/* The MIT License (MIT)
*
* Copyright 2015-2018 Peter A. Bigot
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/**
* Support for translating between Uint8Array instances and JavaScript
* native types.
*
* {@link module:Layout~Layout|Layout} is the basis of a class
* hierarchy that associates property names with sequences of encoded
* bytes.
*
* Layouts are supported for these scalar (numeric) types:
* * {@link module:Layout~UInt|Unsigned integers in little-endian
* format} with {@link module:Layout.u8|8-bit}, {@link
* module:Layout.u16|16-bit}, {@link module:Layout.u24|24-bit},
* {@link module:Layout.u32|32-bit}, {@link
* module:Layout.u40|40-bit}, and {@link module:Layout.u48|48-bit}
* representation ranges;
* * {@link module:Layout~UIntBE|Unsigned integers in big-endian
* format} with {@link module:Layout.u16be|16-bit}, {@link
* module:Layout.u24be|24-bit}, {@link module:Layout.u32be|32-bit},
* {@link module:Layout.u40be|40-bit}, and {@link
* module:Layout.u48be|48-bit} representation ranges;
* * {@link module:Layout~Int|Signed integers in little-endian
* format} with {@link module:Layout.s8|8-bit}, {@link
* module:Layout.s16|16-bit}, {@link module:Layout.s24|24-bit},
* {@link module:Layout.s32|32-bit}, {@link
* module:Layout.s40|40-bit}, and {@link module:Layout.s48|48-bit}
* representation ranges;
* * {@link module:Layout~IntBE|Signed integers in big-endian format}
* with {@link module:Layout.s16be|16-bit}, {@link
* module:Layout.s24be|24-bit}, {@link module:Layout.s32be|32-bit},
* {@link module:Layout.s40be|40-bit}, and {@link
* module:Layout.s48be|48-bit} representation ranges;
* * 64-bit integral values that decode to an exact (if magnitude is
* less than 2^53) or nearby integral Number in {@link
* module:Layout.nu64|unsigned little-endian}, {@link
* module:Layout.nu64be|unsigned big-endian}, {@link
* module:Layout.ns64|signed little-endian}, and {@link
* module:Layout.ns64be|unsigned big-endian} encodings;
* * 32-bit floating point values with {@link
* module:Layout.f32|little-endian} and {@link
* module:Layout.f32be|big-endian} representations;
* * 64-bit floating point values with {@link
* module:Layout.f64|little-endian} and {@link
* module:Layout.f64be|big-endian} representations;
* * {@link module:Layout.const|Constants} that take no space in the
* encoded expression.
*
* and for these aggregate types:
* * {@link module:Layout.seq|Sequence}s of instances of a {@link
* module:Layout~Layout|Layout}, with JavaScript representation as
* an Array and constant or data-dependent {@link
* module:Layout~Sequence#count|length};
* * {@link module:Layout.struct|Structure}s that aggregate a
* heterogeneous sequence of {@link module:Layout~Layout|Layout}
* instances, with JavaScript representation as an Object;
* * {@link module:Layout.union|Union}s that support multiple {@link
* module:Layout~VariantLayout|variant layouts} over a fixed
* (padded) or variable (not padded) span of bytes, using an
* unsigned integer at the start of the data or a separate {@link
* module:Layout.unionLayoutDiscriminator|layout element} to
* determine which layout to use when interpreting the buffer
* contents;
* * {@link module:Layout.bits|BitStructure}s that contain a sequence
* of individual {@link
* module:Layout~BitStructure#addField|BitField}s packed into an 8,
* 16, 24, or 32-bit unsigned integer starting at the least- or
* most-significant bit;
* * {@link module:Layout.cstr|C strings} of varying length;
* * {@link module:Layout.blob|Blobs} of fixed- or variable-{@link
* module:Layout~Blob#length|length} raw data.
*
* All {@link module:Layout~Layout|Layout} instances are immutable
* after construction, to prevent internal state from becoming
* inconsistent.
*
* @local Layout
* @local ExternalLayout
* @local GreedyCount
* @local OffsetLayout
* @local UInt
* @local UIntBE
* @local Int
* @local IntBE
* @local NearUInt64
* @local NearUInt64BE
* @local NearInt64
* @local NearInt64BE
* @local Float
* @local FloatBE
* @local Double
* @local DoubleBE
* @local Sequence
* @local Structure
* @local UnionDiscriminator
* @local UnionLayoutDiscriminator
* @local Union
* @local VariantLayout
* @local BitStructure
* @local BitField
* @local Boolean
* @local Blob
* @local CString
* @local Constant
* @local bindConstructorLayout
* @module Layout
* @license MIT
* @author Peter A. Bigot
* @see {@link https://github.com/pabigot/buffer-layout|buffer-layout on GitHub}
*/
'use strict';
Object.defineProperty(exports, "__esModule", { value: true });
exports.s16 = exports.s8 = exports.nu64be = exports.u48be = exports.u40be = exports.u32be = exports.u24be = exports.u16be = exports.nu64 = exports.u48 = exports.u40 = exports.u32 = exports.u24 = exports.u16 = exports.u8 = exports.offset = exports.greedy = exports.Constant = exports.UTF8 = exports.CString = exports.Blob = exports.Boolean = exports.BitField = exports.BitStructure = exports.VariantLayout = exports.Union = exports.UnionLayoutDiscriminator = exports.UnionDiscriminator = exports.Structure = exports.Sequence = exports.DoubleBE = exports.Double = exports.FloatBE = exports.Float = exports.NearInt64BE = exports.NearInt64 = exports.NearUInt64BE = exports.NearUInt64 = exports.IntBE = exports.Int = exports.UIntBE = exports.UInt = exports.OffsetLayout = exports.GreedyCount = exports.ExternalLayout = exports.bindConstructorLayout = exports.nameWithProperty = exports.Layout = exports.uint8ArrayToBuffer = exports.checkUint8Array = void 0;
exports.constant = exports.utf8 = exports.cstr = exports.blob = exports.unionLayoutDiscriminator = exports.union = exports.seq = exports.bits = exports.struct = exports.f64be = exports.f64 = exports.f32be = exports.f32 = exports.ns64be = exports.s48be = exports.s40be = exports.s32be = exports.s24be = exports.s16be = exports.ns64 = exports.s48 = exports.s40 = exports.s32 = exports.s24 = void 0;
const buffer_1 = require("buffer");
/* Check if a value is a Uint8Array.
*
* @ignore */
function checkUint8Array(b) {
if (!(b instanceof Uint8Array)) {
throw new TypeError('b must be a Uint8Array');
}
}
exports.checkUint8Array = checkUint8Array;
/* Create a Buffer instance from a Uint8Array.
*
* @ignore */
function uint8ArrayToBuffer(b) {
checkUint8Array(b);
return buffer_1.Buffer.from(b.buffer, b.byteOffset, b.length);
}
exports.uint8ArrayToBuffer = uint8ArrayToBuffer;
/**
* Base class for layout objects.
*
* **NOTE** This is an abstract base class; you can create instances
* if it amuses you, but they won't support the {@link
* Layout#encode|encode} or {@link Layout#decode|decode} functions.
*
* @param {Number} span - Initializer for {@link Layout#span|span}. The
* parameter must be an integer; a negative value signifies that the
* span is {@link Layout#getSpan|value-specific}.
*
* @param {string} [property] - Initializer for {@link
* Layout#property|property}.
*
* @abstract
*/
class Layout {
constructor(span, property) {
if (!Number.isInteger(span)) {
throw new TypeError('span must be an integer');
}
/** The span of the layout in bytes.
*
* Positive values are generally expected.
*
* Zero will only appear in {@link Constant}s and in {@link
* Sequence}s where the {@link Sequence#count|count} is zero.
*
* A negative value indicates that the span is value-specific, and
* must be obtained using {@link Layout#getSpan|getSpan}. */
this.span = span;
/** The property name used when this layout is represented in an
* Object.
*
* Used only for layouts that {@link Layout#decode|decode} to Object
* instances. If left undefined the span of the unnamed layout will
* be treated as padding: it will not be mutated by {@link
* Layout#encode|encode} nor represented as a property in the
* decoded Object. */
this.property = property;
}
/** Function to create an Object into which decoded properties will
* be written.
*
* Used only for layouts that {@link Layout#decode|decode} to Object
* instances, which means:
* * {@link Structure}
* * {@link Union}
* * {@link VariantLayout}
* * {@link BitStructure}
*
* If left undefined the JavaScript representation of these layouts
* will be Object instances.
*
* See {@link bindConstructorLayout}.
*/
makeDestinationObject() {
return {};
}
/**
* Calculate the span of a specific instance of a layout.
*
* @param {Uint8Array} b - the buffer that contains an encoded instance.
*
* @param {Number} [offset] - the offset at which the encoded instance
* starts. If absent a zero offset is inferred.
*
* @return {Number} - the number of bytes covered by the layout
* instance. If this method is not overridden in a subclass the
* definition-time constant {@link Layout#span|span} will be
* returned.
*
* @throws {RangeError} - if the length of the value cannot be
* determined.
*/
getSpan(b, offset) {
if (0 > this.span) {
throw new RangeError('indeterminate span');
}
return this.span;
}
/**
* Replicate the layout using a new property.
