interface ConverterInterface {
toBigInt(buf: Buffer, bigEndian?: boolean): bigint;
fromBigInt(num: BigInt, buf: Buffer, bigEndian?: boolean): Buffer;
}
declare var process: {browser: boolean;};
let converter: ConverterInterface;
if (!process.browser) {
try {
converter = require('bindings')('bigint_buffer');
} catch (e) {
console.warn(
'bigint: Failed to load bindings, pure JS will be used (try npm run rebuild?)');
}
}
/**
* Convert a little-endian buffer into a BigInt.
* @param buf The little-endian buffer to convert
* @returns A BigInt with the little-endian representation of buf.
*/
export function toBigIntLE(buf: Buffer): bigint {
if (process.browser || converter === undefined) {
const reversed = Buffer.from(buf);
reversed.reverse();
const hex = reversed.toString('hex');
if (hex.length === 0) {
return BigInt(0);
}
return BigInt(`0x${hex}`);
}
return converter.toBigInt(buf, false);
}
/**
* Convert a big-endian buffer into a BigInt
* @param buf The big-endian buffer to convert.
* @returns A BigInt with the big-endian representation of buf.
*/
export function toBigIntBE(buf: Buffer): bigint {
if (process.browser || converter === undefined) {
const hex = buf.toString('hex');
if (hex.length === 0) {
return BigInt(0);
}
return BigInt(`0x${hex}`);
}
return converter.toBigInt(buf, true);
}
/**
* Convert a BigInt to a little-endian buffer.
* @param num The BigInt to convert.
* @param width The number of bytes that the resulting buffer should be.
* @returns A little-endian buffer representation of num.
*/
export function toBufferLE(num: bigint, width: number): Buffer {
if (process.browser || converter === undefined) {
const hex = num.toString(16);
const buffer =
Buffer.from(hex.padStart(width * 2, '0').slice(0, width * 2), 'hex');
buffer.reverse();
return buffer;
}
// Allocation is done here, since it is slower using napi in C
return converter.fromBigInt(num, Buffer.allocUnsafe(width), false);
}
/**
* Convert a BigInt to a big-endian buffer.
* @param num The BigInt to convert.
* @param width The number of bytes that the resulting buffer should be.
* @returns A big-endian buffer representation of num.
*/
export function toBufferBE(num: bigint, width: number): Buffer {
if (process.browser || converter === undefined) {
const hex = num.toString(16);
return Buffer.from(hex.padStart(width * 2, '0').slice(0, width * 2), 'hex');
}
return converter.fromBigInt(num, Buffer.allocUnsafe(width), true);
}