ethers.js/packages/bignumber/src.ts/bignumber.ts
2021-04-19 20:09:39 -04:00

370 lines
10 KiB
TypeScript

"use strict";
/**
* BigNumber
*
* A wrapper around the BN.js object. We use the BN.js library
* because it is used by elliptic, so it is required regardless.
*
*/
import _BN from "bn.js";
import BN = _BN.BN;
import { Bytes, Hexable, hexlify, isBytes, isHexString } from "@ethersproject/bytes";
import { Logger } from "@ethersproject/logger";
import { version } from "./_version";
const logger = new Logger(version);
const _constructorGuard = { };
const MAX_SAFE = 0x1fffffffffffff;
export type BigNumberish = BigNumber | Bytes | string | number;
export function isBigNumberish(value: any): value is BigNumberish {
return (value != null) && (
BigNumber.isBigNumber(value) ||
(typeof(value) === "number" && (value % 1) === 0) ||
(typeof(value) === "string" && !!value.match(/^-?[0-9]+$/)) ||
isHexString(value) ||
(typeof(value) === "bigint") ||
isBytes(value)
);
}
// Only warn about passing 10 into radix once
let _warnedToStringRadix = false;
export class BigNumber implements Hexable {
readonly _hex: string;
readonly _isBigNumber: boolean;
constructor(constructorGuard: any, hex: string) {
logger.checkNew(new.target, BigNumber);
if (constructorGuard !== _constructorGuard) {
logger.throwError("cannot call constructor directly; use BigNumber.from", Logger.errors.UNSUPPORTED_OPERATION, {
operation: "new (BigNumber)"
});
}
this._hex = hex;
this._isBigNumber = true;
Object.freeze(this);
}
fromTwos(value: number): BigNumber {
return toBigNumber(toBN(this).fromTwos(value));
}
toTwos(value: number): BigNumber {
return toBigNumber(toBN(this).toTwos(value));
}
abs(): BigNumber {
if (this._hex[0] === "-") {
return BigNumber.from(this._hex.substring(1));
}
return this;
}
add(other: BigNumberish): BigNumber {
return toBigNumber(toBN(this).add(toBN(other)));
}
sub(other: BigNumberish): BigNumber {
return toBigNumber(toBN(this).sub(toBN(other)));
}
div(other: BigNumberish): BigNumber {
const o = BigNumber.from(other);
if (o.isZero()) {
throwFault("division by zero", "div");
}
return toBigNumber(toBN(this).div(toBN(other)));
}
mul(other: BigNumberish): BigNumber {
return toBigNumber(toBN(this).mul(toBN(other)));
}
mod(other: BigNumberish): BigNumber {
const value = toBN(other);
if (value.isNeg()) {
throwFault("cannot modulo negative values", "mod");
}
return toBigNumber(toBN(this).umod(value));
}
pow(other: BigNumberish): BigNumber {
const value = toBN(other);
if (value.isNeg()) {
throwFault("cannot raise to negative values", "pow");
}
return toBigNumber(toBN(this).pow(value));
}
and(other: BigNumberish): BigNumber {
const value = toBN(other);
if (this.isNegative() || value.isNeg()) {
throwFault("cannot 'and' negative values", "and");
}
return toBigNumber(toBN(this).and(value));
}
or(other: BigNumberish): BigNumber {
const value = toBN(other);
if (this.isNegative() || value.isNeg()) {
throwFault("cannot 'or' negative values", "or");
}
return toBigNumber(toBN(this).or(value));
}
xor(other: BigNumberish): BigNumber {
const value = toBN(other);
if (this.isNegative() || value.isNeg()) {
throwFault("cannot 'xor' negative values", "xor");
}
return toBigNumber(toBN(this).xor(value));
}
mask(value: number): BigNumber {
if (this.isNegative() || value < 0) {
throwFault("cannot mask negative values", "mask");
}
return toBigNumber(toBN(this).maskn(value));
}
shl(value: number): BigNumber {
if (this.isNegative() || value < 0) {
throwFault("cannot shift negative values", "shl");
}
return toBigNumber(toBN(this).shln(value));
}
shr(value: number): BigNumber {
if (this.isNegative() || value < 0) {
throwFault("cannot shift negative values", "shr");
}
return toBigNumber(toBN(this).shrn(value));
}
eq(other: BigNumberish): boolean {
return toBN(this).eq(toBN(other));
}
lt(other: BigNumberish): boolean {
return toBN(this).lt(toBN(other));
}
lte(other: BigNumberish): boolean {
return toBN(this).lte(toBN(other));
}
gt(other: BigNumberish): boolean {
return toBN(this).gt(toBN(other));
}
gte(other: BigNumberish): boolean {
return toBN(this).gte(toBN(other));
}
isNegative(): boolean {
return (this._hex[0] === "-");
}
isZero(): boolean {
return toBN(this).isZero();
}
toNumber(): number {
try {
return toBN(this).toNumber();
} catch (error) {
throwFault("overflow", "toNumber", this.toString());