*
* This function must be used to get a structurally-equivalent layout
* with a different name since all {@link Layout} instances are
* immutable.
*
* **NOTE** This is a shallow copy. All fields except {@link
* Layout#property|property} are strictly equal to the origin layout.
*
* @param {String} property - the value for {@link
* Layout#property|property} in the replica.
*
* @returns {Layout} - the copy with {@link Layout#property|property}
* set to `property`.
*/
replicate(property) {
const rv = Object.create(this.constructor.prototype);
Object.assign(rv, this);
rv.property = property;
return rv;
}
/**
* Create an object from layout properties and an array of values.
*
* **NOTE** This function returns `undefined` if invoked on a layout
* that does not return its value as an Object. Objects are
* returned for things that are a {@link Structure}, which includes
* {@link VariantLayout|variant layouts} if they are structures, and
* excludes {@link Union}s. If you want this feature for a union
* you must use {@link Union.getVariant|getVariant} to select the
* desired layout.
*
* @param {Array} values - an array of values that correspond to the
* default order for properties. As with {@link Layout#decode|decode}
* layout elements that have no property name are skipped when
* iterating over the array values. Only the top-level properties are
* assigned; arguments are not assigned to properties of contained
* layouts. Any unused values are ignored.
*
* @return {(Object|undefined)}
*/
fromArray(values) {
return undefined;
}
}
exports.Layout = Layout;
/* Provide text that carries a name (such as for a function that will
* be throwing an error) annotated with the property of a given layout
* (such as one for which the value was unacceptable).
*
* @ignore */
function nameWithProperty(name, lo) {
if (lo.property) {
return name + '[' + lo.property + ']';
}
return name;
}
exports.nameWithProperty = nameWithProperty;
/**
* Augment a class so that instances can be encoded/decoded using a
* given layout.
*
* Calling this function couples `Class` with `layout` in several ways:
*
* * `Class.layout_` becomes a static member property equal to `layout`;
* * `layout.boundConstructor_` becomes a static member property equal
* to `Class`;
* * The {@link Layout#makeDestinationObject|makeDestinationObject()}
* property of `layout` is set to a function that returns a `new
* Class()`;
* * `Class.decode(b, offset)` becomes a static member function that
* delegates to {@link Layout#decode|layout.decode}. The
* synthesized function may be captured and extended.
* * `Class.prototype.encode(b, offset)` provides an instance member
* function that delegates to {@link Layout#encode|layout.encode}
* with `src` set to `this`. The synthesized function may be
* captured and extended, but when the extension is invoked `this`
* must be explicitly bound to the instance.
*
* @param {class} Class - a JavaScript class with a nullary
* constructor.
*
* @param {Layout} layout - the {@link Layout} instance used to encode
* instances of `Class`.
*/
// `Class` must be a constructor Function, but the assignment of a `layout_` property to it makes it difficult to type
// eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
function bindConstructorLayout(Class, layout) {
if ('function' !== typeof Class) {
throw new TypeError('Class must be constructor');
}
if (Object.prototype.hasOwnProperty.call(Class, 'layout_')) {
throw new Error('Class is already bound to a layout');
}
if (!(layout && (layout instanceof Layout))) {
throw new TypeError('layout must be a Layout');
}
if (Object.prototype.hasOwnProperty.call(layout, 'boundConstructor_')) {
throw new Error('layout is already bound to a constructor');
}
Class.layout_ = layout;
layout.boundConstructor_ = Class;
layout.makeDestinationObject = (() => new Class());
Object.defineProperty(Class.prototype, 'encode', {
value(b, offset) {
return layout.encode(this, b, offset);
},
writable: true,
});
Object.defineProperty(Class, 'decode', {
value(b, offset) {
return layout.decode(b, offset);
},
writable: true,
});
}
exports.bindConstructorLayout = bindConstructorLayout;
/**
* An object that behaves like a layout but does not consume space
* within its containing layout.
*
* This is primarily used to obtain metadata about a member, such as a
* {@link OffsetLayout} that can provide data about a {@link
* Layout#getSpan|value-specific span}.
*
* **NOTE** This is an abstract base class; you can create instances
* if it amuses you, but they won't support {@link
* ExternalLayout#isCount|isCount} or other {@link Layout} functions.
*
* @param {Number} span - initializer for {@link Layout#span|span}.
* The parameter can range from 1 through 6.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @abstract
* @augments {Layout}
*/
class ExternalLayout extends Layout {
/**
* Return `true` iff the external layout decodes to an unsigned
* integer layout.
*
* In that case it can be used as the source of {@link
* Sequence#count|Sequence counts}, {@link Blob#length|Blob lengths},
* or as {@link UnionLayoutDiscriminator#layout|external union
* discriminators}.
*
* @abstract
*/
isCount() {
throw new Error('ExternalLayout is abstract');
}
}
exports.ExternalLayout = ExternalLayout;
/**
* An {@link ExternalLayout} that determines its {@link
* Layout#decode|value} based on offset into and length of the buffer
* on which it is invoked.
*
* *Factory*: {@link module:Layout.greedy|greedy}
*
* @param {Number} [elementSpan] - initializer for {@link
* GreedyCount#elementSpan|elementSpan}.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {ExternalLayout}
*/
class GreedyCount extends ExternalLayout {
constructor(elementSpan = 1, property) {
if ((!Number.isInteger(elementSpan)) || (0 >= elementSpan)) {
throw new TypeError('elementSpan must be a (positive) integer');
}
super(-1, property);
/** The layout for individual elements of the sequence. The value
* must be a positive integer. If not provided, the value will be
* 1. */
this.elementSpan = elementSpan;
}
/** @override */
isCount() {
return true;
}
/** @override */
decode(b, offset = 0) {
checkUint8Array(b);
const rem = b.length - offset;
return Math.floor(rem / this.elementSpan);
}
/** @override */
encode(src, b, offset) {
return 0;
}
}
exports.GreedyCount = GreedyCount;
/**
* An {@link ExternalLayout} that supports accessing a {@link Layout}
* at a fixed offset from the start of another Layout. The offset may
* be before, within, or after the base layout.
*
* *Factory*: {@link module:Layout.offset|offset}
*
* @param {Layout} layout - initializer for {@link
* OffsetLayout#layout|layout}, modulo `property`.
*
* @param {Number} [offset] - Initializes {@link
* OffsetLayout#offset|offset}. Defaults to zero.
*
* @param {string} [property] - Optional new property name for a
* {@link Layout#replicate| replica} of `layout` to be used as {@link
* OffsetLayout#layout|layout}. If not provided the `layout` is used
* unchanged.
*
* @augments {Layout}
*/
class OffsetLayout extends ExternalLayout {
constructor(layout, offset = 0, property) {
if (!(layout instanceof Layout)) {
throw new TypeError('layout must be a Layout');
}
if (!Number.isInteger(offset)) {
throw new TypeError('offset must be integer or undefined');
}
super(layout.span, property || layout.property);
/** The subordinated layout. */
this.layout = layout;
/** The location of {@link OffsetLayout#layout} relative to the
* start of another layout.
*
* The value may be positive or negative, but an error will thrown
* if at the point of use it goes outside the span of the Uint8Array
* being accessed. */
this.offset = offset;
}
/** @override */
isCount() {
return ((this.layout instanceof UInt)
|| (this.layout instanceof UIntBE));
}
/** @override */
decode(b, offset = 0) {
return this.layout.decode(b, offset + this.offset);
}
/** @override */
encode(src, b, offset = 0) {
return this.layout.encode(src, b, offset + this.offset);
}
}
exports.OffsetLayout = OffsetLayout;
/**
* Represent an unsigned integer in little-endian format.
*
* *Factory*: {@link module:Layout.u8|u8}, {@link
* module:Layout.u16|u16}, {@link module:Layout.u24|u24}, {@link
* module:Layout.u32|u32}, {@link module:Layout.u40|u40}, {@link
* module:Layout.u48|u48}
*
* @param {Number} span - initializer for {@link Layout#span|span}.
* The parameter can range from 1 through 6.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class UInt extends Layout {
constructor(span, property) {
super(span, property);
if (6 < this.span) {
throw new RangeError('span must not exceed 6 bytes');
}
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readUIntLE(offset, this.span);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeUIntLE(src, offset, this.span);
return this.span;
}
}
exports.UInt = UInt;
/**
* Represent an unsigned integer in big-endian format.
*
* *Factory*: {@link module:Layout.u8be|u8be}, {@link
* module:Layout.u16be|u16be}, {@link module:Layout.u24be|u24be},
* {@link module:Layout.u32be|u32be}, {@link
* module:Layout.u40be|u40be}, {@link module:Layout.u48be|u48be}
*
* @param {Number} span - initializer for {@link Layout#span|span}.
* The parameter can range from 1 through 6.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class UIntBE extends Layout {
constructor(span, property) {
super(span, property);
if (6 < this.span) {
throw new RangeError('span must not exceed 6 bytes');
}
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readUIntBE(offset, this.span);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeUIntBE(src, offset, this.span);
return this.span;
}
}
exports.UIntBE = UIntBE;
/**
* Represent a signed integer in little-endian format.
*
* *Factory*: {@link module:Layout.s8|s8}, {@link
* module:Layout.s16|s16}, {@link module:Layout.s24|s24}, {@link
* module:Layout.s32|s32}, {@link module:Layout.s40|s40}, {@link
* module:Layout.s48|s48}
*
* @param {Number} span - initializer for {@link Layout#span|span}.
