com.launchdarkly.client

Interface FeatureStore

All Superinterfaces:

java.lang.AutoCloseable, java.io.Closeable

All Known Implementing Classes:

CachingStoreWrapper, InMemoryFeatureStore, RedisFeatureStore, TestFeatureStore

public interface FeatureStore
extends java.io.Closeable

A thread-safe, versioned store for feature flags and related objects received from the streaming API. Implementations should permit concurrent access and updates.

Delete and upsert requests are versioned-- if the version number in the request is less than the currently stored version of the object, the request should be ignored.

These semantics support the primary use case for the store, which synchronizes a collection of objects based on update messages that may be received out-of-order.

Since:

3.0.0

Method Summary

Modifier and Type	Method and Description
<T extends VersionedData> java.util.Map<java.lang.String,T>	all(VersionedDataKind<T> kind) Returns a Map of all associated objects of a given kind.
<T extends VersionedData> void	delete(VersionedDataKind<T> kind, java.lang.String key, int version) Deletes the object associated with the specified key, if it exists and its version is less than or equal to the specified version.
<T extends VersionedData> T	get(VersionedDataKind<T> kind, java.lang.String key) Returns the object to which the specified key is mapped, or null if the key is not associated or the associated object has been deleted.
void	init(java.util.Map<VersionedDataKind<?>,java.util.Map<java.lang.String,? extends VersionedData>> allData) Initializes (or re-initializes) the store with the specified set of objects.
boolean	initialized() Returns true if this store has been initialized.
<T extends VersionedData> void	upsert(VersionedDataKind<T> kind, T item) Update or insert the object associated with the specified key, if its version is less than or equal to the version specified in the argument object.

Methods inherited from interface java.io.Closeable

close

Method Detail

get

<T extends VersionedData> T get(VersionedDataKind<T> kind,
                                java.lang.String key)

Returns the object to which the specified key is mapped, or null if the key is not associated or the associated object has been deleted.

Type Parameters:

T - class of the object that will be returned

Parameters:

kind - the kind of object to get

key - the key whose associated object is to be returned

Returns:

the object to which the specified key is mapped, or null if the key is not associated or the associated object has been deleted.

all

<T extends VersionedData> java.util.Map<java.lang.String,T> all(VersionedDataKind<T> kind)

Returns a Map of all associated objects of a given kind.

Type Parameters:

T - class of the objects that will be returned in the map

Parameters:

kind - the kind of objects to get

Returns:

a map of all associated object.

init

void init(java.util.Map<VersionedDataKind<?>,java.util.Map<java.lang.String,? extends VersionedData>> allData)

Initializes (or re-initializes) the store with the specified set of objects. Any existing entries will be removed. Implementations can assume that this set of objects is up to date-- there is no need to perform individual version comparisons between the existing objects and the supplied features.

If possible, the store should update the entire data set atomically. If that is not possible, it should iterate through the outer map and then the inner map in the order provided (the SDK will use a Map subclass that has a defined ordering), storing each item, and then delete any leftover items at the very end.

The store should not attempt to modify any of the Maps, and if it needs to retain the data in memory it should copy the Maps.

Parameters:

allData - all objects to be stored

delete

<T extends VersionedData> void delete(VersionedDataKind<T> kind,
                                      java.lang.String key,
                                      int version)

Deletes the object associated with the specified key, if it exists and its version is less than or equal to the specified version.

Type Parameters:

T - class of the object to be deleted

Parameters:

kind - the kind of object to delete

key - the key of the object to be deleted

version - the version for the delete operation

upsert

<T extends VersionedData> void upsert(VersionedDataKind<T> kind,
                                      T item)

Update or insert the object associated with the specified key, if its version is less than or equal to the version specified in the argument object.

Type Parameters:

T - class of the object to be updated

Parameters:

kind - the kind of object to update

item - the object to update or insert

initialized

boolean initialized()

Returns true if this store has been initialized.

Returns:

true if this store has been initialized