AIDC Toolkit / Utility / Transformer

Abstract Class: Transformer

Defined in: transformer.ts:53

Transformer that transforms values in a numeric domain to values in a range equal to the domain or to another range defined by a callback function. In other words, the domain determines valid input values and, without a callback, the range of valid output values.

The concept is similar to format-preserving encryption, where input values within a specified domain (e.g., payment card numbers ranging from 8-19 digits) are transformed into values in the same domain, typically for storage in a database where the data type and length are already fixed and exfiltration of the data can have significant repercussions.

Two subclasses are supported directly by this class: IdentityTransformer (which operates based on a domain only) and EncryptionTransformer (which operates based on a domain and a tweak). If an application is expected to make repeated use of a transformer with the same domain and (optional) tweak and can't manage the transformer object, an in-memory cache is available via the get() method. Properties in IdentityTransformer and EncryptionTransformer are read-only once constructed, so there is no issue with their shared use.

Extended by

• IdentityTransformer
• EncryptionTransformer

Constructors

Constructor

new Transformer(domain): Transformer

Defined in: transformer.ts:70

Constructor.

Parameters

domain

Domain.

number | bigint

Returns

Transformer

Accessors

domain

Get Signature

get domain(): bigint

Defined in: transformer.ts:120

Get the domain.

Returns

bigint

Methods

get()

static get(domain, tweak?): Transformer

Defined in: transformer.ts:95

Get a transformer, constructing it if necessary. The type returned is IdentityTransformer if tweak is undefined, EncryptionTransformer if tweak is defined. Note that although an EncryptionTransformer with a zero tweak operates as an IdentityTransformer, EncryptionTransformer is still the type returned if a zero tweak is explicitly specified.

Parameters

domain

Domain.

number | bigint

tweak?

Tweak.

number | bigint

Returns

Transformer

IdentityTransformer if tweak is undefined, EncryptionTransformer if tweak is defined.

---

doForward()

abstract protected doForward(value): bigint

Defined in: transformer.ts:154

Do the work of transforming a value forward.

Parameters

value

bigint

Value.

Returns

bigint

Transformed value.

---

forward()

Call Signature

forward<TTransformerInput>(valueOrValues): TransformerOutput<TTransformerInput, bigint>

Defined in: transformer.ts:205

Transform value(s) forward.

Type Parameters

TTransformerInput

TTransformerInput extends TransformerInput<number | bigint>

Value(s) input type.

Parameters

valueOrValues

TTransformerInput

Value(s). If this is an instance of Sequence, the minimum and maximum values are validated prior to transformation. Otherwise, the individual value(s) is/are validated at the time of transformation.

Returns

TransformerOutput<TTransformerInput, bigint>

Transformed value(s).

Call Signature

forward<TTransformerInput, TOutput>(valueOrValues, transformerCallback): TransformerOutput<TTransformerInput, TOutput>

Defined in: transformer.ts:226

Transform value(s) forward, optionally applying a transformation.

Type Parameters

TTransformerInput

TTransformerInput extends TransformerInput<number | bigint>

Value(s) input type.

TOutput

TOutput

Transformation callback output type.

Parameters

valueOrValues

TTransformerInput

Value(s). If this is an instance of Sequence, the minimum and maximum values are validated prior to transformation. Otherwise, the individual value(s) is/are validated at the time of transformation.

transformerCallback

IndexedCallback<bigint, TOutput>

Called after each value is transformed to convert it to its final value.

Returns

TransformerOutput<TTransformerInput, TOutput>

Transformed value(s).

---

doReverse()

abstract protected doReverse(transformedValue): bigint

Defined in: transformer.ts:267

Do the work of transforming a value in reverse.

Parameters

transformedValue

bigint

Transformed value.

Returns

bigint

Value.

---

reverse()

reverse(transformedValue): bigint

Defined in: transformer.ts:278

Transform a value in reverse.

Parameters

transformedValue

Transformed value.

number | bigint

Returns

bigint

Value.