* The parameter can range from 1 through 6.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class Int extends Layout {
constructor(span, property) {
super(span, property);
if (6 < this.span) {
throw new RangeError('span must not exceed 6 bytes');
}
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readIntLE(offset, this.span);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeIntLE(src, offset, this.span);
return this.span;
}
}
exports.Int = Int;
/**
* Represent a signed integer in big-endian format.
*
* *Factory*: {@link module:Layout.s8be|s8be}, {@link
* module:Layout.s16be|s16be}, {@link module:Layout.s24be|s24be},
* {@link module:Layout.s32be|s32be}, {@link
* module:Layout.s40be|s40be}, {@link module:Layout.s48be|s48be}
*
* @param {Number} span - initializer for {@link Layout#span|span}.
* The parameter can range from 1 through 6.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class IntBE extends Layout {
constructor(span, property) {
super(span, property);
if (6 < this.span) {
throw new RangeError('span must not exceed 6 bytes');
}
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readIntBE(offset, this.span);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeIntBE(src, offset, this.span);
return this.span;
}
}
exports.IntBE = IntBE;
const V2E32 = Math.pow(2, 32);
/* True modulus high and low 32-bit words, where low word is always
* non-negative. */
function divmodInt64(src) {
const hi32 = Math.floor(src / V2E32);
const lo32 = src - (hi32 * V2E32);
return { hi32, lo32 };
}
/* Reconstruct Number from quotient and non-negative remainder */
function roundedInt64(hi32, lo32) {
return hi32 * V2E32 + lo32;
}
/**
* Represent an unsigned 64-bit integer in little-endian format when
* encoded and as a near integral JavaScript Number when decoded.
*
* *Factory*: {@link module:Layout.nu64|nu64}
*
* **NOTE** Values with magnitude greater than 2^52 may not decode to
* the exact value of the encoded representation.
*
* @augments {Layout}
*/
class NearUInt64 extends Layout {
constructor(property) {
super(8, property);
}
/** @override */
decode(b, offset = 0) {
const buffer = uint8ArrayToBuffer(b);
const lo32 = buffer.readUInt32LE(offset);
const hi32 = buffer.readUInt32LE(offset + 4);
return roundedInt64(hi32, lo32);
}
/** @override */
encode(src, b, offset = 0) {
const split = divmodInt64(src);
const buffer = uint8ArrayToBuffer(b);
buffer.writeUInt32LE(split.lo32, offset);
buffer.writeUInt32LE(split.hi32, offset + 4);
return 8;
}
}
exports.NearUInt64 = NearUInt64;
/**
* Represent an unsigned 64-bit integer in big-endian format when
* encoded and as a near integral JavaScript Number when decoded.
*
* *Factory*: {@link module:Layout.nu64be|nu64be}
*
* **NOTE** Values with magnitude greater than 2^52 may not decode to
* the exact value of the encoded representation.
*
* @augments {Layout}
*/
class NearUInt64BE extends Layout {
constructor(property) {
super(8, property);
}
/** @override */
decode(b, offset = 0) {
const buffer = uint8ArrayToBuffer(b);
const hi32 = buffer.readUInt32BE(offset);
const lo32 = buffer.readUInt32BE(offset + 4);
return roundedInt64(hi32, lo32);
}
/** @override */
encode(src, b, offset = 0) {
const split = divmodInt64(src);
const buffer = uint8ArrayToBuffer(b);
buffer.writeUInt32BE(split.hi32, offset);
buffer.writeUInt32BE(split.lo32, offset + 4);
return 8;
}
}
exports.NearUInt64BE = NearUInt64BE;
/**
* Represent a signed 64-bit integer in little-endian format when
* encoded and as a near integral JavaScript Number when decoded.
*
* *Factory*: {@link module:Layout.ns64|ns64}
*
* **NOTE** Values with magnitude greater than 2^52 may not decode to
* the exact value of the encoded representation.
*
* @augments {Layout}
*/
class NearInt64 extends Layout {
constructor(property) {
super(8, property);
}
/** @override */
decode(b, offset = 0) {
const buffer = uint8ArrayToBuffer(b);
const lo32 = buffer.readUInt32LE(offset);
const hi32 = buffer.readInt32LE(offset + 4);
return roundedInt64(hi32, lo32);
}
/** @override */
encode(src, b, offset = 0) {
const split = divmodInt64(src);
const buffer = uint8ArrayToBuffer(b);
buffer.writeUInt32LE(split.lo32, offset);
buffer.writeInt32LE(split.hi32, offset + 4);
return 8;
}
}
exports.NearInt64 = NearInt64;
/**
* Represent a signed 64-bit integer in big-endian format when
* encoded and as a near integral JavaScript Number when decoded.
*
* *Factory*: {@link module:Layout.ns64be|ns64be}
*
* **NOTE** Values with magnitude greater than 2^52 may not decode to
* the exact value of the encoded representation.
*
* @augments {Layout}
*/
class NearInt64BE extends Layout {
constructor(property) {
super(8, property);
}
/** @override */
decode(b, offset = 0) {
const buffer = uint8ArrayToBuffer(b);
const hi32 = buffer.readInt32BE(offset);
const lo32 = buffer.readUInt32BE(offset + 4);
return roundedInt64(hi32, lo32);
}
/** @override */
encode(src, b, offset = 0) {
const split = divmodInt64(src);
const buffer = uint8ArrayToBuffer(b);
buffer.writeInt32BE(split.hi32, offset);
buffer.writeUInt32BE(split.lo32, offset + 4);
return 8;
}
}
exports.NearInt64BE = NearInt64BE;
/**
* Represent a 32-bit floating point number in little-endian format.
*
* *Factory*: {@link module:Layout.f32|f32}
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class Float extends Layout {
constructor(property) {
super(4, property);
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readFloatLE(offset);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeFloatLE(src, offset);
return 4;
}
}
exports.Float = Float;
/**
* Represent a 32-bit floating point number in big-endian format.
*
* *Factory*: {@link module:Layout.f32be|f32be}
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class FloatBE extends Layout {
constructor(property) {
super(4, property);
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readFloatBE(offset);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeFloatBE(src, offset);
return 4;
}
}
exports.FloatBE = FloatBE;
/**
* Represent a 64-bit floating point number in little-endian format.
*
* *Factory*: {@link module:Layout.f64|f64}
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class Double extends Layout {
constructor(property) {
super(8, property);
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readDoubleLE(offset);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeDoubleLE(src, offset);
return 8;
}
}
exports.Double = Double;
/**
* Represent a 64-bit floating point number in big-endian format.
*
* *Factory*: {@link module:Layout.f64be|f64be}
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class DoubleBE extends Layout {
constructor(property) {
super(8, property);
}
/** @override */
decode(b, offset = 0) {
return uint8ArrayToBuffer(b).readDoubleBE(offset);
}
/** @override */
encode(src, b, offset = 0) {
uint8ArrayToBuffer(b).writeDoubleBE(src, offset);
return 8;
}
}
exports.DoubleBE = DoubleBE;
/**
* Represent a contiguous sequence of a specific layout as an Array.
*
* *Factory*: {@link module:Layout.seq|seq}
*
* @param {Layout} elementLayout - initializer for {@link
* Sequence#elementLayout|elementLayout}.
*
* @param {(Number|ExternalLayout)} count - initializer for {@link
* Sequence#count|count}. The parameter must be either a positive
* integer or an instance of {@link ExternalLayout}.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class Sequence extends Layout {
constructor(elementLayout, count, property) {
if (!(elementLayout instanceof Layout)) {
throw new TypeError('elementLayout must be a Layout');
}
if (!(((count instanceof ExternalLayout) && count.isCount())
|| (Number.isInteger(count) && (0 <= count)))) {
throw new TypeError('count must be non-negative integer '
+ 'or an unsigned integer ExternalLayout');
}
let span = -1;
if ((!(count instanceof ExternalLayout))
&& (0 < elementLayout.span)) {
span = count * elementLayout.span;
}
super(span, property);
/** The layout for individual elements of the sequence. */
this.elementLayout = elementLayout;
/** The number of elements in the sequence.
*
* This will be either a non-negative integer or an instance of
* {@link ExternalLayout} for which {@link
* ExternalLayout#isCount|isCount()} is `true`. */
this.count = count;
}
/** @override */
getSpan(b, offset = 0) {
if (0 <= this.span) {
return this.span;
}
let span = 0;
let count = this.count;
if (count instanceof ExternalLayout) {
count = count.decode(b, offset);
}
if (0 < this.elementLayout.span) {
span = count * this.elementLayout.span;
}
else {
let idx = 0;
while (idx < count) {
span += this.elementLayout.getSpan(b, offset + span);
++idx;
}
}
return span;
}
/** @override */
decode(b, offset = 0) {
const rv = [];
let i = 0;
let count = this.count;
if (count instanceof ExternalLayout) {
count = count.decode(b, offset);
}
while (i < count) {
rv.push(this.elementLayout.decode(b, offset));
offset += this.elementLayout.getSpan(b, offset);
i += 1;
}
return rv;
}
/** Implement {@link Layout#encode|encode} for {@link Sequence}.
