Core Functions and Classes

These are the core classes. More...

Classes
struct	DataShardKey
	A key that uniquely identifies and provides access to data shards in the DataShard system. DataShardKey combines an object reference (owner) and a string name to form a unique identifier, that can be used to access and manage data within the DataShardSubsystem. More...
class	DataShardObject
	DataShardObject is the core container class for data in the DataShard system. This class provides a flexible data storage mechanism that can hold any Unreal property type. It uses a type-erased byte buffer approach with a property reference to correctly interpret the stored data. The system maintains these objects in a pool (DataShardPool) for efficient reuse. Key capabilities: More...
class	DataShardSubsystem
	DataShardSubsystem manages the creation, access, and lifecycle of DataShards. DataShards are a flexible data-sharing system that allows game objects to store and access type-safe data throughout the game. More...

Functions
bool	DataShardSubsystem::CreateShard (const FDataShardKey &Key, const FProperty *InProperty, const void *InData=nullptr)
bool	DataShardSubsystem::CreateShard (const FDataShardKey &Key, const UObject *Container, const FName &PropertyName)
bool	DataShardSubsystem::GetShardData (const FDataShardKey &Key, const void *&OutData) const
template<typename T>
const T *	DataShardSubsystem::GetShardData (const FDataShardKey &Key, const bool bCheck=false) const
template<typename T>
const T *	DataShardSubsystem::GetShardData (const int32 &ID, const bool bCheck=false) const
template<typename T>
TSharedPtr< const T >	DataShardSubsystem::GetShardDataCopy (const FDataShardKey &Key, const bool bCheck=false) const
template<typename T>
TSharedPtr< const T >	DataShardSubsystem::GetShardDataCopy (const int32 &ID, const bool bCheck=false) const
bool	DataShardSubsystem::SetShardData (const FDataShardKey &Key, const void *InData, const FProperty *InProperty) const
bool	DataShardSubsystem::SetShardData (const FDataShardKey &Key, const UObject *Container, const FName &PropertyName) const
bool	DataShardSubsystem::RemoveKey (const FDataShardKey &Key)
bool	DataShardSubsystem::CreateBoundKey (const FDataShardKey &Parent, const FDataShardKey &KeyInfo, FDataShardKey &OutKey)
FDataShardKey	DataShardSubsystem::CreateBoundKey (const FDataShardKey &Parent, const FDataShardKey &KeyInfo)

Detailed Description

These are the core classes.

Function Documentation

CreateBoundKey() [1/2]

FDataShardKey DataShardSubsystem::CreateBoundKey	(	const FDataShardKey &	Parent,
		const FDataShardKey &	KeyInfo )

Creates and returns a new key that references the same shard as an existing key This allows multiple actors to share the same data

Parameters

Parent	- The existing key that points to the shard
KeyInfo	- Information for the new key (object owner and name)

Returns

The newly created key (will be invalid if creation failed)

CreateBoundKey() [2/2]

bool DataShardSubsystem::CreateBoundKey	(	const FDataShardKey &	Parent,
		const FDataShardKey &	KeyInfo,
		FDataShardKey &	OutKey )

Creates a new key that references the same shard as an existing key This allows multiple actors to share the same data

Parameters

Parent	- The existing key that points to the shard
KeyInfo	- Information for the new key (object owner and name)
OutKey	- [Out] The newly created key if successful

Returns

true if the new bound key was created successfully, false if the parent key is invalid

CreateShard() [1/2]

bool DataShardSubsystem::CreateShard	(	const FDataShardKey &	Key,
		const FProperty *	InProperty,
		const void *	InData = nullptr )

Creates a new data shard and initializes it with the specified property and data

Parameters

Key	- The key used to access and identify the shard. Contains owner object and name
InProperty	- The property that defines the data type and structure (will be copied)
InData	- Pointer to initial data to copy into the shard. If nullptr, the shard is created with default values

Returns

true if the shard was successfully created, false if invalid parameters or if the key already exists

CreateShard() [2/2]

bool DataShardSubsystem::CreateShard	(	const FDataShardKey &	Key,
		const UObject *	Container,
		const FName &	PropertyName )

