Varint

encode whole numbers to an array of protobuf-style Varint bytes and also decode them.

import { Varint } from "https://code4fukui.github.io/Varint/Varint.js";

const bytes = Varint.encode(300) // === [172, 2]
console.log(bytes);
const n = Varint.decode(bytes);
console.log(n); // 300
console.log(Varint.length(n)); // 2

api

Varint.encode(num[, buffer=[], offset=0]) -> Uint8Array

Encodes num into buffer starting at offset. returns buffer, with the encoded Varint written into it. If buffer is not provided, it will default to a new array.

Varint.encode.bytes will now be set to the number of bytes modified.

Varint.decode(data[, offset=0]) -> number

decodes data, which can be either a buffer or array of integers, from position offset or default 0 and returns the decoded original integer.

Throws a RangeError when data does not represent a valid encoding.

Varint.encodingLength(num)

returns the number of bytes this number will be encoded as, up to a maximum of 8.

usage notes

If Varint is passed a buffer that does not contain a valid end byte, then decode will throw RangeError, and decode.bytes will be set to 0. If you are reading from a streaming source, it's okay to pass an incomplete buffer into decode, detect this case, and then concatenate the next buffer.

License

MIT