com.netflix.hollow.core.util

Class HollowWriteStateCreator

java.lang.Object

com.netflix.hollow.core.util.HollowWriteStateCreator

public class HollowWriteStateCreator
extends java.lang.Object

Use to pre-populate, or create a HollowWriteStateEngine which is pre-populated, with a particular data model.

Constructor Summary

Constructors

Constructor and Description
HollowWriteStateCreator()

Method Summary

Methods

Modifier and Type	Method and Description
static HollowWriteStateEngine	createWithSchemas(java.util.Collection<HollowSchema> schemas)
static void	populateStateEngineWithTypeWriteStates(HollowWriteStateEngine stateEngine, java.util.Collection<HollowSchema> schemas) Pre-populate a HollowWriteStateEngine with a specified data model.
static void	populateUsingReadEngine(HollowWriteStateEngine writeEngine, HollowReadStateEngine readEngine) Populate the supplied HollowWriteStateEngine with all of the records from the supplied HollowReadStateEngine.
static HollowWriteStateEngine	recreateAndPopulateUsingReadEngine(HollowReadStateEngine readEngine) Recreate a HollowWriteStateEngine which can be used to write a snapshot of or continue a delta chain from the supplied HollowReadStateEngine.

Methods inherited from class java.lang.Object

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

Constructor Detail

HollowWriteStateCreator

public HollowWriteStateCreator()

Method Detail

createWithSchemas

public static HollowWriteStateEngine createWithSchemas(java.util.Collection<HollowSchema> schemas)

Parameters:

schemas - The schemas from the data model

Returns:

a write state engine which is pre-populated with the specified data model.

populateStateEngineWithTypeWriteStates

public static void populateStateEngineWithTypeWriteStates(HollowWriteStateEngine stateEngine,
                                          java.util.Collection<HollowSchema> schemas)

Pre-populate a HollowWriteStateEngine with a specified data model.

Parameters:

stateEngine - The state engine to pre-populate

schemas - The schemas from the data model.

recreateAndPopulateUsingReadEngine

public static HollowWriteStateEngine recreateAndPopulateUsingReadEngine(HollowReadStateEngine readEngine)

Recreate a HollowWriteStateEngine which can be used to write a snapshot of or continue a delta chain from the supplied HollowReadStateEngine.

The returned state engine will be ready to write a snapshot which will exactly recreate the data in the supplied HollowReadStateEngine. A delta chain may be continued from this state by calling HollowWriteStateEngine.prepareForNextCycle().

Parameters:

readEngine -

Returns:

populateUsingReadEngine

public static void populateUsingReadEngine(HollowWriteStateEngine writeEngine,
                           HollowReadStateEngine readEngine)

Populate the supplied HollowWriteStateEngine with all of the records from the supplied HollowReadStateEngine.

• If fields or types have been removed, then those are ignored when copying records.
• If fields have been added to existing types, those fields will be null in the copied records.
• If types have been added, those types will have no records.

The supplied HollowWriteStateEngine must be newly created, initialized with a data model, and empty. After this call, the write engine will be ready to write a snapshot which will exactly recreate the data in the supplied HollowReadStateEngine, except with the data model which was initialized.

A delta chain may be continued from this state by calling HollowWriteStateEngine.prepareForNextCycle().

Parameters:

readEngine -