launchdarkly::server_side::data_interfaces::ISerializedDestination Class Reference

This interface is used for persisting data to databases, or any other component that can store feature flag / segment data. More...

#include <iserialized_destination.hpp>

Public Types
enum class	InitResult { kSuccess , kError }
enum class	UpsertResult { kSuccess , kError , kNotUpdated }
using	Key = std::string
template<typename T >
using	Keyed = std::pair< Key, T >
using	OrderedNamepace = std::vector< Keyed< integrations::SerializedItemDescriptor > >
using	ItemCollection = std::pair< integrations::ISerializedItemKind const &, OrderedNamepace >

Public Member Functions
virtual InitResult	Init (std::vector< ItemCollection > sdk_data_set)=0
	Overwrites the Destination's contents with a set of items for each collection. All previous data should be disgraded regardless of versioning.
virtual UpsertResult	Upsert (integrations::ISerializedItemKind const &kind, std::string const &key, integrations::SerializedItemDescriptor item)=0
	Upserts a single item (update if exist, insert if not.)
virtual std::string const &	Identity () const =0
	ISerializedDestination (ISerializedDestination const &item)=delete
	ISerializedDestination (ISerializedDestination &&item)=delete
ISerializedDestination &	operator= (ISerializedDestination const &)=delete
ISerializedDestination &	operator= (ISerializedDestination &&)=delete

Detailed Description

This interface is used for persisting data to databases, or any other component that can store feature flag / segment data.

The SDK automatically converts between its in-memory data model and a serialized string form, which is what this interface interacts with.

Each item in the store is conceptually a SerializedItemDescriptor containing a version and the serialized form. The serialized form might represent a flag/segment, or a "tombstone" representing the (absence) of an item.

It's possible to satisfy the interface in two ways:

1. The Destination can store the version number, deleted state, and item separately. This is preferred because it avoids the need to deserialize the entire item just to inspect the version/deleted state when performing an Upsert operation. If implementing this strategy, the Destination may ignore deleted SerializeItemDescriptor's serializedItem members on Upserts.
2. If there's no way to store the version number, deleted state, and item separately in an efficient way, then the store may instead persist the serializedItem as-is during an Upsert. The item will contain a "tombstone" representation which the SDK will later use to determine if the item is deleted or not.

Member Enumeration Documentation

InitResult

enum class launchdarkly::server_side::data_interfaces::ISerializedDestination::InitResult

strong

Enumerator
kSuccess	The init operation completed successfully.
kError	There was an error with the init operation.

UpsertResult

enum class launchdarkly::server_side::data_interfaces::ISerializedDestination::UpsertResult

strong

Enumerator
kSuccess	The upsert completed successfully.
kError	There was an error with the upsert operation.
kNotUpdated	The upsert did not encounter errors, but the version of the existing item was greater than that the version of the upsert item.

Member Function Documentation

Identity()

virtual std::string const & launchdarkly::server_side::data_interfaces::ISerializedDestination::Identity ( ) const

pure virtual

Returns

Identity of the destination. Used in logs.

Init()

virtual InitResult launchdarkly::server_side::data_interfaces::ISerializedDestination::Init ( std::vector< ItemCollection >  sdk_data_set )

pure virtual

Overwrites the Destination's contents with a set of items for each collection. All previous data should be disgraded regardless of versioning.

The update should be done atomically. If that's not possible, the store must first add or update each item in the same order that they are given in the input data, and then delete any previously stored items that were not in the input data.

Parameters

sdk_data_set

A series of collections, where each collection is named by an ISerializedItemKind and contains a list of key/value pairs representing the key of the item and the serialized form of the item.

Returns

InitResult::kSuccess if all data items were stored, or InitResult::kError if any error occoured.

Upsert()

virtual UpsertResult launchdarkly::server_side::data_interfaces::ISerializedDestination::Upsert ( integrations::ISerializedItemKind const &  kind, std::string const &  key, integrations::SerializedItemDescriptor  item  )

pure virtual

Upserts a single item (update if exist, insert if not.)

If the given key already exists in the collection named by kind, then the Destination must check the version number corresponding to that key. Note that the item corresponding to that key may be a tombstone representing an absent item.

If the version of the existing item is >= the version of the new item, return UpsertResult::kNotUpdated. If the Destination can't determine the version number of the existing item without full deserialization, then it may call integrations::ISerializedItemKind::Version on the data to obtain it.

If the given item's deleted flag is true, the Destination must persist this fact. It can either store a tombstone (value of serializedItem), or if deletion state is stored separate from the item, it can use that mechanism. In any case, it should not delete/forget about the item.

Parameters

kind	The item kind.
key	The item key.
item	Serialized form of the item.

Returns

UpsertResult::kSuccess if the operation was successful. UpsertResult::kError if an error occured. Otherwise, UpsertResult::kNotUpdated if the existing item version was greater than the version passed in.

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The documentation for this class was generated from the following file:

• src/data_interfaces/destination/iserialized_destination.hpp