FInstancedStructStream

A stream where you can append heterogeneous structs, and iterate over them in order (no random access).

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References

Module	StructUtils
Header	/Engine/Plugins/Experimental/StructUtils/Source/StructUtils/Public/InstancedStructStream.h
Include	#include "InstancedStructStream.h"

Syntax

USTRUCT()
struct FInstancedStructStream

Remarks

A stream where you can append heterogeneous structs, and iterate over them in order (no random access). The structs are stored in chunks of specified size, and reused when the stream is reset. Each chunk can hold up to MaxScriptStructsPerChunk types, on overflow new chunk is allocated. The stream can be iterated over using one of the ForEach*() methods.

If you use move assign or Append(&&), make sure to call Compact() or you may end up with large free list.

Variables

	Name	Description
int32	ChunkSize	Number of items stored in the buffer
FChunkHeader &#...	First
FChunkHeader &#...	FreeList	Pointer to the last chunk in use
FChunkHeader &#...	Head	Pointer to the first chunk in use
int32	NumItems	Free list of unused chunks

Constructors

	Name	Description
	FInstancedStructStream ( const int32 InChunkSize )
	FInstancedStructStream ( const FInstancedStructStream& Othe... )
	FInstancedStructStream ( FInstancedStructStream&& Other )

Destructors

	Name	Description
	~FInstancedStructStream()

Functions

	Name	Description
void	Add ( const FStructView Struct )	Adds struct to the buffer based on ScriptStruct and pointer.
void	Add ( const T& InStruct )	Add new struct in the buffer.
T &	Add_GetRef ( const T& InStruct )	Add new struct in the buffer, and return reference to it.
void	AddStructReferencedObjects ( FReferenceCollector& Collector )
void	AllocateNewChunk()	Allocates a new chunk and makes it the head of the chunk list.
uint8 *	AllocItem ( const UScriptStruct* InScriptS... )	Allocates an item of specified type.
void	Append ( const FInstancedStructStream& Othe... )
void	Append ( FInstancedStructStream&& Other )
void	Clear()	Resets and clears all structs, and releases unused internal memory.
void	Compact()	Releases unused internal memory.
void	Emplace ( TArgs&&... InArgs )	Emplaces struct in the buffer.
T &	Emplace_GetRef ( TArgs&&... InArgs )	Emplaces struct in the buffer, and returns reference to it.
void	ForEach ( TFunc&& Function )	Iterates over all structs of specified type T and calls Function on each item.
void	ForEach ( TFunc&& Function )	Iterates over all structs and calls Function on each item
void	ForEachFiltered ( TArrayView< const UScriptStruct..., TFunc&& Function )	Iterates over all structs of specified types and calls Function on each item
SIZE_T	GetAllocatedSize()	Helper function to return the amount of memory allocated by this container.
int32	GetChunkSize()
int32	GetNumFreeChunks()
int32	GetNumUsedChunks()
void	GetScriptStructs ( TArray< const UScriptStruct* >... )	Returns struct types in the buffer
bool	IsEmpty()
int32	Num()
void	Reset()	Resets and clears all structs, keeps internal memory.

Operators

		Name	Description
	FInstancedSt...	operator= ( const FInstancedStructStream& Othe... )
	FInstancedSt...	operator= ( FInstancedStructStream&& Other )

Classes

	Name	Description
	FChunkHeader	Header for a chunk of items.
	FItemHeader	Header for each item in a chunk. Allocated before the item in tge chunk memory.

Constants

Name	Description
DefaultChunkSize
MaxScriptStructsPerChunk	Number of unique struct types that can be stored per chunk.