}
return null;
}
toBigInt(): bigint {
try {
return BigInt(this.toString());
} catch (e) { }
return logger.throwError("this platform does not support BigInt", Logger.errors.UNSUPPORTED_OPERATION, {
value: this.toString()
});
}
toString(): string {
// Lots of people expect this, which we do not support, so check (See: #889)
if (arguments.length > 0) {
if (arguments[0] === 10) {
if (!_warnedToStringRadix) {
_warnedToStringRadix = true;
logger.warn("BigNumber.toString does not accept any parameters; base-10 is assumed");
}
} else if (arguments[0] === 16) {
logger.throwError("BigNumber.toString does not accept any parameters; use bigNumber.toHexString()", Logger.errors.UNEXPECTED_ARGUMENT, { });
} else {
logger.throwError("BigNumber.toString does not accept parameters", Logger.errors.UNEXPECTED_ARGUMENT, { });
}
}
return toBN(this).toString(10);
}
toHexString(): string {
return this._hex;
}
toJSON(key?: string): any {
return { type: "BigNumber", hex: this.toHexString() };
}
static from(value: any): BigNumber {
if (value instanceof BigNumber) { return value; }
if (typeof(value) === "string") {
if (value.match(/^-?0x[0-9a-f]+$/i)) {
return new BigNumber(_constructorGuard, toHex(value));
}
if (value.match(/^-?[0-9]+$/)) {
return new BigNumber(_constructorGuard, toHex(new BN(value)));
}
return logger.throwArgumentError("invalid BigNumber string", "value", value);
}
if (typeof(value) === "number") {
if (value % 1) {
throwFault("underflow", "BigNumber.from", value);
}
if (value >= MAX_SAFE || value <= -MAX_SAFE) {
throwFault("overflow", "BigNumber.from", value);
}
return BigNumber.from(String(value));
}
const anyValue = <any>value;
if (typeof(anyValue) === "bigint") {
return BigNumber.from(anyValue.toString());
}
if (isBytes(anyValue)) {
return BigNumber.from(hexlify(anyValue));
}
if (anyValue) {
// Hexable interface (takes piority)
if (anyValue.toHexString) {
const hex = anyValue.toHexString();
if (typeof(hex) === "string") {
return BigNumber.from(hex);
}
} else {
// For now, handle legacy JSON-ified values (goes away in v6)
let hex = anyValue._hex;
// New-form JSON
if (hex == null && anyValue.type === "BigNumber") {
hex = anyValue.hex;
}
if (typeof(hex) === "string") {
if (isHexString(hex) || (hex[0] === "-" && isHexString(hex.substring(1)))) {
return BigNumber.from(hex);
}
}
}
}
return logger.throwArgumentError("invalid BigNumber value", "value", value);
}
static isBigNumber(value: any): value is BigNumber {
return !!(value && value._isBigNumber);
}
}
// Normalize the hex string
function toHex(value: string | BN): string {
// For BN, call on the hex string
if (typeof(value) !== "string") {
return toHex(value.toString(16));
}
// If negative, prepend the negative sign to the normalized positive value
if (value[0] === "-") {
// Strip off the negative sign
value = value.substring(1);
// Cannot have mulitple negative signs (e.g. "--0x04")
if (value[0] === "-") { logger.throwArgumentError("invalid hex", "value", value); }
// Call toHex on the positive component
value = toHex(value);
// Do not allow "-0x00"
if (value === "0x00") { return value; }
// Negate the value
return "-" + value;
}
// Add a "0x" prefix if missing
if (value.substring(0, 2) !== "0x") { value = "0x" + value; }
// Normalize zero
if (value === "0x") { return "0x00"; }
// Make the string even length
if (value.length % 2) { value = "0x0" + value.substring(2); }
// Trim to smallest even-length string
while (value.length > 4 && value.substring(0, 4) === "0x00") {
value = "0x" + value.substring(4);
}
return value;
}
function toBigNumber(value: BN): BigNumber {
return BigNumber.from(toHex(value));
}
function toBN(value: BigNumberish): BN {
const hex = BigNumber.from(value).toHexString();
if (hex[0] === "-") {
return (new BN("-" + hex.substring(3), 16));
}
return new BN(hex.substring(2), 16);
}
function throwFault(fault: string, operation: string, value?: any): never {
const params: any = { fault: fault, operation: operation };
if (value != null) { params.value = value; }
return logger.throwError(fault, Logger.errors.NUMERIC_FAULT, params);
}
// value should have no prefix
export function _base36To16(value: string): string {
return (new BN(value, 36)).toString(16);
}
// value should have no prefix
export function _base16To36(value: string): string {
return (new BN(value, 16)).toString(36);
}