*
* **NOTE** If `src` is shorter than {@link Sequence#count|count} then
* the unused space in the buffer is left unchanged. If `src` is
* longer than {@link Sequence#count|count} the unneeded elements are
* ignored.
*
* **NOTE** If {@link Layout#count|count} is an instance of {@link
* ExternalLayout} then the length of `src` will be encoded as the
* count after `src` is encoded. */
encode(src, b, offset = 0) {
const elo = this.elementLayout;
const span = src.reduce((span, v) => {
return span + elo.encode(v, b, offset + span);
}, 0);
if (this.count instanceof ExternalLayout) {
this.count.encode(src.length, b, offset);
}
return span;
}
}
exports.Sequence = Sequence;
/**
* Represent a contiguous sequence of arbitrary layout elements as an
* Object.
*
* *Factory*: {@link module:Layout.struct|struct}
*
* **NOTE** The {@link Layout#span|span} of the structure is variable
* if any layout in {@link Structure#fields|fields} has a variable
* span. When {@link Layout#encode|encoding} we must have a value for
* all variable-length fields, or we wouldn't be able to figure out
* how much space to use for storage. We can only identify the value
* for a field when it has a {@link Layout#property|property}. As
* such, although a structure may contain both unnamed fields and
* variable-length fields, it cannot contain an unnamed
* variable-length field.
*
* @param {Layout[]} fields - initializer for {@link
* Structure#fields|fields}. An error is raised if this contains a
* variable-length field for which a {@link Layout#property|property}
* is not defined.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @param {Boolean} [decodePrefixes] - initializer for {@link
* Structure#decodePrefixes|property}.
*
* @throws {Error} - if `fields` contains an unnamed variable-length
* layout.
*
* @augments {Layout}
*/
class Structure extends Layout {
constructor(fields, property, decodePrefixes) {
if (!(Array.isArray(fields)
&& fields.reduce((acc, v) => acc && (v instanceof Layout), true))) {
throw new TypeError('fields must be array of Layout instances');
}
if (('boolean' === typeof property)
&& (undefined === decodePrefixes)) {
decodePrefixes = property;
property = undefined;
}
/* Verify absence of unnamed variable-length fields. */
for (const fd of fields) {
if ((0 > fd.span)
&& (undefined === fd.property)) {
throw new Error('fields cannot contain unnamed variable-length layout');
}
}
let span = -1;
try {
span = fields.reduce((span, fd) => span + fd.getSpan(), 0);
}
catch (e) {
// ignore error
}
super(span, property);
/** The sequence of {@link Layout} values that comprise the
* structure.
*
* The individual elements need not be the same type, and may be
* either scalar or aggregate layouts. If a member layout leaves
* its {@link Layout#property|property} undefined the
* corresponding region of the buffer associated with the element
* will not be mutated.
*
* @type {Layout[]} */
this.fields = fields;
/** Control behavior of {@link Layout#decode|decode()} given short
* buffers.
*
* In some situations a structure many be extended with additional
* fields over time, with older installations providing only a
* prefix of the full structure. If this property is `true`
* decoding will accept those buffers and leave subsequent fields
* undefined, as long as the buffer ends at a field boundary.
* Defaults to `false`. */
this.decodePrefixes = !!decodePrefixes;
}
/** @override */
getSpan(b, offset = 0) {
if (0 <= this.span) {
return this.span;
}
let span = 0;
try {
span = this.fields.reduce((span, fd) => {
const fsp = fd.getSpan(b, offset);
offset += fsp;
return span + fsp;
}, 0);
}
catch (e) {
throw new RangeError('indeterminate span');
}
return span;
}
/** @override */
decode(b, offset = 0) {
checkUint8Array(b);
const dest = this.makeDestinationObject();
for (const fd of this.fields) {
if (undefined !== fd.property) {
dest[fd.property] = fd.decode(b, offset);
}
offset += fd.getSpan(b, offset);
if (this.decodePrefixes
&& (b.length === offset)) {
break;
}
}
return dest;
}
/** Implement {@link Layout#encode|encode} for {@link Structure}.
*
* If `src` is missing a property for a member with a defined {@link
* Layout#property|property} the corresponding region of the buffer is
* left unmodified. */
encode(src, b, offset = 0) {
const firstOffset = offset;
let lastOffset = 0;
let lastWrote = 0;
for (const fd of this.fields) {
let span = fd.span;
lastWrote = (0 < span) ? span : 0;
if (undefined !== fd.property) {
const fv = src[fd.property];
if (undefined !== fv) {
lastWrote = fd.encode(fv, b, offset);
if (0 > span) {
/* Read the as-encoded span, which is not necessarily the
* same as what we wrote. */
span = fd.getSpan(b, offset);
}
}
}
lastOffset = offset;
offset += span;
}
/* Use (lastOffset + lastWrote) instead of offset because the last
* item may have had a dynamic length and we don't want to include
* the padding between it and the end of the space reserved for
* it. */
return (lastOffset + lastWrote) - firstOffset;
}
/** @override */
fromArray(values) {
const dest = this.makeDestinationObject();
for (const fd of this.fields) {
if ((undefined !== fd.property)
&& (0 < values.length)) {
dest[fd.property] = values.shift();
}
}
return dest;
}
/**
* Get access to the layout of a given property.
*
* @param {String} property - the structure member of interest.
*
* @return {Layout} - the layout associated with `property`, or
* undefined if there is no such property.
*/
layoutFor(property) {
if ('string' !== typeof property) {
throw new TypeError('property must be string');
}
for (const fd of this.fields) {
if (fd.property === property) {
return fd;
}
}
return undefined;
}
/**
* Get the offset of a structure member.
*
* @param {String} property - the structure member of interest.
*
* @return {Number} - the offset in bytes to the start of `property`
* within the structure, or undefined if `property` is not a field
* within the structure. If the property is a member but follows a
* variable-length structure member a negative number will be
* returned.
*/
offsetOf(property) {
if ('string' !== typeof property) {
throw new TypeError('property must be string');
}
let offset = 0;
for (const fd of this.fields) {
if (fd.property === property) {
return offset;
}
if (0 > fd.span) {
offset = -1;
}
else if (0 <= offset) {
offset += fd.span;
}
}
return undefined;
}
}
exports.Structure = Structure;
/**
* An object that can provide a {@link
* Union#discriminator|discriminator} API for {@link Union}.
*
* **NOTE** This is an abstract base class; you can create instances
* if it amuses you, but they won't support the {@link
* UnionDiscriminator#encode|encode} or {@link
* UnionDiscriminator#decode|decode} functions.
*
* @param {string} [property] - Default for {@link
* UnionDiscriminator#property|property}.
*
* @abstract
*/
class UnionDiscriminator {
constructor(property) {
/** The {@link Layout#property|property} to be used when the
* discriminator is referenced in isolation (generally when {@link
* Union#decode|Union decode} cannot delegate to a specific
* variant). */
this.property = property;
}
/** Analog to {@link Layout#decode|Layout decode} for union discriminators.
*
* The implementation of this method need not reference the buffer if
* variant information is available through other means. */
decode(b, offset) {
throw new Error('UnionDiscriminator is abstract');
}
/** Analog to {@link Layout#decode|Layout encode} for union discriminators.
*
* The implementation of this method need not store the value if
* variant information is maintained through other means. */
encode(src, b, offset) {
throw new Error('UnionDiscriminator is abstract');
}
}
exports.UnionDiscriminator = UnionDiscriminator;
/**
* An object that can provide a {@link
* UnionDiscriminator|discriminator API} for {@link Union} using an
* unsigned integral {@link Layout} instance located either inside or
* outside the union.
*
* @param {ExternalLayout} layout - initializes {@link
* UnionLayoutDiscriminator#layout|layout}. Must satisfy {@link
* ExternalLayout#isCount|isCount()}.
*
* @param {string} [property] - Default for {@link
* UnionDiscriminator#property|property}, superseding the property
* from `layout`, but defaulting to `variant` if neither `property`
* nor layout provide a property name.
*
* @augments {UnionDiscriminator}
*/
class UnionLayoutDiscriminator extends UnionDiscriminator {
constructor(layout, property) {
if (!((layout instanceof ExternalLayout)
&& layout.isCount())) {
throw new TypeError('layout must be an unsigned integer ExternalLayout');
}
super(property || layout.property || 'variant');
/** The {@link ExternalLayout} used to access the discriminator
* value. */
this.layout = layout;
}
/** Delegate decoding to {@link UnionLayoutDiscriminator#layout|layout}. */
decode(b, offset) {
return this.layout.decode(b, offset);
}
/** Delegate encoding to {@link UnionLayoutDiscriminator#layout|layout}. */
encode(src, b, offset) {
return this.layout.encode(src, b, offset);
}
}
exports.UnionLayoutDiscriminator = UnionLayoutDiscriminator;
/**
* Represent any number of span-compatible layouts.
*
* *Factory*: {@link module:Layout.union|union}
*
* If the union has a {@link Union#defaultLayout|default layout} that
* layout must have a non-negative {@link Layout#span|span}. The span
* of a fixed-span union includes its {@link
* Union#discriminator|discriminator} if the variant is a {@link
* Union#usesPrefixDiscriminator|prefix of the union}, plus the span
* of its {@link Union#defaultLayout|default layout}.
*
* If the union does not have a default layout then the encoded span
* of the union depends on the encoded span of its variant (which may
* be fixed or variable).
