protobuf-varint

⚡️

Fast encoding and decoding for all variable protobuf-style varint bytes and also decode them.

• Supports 64bit values using longfn or long.js compatible objects.
• Protocol-buffer compatible for all edge cases
• Codecs for all types: int32, sint32, uint32, int64, sint64 and uint64
• Pure JavaScript
• No dependencies
• TypeScript declaration files 😉

Usage

Encoding

import { uint64 } from 'protobuf-varint'
import { fromBigInt } from 'longfn'

// You can use numbers for the whole uint64 range with the longfn
// lib to be easily created from a variety of formats
const long = fromBigInt(0xffffffffffffffffn)

const fixedEncoder = uint64.fixedEncoder(long)
const buffer = new Uint8Array(
  fixedEncoder.bytes, // The fixedEncoder containst the size needed to write the var-int
)
fixedEncoder.encode(long, buffer, 0) // Profit!

Decoding

// Use a operation object to reduce memory consumption
const target = { low: 0, high: 0, unsigned: false }
uint64.decode(buffer, 0, target)
// `target` now contains the value from the buffer!

uint64.decode.bytes // amount of bytes that were previously read

Backwards Compatibility

Other encoding systems tend to use the encode and encodeLength functions to encode content. This is discouraged because there is nearly no use-case for encode on its own. fixedEncoder removes the need for a set of preconditions checks that would need to be done twice, still you can use encode and encodeLength as with others.

import { encode, encodeLength } from 'protobuf-varint/sint32'

// Note this is deprecated! Use `fixedEncoder`!

const int32 = -1311313
const buffer = new Uint8Array(encodeLength(int32))
encode(int32, buffer, 0)

Flexible Partial Access

Depending on your usage you can choose different variants matching your needs.

import { uint64 } from 'protobuf-varint'
import * as int32 from 'protobuf-varint/int32'
import { fixedEncoder } from 'protobuf-varint/sint64'
import { decode as decodeSInt32 } from 'protobuf-varint/sint32'
import { decode as decodeSInt64 } from 'protobuf-varint/sint64'
import { codecs } from 'protobuf-varint'
codecs.int64

License

MIT