NDArray< T > Class Template Reference

Runtime Library v0.30 Mobilint SDK qb

• mobilint
• NDArray

Public Types | Public Member Functions | List of all members

mobilint::NDArray< T > Class Template Reference

C++ API Reference

A class representing an N-dimensional array (NDArray). More...

#include <ndarray.h>

Public Types
using	value_type = T

Public Member Functions
	NDArray ()=default
	Default constructor. Creates an empty NDArray.
	NDArray (const std::vector< int64_t > &shape, StatusCode &sc)
	Constructs an NDArray with the given shape, allocating memory for elements.
	NDArray (T *ptr, const std::vector< int64_t > &shape)
	Constructs an NDArray from a raw pointer without taking ownership.
	NDArray (T *ptr, const std::vector< int64_t > &shape, bool owner)
	Constructs an NDArray from a raw pointer without taking ownership.
	NDArray (std::shared_ptr< void > data, const std::vector< int64_t > &shape)
	Constructs an NDArray from a shared memory block with shared ownership.
T *	data () const
	Returns a pointer to the underlying data.
const std::vector< int64_t > &	shape () const
	Returns the shape (dimensions) of the array.
std::size_t	ndim () const
	Returns the number of dimensions of the array.
int64_t	size () const
	Returns the total number of elements in the array.
T *	begin ()
	Returns an iterator to the beginning of the data.
T *	end ()
	Returns an iterator to the end of the data.
const T *	begin () const
	Returns a constant iterator to the beginning of the data.
const T *	end () const
	Returns a constant iterator to the end of the data.
T &	operator[] (size_t idx)
	Accesses an element of the array.
T	operator[] (size_t idx) const
	Accesses an element of the array (const version).

Detailed Description

template<typename T>
class mobilint::NDArray< T >

A class representing an N-dimensional array (NDArray).

The class automatically manages memory when it owns the data. If the NDArray is created from a raw pointer without taking ownership, it simply acts as a view of the existing data, and no memory management is performed by the NDArray.

NDArray is the recommended way for providing input and receiving output to/from model inferences. By using NDArray, unnecessary copies inside the maccel runtime are avoided, which helps improve performance during model inference operations.

Template Parameters

T	The type of the elements in the array.

Definition at line 77 of file ndarray.h.

Member Typedef Documentation

◆ value_type

template<typename T>

using mobilint::NDArray< T >::value_type = T

Definition at line 79 of file ndarray.h.

Constructor & Destructor Documentation

◆ NDArray() [1/4]

template<typename T>

mobilint::NDArray< T >::NDArray ( const std::vector< int64_t > & shape, StatusCode & sc )

inline

Constructs an NDArray with the given shape, allocating memory for elements.

This constructor allocates memory for the array and takes ownership of the allocated data. The memory is automatically managed by the NDArray instance.

Parameters

[in]	shape	The shape (dimensions) of the array.
[out]	sc	Status code indicating success or failure of memory allocation.

Definition at line 95 of file ndarray.h.

◆ NDArray() [2/4]

template<typename T>

mobilint::NDArray< T >::NDArray ( T * ptr, const std::vector< int64_t > & shape )

inline

Constructs an NDArray from a raw pointer without taking ownership.

This constructor creates an NDArray that acts as a view of the provided data. It does not manage the memory, and the memory is not owned by the NDArray instance. The user is responsible for ensuring that the data remains valid for the lifetime of the NDArray.

Parameters

[in]	ptr	A pointer to the data.
[in]	shape	The shape (dimensions) of the array.

Definition at line 109 of file ndarray.h.

◆ NDArray() [3/4]

template<typename T>

mobilint::NDArray< T >::NDArray ( T * ptr, const std::vector< int64_t > & shape, bool owner )

inline

Constructs an NDArray from a raw pointer without taking ownership.

Deprecated

This constructor is deprecated. Use NDArray(T*, const std::vector<int64_t>&) instead.

