Package com.googlecode.objectify.impl

Class ObjectifyImpl

java.lang.Object
com.googlecode.objectify.impl.ObjectifyImpl
All Implemented Interfaces:
Objectify, Closeable, Closeable, AutoCloseable
public class ObjectifyImpl extends Object implements Objectify, Closeable

Implementation of the Objectify interface. This is also suitable for subclassing; you can return your own subclass by overriding ObjectifyFactory.begin().

Note we *always* use the AsyncDatastoreService methods that use transactions to avoid the confusion of implicit transactions.

Author:
Jeff Schnitzer invalid input: '<'[email protected]>

  • Field Details

  • Constructor Details

  • Method Details

    • factory

      public ObjectifyFactory factory()
      Description copied from interface: Objectify
      Obtain the ObjectifyFactory from which this Objectify instance was created.
      Specified by:
      factory in interface Objectify
      Returns:
      the ObjectifyFactory associated with this Objectify instance.

    • namespace

      public Objectify namespace(String namespace)
      Description copied from interface: Objectify

      Explicitly sets the namespace for keys generated in load, save, delete operations.

      This overrides the setting of NamespaceManager.set().

      Note that this only affects implicitly created keys; if you pass key objects into load or delete methods, the namespace contained in the key will be used.

           final Key<Foo> key = Key.create(Foo.class, 123);
     ofy().namespace("blah").load().key(key);  // namespace() has no effect! The key already has the default namespace.
     ofy().namespace("blah").load().type(Foo.class).id(123);    // namespace() works as expected

      All command objects are immutable; this method returns a new object instead of modifying the current command object.

      Specified by:
      namespace in interface Objectify
      Parameters:
      namespace - is the namespace to pick; "" (empty string) forces the datastore default namespace; null restores the check for NamespaceManager.set()
      Returns:
      the next step in the immutable command chain, which allows you to start an operation.

    • load

      public Loader load()
      Description copied from interface: Objectify

      Start a load command chain. This is where you begin for any request that fetches data from the datastore: gets and queries.

      A quick example: Map<Key<Thing>, Thing> things = ofy().load().type(Thing.class).parent(par).ids(123L, 456L);

      All command objects are immutable; this method returns a new object rather than modifying the current command object.

      Specified by:
      load in interface Objectify
      Returns:
      the next step in the immutable command chain.

    • save

      public Saver save()
      Description copied from interface: Objectify

      Start a save command chain. Allows you to save (or re-save) entity objects. Note that all command chain objects are immutable.

      Saves do NOT cascade; if you wish to save an object graph, you must save each individual entity.

      A quick example: ofy().save().entities(e1, e2, e3).now();

      All command objects are immutable; this method returns a new object rather than modifying the current command object.

      Specified by:
      save in interface Objectify
      Returns:
      the next step in the immutable command chain.

    • delete

      public Deleter delete()
      Description copied from interface: Objectify

      Start a delete command chain. Lets you delete entities or keys.

      Deletes do NOT cascade; if you wish to delete an object graph, you must delete each individual entity.

      A quick example: ofy().delete().entities(e1, e2, e3).now();

      All command objects are immutable; this method returns a new object rather than modifying the current command object.

      Specified by:
      delete in interface Objectify
      Returns:
      the next step in the immutable command chain.

    • defer

      public Deferred defer()
      Description copied from interface: Objectify

      Start a deferred command chain, which lets you make multiple save or delete calls on a single entity without incurring multiple datastore operations. Deferred operations are executed at the end of a unit-of-work (transaction, or http request if not in a transaction).

      Deferred operations are reflected in the session cache immediately. However query operations may not reflect these changes. For example, newly indexed entities may not show up, even with an otherwise strongly consistent ancestor query. This should not be surprising since the actual save operation has not occurred yet.

      In the case of deferred save() and delete() operations on the same entity, the last one wins.

      Specified by:
      defer in interface Objectify
      Returns:
      the next step in the immutable command chain.

    • deadline

      public Objectify deadline(Double value)
      Description copied from interface: Objectify

      Provides a new Objectify instance with a limit, in seconds, for datastore calls. If datastore calls take longer than this amount, a timeout exception will be thrown.

      The new instance will inherit all other characteristics (transaction, cache policy, session cache contents, etc) from this instance.

      All command objects are immutable; this method returns a new object rather than modifying the current command object.

