Package org.rocksdb

Class ComparatorOptions

java.lang.Object
org.rocksdb.AbstractNativeReference
org.rocksdb.AbstractImmutableNativeReference
org.rocksdb.RocksObject
org.rocksdb.ComparatorOptions
All Implemented Interfaces:
AutoCloseable
public class ComparatorOptions extends RocksObject
This class controls the behaviour of Java implementations of AbstractComparator

Note that dispose() must be called before a ComparatorOptions instance becomes out-of-scope to release the allocated memory in C++.

  • Constructor Details

    • ComparatorOptions

      public ComparatorOptions()

  • Method Details

    • reusedSynchronisationType

      public ReusedSynchronisationType reusedSynchronisationType()
      Get the synchronisation type used to guard the reused buffers. Only used if maxReusedBufferSize() > 0 Default: ReusedSynchronisationType.ADAPTIVE_MUTEX
      Returns:
      the synchronisation type

    • setReusedSynchronisationType

      public ComparatorOptions setReusedSynchronisationType(ReusedSynchronisationType reusedSynchronisationType)
      Set the synchronisation type used to guard the reused buffers. Only used if maxReusedBufferSize() > 0 Default: ReusedSynchronisationType.ADAPTIVE_MUTEX
      Parameters:
      reusedSynchronisationType - the synchronisation type
      Returns:
      the reference to the current comparator options.

    • useDirectBuffer

      public boolean useDirectBuffer()
      Indicates if a direct byte buffer (i.e. outside the normal garbage-collected heap) is used, as opposed to a non-direct byte buffer which is a wrapper around an on-heap byte[].

      Default: true

      Returns:
      true if a direct byte buffer will be used, false otherwise

    • setUseDirectBuffer

      public ComparatorOptions setUseDirectBuffer(boolean useDirectBuffer)
      Controls whether a direct byte buffer (i.e. outside the normal garbage-collected heap) is used, as opposed to a non-direct byte buffer which is a wrapper around an on-heap byte[].

      Default: true

      Parameters:
      useDirectBuffer - true if a direct byte buffer should be used, false otherwise
      Returns:
      the reference to the current comparator options.

    • maxReusedBufferSize

      public int maxReusedBufferSize()
      Maximum size of a buffer (in bytes) that will be reused. Comparators will use 5 of these buffers, so the retained memory size will be 5 * max_reused_buffer_size. When a buffer is needed for transferring data to a callback, if it requires less than maxReuseBufferSize, then an existing buffer will be reused, else a new buffer will be allocated just for that callback.

      Default: 64 bytes

      Returns:
      the maximum size of a buffer which is reused, or 0 if reuse is disabled

    • setMaxReusedBufferSize

      public ComparatorOptions setMaxReusedBufferSize(int maxReusedBufferSize)
      Sets the maximum size of a buffer (in bytes) that will be reused. Comparators will use 5 of these buffers, so the retained memory size will be 5 * max_reused_buffer_size. When a buffer is needed for transferring data to a callback, if it requires less than maxReuseBufferSize, then an existing buffer will be reused, else a new buffer will be allocated just for that callback.

      Default: 64 bytes

      Parameters:
      maxReusedBufferSize - the maximum size for a buffer to reuse, or 0 to disable reuse
      Returns:
      the maximum size of a buffer which is reused

    • disposeInternal

      protected final void disposeInternal(long handle)
      Specified by:
      disposeInternal in class RocksObject