Parameters

[in]	ptr	A pointer to the data.
[in]	shape	The shape (dimensions) of the array.
	owner	Ignored parameter (was intended to indicate ownership).

Definition at line 122 of file ndarray.h.

◆ NDArray() [4/4]

template<typename T>

mobilint::NDArray< T >::NDArray ( std::shared_ptr< void > data, const std::vector< int64_t > & shape )

inline

Constructs an NDArray from a shared memory block with shared ownership.

This constructor allows the NDArray to share ownership of an existing memory buffer, preventing unnecessary copies. The data parameter should be a std::shared_ptr<void> pointing to a valid memory block.

Example usage:

size_t bytesize = sizeof(float) * 100; // Allocate memory for 100 floats

void* raw_ptr = std::malloc(bytesize);

if (!raw_ptr) {

// Handle memory allocation failure

}

auto buffer = std::shared_ptr<void>(raw_ptr, std::free);

NDArray<float> array(buffer, {10, 10}); // Create a 10x10 array

mobilint::NDArray

A class representing an N-dimensional array (NDArray).

Definition ndarray.h:77

Parameters

[in]	data	A shared pointer to the memory buffer. For example, it can be initialized using std::shared_ptr<void>(std::malloc(bytesize), std::free), but ensure that the allocation succeeds before passing it.
[in]	shape	The shape (dimensions) of the array.

Definition at line 149 of file ndarray.h.

Member Function Documentation

◆ data()

template<typename T>

T * mobilint::NDArray< T >::data ( ) const

inline

Returns a pointer to the underlying data.

Returns

A pointer to the array's data.

Definition at line 157 of file ndarray.h.

◆ shape()

template<typename T>

const std::vector< int64_t > & mobilint::NDArray< T >::shape ( ) const

inline

Returns the shape (dimensions) of the array.

Returns

A reference to the vector representing the shape.

Definition at line 164 of file ndarray.h.

◆ ndim()

template<typename T>

std::size_t mobilint::NDArray< T >::ndim ( ) const

inline

Returns the number of dimensions of the array.

Returns

The number of dimensions.

Definition at line 171 of file ndarray.h.

◆ size()

template<typename T>

int64_t mobilint::NDArray< T >::size ( ) const

inline

Returns the total number of elements in the array.

Returns

The total number of elements.

Definition at line 178 of file ndarray.h.

◆ begin() [1/2]

template<typename T>

T * mobilint::NDArray< T >::begin ( )

inline

Returns an iterator to the beginning of the data.

Returns

A pointer to the first element.

Definition at line 185 of file ndarray.h.

◆ end() [1/2]

template<typename T>

T * mobilint::NDArray< T >::end ( )

inline

Returns an iterator to the end of the data.

Returns

A pointer past the last element.

Definition at line 192 of file ndarray.h.

◆ begin() [2/2]

template<typename T>

const T * mobilint::NDArray< T >::begin ( ) const

inline

Returns a constant iterator to the beginning of the data.

Returns

A pointer to the first element.

Definition at line 199 of file ndarray.h.

◆ end() [2/2]

template<typename T>

const T * mobilint::NDArray< T >::end ( ) const

inline

Returns a constant iterator to the end of the data.

Returns

A pointer past the last element.

Definition at line 206 of file ndarray.h.

◆ operator[]() [1/2]

template<typename T>

T & mobilint::NDArray< T >::operator[] ( size_t idx )

inline

Accesses an element of the array.

Parameters

idx	The index of the element.

Returns

A reference to the element at the specified index.

Definition at line 214 of file ndarray.h.

◆ operator[]() [2/2]

template<typename T>

T mobilint::NDArray< T >::operator[] ( size_t idx ) const

inline

Accesses an element of the array (const version).

Parameters

idx	The index of the element.

Returns

A copy of the element at the specified index.

Definition at line 222 of file ndarray.h.

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

• ndarray.h

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