com.launchdarkly.client.utils

Interface FeatureStoreCore

All Superinterfaces:

java.lang.AutoCloseable, java.io.Closeable

public interface FeatureStoreCore
extends java.io.Closeable

FeatureStoreCore is an interface for a simplified subset of the functionality of FeatureStore, to be used in conjunction with CachingStoreWrapper. This allows developers of custom FeatureStore implementations to avoid repeating logic that would commonly be needed in any such implementation, such as caching. Instead, they can implement only FeatureStoreCore and then create a CachingStoreWrapper.

Note that these methods do not take any generic type parameters; all storeable entities are treated as implementations of the VersionedData interface, and a VersionedDataKind instance is used to specify what kind of entity is being referenced. If entities will be marshaled and unmarshaled, this must be done by reflection, using the type specified by VersionedDataKind.getItemClass(); the methods in FeatureStoreHelpers may be useful for this.

Since:

4.6.0

Method Summary

Modifier and Type	Method and Description
java.util.Map<java.lang.String,VersionedData>	getAllInternal(VersionedDataKind<?> kind) Returns a Map of all associated objects of a given kind.
VersionedData	getInternal(VersionedDataKind<?> kind, java.lang.String key) Returns the object to which the specified key is mapped, or null if no such item exists.
boolean	initializedInternal() Returns true if this store has been initialized.
void	initInternal(java.util.Map<VersionedDataKind<?>,java.util.Map<java.lang.String,VersionedData>> allData) Initializes (or re-initializes) the store with the specified set of objects.
VersionedData	upsertInternal(VersionedDataKind<?> kind, VersionedData item) Updates or inserts the object associated with the specified key.

Methods inherited from interface java.io.Closeable

close

Method Detail

getInternal

VersionedData getInternal(VersionedDataKind<?> kind,
                          java.lang.String key)

Returns the object to which the specified key is mapped, or null if no such item exists. The method should not attempt to filter out any items based on their isDeleted() property, nor to cache any items.

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

getAllInternal

java.util.Map<java.lang.String,VersionedData> getAllInternal(VersionedDataKind<?> kind)

Returns a Map of all associated objects of a given kind. The method should not attempt to filter out any items based on their isDeleted() property, nor to cache any items.

Parameters:

kind - the kind of objects to get

Returns:

a map of all associated objects.

initInternal

void initInternal(java.util.Map<VersionedDataKind<?>,java.util.Map<java.lang.String,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 data.

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.

Parameters:

allData - all objects to be stored

upsertInternal

VersionedData upsertInternal(VersionedDataKind<?> kind,
                             VersionedData item)

Updates or inserts the object associated with the specified key. If an item with the same key already exists, it should update it only if the new item's getVersion() value is greater than the old one. It should return the final state of the item, i.e. if the update succeeded then it returns the item that was passed in, and if the update failed due to the version check then it returns the item that is currently in the data store (this ensures that CachingStoreWrapper will update the cache correctly).

Parameters:

kind - the kind of object to update

item - the object to update or insert

Returns:

the state of the object after the update

initializedInternal

boolean initializedInternal()

Returns true if this store has been initialized. In a shared data store, it should be able to detect this even if initInternal was called in a different process, i.e. the test should be based on looking at what is in the data store. The method does not need to worry about caching this value; CachingStoreWrapper will only call it when necessary.

Returns:

true if this store has been initialized