Class MemoryHelper

Helper static class containing functions that aid dealing with unmanaged memory to managed memory conversions.

Inheritance

object

MemoryHelper

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: SharpAssimp

Assembly: SharpAssimp.dll

Syntax

public static class MemoryHelper

Methods

AllocateMemory(int, int)

Allocates unmanaged memory. This memory should only be freed by this helper.

Declaration

public static nint AllocateMemory(int sizeInBytes, int alignment = 16)

Parameters

Type	Name	Description
int	sizeInBytes	Size to allocate
int	alignment	Alignment of the memory, by default aligned along 16-byte boundary.

Returns

Type	Description
nint	Pointer to the allocated unmanaged memory.

AsRef<T>(nint)

Casts the pointer into a by-ref value of the specified type.

Declaration

public static ref T AsRef<T>(nint pSrc) where T : struct

Parameters

Type	Name	Description
nint	pSrc	Memory location.

Returns

Type	Description
T	By-ref value.

Type Parameters

Name	Description
T	Struct type.

ClearMemory(nint, int)

Clears the memory to zero.

Declaration

public static void ClearMemory(nint memoryPtr, int sizeInBytesToClear)

Parameters

Type	Name	Description
nint	memoryPtr	Pointer to the memory.
int	sizeInBytesToClear	Number of bytes, starting from the memory pointer, to clear.

CopyMemory(nint, nint, int)

Performs a memcopy that copies data from the memory pointed to by the source pointer to the memory pointer by the destination pointer.

Declaration

public static void CopyMemory(nint pDest, nint pSrc, int sizeInBytesToCopy)

Parameters

Type	Name	Description
nint	pDest	Destination memory location
nint	pSrc	Source memory location
int	sizeInBytesToCopy	Number of bytes to copy

FreeMemory(nint)

Frees unmanaged memory that was allocated by this helper.

Declaration

public static void FreeMemory(nint memoryPtr)

Parameters

Type	Name	Description
nint	memoryPtr	Pointer to unmanaged memory to free.

FreeNativeArray<T>(nint, int, FreeNativeDelegate, bool)

Frees an unmanaged array and performs cleanup for each value. Optionally can free an array of pointers. This can be used on any type that can be marshaled into unmanaged memory.

Declaration

public static void FreeNativeArray<T>(nint nativeArray, int length, FreeNativeDelegate action, bool arrayOfPointers = false) where T : struct

Parameters

Type	Name	Description
nint	nativeArray	Pointer to unmanaged memory
int	length	Number of elements to free
FreeNativeDelegate	action	Delegate that performs the necessary cleanup
bool	arrayOfPointers	True if the pointer is an array of pointers, false otherwise.

Type Parameters

Name	Description
T	Struct type

FromNativeArray<T>(nint, int)

Marshals an array of blittable structs from a c-style unmanaged array (void*). This should not be used on non-blittable types that require marshaling by the runtime (e.g. has MarshalAs attributes).

Declaration

public static T[] FromNativeArray<T>(nint nativeArray, int length) where T : struct

Parameters

Type	Name	Description
nint	nativeArray	Pointer to unmanaged memory
int	length	Number of elements to read

Returns

Type	Description
T[]	Managed array

Type Parameters

Name	Description
T	Struct type

FromNativeArray<Managed, Native>(nint, int, bool)

Marshals an array of managed values from a c-style unmanaged array (void*). This also can optionally marshal from an unmanaged array of pointers (void**).

Declaration

public static Managed[] FromNativeArray<Managed, Native>(nint nativeArray, int length, bool arrayOfPointers = false) where Managed : class, IMarshalable<Managed, Native>, new() where Native : struct

Parameters

Type	Name	Description
nint	nativeArray	Pointer to unmanaged memory
int	length	Number of elements to marshal
bool	arrayOfPointers	True if the pointer is an array of pointers, false otherwise.

