ethers.js/packages/bignumber/src.ts/fixednumber.ts

403 lines
13 KiB
TypeScript

"use strict";
import { arrayify, BytesLike, hexZeroPad, isBytes } from "@ethersproject/bytes";
import { Logger } from "@ethersproject/logger";
import { version } from "./_version";
const logger = new Logger(version);
import { BigNumber, BigNumberish, isBigNumberish } from "./bignumber";
const _constructorGuard = { };
const Zero = BigNumber.from(0);
const NegativeOne = BigNumber.from(-1);
function throwFault(message: string, fault: string, operation: string, value?: any): never {
const params: any = { fault: fault, operation: operation };
if (value !== undefined) { params.value = value; }
return logger.throwError(message, Logger.errors.NUMERIC_FAULT, params);
}
// Constant to pull zeros from for multipliers
let zeros = "0";
while (zeros.length < 256) { zeros += zeros; }
// Returns a string "1" followed by decimal "0"s
function getMultiplier(decimals: BigNumberish): string {
if (typeof(decimals) !== "number") {
try {
decimals = BigNumber.from(decimals).toNumber();
} catch (e) { }
}
if (typeof(decimals) === "number" && decimals >= 0 && decimals <= 256 && !(decimals % 1)) {
return ("1" + zeros.substring(0, decimals));
}
return logger.throwArgumentError("invalid decimal size", "decimals", decimals);
}
export function formatFixed(value: BigNumberish, decimals?: string | BigNumberish): string {
if (decimals == null) { decimals = 0; }
const multiplier = getMultiplier(decimals);
// Make sure wei is a big number (convert as necessary)
value = BigNumber.from(value);
const negative = value.lt(Zero);
if (negative) { value = value.mul(NegativeOne); }
let fraction = value.mod(multiplier).toString();
while (fraction.length < multiplier.length - 1) { fraction = "0" + fraction; }
// Strip training 0
fraction = fraction.match(/^([0-9]*[1-9]|0)(0*)/)[1];
const whole = value.div(multiplier).toString();
if (multiplier.length === 1) {
value = whole;
} else {
value = whole + "." + fraction;
}
if (negative) { value = "-" + value; }
return value;
}
export function parseFixed(value: string, decimals?: BigNumberish): BigNumber {
if (decimals == null) { decimals = 0; }
const multiplier = getMultiplier(decimals);
if (typeof(value) !== "string" || !value.match(/^-?[0-9.,]+$/)) {
logger.throwArgumentError("invalid decimal value", "value", value);
}
// Is it negative?
const negative = (value.substring(0, 1) === "-");
if (negative) { value = value.substring(1); }
if (value === ".") {
logger.throwArgumentError("missing value", "value", value);
}
// Split it into a whole and fractional part
const comps = value.split(".");
if (comps.length > 2) {
logger.throwArgumentError("too many decimal points", "value", value);
}
let whole = comps[0], fraction = comps[1];
if (!whole) { whole = "0"; }
if (!fraction) { fraction = "0"; }
// Get significant digits to check truncation for underflow
{
const sigFraction = fraction.replace(/^([0-9]*?)(0*)$/, (all, sig, zeros) => (sig));
if (sigFraction.length > multiplier.length - 1) {
throwFault("fractional component exceeds decimals", "underflow", "parseFixed");
}
}
// Fully pad the string with zeros to get to wei
while (fraction.length < multiplier.length - 1) { fraction += "0"; }
const wholeValue = BigNumber.from(whole);
const fractionValue = BigNumber.from(fraction);
let wei = (wholeValue.mul(multiplier)).add(fractionValue);
if (negative) { wei = wei.mul(NegativeOne); }
return wei;
}
export class FixedFormat {
readonly signed: boolean;
readonly width: number;
readonly decimals: number;
readonly name: string;
readonly _multiplier: string;
constructor(constructorGuard: any, signed: boolean, width: number, decimals: number) {
if (constructorGuard !== _constructorGuard) {
logger.throwError("cannot use FixedFormat constructor; use FixedFormat.from", Logger.errors.UNSUPPORTED_OPERATION, {
operation: "new FixedFormat"
});
}
this.signed = signed;
this.width = width;
this.decimals = decimals;
this.name = (signed ? "": "u") + "fixed" + String(width) + "x" + String(decimals);
this._multiplier = getMultiplier(decimals);
Object.freeze(this);
}
static from(value: any): FixedFormat {
if (value instanceof FixedFormat) { return value; }
if (typeof(value) === "number") {
value = `fixed128x${value}`
}
let signed = true;
let width = 128;
let decimals = 18;
if (typeof(value) === "string") {
if (value === "fixed") {
// defaults...