      Specified by:
      deadline in interface Objectify
      Parameters:
      value - - limit in seconds, or null to indicate no deadline (other than the standard whole request deadline of 30s/10m).
      Returns:
      a new immutable Objectify instance with the specified deadline

    • cache

      public Objectify cache(boolean value)
      Description copied from interface: Objectify

      Provides a new Objectify instance which uses (or doesn't use) a 2nd-level memcache. If true, Objectify will obey the @Cache annotation on entity classes, saving entity data to the GAE memcache service. Fetches from the datastore for @Cache entities will look in the memcache service first. This cache is shared across all versions of your application across the entire GAE cluster.

      Objectify instances are cache(true) by default.

      All command objects are immutable; this method returns a new object rather than modifying the current command object.

      Specified by:
      cache in interface Objectify
      Returns:
      a new immutable Objectify instance which will (or won't) use the global cache

    • mandatoryTransactions

      public Objectify mandatoryTransactions(boolean value)
      Description copied from interface: Objectify

      Provides a new Objectify instance which throws an exception whenever save() or delete() is called from outside a transaction context. This is a reasonable sanity check for most business workloads; you may wish to enable it globally by overriding ObjectifyFactory.begin() to twiddle this flag on the returned object.

      Objectify instances are mandatoryTransactions(false) by default.

      All command objects are immutable; this method returns a new object rather than modifying the current command object.

      Specified by:
      mandatoryTransactions in interface Objectify
      Returns:
      a new immutable Objectify instance which will (or won't) require transactions for save() and delete().

    • makeNew

      protected ObjectifyImpl makeNew(ObjectifyOptions opts, Transactor transactor)
      Can be overriden if you want to subclass the ObjectifyImpl

    • getTransaction

      public AsyncTransaction getTransaction()
      Description copied from interface: Objectify

      This used to have meaning in the old GAE SDK but no longer does. Right now this is pretty much only useful as a null test to see if you are currently in a transaction. This method will probably be removed.

      Specified by:
      getTransaction in interface Objectify

    • execute

      public <R> R execute(TxnType txnType, Work<R> work)
      Description copied from interface: Objectify

      Executes the work with the transactional behavior defined by the parameter txnType. This is very similar to EJB semantics. The work can inherit a transaction, create a new transaction, prevent transactions, etc.

      This method principally exists to facilitate implementation of AOP interceptors that provide EJB-like behavior. Usually you will call transact() or transactNew() when writing code.

      Note that ConcurrentModificationExceptions will cause the transaction to repeat as many times as necessary to finish the job. Work MUST idempotent.

      Within Work.run(), obtain the correct Objectify instance by calling ObjectifyService.ofy()

      Specified by:
      execute in interface Objectify
      Parameters:
      txnType - defines what kind of transaction context the work should be executed in.
      work - defines the work to be done; possibly in a transaction, possibly not as defined by txnType
      Returns:
      the result of the work

    • execute

      public void execute(TxnType txnType, Runnable work)
      Description copied from interface: Objectify

      Exactly the same behavior as the Work version, but doesn't return anything. Convenient for Java8 so you don't have to return something from the lambda.

      Specified by:
      execute in interface Objectify

    • transactionless

      public <R> R transactionless(Work<R> work)
      Description copied from interface: Objectify

      Executes work outside of a transaction. This is a way to "escape" from a transaction and perform datastore operations that would otherwise not be allowed (or perhaps to load data without hitting entity group limits). If there is not already a transaction running, the work is executed normally in the current session.

      For example, to return an entity fetched outside of a transaction: Thing th = ofy().transactionless(() -> ofy().load().key(thingKey).now())

      Specified by:
      transactionless in interface Objectify
      Parameters:
      work - defines the work to be done outside of a transaction
      Returns:
      the result of the work

    • transactionless

      public void transactionless(Runnable work)
      Description copied from interface: Objectify

      Exactly the same behavior as the Work version, but doesn't return anything. Convenient for Java8 so you don't have to return something from the lambda.

      Specified by:
      transactionless in interface Objectify

    • transact

      public <R> R transact(Work<R> work)
      Description copied from interface: Objectify

      Executes work in a transaction. If there is already a transaction context, that context will be inherited. If there is not already a transaction context, a new transaction will be started.

