Module com.conveyal.kryo_tools
Package com.conveyal.kryo

Class InstanceCountingClassResolver

java.lang.Object
com.esotericsoftware.kryo.util.DefaultClassResolver
com.conveyal.kryo.InstanceCountingClassResolver
All Implemented Interfaces:
com.esotericsoftware.kryo.ClassResolver
public class InstanceCountingClassResolver extends com.esotericsoftware.kryo.util.DefaultClassResolver
This class is used for configuring and optimizing Kryo configuration. Kryo lets you register specific serializers for specific concrete classes, but also has quite a few built-in default serializers for individual classes or trees of classes under some interface (e.g. Collection). Writing and registering a custom serializer or choosing between a third party class's built-in Externalizable method and such a custom serializer can have significant effects on the speed of serialization and size of the resulting serialized data. In order to apply the 80/20 rule it's helpful to have a list of how often various classes are serialized in your application. This class works by wrapping one method in the Kryo framework that is called for every serialized instance: the method that looks up the serializer for a given class. It counts how many times each class is looked up, and can print out a summary of those frequencies as well as the serializer that was associated with each class. Note that if you have already registered serializers that are non-recursive, e.g. they write out all the values in an internal int array within an ArrayList implementation, those internal fields will of course not be counted. We could achieve the same thing by extending the ReferenceResolver in the same way, but here in ClassResolver we have easy access to the map of Class-Serializer associations. To use this you need to specify a custom class resolver when creating Kryo: Kryo kryo = new Kryo(new InstanceCountingClassResolver(), new MapReferenceResolver(), new DefaultStreamFactory()); kryo.setRegistrationRequired(false); [...] ((InstanceCountingClassResolver)kryo.getClassResolver()).summarize(); In the case of R5 serialization, this can be enabled with a boolean constant in KryoNetworkSerializer. Created by abyrd on 2018-08-29

  • Field Summary

    Fields inherited from class com.esotericsoftware.kryo.util.DefaultClassResolver

    classToNameId, classToRegistration, idToRegistration, kryo, NAME, nameIdToClass, nameToClass, nextNameId

  • Constructor Summary

    Constructors
    Constructor
    Description
    InstanceCountingClassResolver()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    com.esotericsoftware.kryo.Registration
    getRegistration(Class type)
     
    void
    summarize()
    The output from this method can be sorted in a spreadsheet and formatted into a markdown table with http://www.tablesgenerator.com/markdown_tables for inclusion in Github issue or pull request comments.

    Methods inherited from class com.esotericsoftware.kryo.util.DefaultClassResolver

    getRegistration, getTypeByName, readClass, readName, register, registerImplicit, reset, setKryo, unregister, writeClass, writeName

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • InstanceCountingClassResolver

      public InstanceCountingClassResolver()

  • Method Details

    • getRegistration

      public com.esotericsoftware.kryo.Registration getRegistration(Class type)
      Specified by:
      getRegistration in interface com.esotericsoftware.kryo.ClassResolver
      Overrides:
      getRegistration in class com.esotericsoftware.kryo.util.DefaultClassResolver

    • summarize

      public void summarize()
      The output from this method can be sorted in a spreadsheet and formatted into a markdown table with http://www.tablesgenerator.com/markdown_tables for inclusion in Github issue or pull request comments.