*
* {@link VariantLayout#layout|Variant layout}s are added through
* {@link Union#addVariant|addVariant}. If the union has a default
* layout, the span of the {@link VariantLayout#layout|layout
* contained by the variant} must not exceed the span of the {@link
* Union#defaultLayout|default layout} (minus the span of a {@link
* Union#usesPrefixDiscriminator|prefix disriminator}, if used). The
* span of the variant will equal the span of the union itself.
*
* The variant for a buffer can only be identified from the {@link
* Union#discriminator|discriminator} {@link
* UnionDiscriminator#property|property} (in the case of the {@link
* Union#defaultLayout|default layout}), or by using {@link
* Union#getVariant|getVariant} and examining the resulting {@link
* VariantLayout} instance.
*
* A variant compatible with a JavaScript object can be identified
* using {@link Union#getSourceVariant|getSourceVariant}.
*
* @param {(UnionDiscriminator|ExternalLayout|Layout)} discr - How to
* identify the layout used to interpret the union contents. The
* parameter must be an instance of {@link UnionDiscriminator}, an
* {@link ExternalLayout} that satisfies {@link
* ExternalLayout#isCount|isCount()}, or {@link UInt} (or {@link
* UIntBE}). When a non-external layout element is passed the layout
* appears at the start of the union. In all cases the (synthesized)
* {@link UnionDiscriminator} instance is recorded as {@link
* Union#discriminator|discriminator}.
*
* @param {(Layout|null)} defaultLayout - initializer for {@link
* Union#defaultLayout|defaultLayout}. If absent defaults to `null`.
* If `null` there is no default layout: the union has data-dependent
* length and attempts to decode or encode unrecognized variants will
* throw an exception. A {@link Layout} instance must have a
* non-negative {@link Layout#span|span}, and if it lacks a {@link
* Layout#property|property} the {@link
* Union#defaultLayout|defaultLayout} will be a {@link
* Layout#replicate|replica} with property `content`.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class Union extends Layout {
constructor(discr, defaultLayout, property) {
let discriminator;
if ((discr instanceof UInt)
|| (discr instanceof UIntBE)) {
discriminator = new UnionLayoutDiscriminator(new OffsetLayout(discr));
}
else if ((discr instanceof ExternalLayout)
&& discr.isCount()) {
discriminator = new UnionLayoutDiscriminator(discr);
}
else if (!(discr instanceof UnionDiscriminator)) {
throw new TypeError('discr must be a UnionDiscriminator '
+ 'or an unsigned integer layout');
}
else {
discriminator = discr;
}
if (undefined === defaultLayout) {
defaultLayout = null;
}
if (!((null === defaultLayout)
|| (defaultLayout instanceof Layout))) {
throw new TypeError('defaultLayout must be null or a Layout');
}
if (null !== defaultLayout) {
if (0 > defaultLayout.span) {
throw new Error('defaultLayout must have constant span');
}
if (undefined === defaultLayout.property) {
defaultLayout = defaultLayout.replicate('content');
}
}
/* The union span can be estimated only if there's a default
* layout. The union spans its default layout, plus any prefix
* variant layout. By construction both layouts, if present, have
* non-negative span. */
let span = -1;
if (defaultLayout) {
span = defaultLayout.span;
if ((0 <= span) && ((discr instanceof UInt)
|| (discr instanceof UIntBE))) {
span += discriminator.layout.span;
}
}
super(span, property);
/** The interface for the discriminator value in isolation.
*
* This a {@link UnionDiscriminator} either passed to the
* constructor or synthesized from the `discr` constructor
* argument. {@link
* Union#usesPrefixDiscriminator|usesPrefixDiscriminator} will be
* `true` iff the `discr` parameter was a non-offset {@link
* Layout} instance. */
this.discriminator = discriminator;
/** `true` if the {@link Union#discriminator|discriminator} is the
* first field in the union.
*
* If `false` the discriminator is obtained from somewhere
* else. */
this.usesPrefixDiscriminator = (discr instanceof UInt)
|| (discr instanceof UIntBE);
/** The layout for non-discriminator content when the value of the
* discriminator is not recognized.
*
* This is the value passed to the constructor. It is
* structurally equivalent to the second component of {@link
* Union#layout|layout} but may have a different property
* name. */
this.defaultLayout = defaultLayout;
/** A registry of allowed variants.
*
* The keys are unsigned integers which should be compatible with
* {@link Union.discriminator|discriminator}. The property value
* is the corresponding {@link VariantLayout} instances assigned
* to this union by {@link Union#addVariant|addVariant}.
*
* **NOTE** The registry remains mutable so that variants can be
* {@link Union#addVariant|added} at any time. Users should not
* manipulate the content of this property. */
this.registry = {};
/* Private variable used when invoking getSourceVariant */
let boundGetSourceVariant = this.defaultGetSourceVariant.bind(this);
/** Function to infer the variant selected by a source object.
*
* Defaults to {@link
* Union#defaultGetSourceVariant|defaultGetSourceVariant} but may
* be overridden using {@link
* Union#configGetSourceVariant|configGetSourceVariant}.
*
* @param {Object} src - as with {@link
* Union#defaultGetSourceVariant|defaultGetSourceVariant}.
*
* @returns {(undefined|VariantLayout)} The default variant
* (`undefined`) or first registered variant that uses a property
* available in `src`. */
this.getSourceVariant = function (src) {
return boundGetSourceVariant(src);
};
/** Function to override the implementation of {@link
* Union#getSourceVariant|getSourceVariant}.
*
* Use this if the desired variant cannot be identified using the
* algorithm of {@link
* Union#defaultGetSourceVariant|defaultGetSourceVariant}.
*
* **NOTE** The provided function will be invoked bound to this
* Union instance, providing local access to {@link
* Union#registry|registry}.
*
* @param {Function} gsv - a function that follows the API of
* {@link Union#defaultGetSourceVariant|defaultGetSourceVariant}. */
this.configGetSourceVariant = function (gsv) {
boundGetSourceVariant = gsv.bind(this);
};
}
/** @override */
getSpan(b, offset = 0) {
if (0 <= this.span) {
return this.span;
}
/* Default layouts always have non-negative span, so we don't have
* one and we have to recognize the variant which will in turn
* determine the span. */
const vlo = this.getVariant(b, offset);
if (!vlo) {
throw new Error('unable to determine span for unrecognized variant');
}
return vlo.getSpan(b, offset);
}
/**
* Method to infer a registered Union variant compatible with `src`.
*
* The first satisfied rule in the following sequence defines the
* return value:
* * If `src` has properties matching the Union discriminator and
* the default layout, `undefined` is returned regardless of the
* value of the discriminator property (this ensures the default
* layout will be used);
* * If `src` has a property matching the Union discriminator, the
* value of the discriminator identifies a registered variant, and
* either (a) the variant has no layout, or (b) `src` has the
* variant's property, then the variant is returned (because the
* source satisfies the constraints of the variant it identifies);
* * If `src` does not have a property matching the Union
* discriminator, but does have a property matching a registered
* variant, then the variant is returned (because the source
* matches a variant without an explicit conflict);
* * An error is thrown (because we either can't identify a variant,
* or we were explicitly told the variant but can't satisfy it).
*
* @param {Object} src - an object presumed to be compatible with
* the content of the Union.
*
* @return {(undefined|VariantLayout)} - as described above.
*
* @throws {Error} - if `src` cannot be associated with a default or
* registered variant.
*/
defaultGetSourceVariant(src) {
if (Object.prototype.hasOwnProperty.call(src, this.discriminator.property)) {
if (this.defaultLayout && this.defaultLayout.property
&& Object.prototype.hasOwnProperty.call(src, this.defaultLayout.property)) {
return undefined;
}
const vlo = this.registry[src[this.discriminator.property]];
if (vlo
&& ((!vlo.layout)
|| (vlo.property && Object.prototype.hasOwnProperty.call(src, vlo.property)))) {
return vlo;
}
}
else {
for (const tag in this.registry) {
const vlo = this.registry[tag];
if (vlo.property && Object.prototype.hasOwnProperty.call(src, vlo.property)) {
return vlo;
}
}
}
throw new Error('unable to infer src variant');
}
/** Implement {@link Layout#decode|decode} for {@link Union}.
*
* If the variant is {@link Union#addVariant|registered} the return
* value is an instance of that variant, with no explicit
* discriminator. Otherwise the {@link Union#defaultLayout|default
* layout} is used to decode the content. */
decode(b, offset = 0) {
let dest;
const dlo = this.discriminator;
const discr = dlo.decode(b, offset);
const clo = this.registry[discr];
if (undefined === clo) {
const defaultLayout = this.defaultLayout;
let contentOffset = 0;
if (this.usesPrefixDiscriminator) {
contentOffset = dlo.layout.span;
}
dest = this.makeDestinationObject();
dest[dlo.property] = discr;
// defaultLayout.property can be undefined, but this is allowed by buffer-layout
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
dest[defaultLayout.property] = defaultLayout.decode(b, offset + contentOffset);
}
else {
dest = clo.decode(b, offset);
}
return dest;
}
/** Implement {@link Layout#encode|encode} for {@link Union}.