Creates a new data shard using values from a property in a UObject

Parameters

Key	- The key used to access and identify the shard. Contains owner object and name
Container	- The UObject containing the property to copy data from
PropertyName	- The name of the property within the Container to source data from

Returns

true if the shard was successfully created, false if invalid parameters or if the key already exists

GetShardData() [1/3]

template<typename T>

const T * DataShardSubsystem::GetShardData	(	const FDataShardKey &	Key,
		const bool	bCheck = false ) const

Template function to get typed data from a shard

Template Parameters

T	- The data type expected to be stored in the shard

Parameters

Key	- The key of the shard to access
bCheck	- If true, will check the shard exist

Returns

Pointer to the typed data (nullptr if not found or type mismatch)

Note

The returned pointer is owned by the shard and should not be deleted by the caller

GetShardData() [2/3]

bool DataShardSubsystem::GetShardData	(	const FDataShardKey &	Key,
		const void *&	OutData ) const

Retrieves a pointer to the raw data stored in a shard

Parameters

Key	- The key of the shard to access
OutData	- [Out] Reference to a void pointer that will be set to point to the shard data

Returns

true if the data was found and OutData was set, false otherwise

Note

The caller is responsible for casting the data to the correct type

GetShardData() [3/3]

template<typename T>

const T * DataShardSubsystem::GetShardData	(	const int32 &	ID,
		const bool	bCheck = false ) const

Template function to get typed data from a shard

Template Parameters

T	- The data type expected to be stored in the shard

Parameters

ID	- The ID of the shard to access
bCheck	- If true, will check the shard exist

Returns

Pointer to the typed data (nullptr if not found or type mismatch)

Note

The returned pointer is owned by the shard and should not be deleted by the caller

GetShardDataCopy() [1/2]

template<typename T>

TSharedPtr< const T > DataShardSubsystem::GetShardDataCopy	(	const FDataShardKey &	Key,
		const bool	bCheck = false ) const

Creates and returns a copy of data stored in a shard

Template Parameters

T	- The data type expected to be stored in the shard

Parameters

Key	- The key of the shard to access
bCheck	- If true, will verify the shard contains the expected data type

Returns

Shared pointer to a copy of the data (nullptr if not found or type mismatch)

Note

The returned copy will not be updated if the original shard data changes

GetShardDataCopy() [2/2]

template<typename T>

TSharedPtr< const T > DataShardSubsystem::GetShardDataCopy	(	const int32 &	ID,
		const bool	bCheck = false ) const

Creates and returns a copy of data stored in a shard

Template Parameters

T	- The data type expected to be stored in the shard

Parameters

ID	- The ID of the shard to access
bCheck	- If true, will verify the shard contains the expected data type

Returns

Shared pointer to a copy of the data (nullptr if not found or type mismatch)

Note

The returned copy will not be updated if the original shard data changes

RemoveKey()

bool DataShardSubsystem::RemoveKey

(

const FDataShardKey &

Key

)

Removes a key and decrements the reference count for its associated shard If the reference count reaches zero, the shard will be marked for garbage collection

Parameters

Key	- The key to remove

Returns

true if the key was found and removed successfully, false otherwise

SetShardData() [1/2]

bool DataShardSubsystem::SetShardData	(	const FDataShardKey &	Key,
		const UObject *	Container,
		const FName &	PropertyName ) const

Updates the data stored in an existing shard using values from a property in a UObject

Parameters

Key	- The key of the shard to update
Container	- The UObject containing the property to copy data from
PropertyName	- The name of the property within the Container to source data from

Returns

true if the data was successfully updated, false if the shard wasn't found or the property type doesn't match

SetShardData() [2/2]

bool DataShardSubsystem::SetShardData	(	const FDataShardKey &	Key,
		const void *	InData,
		const FProperty *	InProperty ) const

Updates the data stored in an existing shard

Parameters

Key	- The key of the shard to update
InData	- Pointer to the new data to copy into the shard
InProperty	- The property that defines the data type and structure (must match the shard's existing property type)

Returns

true if the data was successfully updated, false if the shard wasn't found or the property type doesn't match