varint-wasm

A varint implementation for WebAssembly (WASM) written in ZZ that implements an Abstract Encoding interface.

Installation

Node

$ npm install @12core/varint-wasm

WAPM

$ wapm install jwerle/varint-wasm

Usage

const varint = require('varint-wasm')

// wait for module to be ready if loading in a browser environment
varint.ready(() => {
  const encoded = varint.encode(64 * 1024)
  console.log(encoded) // <Buffer 80 80 04>

  const decoded = varint.decode(encoded)
  console.log(decoded) // 65536
})

API

buffer = encode(number[, buffer[, offset]])

Encode a number optionally into buffer at an optionally specified offset.

number = decode(buffer[, offset])

Decode an input buffer into an integer optionally an optionally specified offset.

promise = ready(callback)

Returns a promise that resolves or rejects when the WebAssembly exports are loading. In some cases, this may happen synchronously when this module is loaded.

await b64.ready()

Limits

Max Integer

Because 32-bit integers are only supported in WASM at the time of writing, you can only encode numbers up 2**31 -1.

Initial Memory

By default, this module allocates 2 pages of memory for the WebAssembly module. That is 2 * 64 * 1024 bytes.

Maximum Memory

This module allows at most 256 pages of memory. That is 256 * 64 * 1024 bytes.

See Also

• https://github.com/chrisdickinson/varint

License

MIT