*
* This API assumes the `src` object is consistent with the union's
* {@link Union#defaultLayout|default layout}. To encode variants
* use the appropriate variant-specific {@link VariantLayout#encode}
* method. */
encode(src, b, offset = 0) {
const vlo = this.getSourceVariant(src);
if (undefined === vlo) {
const dlo = this.discriminator;
// this.defaultLayout is not undefined when vlo is undefined
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
const clo = this.defaultLayout;
let contentOffset = 0;
if (this.usesPrefixDiscriminator) {
contentOffset = dlo.layout.span;
}
dlo.encode(src[dlo.property], b, offset);
// clo.property is not undefined when vlo is undefined
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
return contentOffset + clo.encode(src[clo.property], b, offset + contentOffset);
}
return vlo.encode(src, b, offset);
}
/** Register a new variant structure within a union. The newly
* created variant is returned.
*
* @param {Number} variant - initializer for {@link
* VariantLayout#variant|variant}.
*
* @param {Layout} layout - initializer for {@link
* VariantLayout#layout|layout}.
*
* @param {String} property - initializer for {@link
* Layout#property|property}.
*
* @return {VariantLayout} */
addVariant(variant, layout, property) {
const rv = new VariantLayout(this, variant, layout, property);
this.registry[variant] = rv;
return rv;
}
/**
* Get the layout associated with a registered variant.
*
* If `vb` does not produce a registered variant the function returns
* `undefined`.
*
* @param {(Number|Uint8Array)} vb - either the variant number, or a
* buffer from which the discriminator is to be read.
*
* @param {Number} offset - offset into `vb` for the start of the
* union. Used only when `vb` is an instance of {Uint8Array}.
*
* @return {({VariantLayout}|undefined)}
*/
getVariant(vb, offset = 0) {
let variant;
if (vb instanceof Uint8Array) {
variant = this.discriminator.decode(vb, offset);
}
else {
variant = vb;
}
return this.registry[variant];
}
}
exports.Union = Union;
/**
* Represent a specific variant within a containing union.
*
* **NOTE** The {@link Layout#span|span} of the variant may include
* the span of the {@link Union#discriminator|discriminator} used to
* identify it, but values read and written using the variant strictly
* conform to the content of {@link VariantLayout#layout|layout}.
*
* **NOTE** User code should not invoke this constructor directly. Use
* the union {@link Union#addVariant|addVariant} helper method.
*
* @param {Union} union - initializer for {@link
* VariantLayout#union|union}.
*
* @param {Number} variant - initializer for {@link
* VariantLayout#variant|variant}.
*
* @param {Layout} [layout] - initializer for {@link
* VariantLayout#layout|layout}. If absent the variant carries no
* data.
*
* @param {String} [property] - initializer for {@link
* Layout#property|property}. Unlike many other layouts, variant
* layouts normally include a property name so they can be identified
* within their containing {@link Union}. The property identifier may
* be absent only if `layout` is is absent.
*
* @augments {Layout}
*/
class VariantLayout extends Layout {
constructor(union, variant, layout, property) {
if (!(union instanceof Union)) {
throw new TypeError('union must be a Union');
}
if ((!Number.isInteger(variant)) || (0 > variant)) {
throw new TypeError('variant must be a (non-negative) integer');
}
if (('string' === typeof layout)
&& (undefined === property)) {
property = layout;
layout = null;
}
if (layout) {
if (!(layout instanceof Layout)) {
throw new TypeError('layout must be a Layout');
}
if ((null !== union.defaultLayout)
&& (0 <= layout.span)
&& (layout.span > union.defaultLayout.span)) {
throw new Error('variant span exceeds span of containing union');
}
if ('string' !== typeof property) {
throw new TypeError('variant must have a String property');
}
}
let span = union.span;
if (0 > union.span) {
span = layout ? layout.span : 0;
if ((0 <= span) && union.usesPrefixDiscriminator) {
span += union.discriminator.layout.span;
}
}
super(span, property);
/** The {@link Union} to which this variant belongs. */
this.union = union;
/** The unsigned integral value identifying this variant within
* the {@link Union#discriminator|discriminator} of the containing
* union. */
this.variant = variant;
/** The {@link Layout} to be used when reading/writing the
* non-discriminator part of the {@link
* VariantLayout#union|union}. If `null` the variant carries no
* data. */
this.layout = layout || null;
}
/** @override */
getSpan(b, offset = 0) {
if (0 <= this.span) {
/* Will be equal to the containing union span if that is not
* variable. */
return this.span;
}
let contentOffset = 0;
if (this.union.usesPrefixDiscriminator) {
contentOffset = this.union.discriminator.layout.span;
}
/* Span is defined solely by the variant (and prefix discriminator) */
let span = 0;
if (this.layout) {
span = this.layout.getSpan(b, offset + contentOffset);
}
return contentOffset + span;
}
/** @override */
decode(b, offset = 0) {
const dest = this.makeDestinationObject();
if (this !== this.union.getVariant(b, offset)) {
throw new Error('variant mismatch');
}
let contentOffset = 0;
if (this.union.usesPrefixDiscriminator) {
contentOffset = this.union.discriminator.layout.span;
}
if (this.layout) {
dest[this.property] = this.layout.decode(b, offset + contentOffset);
}
else if (this.property) {
dest[this.property] = true;
}
else if (this.union.usesPrefixDiscriminator) {
dest[this.union.discriminator.property] = this.variant;
}
return dest;
}
/** @override */
encode(src, b, offset = 0) {
let contentOffset = 0;
if (this.union.usesPrefixDiscriminator) {
contentOffset = this.union.discriminator.layout.span;
}
if (this.layout
&& (!Object.prototype.hasOwnProperty.call(src, this.property))) {
throw new TypeError('variant lacks property ' + this.property);
}
this.union.discriminator.encode(this.variant, b, offset);
let span = contentOffset;
if (this.layout) {
this.layout.encode(src[this.property], b, offset + contentOffset);
span += this.layout.getSpan(b, offset + contentOffset);
if ((0 <= this.union.span)
&& (span > this.union.span)) {
throw new Error('encoded variant overruns containing union');
}
}
return span;
}
/** Delegate {@link Layout#fromArray|fromArray} to {@link
* VariantLayout#layout|layout}. */
fromArray(values) {
if (this.layout) {
return this.layout.fromArray(values);
}
return undefined;
}
}
exports.VariantLayout = VariantLayout;
/** JavaScript chose to define bitwise operations as operating on
* signed 32-bit values in 2's complement form, meaning any integer
* with bit 31 set is going to look negative. For right shifts that's
* not a problem, because `>>>` is a logical shift, but for every
* other bitwise operator we have to compensate for possible negative
* results. */
function fixBitwiseResult(v) {
if (0 > v) {
v += 0x100000000;
}
return v;
}
/**
* Contain a sequence of bit fields as an unsigned integer.
*
* *Factory*: {@link module:Layout.bits|bits}
*
* This is a container element; within it there are {@link BitField}
* instances that provide the extracted properties. The container
* simply defines the aggregate representation and its bit ordering.
* The representation is an object containing properties with numeric
* or {@link Boolean} values.
*
* {@link BitField}s are added with the {@link
* BitStructure#addField|addField} and {@link
* BitStructure#addBoolean|addBoolean} methods.
* @param {Layout} word - initializer for {@link
* BitStructure#word|word}. The parameter must be an instance of
* {@link UInt} (or {@link UIntBE}) that is no more than 4 bytes wide.
*
* @param {bool} [msb] - `true` if the bit numbering starts at the
* most significant bit of the containing word; `false` (default) if
* it starts at the least significant bit of the containing word. If
* the parameter at this position is a string and `property` is
* `undefined` the value of this argument will instead be used as the
* value of `property`.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class BitStructure extends Layout {
constructor(word, msb, property) {
if (!((word instanceof UInt)
|| (word instanceof UIntBE))) {
throw new TypeError('word must be a UInt or UIntBE layout');
}
if (('string' === typeof msb)
&& (undefined === property)) {
property = msb;
msb = false;
}
if (4 < word.span) {
throw new RangeError('word cannot exceed 32 bits');
}
super(word.span, property);
/** The layout used for the packed value. {@link BitField}
* instances are packed sequentially depending on {@link
* BitStructure#msb|msb}. */
this.word = word;
/** Whether the bit sequences are packed starting at the most
* significant bit growing down (`true`), or the least significant
* bit growing up (`false`).
*
* **NOTE** Regardless of this value, the least significant bit of
* any {@link BitField} value is the least significant bit of the
* corresponding section of the packed value. */
this.msb = !!msb;
/** The sequence of {@link BitField} layouts that comprise the
* packed structure.
*
* **NOTE** The array remains mutable to allow fields to be {@link
* BitStructure#addField|added} after construction. Users should
* not manipulate the content of this property.*/
this.fields = [];
/* Storage for the value. Capture a variable instead of using an
* instance property because we don't want anything to change the
* value without going through the mutator. */
let value = 0;
this._packedSetValue = function (v) {
value = fixBitwiseResult(v);
return this;
};
this._packedGetValue = function () {
return value;
};
}
/** @override */
decode(b, offset = 0) {
const dest = this.makeDestinationObject();
const value = this.word.decode(b, offset);
this._packedSetValue(value);
for (const fd of this.fields) {
if (undefined !== fd.property) {
dest[fd.property] = fd.decode(b);
}
}
return dest;
}
/** Implement {@link Layout#encode|encode} for {@link BitStructure}.
