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@sapphire/string-store

High-capacity raw data storage in UTF-16 strings.

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Description​

A package that can store large chunks of data in a short UTF-16 string, useful for storing data in length-limited locations such as Discord's custom_id field in message components.

Features​

  • Written in TypeScript
  • Bundled with esbuild so it can be used in NodeJS and browsers
  • Offers CommonJS, ESM, and UMD bundles
  • Fully tested

Installation​

You can use the following command to install this package, or replace npm install with your package manager of choice.

npm install @sapphire/string-store

Usage​

Note: While this section uses require, the imports match 1:1 with ESM imports. For example, const { SchemaStore } = require('@sapphire/string-store') is equivalent to import { SchemaStore } from '@sapphire/string-store'.

// Require the store classes
const { SchemaStore, Schema, t } = require('@sapphire/string-store');

// Define the enum with the IDs and export it
export const Id = Object.freeze({
	AgeUpdate: 0,
	StrengthUpdate: 1,
	Planet: 2,
	User: 3
});

// Create the store in a file and export it
export const store = new SchemaStore()
	// Add a schema with an age field stored as a int32:
	// Schema<Id.AgeUpdate, { age: number }>
	.add(new Schema(Id.AgeUpdate).int32('age'))
	// Add a schema with a strength field stored as a float32:
	// Schema<Id.StrengthUpdate, { strength: number }>
	.add(new Schema(Id.StrengthUpdate).float32('strength'));

// Serialize an `Id.AgeUpdate` object into a string containing:
// - The schema ID (0)
// - The age field (20)
const buffer = store.serialize(Id.AgeUpdate, { age: 20 }).toString();

[!Important] The IDs passed in the Schema constant need to be known at compile time, this can be done in the following ways:

  • (TS) An enum object, which has all of its members strictly typed.
  • (TS) An object with as const, which makes the values known at compile time.
  • An object with Object.freeze as shown in the example, which is equivalent as the previous.
  • An object with a JSDoc defining the types as the specific values.
  • Multiple constants for each value, or
    • (TS) Class fields marked as readonly.

[!Tip] The serialized string is encoded in UTF-16, meaning it can store 16 bits per character. Each type stores a different number of bits, for example, a single character can store:

  • 16 booleans
  • 8 2-bit unsigned integers (0-3)
  • 4 4-bit unsigned integers (0-15)
  • 2 8-bit unsigned integers (0-255)
  • 1 16-bit integer (0-65535)

As a use-case, Discord's custom_id field in message components can store up to 100 UTF-16 characters, which means it has a storage of 1600 bits, below you can see the supported types and their storage in bits. Keep in mind that the schema ID is stored as a 16-bit integer, and that the property names are not stored.

The schema can be defined using the following methods:

array​

Adds an array with a dynamic length to the schema.

// A schema with a single field `names` that is an array of strings:

const schema = new Schema(Id.Planets).array('names', t.string);
// → Schema<Id.Planets, { names: string[] }>

To track the length of the array, it will serialize a 16-bit unsigned integer before the array.

fixedLengthArray​

An alternative to array that has a fixed length. This variant requires the exact number of elements to be serialized, but it will save space by not storing the length of the array.

// A schema with a single field `names` that is an array of exactly 3 strings:

const schema = new Schema(Id.Planets).fixedLengthArray('names', t.string, 3);
// → Schema<Id.Planets, { names: [string, string, string] }>

nullable​

Adds a nullable property of the specified type to the schema.

// A schema with a single field `capitalId` that is a nullable string:

const schema = new Schema(Id.Planets).nullable('capitalId', t.uint32);
// → Schema<Id.Planets, { capitalId: number | null }>

To track whether or not a property is optional, it will serialize a bit, which signals whether or not the value is defined, due to this, its bit size is null.

string​

Adds a string to the schema.

// A schema with a single field `name` that is a string:

const schema = new Schema(Id.Planet).string('name');
// → Schema<Id.Planets, { name: string }>

The string is serialized as UTF-8, and the length is serialized as a 16-bit unsigned integer before the string.

boolean​

Adds a boolean (single bit) to the schema.

// A schema with a single field `isHabitable` that is a boolean:

const schema = new Schema(Id.Planet).boolean('isHabitable');
// → Schema<Id.Planets, { isHabitable: boolean }>

bit​

Adds a bit (0 or 1) to the schema. This is a numeric version of boolean.

// A schema with a single field `isHabitable` that is a bit:

const schema = new Schema(Id.Planet).bit('isHabitable');
// → Schema<Id.Planets, { isHabitable: 0 | 1 }>

int2​

Adds a 2-bit signed integer to the schema. It can store values from -2 to 1, inclusive.

// A schema with a single field `type` that is a 2-bit signed integer:

const schema = new Schema(Id.Planet).int2('type');
// → Schema<Id.Planets, { type: -2 | -1 | 0 | 1 }>

uint2​

Adds a 2-bit unsigned integer to the schema. It can store values from 0 to 3, inclusive.

// A schema with a single field `type` that is a 2-bit unsigned integer:

const schema = new Schema(Id.Planet).uint2('type');
// → Schema<Id.Planets, { type: 0 | 1 | 2 | 3 }>

int4​

Adds a 4-bit signed integer to the schema. It can store values from -8 to 7, inclusive.

// A schema with a single field `type` that is a 4-bit signed integer:

const schema = new Schema(Id.Planet).int4('type');
// → Schema<Id.Planets, { type: -8..=7 }>

uint4​

Adds a 4-bit unsigned integer to the schema. It can store values from 0 to 15, inclusive.