} else if (value === "ufixed") {
signed = false;
} else {
const match = value.match(/^(u?)fixed([0-9]+)x([0-9]+)$/);
if (!match) { logger.throwArgumentError("invalid fixed format", "format", value); }
signed = (match[1] !== "u");
width = parseInt(match[2]);
decimals = parseInt(match[3]);
}
} else if (value) {
const check = (key: string, type: string, defaultValue: any): any => {
if (value[key] == null) { return defaultValue; }
if (typeof(value[key]) !== type) {
logger.throwArgumentError("invalid fixed format (" + key + " not " + type +")", "format." + key, value[key]);
}
return value[key];
}
signed = check("signed", "boolean", signed);
width = check("width", "number", width);
decimals = check("decimals", "number", decimals);
}
if (width % 8) {
logger.throwArgumentError("invalid fixed format width (not byte aligned)", "format.width", width);
}
if (decimals > 80) {
logger.throwArgumentError("invalid fixed format (decimals too large)", "format.decimals", decimals);
}
return new FixedFormat(_constructorGuard, signed, width, decimals);
}
}
export class FixedNumber {
readonly format: FixedFormat;
readonly _hex: string;
readonly _value: string;
readonly _isFixedNumber: boolean;
constructor(constructorGuard: any, hex: string, value: string, format?: FixedFormat) {
logger.checkNew(new.target, FixedNumber);
if (constructorGuard !== _constructorGuard) {
logger.throwError("cannot use FixedNumber constructor; use FixedNumber.from", Logger.errors.UNSUPPORTED_OPERATION, {
operation: "new FixedFormat"
});
}
this.format = format;
this._hex = hex;
this._value = value;
this._isFixedNumber = true;
Object.freeze(this);
}
_checkFormat(other: FixedNumber): void {
if (this.format.name !== other.format.name) {
logger.throwArgumentError("incompatible format; use fixedNumber.toFormat", "other", other);
}
}
addUnsafe(other: FixedNumber): FixedNumber {
this._checkFormat(other);
const a = parseFixed(this._value, this.format.decimals);
const b = parseFixed(other._value, other.format.decimals);
return FixedNumber.fromValue(a.add(b), this.format.decimals, this.format);
}
subUnsafe(other: FixedNumber): FixedNumber {
this._checkFormat(other);
const a = parseFixed(this._value, this.format.decimals);
const b = parseFixed(other._value, other.format.decimals);
return FixedNumber.fromValue(a.sub(b), this.format.decimals, this.format);
}
mulUnsafe(other: FixedNumber): FixedNumber {
this._checkFormat(other);
const a = parseFixed(this._value, this.format.decimals);
const b = parseFixed(other._value, other.format.decimals);
return FixedNumber.fromValue(a.mul(b).div(this.format._multiplier), this.format.decimals, this.format);
}
divUnsafe(other: FixedNumber): FixedNumber {
this._checkFormat(other);
const a = parseFixed(this._value, this.format.decimals);
const b = parseFixed(other._value, other.format.decimals);
return FixedNumber.fromValue(a.mul(this.format._multiplier).div(b), this.format.decimals, this.format);
}
floor(): FixedNumber {
const comps = this.toString().split(".");
if (comps.length === 1) { comps.push("0"); }
let result = FixedNumber.from(comps[0], this.format);
const hasFraction = !comps[1].match(/^(0*)$/);
if (this.isNegative() && hasFraction) {
result = result.subUnsafe(ONE);
}
return result;
}
ceiling(): FixedNumber {
const comps = this.toString().split(".");
if (comps.length === 1) { comps.push("0"); }
let result = FixedNumber.from(comps[0], this.format);
const hasFraction = !comps[1].match(/^(0*)$/);
if (!this.isNegative() && hasFraction) {
result = result.addUnsafe(ONE);
}
return result;
}
// @TODO: Support other rounding algorithms