*
* If `src` is missing a property for a member with a defined {@link
* Layout#property|property} the corresponding region of the packed
* value is left unmodified. Unused bits are also left unmodified. */
encode(src, b, offset = 0) {
const value = this.word.decode(b, offset);
this._packedSetValue(value);
for (const fd of this.fields) {
if (undefined !== fd.property) {
const fv = src[fd.property];
if (undefined !== fv) {
fd.encode(fv);
}
}
}
return this.word.encode(this._packedGetValue(), b, offset);
}
/** Register a new bitfield with a containing bit structure. The
* resulting bitfield is returned.
*
* @param {Number} bits - initializer for {@link BitField#bits|bits}.
*
* @param {string} property - initializer for {@link
* Layout#property|property}.
*
* @return {BitField} */
addField(bits, property) {
const bf = new BitField(this, bits, property);
this.fields.push(bf);
return bf;
}
/** As with {@link BitStructure#addField|addField} for single-bit
* fields with `boolean` value representation.
*
* @param {string} property - initializer for {@link
* Layout#property|property}.
*
* @return {Boolean} */
// `Boolean` conflicts with the native primitive type
// eslint-disable-next-line @typescript-eslint/ban-types
addBoolean(property) {
// This is my Boolean, not the Javascript one.
const bf = new Boolean(this, property);
this.fields.push(bf);
return bf;
}
/**
* Get access to the bit field for a given property.
*
* @param {String} property - the bit field of interest.
*
* @return {BitField} - the field associated with `property`, or
* undefined if there is no such property.
*/
fieldFor(property) {
if ('string' !== typeof property) {
throw new TypeError('property must be string');
}
for (const fd of this.fields) {
if (fd.property === property) {
return fd;
}
}
return undefined;
}
}
exports.BitStructure = BitStructure;
/**
* Represent a sequence of bits within a {@link BitStructure}.
*
* All bit field values are represented as unsigned integers.
*
* **NOTE** User code should not invoke this constructor directly.
* Use the container {@link BitStructure#addField|addField} helper
* method.
*
* **NOTE** BitField instances are not instances of {@link Layout}
* since {@link Layout#span|span} measures 8-bit units.
*
* @param {BitStructure} container - initializer for {@link
* BitField#container|container}.
*
* @param {Number} bits - initializer for {@link BitField#bits|bits}.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*/
class BitField {
constructor(container, bits, property) {
if (!(container instanceof BitStructure)) {
throw new TypeError('container must be a BitStructure');
}
if ((!Number.isInteger(bits)) || (0 >= bits)) {
throw new TypeError('bits must be positive integer');
}
const totalBits = 8 * container.span;
const usedBits = container.fields.reduce((sum, fd) => sum + fd.bits, 0);
if ((bits + usedBits) > totalBits) {
throw new Error('bits too long for span remainder ('
+ (totalBits - usedBits) + ' of '
+ totalBits + ' remain)');
}
/** The {@link BitStructure} instance to which this bit field
* belongs. */
this.container = container;
/** The span of this value in bits. */
this.bits = bits;
/** A mask of {@link BitField#bits|bits} bits isolating value bits
* that fit within the field.
*
* That is, it masks a value that has not yet been shifted into
* position within its containing packed integer. */
this.valueMask = (1 << bits) - 1;
if (32 === bits) { // shifted value out of range
this.valueMask = 0xFFFFFFFF;
}
/** The offset of the value within the containing packed unsigned
* integer. The least significant bit of the packed value is at
* offset zero, regardless of bit ordering used. */
this.start = usedBits;
if (this.container.msb) {
this.start = totalBits - usedBits - bits;
}
/** A mask of {@link BitField#bits|bits} isolating the field value
* within the containing packed unsigned integer. */
this.wordMask = fixBitwiseResult(this.valueMask << this.start);
/** The property name used when this bitfield is represented in an
* Object.
*
* Intended to be functionally equivalent to {@link
* Layout#property}.
*
* If left undefined the corresponding span of bits will be
* treated as padding: it will not be mutated by {@link
* Layout#encode|encode} nor represented as a property in the
* decoded Object. */
this.property = property;
}
/** Store a value into the corresponding subsequence of the containing
* bit field. */
decode(b, offset) {
const word = this.container._packedGetValue();
const wordValue = fixBitwiseResult(word & this.wordMask);
const value = wordValue >>> this.start;
return value;
}
/** Store a value into the corresponding subsequence of the containing
* bit field.
*
* **NOTE** This is not a specialization of {@link
* Layout#encode|Layout.encode} and there is no return value. */
encode(value) {
if ('number' !== typeof value
|| !Number.isInteger(value)
|| (value !== fixBitwiseResult(value & this.valueMask))) {
throw new TypeError(nameWithProperty('BitField.encode', this)
+ ' value must be integer not exceeding ' + this.valueMask);
}
const word = this.container._packedGetValue();
const wordValue = fixBitwiseResult(value << this.start);
this.container._packedSetValue(fixBitwiseResult(word & ~this.wordMask)
| wordValue);
}
}
exports.BitField = BitField;
/**
* Represent a single bit within a {@link BitStructure} as a
* JavaScript boolean.
*
* **NOTE** User code should not invoke this constructor directly.
* Use the container {@link BitStructure#addBoolean|addBoolean} helper
* method.
*
* @param {BitStructure} container - initializer for {@link
* BitField#container|container}.
*
* @param {string} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {BitField}
*/
/* eslint-disable no-extend-native */
class Boolean extends BitField {
constructor(container, property) {
super(container, 1, property);
}
/** Override {@link BitField#decode|decode} for {@link Boolean|Boolean}.
*
* @returns {boolean} */
decode(b, offset) {
return !!super.decode(b, offset);
}
/** @override */
encode(value) {
if ('boolean' === typeof value) {
// BitField requires integer values
value = +value;
}
super.encode(value);
}
}
exports.Boolean = Boolean;
/* eslint-enable no-extend-native */
/**
* Contain a fixed-length block of arbitrary data, represented as a
* Uint8Array.
*
* *Factory*: {@link module:Layout.blob|blob}
*
* @param {(Number|ExternalLayout)} length - initializes {@link
* Blob#length|length}.
*
* @param {String} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class Blob extends Layout {
constructor(length, property) {
if (!(((length instanceof ExternalLayout) && length.isCount())
|| (Number.isInteger(length) && (0 <= length)))) {
throw new TypeError('length must be positive integer '
+ 'or an unsigned integer ExternalLayout');
}
let span = -1;
if (!(length instanceof ExternalLayout)) {
span = length;
}
super(span, property);
/** The number of bytes in the blob.
*
* This may be a non-negative integer, or an instance of {@link
* ExternalLayout} that satisfies {@link
* ExternalLayout#isCount|isCount()}. */
this.length = length;
}
/** @override */
getSpan(b, offset) {
let span = this.span;
if (0 > span) {
span = this.length.decode(b, offset);
}
return span;
}
/** @override */
decode(b, offset = 0) {
let span = this.span;
if (0 > span) {
span = this.length.decode(b, offset);
}
return uint8ArrayToBuffer(b).slice(offset, offset + span);
}
/** Implement {@link Layout#encode|encode} for {@link Blob}.
*
* **NOTE** If {@link Layout#count|count} is an instance of {@link
* ExternalLayout} then the length of `src` will be encoded as the
* count after `src` is encoded. */
encode(src, b, offset) {
let span = this.length;
if (this.length instanceof ExternalLayout) {
span = src.length;
}
if (!(src instanceof Uint8Array && span === src.length)) {
throw new TypeError(nameWithProperty('Blob.encode', this)
+ ' requires (length ' + span + ') Uint8Array as src');
}
if ((offset + span) > b.length) {
throw new RangeError('encoding overruns Uint8Array');
}
const srcBuffer = uint8ArrayToBuffer(src);
uint8ArrayToBuffer(b).write(srcBuffer.toString('hex'), offset, span, 'hex');
if (this.length instanceof ExternalLayout) {
this.length.encode(span, b, offset);
}
return span;
}
}
exports.Blob = Blob;
/**
* Contain a `NUL`-terminated UTF8 string.
*
* *Factory*: {@link module:Layout.cstr|cstr}
*
* **NOTE** Any UTF8 string that incorporates a zero-valued byte will
* not be correctly decoded by this layout.
*
* @param {String} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class CString extends Layout {
constructor(property) {
super(-1, property);
}
/** @override */
getSpan(b, offset = 0) {
checkUint8Array(b);
let idx = offset;
while ((idx < b.length) && (0 !== b[idx])) {
idx += 1;
}
return 1 + idx - offset;
}
/** @override */
decode(b, offset = 0) {
const span = this.getSpan(b, offset);
return uint8ArrayToBuffer(b).slice(offset, offset + span - 1).toString('utf-8');
}
/** @override */
encode(src, b, offset = 0) {
/* Must force this to a string, lest it be a number and the
* "utf8-encoding" below actually allocate a buffer of length
* src */
if ('string' !== typeof src) {
src = String(src);
}
const srcb = buffer_1.Buffer.from(src, 'utf8');
const span = srcb.length;
if ((offset + span) > b.length) {
throw new RangeError('encoding overruns Buffer');
}
const buffer = uint8ArrayToBuffer(b);
srcb.copy(buffer, offset);
buffer[offset + span] = 0;
return span + 1;
}
}
exports.CString = CString;
/**
* Contain a UTF8 string with implicit length.