Returns

Type	Description
Managed[]	Marshaled managed values

Type Parameters

Name	Description
Managed	Managed type
Native	Native type

FromNativePointer<Managed, Native>(nint)

Marshals a managed value from unmanaged memory.

Declaration

public static Managed? FromNativePointer<Managed, Native>(nint ptr) where Managed : class, IMarshalable<Managed, Native>, new() where Native : struct

Parameters

Type	Name	Description
nint	ptr	Pointer to unmanaged memory

Returns

Type	Description
Managed	The marshaled managed value

Type Parameters

Name	Description
Managed	Managed type
Native	Unmanaged type

MarshalPointer<T>(in T, nint)

Convienence method for marshaling a structure to a pointer. Only use if the type is not blittable, otherwise use the write methods for blittable types.

Declaration

public static void MarshalPointer<T>(in T value, nint ptr) where T : struct

Parameters

Type	Name	Description
T	value	Struct to marshal
nint	ptr	Pointer to unmanaged chunk of memory which must be allocated prior to this call

Type Parameters

Name	Description
T	Struct type

MarshalSizeOf<T>()

Computes the size of the struct type using Marshal SizeOf. Only use if the type is not blittable, thus requiring marshaling by the runtime, (e.g. has MarshalAs attributes), otherwise use the SizeOf methods for blittable types.

Declaration

public static int MarshalSizeOf<T>() where T : struct

Returns

Type	Description
int	Size of the struct in bytes.

Type Parameters

Name	Description
T	Struct type

MarshalStructure<T>(nint)

Convienence method for marshaling a pointer to a structure. Only use if the type is not blittable, otherwise use the read methods for blittable types.

Declaration

public static T MarshalStructure<T>(nint ptr) where T : struct

Parameters

Type	Name	Description
nint	ptr	Pointer to marshal

Returns

Type	Description
T	The marshaled structure

Type Parameters

Name	Description
T	Struct type

MarshalStructure<T>(nint, out T)

Convienence method for marshaling a pointer to a structure. Only use if the type is not blittable, otherwise use the read methods for blittable types.

Declaration

public static void MarshalStructure<T>(nint ptr, out T value) where T : struct

Parameters

Type	Name	Description
nint	ptr	Pointer to marshal
T	value	The marshaled structure

Type Parameters

Name	Description
T	Struct type

ReadStreamFully(Stream, int)

Reads a stream until the end is reached into a byte array. Based on Jon Skeet's implementation. It is up to the caller to dispose of the stream.

Declaration

public static byte[] ReadStreamFully(Stream stream, int initialLength)

Parameters

Type	Name	Description
Stream	stream	Stream to read all bytes from
int	initialLength	Initial buffer length, default is 32K

Returns

Type	Description
byte[]	The byte array containing all the bytes from the stream

Read<T>(nint)

Reads a single element from the memory location.

Declaration

public static T Read<T>(nint pSrc) where T : struct

Parameters

Type	Name	Description
nint	pSrc	Pointer to memory location

Returns

Type	Description
T	The read value

Type Parameters

Name	Description
T	Struct type

Read<T>(nint, out T)

Reads a single element from the memory location.

Declaration

public static void Read<T>(nint pSrc, out T value) where T : struct

Parameters

Type	Name	Description
nint	pSrc	Pointer to memory location
T	value	The read value.

Type Parameters

Name	Description
T	Struct type

Read<T>(nint, T[], int, int)

Reads data from the memory location into the array.

Declaration

public static void Read<T>(nint pSrc, T[] data, int startIndexInArray, int count) where T : struct

Parameters

Type	Name	Description
nint	pSrc	Pointer to memory location
T[]	data	Array to store the copied data
int	startIndexInArray	Zero-based element index to start writing data to in the element array.
int	count	Number of elements to copy

Type Parameters

Name	Description
T	Struct type

SizeOf<T>()

Computes the size of the struct type.