round(decimals?: number): FixedNumber {
if (decimals == null) { decimals = 0; }
// If we are already in range, we're done
const comps = this.toString().split(".");
if (comps.length === 1) { comps.push("0"); }
if (decimals < 0 || decimals > 80 || (decimals % 1)) {
logger.throwArgumentError("invalid decimal count", "decimals", decimals);
}
if (comps[1].length <= decimals) { return this; }
const factor = FixedNumber.from("1" + zeros.substring(0, decimals));
return this.mulUnsafe(factor).addUnsafe(BUMP).floor().divUnsafe(factor);
}
isZero(): boolean {
return (this._value === "0.0" || this._value === "0");
}
isNegative(): boolean {
return (this._value[0] === "-");
}
toString(): string { return this._value; }
toHexString(width?: number): string {
if (width == null) { return this._hex; }
if (width % 8) { logger.throwArgumentError("invalid byte width", "width", width); }
const hex = BigNumber.from(this._hex).fromTwos(this.format.width).toTwos(width).toHexString();
return hexZeroPad(hex, width / 8);
}
toUnsafeFloat(): number { return parseFloat(this.toString()); }
toFormat(format: FixedFormat | string): FixedNumber {
return FixedNumber.fromString(this._value, format);
}
static fromValue(value: BigNumber, decimals?: BigNumberish, format?: FixedFormat | string | number): FixedNumber {
// If decimals looks more like a format, and there is no format, shift the parameters
if (format == null && decimals != null && !isBigNumberish(decimals)) {
format = decimals;
decimals = null;
}
if (decimals == null) { decimals = 0; }
if (format == null) { format = "fixed"; }
return FixedNumber.fromString(formatFixed(value, decimals), FixedFormat.from(format));
}
static fromString(value: string, format?: FixedFormat | string | number): FixedNumber {
if (format == null) { format = "fixed"; }
const fixedFormat = FixedFormat.from(format);
const numeric = parseFixed(value, fixedFormat.decimals);
if (!fixedFormat.signed && numeric.lt(Zero)) {
throwFault("unsigned value cannot be negative", "overflow", "value", value);
}
let hex: string = null;
if (fixedFormat.signed) {
hex = numeric.toTwos(fixedFormat.width).toHexString();
} else {
hex = numeric.toHexString();
hex = hexZeroPad(hex, fixedFormat.width / 8);
}
const decimal = formatFixed(numeric, fixedFormat.decimals);
return new FixedNumber(_constructorGuard, hex, decimal, fixedFormat);
}
static fromBytes(value: BytesLike, format?: FixedFormat | string | number): FixedNumber {
if (format == null) { format = "fixed"; }
const fixedFormat = FixedFormat.from(format);
if (arrayify(value).length > fixedFormat.width / 8) {
throw new Error("overflow");
}
let numeric = BigNumber.from(value);
if (fixedFormat.signed) { numeric = numeric.fromTwos(fixedFormat.width); }
const hex = numeric.toTwos((fixedFormat.signed ? 0: 1) + fixedFormat.width).toHexString();
const decimal = formatFixed(numeric, fixedFormat.decimals);
return new FixedNumber(_constructorGuard, hex, decimal, fixedFormat);
}
static from(value: any, format?: FixedFormat | string | number) {
if (typeof(value) === "string") {
return FixedNumber.fromString(value, format);
}
if (isBytes(value)) {
return FixedNumber.fromBytes(value, format);
}
try {
return FixedNumber.fromValue(value, 0, format);
} catch (error) {
// Allow NUMERIC_FAULT to bubble up
if (error.code !== Logger.errors.INVALID_ARGUMENT) {
throw error;
}
}
return logger.throwArgumentError("invalid FixedNumber value", "value", value);
}
static isFixedNumber(value: any): value is FixedNumber {
return !!(value && value._isFixedNumber);
}
}
const ONE = FixedNumber.from(1);
const BUMP = FixedNumber.from("0.5");