Package org.rocksdb

Class AbstractNativeReference

java.lang.Object
org.rocksdb.AbstractNativeReference
All Implemented Interfaces:
AutoCloseable
Direct Known Subclasses:
AbstractImmutableNativeReference, RocksMutableObject
public abstract class AbstractNativeReference extends Object implements AutoCloseable
AbstractNativeReference is the base-class of all RocksDB classes that have a pointer to a native C++ rocksdb object.

AbstractNativeReference has the close() method, which frees its associated C++ object.

This function should be called manually, or even better, called implicitly using a try-with-resources statement, when you are finished with the object. It is no longer called automatically during the regular Java GC process via finalization Object.finalize().

which is deprecated from Java 9.

Explanatory note - When or if the Garbage Collector calls Object.finalize() depends on the JVM implementation and system conditions, which the programmer cannot control. In addition, the GC cannot see through the native reference long member variable (which is the C++ pointer value to the native object), and cannot know what other resources depend on it.

  • Constructor Details

    • AbstractNativeReference

      public AbstractNativeReference()

  • Method Details

    • isOwningHandle

      protected abstract boolean isOwningHandle()
      Returns true if we are responsible for freeing the underlying C++ object
      Returns:
      true if we are responsible to free the C++ object

    • close

      public abstract void close()
      Frees the underlying C++ object

      It is strong recommended that the developer calls this after they have finished using the object.

      Note, that once an instance of AbstractNativeReference has been closed, calling any of its functions will lead to undefined behavior.

      Specified by:
      close in interface AutoCloseable