      Within Work.run(), obtain the correct transactional Objectify instance by calling ObjectifyService.ofy()

      ConcurrentModificationExceptions will cause the transaction to repeat as many times as necessary to finish the job. Work MUST idempotent.

      Specified by:
      transact in interface Objectify
      Parameters:
      work - defines the work to be done in a transaction. If this method started a new transaction, it will be committed when work is complete. If transactional context was inherited, no commit is issued until the full transaction completes normally.
      Returns:
      the result of the work

    • transact

      public void transact(Runnable work)
      Description copied from interface: Objectify

      Exactly the same behavior as the Work version, but doesn't force you to return something from your lambda.

      Specified by:
      transact in interface Objectify

    • transactNew

      public <R> R transactNew(Work<R> work)
      Description copied from interface: Objectify

      Executes work in a new transaction. Note that this is equivalent to transactNew(Integer.MAX_VALUE, work);

      ConcurrentModificationExceptions will cause the transaction to repeat as many times as necessary to finish the job. Work MUST idempotent.

      Within Work.run(), obtain the new transactional Objectify instance by calling ObjectifyService.ofy()

      Specified by:
      transactNew in interface Objectify
      Parameters:
      work - defines the work to be done in a transaction. After the method exits, the transaction will commit.
      Returns:
      the result of the work

    • transactNew

      public void transactNew(Runnable work)
      Description copied from interface: Objectify

      Exactly the same behavior as the Work version, but doesn't return anything. Convenient for Java8 so you don't have to return something from the lambda.

      Specified by:
      transactNew in interface Objectify

    • transactNew

      public <R> R transactNew(int limitTries, Work<R> work)
      Description copied from interface: Objectify

      Executes the work in a new transaction, repeating up to limitTries times when a ConcurrentModificationException is thrown. This requires your Work to be idempotent; otherwise limit tries to 1.

      Within Work.run(), obtain the new transactional Objectify instance by calling ObjectifyService.ofy()

      Specified by:
      transactNew in interface Objectify
      Parameters:
      limitTries - is the max # of tries. Must be > 0. A value of 1 means "try only once".
      work - defines the work to be done in a transaction. After the method exits, the transaction will commit.
      Returns:
      the result of the work

    • transactNew

      public void transactNew(int limitTries, Runnable work)
      Description copied from interface: Objectify

      Exactly the same behavior as the Work version, but doesn't return anything. Convenient for Java8 so you don't have to return something from the lambda.

      Specified by:
      transactNew in interface Objectify

    • clear

      public void clear()
      Description copied from interface: Objectify

      Clears the session; all subsequent requests (or Refinvalid input: '<'?>.get() calls) will go to the datastore/memcache to repopulate the session. This should rarely, if ever be necessary. Note that if you iterate query results you should only perform this action on chunk boundaries, otherwise performance will suffer. This is a "use only if you really know what you are doing" feature.

      Specified by:
      clear in interface Objectify

    • asyncDatastore

      protected AsyncDatastoreReaderWriter asyncDatastore()

    • createWriteEngine

      protected WriteEngine createWriteEngine()
      Use this once for one operation and then throw it away
      Returns:
      a fresh engine that handles fundamental datastore operations for saving and deleting

    • makeFilterable

      public com.google.cloud.datastore.Value<?> makeFilterable(Object value)

      Translates the value of a filter clause into something the datastore understands. Keyinvalid input: '<'?> goes to native Key, entities go to native Key, java.sql.Date goes to java.util.Date, etc. It uses the same translation system that is used for standard entity fields, but does no checking to see if the value is appropriate for the field.

      Unrecognized types are returned as-is.

      A future version of this method might check for type validity.

      Returns:
      whatever can be put into a filter clause.

    • getSession

      protected Session getSession()

    • isLoaded

      public boolean isLoaded(Key<?> key)
      Specified by:
      isLoaded in interface Objectify
      Returns:
      true if the key has been loaded into the session; false if loading the key would result in a datastore (or memcache) fetch.

    • flush

      public void flush()
      Description copied from interface: Objectify
      Synchronously flushes any deferred operations to the datastore. Objectify does this for you at the end of transactions and requests, but if you need data to be written immediately - say, you're about to perform a strongly-consistent ancestor query and you need to see the updated indexes immediately - you can call this method. If there are no deferred operations, this does nothing.
      Specified by:
      flush in interface Objectify

    • close

      public void close()
      Ends this transactional scope.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface Closeable