// A schema with a single field `type` that is a 4-bit unsigned integer:

const schema = new Schema(Id.Planet).uint4('type');
// → Schema<Id.Planets, { type: 0..=15 }>

int8​

Adds an 8-bit signed integer to the schema. It can store values from -128 to 127, inclusive.

// A schema with a single field `type` that is an 8-bit signed integer:

const schema = new Schema(Id.Planet).int8('type');
// → Schema<Id.Planets, { type: -128..=127 }>

uint8​

Adds an 8-bit unsigned integer to the schema. It can store values from 0 to 255, inclusive.

// A schema with a single field `type` that is an 8-bit unsigned integer:

const schema = new Schema(Id.Planet).uint8('type');
// → Schema<Id.Planets, { type: 0..=255 }>

int16​

Adds a 16-bit signed integer to the schema. It can store values from -32768 to 32767, inclusive.

// A schema with a single field `type` that is a 16-bit signed integer:

const schema = new Schema(Id.Planet).int16('type');
// → Schema<Id.Planets, { type: -32768..=32767 }>

uint16​

Adds a 16-bit unsigned integer to the schema. It can store values from 0 to 65535, inclusive.

// A schema with a single field `type` that is a 16-bit unsigned integer:

const schema = new Schema(Id.Planet).uint16('type');
// → Schema<Id.Planets, { type: 0..=65535 }>

int32​

Adds a 32-bit signed integer to the schema. It can store values from 2,147,483,648 to 2,147,483,647, inclusive.

// A schema with a single field `type` that is a 32-bit signed integer:

const schema = new Schema(Id.Planet).int32('type');
// → Schema<Id.Planets, { type: 2_147_483_648..=2_147_483_647 }>

uint32​

Adds a 32-bit unsigned integer to the schema. It can store values from 0 to 4,294,967,295, inclusive.

// A schema with a single field `type` that is a 32-bit unsigned integer:

const schema = new Schema(Id.Planet).uint32('type');
// → Schema<Id.Planets, { type: 0..=4294967295 }>

int64​

Adds a 64-bit signed integer to the schema. It can store values from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807, inclusive.

Note: values smaller than Number.MIN_SAFE_INTEGER or larger than Number.MAX_SAFE_INTEGER will lose precision, if you need to store larger numbers, consider using bigInt64.

// A schema with a single field `type` that is a 64-bit signed integer:

const schema = new Schema(Id.Planet).int64('type');
// → Schema<Id.Planets, { type: -9_223_372_036_854_775_808..=9_223_372_036_854_775_807 }>

uint64​

Adds a 64-bit unsigned integer to the schema. It can store values from 0 to 18,446,744,073,709,551,615, inclusive.

Note: values larger than 9,007,199,254,740,991 (Number.MAX_SAFE_INTEGER) will lose precision, if you need to store larger numbers, use bigUint64.

// A schema with a single field `type` that is a 64-bit unsigned integer:

const schema = new Schema(Id.Planet).uint64('type');
// → Schema<Id.Planets, { type: 0..=18_446_744_073_709_551_615 }>

Note: values larger than Number.MAX_SAFE_INTEGER will be truncated.

bigInt32​

Alternative to int32 that uses BigInt. It can store values from 2,147,483,648 to 2,147,483,647, inclusive.

// A schema with a single field `type` that is a 32-bit integer:

const schema = new Schema(Id.Planet).bigInt32('type');
// → Schema<Id.Planets, { type: 2_147_483_648n..=2_147_483_647n }>

bigUint32​

Alternative to uint32 that uses BigInt. It can store values from 0 to 4,294,967,295, inclusive.

// A schema with a single field `type` that is a 32-bit integer:

const schema = new Schema(Id.Planet).bigUint32('type');
// → Schema<Id.Planets, { type: 0n..=4294967295n }>

bigInt64​

Alternative to int64 that uses BigInt. It can store values from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807, inclusive.

// A schema with a single field `type` that is a 64-bit integer:

const schema = new Schema(Id.Planet).bigInt64('type');
// → Schema<Id.Planets, { type: -9_223_372_036_854_775_808n..=9_223_372_036_854_775_807n }>

bigUint64​

Alternative to uint64 that uses BigInt. It can store values from 0 to 18,446,744,073,709,551,615, inclusive.

// A schema with a single field `type` that is a 64-bit integer:

const schema = new Schema(Id.Planet).bigUint64('type');
// → Schema<Id.Planets, { type: 0n..=18_446_744_073_709_551_615n }>

float32​

Adds a 32-bit floating-point number to the schema.

// A schema with a single field `radius` that is a 32-bit floating-point number:

const schema = new Schema(Id.Planet).float32('radius');
// → Schema<Id.Planets, { radius: number }>

float64​

Adds a 64-bit floating-point number to the schema.

// A schema with a single field `radius` that is a 64-bit floating-point number:

const schema = new Schema(Id.Planet).float64('radius');
// → Schema<Id.Planets, { radius: number }>

snowflake​

Adds a 64-bit snowflake to the schema.

const schema = new Schema(Id.User).snowflake('id');
// → Schema<Id.User, { id: bigint }>

constant​

A constant value that will not get serialized into the buffer, useful for adding extra information to the resulting payloads, such as the name of a piece to run.

// A schema with a single field `handlerName` that is a specific constant:

const schema = new Schema(Id.Planets).constant('handlerFileName', 'planets.ts');
// → Schema<Id.Planets, { handlerFileName: 'planets.ts' }>

Buy us some doughnuts​

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Contributors​

Please make sure to read the Contributing Guide before making a pull request.

Thank you to all the people who already contributed to Sapphire!