*
* *Factory*: {@link module:Layout.utf8|utf8}
*
* **NOTE** Because the length is implicit in the size of the buffer
* this layout should be used only in isolation, or in a situation
* where the length can be expressed by operating on a slice of the
* containing buffer.
*
* @param {Number} [maxSpan] - the maximum length allowed for encoded
* string content. If not provided there is no bound on the allowed
* content.
*
* @param {String} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class UTF8 extends Layout {
constructor(maxSpan, property) {
if (('string' === typeof maxSpan) && (undefined === property)) {
property = maxSpan;
maxSpan = undefined;
}
if (undefined === maxSpan) {
maxSpan = -1;
}
else if (!Number.isInteger(maxSpan)) {
throw new TypeError('maxSpan must be an integer');
}
super(-1, property);
/** The maximum span of the layout in bytes.
*
* Positive values are generally expected. Zero is abnormal.
* Attempts to encode or decode a value that exceeds this length
* will throw a `RangeError`.
*
* A negative value indicates that there is no bound on the length
* of the content. */
this.maxSpan = maxSpan;
}
/** @override */
getSpan(b, offset = 0) {
checkUint8Array(b);
return b.length - offset;
}
/** @override */
decode(b, offset = 0) {
const span = this.getSpan(b, offset);
if ((0 <= this.maxSpan)
&& (this.maxSpan < span)) {
throw new RangeError('text length exceeds maxSpan');
}
return uint8ArrayToBuffer(b).slice(offset, offset + span).toString('utf-8');
}
/** @override */
encode(src, b, offset = 0) {
/* Must force this to a string, lest it be a number and the
* "utf8-encoding" below actually allocate a buffer of length
* src */
if ('string' !== typeof src) {
src = String(src);
}
const srcb = buffer_1.Buffer.from(src, 'utf8');
const span = srcb.length;
if ((0 <= this.maxSpan)
&& (this.maxSpan < span)) {
throw new RangeError('text length exceeds maxSpan');
}
if ((offset + span) > b.length) {
throw new RangeError('encoding overruns Buffer');
}
srcb.copy(uint8ArrayToBuffer(b), offset);
return span;
}
}
exports.UTF8 = UTF8;
/**
* Contain a constant value.
*
* This layout may be used in cases where a JavaScript value can be
* inferred without an expression in the binary encoding. An example
* would be a {@link VariantLayout|variant layout} where the content
* is implied by the union {@link Union#discriminator|discriminator}.
*
* @param {Object|Number|String} value - initializer for {@link
* Constant#value|value}. If the value is an object (or array) and
* the application intends the object to remain unchanged regardless
* of what is done to values decoded by this layout, the value should
* be frozen prior passing it to this constructor.
*
* @param {String} [property] - initializer for {@link
* Layout#property|property}.
*
* @augments {Layout}
*/
class Constant extends Layout {
constructor(value, property) {
super(0, property);
/** The value produced by this constant when the layout is {@link
* Constant#decode|decoded}.
*
* Any JavaScript value including `null` and `undefined` is
* permitted.
*
* **WARNING** If `value` passed in the constructor was not
* frozen, it is possible for users of decoded values to change
* the content of the value. */
this.value = value;
}
/** @override */
decode(b, offset) {
return this.value;
}
/** @override */
encode(src, b, offset) {
/* Constants take no space */
return 0;
}
}
exports.Constant = Constant;
/** Factory for {@link GreedyCount}. */
exports.greedy = ((elementSpan, property) => new GreedyCount(elementSpan, property));
/** Factory for {@link OffsetLayout}. */
exports.offset = ((layout, offset, property) => new OffsetLayout(layout, offset, property));
/** Factory for {@link UInt|unsigned int layouts} spanning one
* byte. */
exports.u8 = ((property) => new UInt(1, property));
/** Factory for {@link UInt|little-endian unsigned int layouts}
* spanning two bytes. */
exports.u16 = ((property) => new UInt(2, property));
/** Factory for {@link UInt|little-endian unsigned int layouts}
* spanning three bytes. */
exports.u24 = ((property) => new UInt(3, property));
/** Factory for {@link UInt|little-endian unsigned int layouts}
* spanning four bytes. */
exports.u32 = ((property) => new UInt(4, property));
/** Factory for {@link UInt|little-endian unsigned int layouts}
* spanning five bytes. */
exports.u40 = ((property) => new UInt(5, property));
/** Factory for {@link UInt|little-endian unsigned int layouts}
* spanning six bytes. */
exports.u48 = ((property) => new UInt(6, property));
/** Factory for {@link NearUInt64|little-endian unsigned int
* layouts} interpreted as Numbers. */
exports.nu64 = ((property) => new NearUInt64(property));
/** Factory for {@link UInt|big-endian unsigned int layouts}
* spanning two bytes. */
exports.u16be = ((property) => new UIntBE(2, property));
/** Factory for {@link UInt|big-endian unsigned int layouts}
* spanning three bytes. */
exports.u24be = ((property) => new UIntBE(3, property));
/** Factory for {@link UInt|big-endian unsigned int layouts}
* spanning four bytes. */
exports.u32be = ((property) => new UIntBE(4, property));
/** Factory for {@link UInt|big-endian unsigned int layouts}
* spanning five bytes. */
exports.u40be = ((property) => new UIntBE(5, property));
/** Factory for {@link UInt|big-endian unsigned int layouts}
* spanning six bytes. */
exports.u48be = ((property) => new UIntBE(6, property));
/** Factory for {@link NearUInt64BE|big-endian unsigned int
* layouts} interpreted as Numbers. */
exports.nu64be = ((property) => new NearUInt64BE(property));
/** Factory for {@link Int|signed int layouts} spanning one
* byte. */
exports.s8 = ((property) => new Int(1, property));
/** Factory for {@link Int|little-endian signed int layouts}
* spanning two bytes. */
exports.s16 = ((property) => new Int(2, property));
/** Factory for {@link Int|little-endian signed int layouts}
* spanning three bytes. */
exports.s24 = ((property) => new Int(3, property));
/** Factory for {@link Int|little-endian signed int layouts}
* spanning four bytes. */
exports.s32 = ((property) => new Int(4, property));
/** Factory for {@link Int|little-endian signed int layouts}
* spanning five bytes. */
exports.s40 = ((property) => new Int(5, property));
/** Factory for {@link Int|little-endian signed int layouts}
* spanning six bytes. */
exports.s48 = ((property) => new Int(6, property));
/** Factory for {@link NearInt64|little-endian signed int layouts}
* interpreted as Numbers. */
exports.ns64 = ((property) => new NearInt64(property));
/** Factory for {@link Int|big-endian signed int layouts}
* spanning two bytes. */
exports.s16be = ((property) => new IntBE(2, property));
/** Factory for {@link Int|big-endian signed int layouts}
* spanning three bytes. */
exports.s24be = ((property) => new IntBE(3, property));
/** Factory for {@link Int|big-endian signed int layouts}
* spanning four bytes. */
exports.s32be = ((property) => new IntBE(4, property));
/** Factory for {@link Int|big-endian signed int layouts}
* spanning five bytes. */
exports.s40be = ((property) => new IntBE(5, property));
/** Factory for {@link Int|big-endian signed int layouts}
* spanning six bytes. */
exports.s48be = ((property) => new IntBE(6, property));
/** Factory for {@link NearInt64BE|big-endian signed int layouts}
* interpreted as Numbers. */
exports.ns64be = ((property) => new NearInt64BE(property));
/** Factory for {@link Float|little-endian 32-bit floating point} values. */
exports.f32 = ((property) => new Float(property));
/** Factory for {@link FloatBE|big-endian 32-bit floating point} values. */
exports.f32be = ((property) => new FloatBE(property));
/** Factory for {@link Double|little-endian 64-bit floating point} values. */
exports.f64 = ((property) => new Double(property));
/** Factory for {@link DoubleBE|big-endian 64-bit floating point} values. */
exports.f64be = ((property) => new DoubleBE(property));
/** Factory for {@link Structure} values. */
exports.struct = ((fields, property, decodePrefixes) => new Structure(fields, property, decodePrefixes));
/** Factory for {@link BitStructure} values. */
exports.bits = ((word, msb, property) => new BitStructure(word, msb, property));
/** Factory for {@link Sequence} values. */
exports.seq = ((elementLayout, count, property) => new Sequence(elementLayout, count, property));
/** Factory for {@link Union} values. */
exports.union = ((discr, defaultLayout, property) => new Union(discr, defaultLayout, property));
/** Factory for {@link UnionLayoutDiscriminator} values. */
exports.unionLayoutDiscriminator = ((layout, property) => new UnionLayoutDiscriminator(layout, property));
/** Factory for {@link Blob} values. */
exports.blob = ((length, property) => new Blob(length, property));
/** Factory for {@link CString} values. */
exports.cstr = ((property) => new CString(property));
/** Factory for {@link UTF8} values. */
exports.utf8 = ((maxSpan, property) => new UTF8(maxSpan, property));
/** Factory for {@link Constant} values. */
exports.constant = ((value, property) => new Constant(value, property));
//# sourceMappingURL=Layout.js.map