Package com.googlecode.objectify.impl

Class LoadEngine

java.lang.Object
com.googlecode.objectify.impl.LoadEngine
public class LoadEngine extends Object
Represents one "batch" of loading. Get a number of Result<?> objects, then execute(). Some work is done right away, some work is done on the first get(). There might be multiple rounds of execution to process all the @Load groups, but that is invisible outside this class.
Author:
Jeff Schnitzer <[email protected]>

  • Constructor Summary

    Constructors
    Constructor
    Description
    LoadEngine(ObjectifyImpl ofy, Session session, AsyncDatastoreReaderWriter datastore, LoadArrangement loadArrangement, com.google.common.collect.ImmutableSet<com.google.cloud.datastore.ReadOption> readOptions)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    execute()
    Starts asychronous fetching of the batch.
    Result<Map<com.google.cloud.datastore.Key,com.google.cloud.datastore.Entity>>
    fetch(Set<com.google.cloud.datastore.Key> keys)
    Fetch the keys from the async datastore using the current transaction context
    <T> T
    load(com.google.cloud.datastore.BaseEntity<com.google.cloud.datastore.Key> ent, LoadContext ctx)
    Converts a datastore entity into a typed pojo object
    <T> Result<T>
    load(Key<T> key)
    Gets the result, possibly from the session, putting it in the session if necessary.
    <T> Ref<T>
    makeRef(Key<?> rootEntity, LoadConditions loadConditions, Key<T> key)
    Create a Ref for the key, and maybe start a load operation depending on current load groups.
    boolean
    shouldLoad(LoadConditions loadConditions)
     
    void
    stuff(com.google.cloud.datastore.Entity ent)
    Stuffs an Entity into a place where values in the round can be obtained instead of going to the datastore.
    Result<Map<Key<?>,Object>>
    translate(Result<Map<com.google.cloud.datastore.Key,com.google.cloud.datastore.Entity>> raw)
    Asynchronously translate raw to processed; might produce successive load operations as refs are filled in

    Methods inherited from class java.lang.Object

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

  • Constructor Details

  • Method Details

    • load

      public <T> Result<T> load(Key<T> key)
      Gets the result, possibly from the session, putting it in the session if necessary. Also will recursively prepare the session with @Load parents as appropriate.
      Throws:
      NullPointerException - if key is null

    • execute

      public void execute()
      Starts asychronous fetching of the batch.

    • makeRef

      public <T> Ref<T> makeRef(Key<?> rootEntity, LoadConditions loadConditions, Key<T> key)
      Create a Ref for the key, and maybe start a load operation depending on current load groups.
      Parameters:
      rootEntity - is the entity key which holds this property (possibly through some level of embedded objects)

    • shouldLoad

      public boolean shouldLoad(LoadConditions loadConditions)
      Returns:
      true if the specified property should be loaded in this batch

    • stuff

      public void stuff(com.google.cloud.datastore.Entity ent)
      Stuffs an Entity into a place where values in the round can be obtained instead of going to the datastore. Called by non-hybrid queries to add results and eliminate batch fetching.

    • translate

      public Result<Map<Key<?>,Object>> translate(Result<Map<com.google.cloud.datastore.Key,com.google.cloud.datastore.Entity>> raw)
      Asynchronously translate raw to processed; might produce successive load operations as refs are filled in

    • fetch

      public Result<Map<com.google.cloud.datastore.Key,com.google.cloud.datastore.Entity>> fetch(Set<com.google.cloud.datastore.Key> keys)
      Fetch the keys from the async datastore using the current transaction context

    • load

      public <T> T load(com.google.cloud.datastore.BaseEntity<com.google.cloud.datastore.Key> ent, LoadContext ctx)
      Converts a datastore entity into a typed pojo object
      Returns:
      an assembled pojo, or the Entity itself if the kind is not registered, or null if the input value was null