Declaration

public static int SizeOf<T>() where T : struct

Returns

Type	Description
int	Size of the struct in bytes.

Type Parameters

Name	Description
T	Struct type

SizeOf<T>(T[])

Computes the size of the struct array.

Declaration

public static int SizeOf<T>(T[] array) where T : struct

Parameters

Type	Name	Description
T[]	array	Array of structs

Returns

Type	Description
int	Total size, in bytes, of the array's contents.

Type Parameters

Name	Description
T	Struct type

ToNativeArray<T>(List<T>)

Marshals a list of blittable structs to a c-style unmanaged array (void*). This should not be used on non-blittable types that require marshaling by the runtime (e.g. has MarshalAs attributes).

Declaration

public static nint ToNativeArray<T>(List<T> managedArray) where T : struct

Parameters

Type	Name	Description
List<T>	managedArray	Managed list of structs

Returns

Type	Description
nint	Pointer to unmanaged memory

Type Parameters

Name	Description
T	Struct type

ToNativeArray<T>(T[]?)

Marshals an array of blittable structs to a c-style unmanaged array (void*). This should not be used on non-blittable types that require marshaling by the runtime (e.g. has MarshalAs attributes).

Declaration

public static nint ToNativeArray<T>(T[]? managedArray) where T : struct

Parameters

Type	Name	Description
T[]	managedArray	Managed array of structs

Returns

Type	Description
nint	Pointer to unmanaged memory

Type Parameters

Name	Description
T	Struct type

ToNativeArray<Managed, Native>(IReadOnlyCollection<Managed>?, bool)

Marshals an array of managed values to a c-style unmanaged array (void*). This also can optionally marshal to an unmanaged array of pointers (void**).

Declaration

public static nint ToNativeArray<Managed, Native>(IReadOnlyCollection<Managed>? managedColl, bool arrayOfPointers = false) where Managed : class, IMarshalable<Managed, Native>, new() where Native : struct

Parameters

Type	Name	Description
IReadOnlyCollection<Managed>	managedColl	Collection of managed values
bool	arrayOfPointers	True if the pointer is an array of pointers, false otherwise.

Returns

Type	Description
nint	Pointer to unmanaged memory

Type Parameters

Name	Description
Managed	Managed type
Native	Native type

ToNativePointer<Managed, Native>(Managed)

Marshals a managed value to unmanaged memory.

Declaration

public static nint ToNativePointer<Managed, Native>(Managed managedValue) where Managed : class, IMarshalable<Managed, Native>, new() where Native : struct

Parameters

Type	Name	Description
Managed	managedValue	Managed value to marshal

Returns

Type	Description
nint	Pointer to unmanaged memory

Type Parameters

Name	Description
Managed	Managed type
Native	Unmanaged type

Write<T>(nint, List<T>, int, int)

Writes data from the list to the memory location.

Declaration

public static void Write<T>(nint pDest, List<T> data, int startIndexInArray, int count) where T : struct

Parameters

Type	Name	Description
nint	pDest	Pointer to memory location
List<T>	data	List containing data to write
int	startIndexInArray	Zero-based element index to start reading data from in the element array.
int	count	Number of elements to copy

Type Parameters

Name	Description
T	Struct type

Write<T>(nint, in T)

Writes a single element to the memory location.

Declaration

public static void Write<T>(nint pDest, in T data) where T : struct

Parameters

Type	Name	Description
nint	pDest	Pointer to memory location
T	data	The value to write

Type Parameters

Name	Description
T	Struct type

Write<T>(nint, T[], int, int)

Writes data from the array to the memory location.

Declaration

public static void Write<T>(nint pDest, T[] data, int startIndexInArray, int count) where T : struct

Parameters

Type	Name	Description
nint	pDest	Pointer to memory location
T[]	data	Array containing data to write
int	startIndexInArray	Zero-based element index to start reading data from in the element array.
int	count	Number of elements to copy

Type Parameters

Name	Description
T	Struct type