to remove.

    • supportsRichIndex

      public boolean supportsRichIndex()
      Description copied from interface: SegmentCache
      Tells Mondrian whether this segment cache uses the SegmentHeader objects as an index, thus preserving them in a serialized state, or if it uses its identification number only.

      Not using a rich index prevents Mondrian from doing partial cache invalidation.

      It is assumed that this method returns fairly quickly, and for a given cache always returns the same value.

      Specified by:
      supportsRichIndex in interface SegmentCache
      Returns:
      Whether this segment cache preserves headers in serialized state

    • fireSegmentCacheEvent

      public void fireSegmentCacheEvent(SegmentCache.SegmentCacheListener.SegmentCacheEvent evt)