@polkadot/types-codec
Version:
Implementation of the SCALE codec
227 lines (226 loc) • 8.55 kB
JavaScript
import { BN, BN_BILLION, BN_HUNDRED, BN_MILLION, BN_QUINTILL, bnToBn, bnToHex, bnToU8a, formatBalance, formatNumber, hexToBn, isBigInt, isBn, isFunction, isHex, isNumber, isObject, isString, isU8a, u8aToBn, u8aToNumber } from '@polkadot/util';
export const DEFAULT_UINT_BITS = 64;
const MAX_NUMBER_BITS = 52;
const MUL_P = new BN(1_00_00);
const FORMATTERS = [
['Perquintill', BN_QUINTILL],
['Perbill', BN_BILLION],
['Permill', BN_MILLION],
['Percent', BN_HUNDRED]
];
function isToBn(value) {
return isFunction(value.toBn);
}
function toPercentage(value, divisor) {
return `${(value.mul(MUL_P).div(divisor).toNumber() / 100).toFixed(2)}%`;
}
/** @internal */
function decodeAbstractInt(value, isNegative) {
if (isNumber(value)) {
if (!Number.isInteger(value) || value > Number.MAX_SAFE_INTEGER || value < Number.MIN_SAFE_INTEGER) {
throw new Error('Number needs to be an integer <= Number.MAX_SAFE_INTEGER, i.e. 2 ^ 53 - 1');
}
return value;
}
else if (isString(value)) {
if (isHex(value, -1, true)) {
return hexToBn(value, { isLe: false, isNegative }).toString();
}
if (value.includes('.') || value.includes(',') || value.includes('e')) {
throw new Error('String should not contain decimal points or scientific notation');
}
return value;
}
else if (isBn(value) || isBigInt(value)) {
return value.toString();
}
else if (isObject(value)) {
if (isToBn(value)) {
return value.toBn().toString();
}
// Allow the construction from an object with a single top-level key. This means that
// single key objects can be treated equivalently to numbers, assuming they meet the
// specific requirements. (This is useful in Weights 1.5 where Objects are compact)
const keys = Object.keys(value);
if (keys.length !== 1) {
throw new Error('Unable to construct number from multi-key object');
}
return decodeAbstractInt(value[keys[0]], isNegative);
}
else if (!value) {
return 0;
}
throw new Error(`Unable to create BN from unknown type ${typeof value}`);
}
/**
* @name AbstractInt
* @ignore
* @noInheritDoc
*/
export class AbstractInt extends BN {
registry;
encodedLength;
isUnsigned;
createdAtHash;
initialU8aLength;
isStorageFallback;
__internal__bitLength;
constructor(registry, value = 0, bitLength = DEFAULT_UINT_BITS, isSigned = false) {
// Construct via a string/number, which will be passed in the BN constructor.
// It would be ideal to actually return a BN, but there is an issue:
// https://github.com/indutny/bn.js/issues/206
super(
// shortcut isU8a as used in SCALE decoding
isU8a(value)
? bitLength <= 48
? u8aToNumber(value.subarray(0, bitLength / 8), { isNegative: isSigned })
: u8aToBn(value.subarray(0, bitLength / 8), { isLe: true, isNegative: isSigned }).toString()
: decodeAbstractInt(value, isSigned));
this.registry = registry;
this.__internal__bitLength = bitLength;
this.encodedLength = this.__internal__bitLength / 8;
this.initialU8aLength = this.__internal__bitLength / 8;
this.isUnsigned = !isSigned;
const isNegative = this.isNeg();
const maxBits = bitLength - (isSigned && !isNegative ? 1 : 0);
if (isNegative && !isSigned) {
throw new Error(`${this.toRawType()}: Negative number passed to unsigned type`);
}
else if (super.bitLength() > maxBits) {
throw new Error(`${this.toRawType()}: Input too large. Found input with ${super.bitLength()} bits, expected ${maxBits}`);
}
}
/**
* @description returns a hash of the contents
*/
get hash() {
return this.registry.hash(this.toU8a());
}
/**
* @description Checks if the value is a zero value (align elsewhere)
*/
get isEmpty() {
return this.isZero();
}
/**
* @description Returns the number of bits in the value
*/
bitLength() {
return this.__internal__bitLength;
}
/**
* @description Compares the value of the input to see if there is a match
*/
// eslint-disable-next-line @typescript-eslint/no-explicit-any
eq(other) {
// Here we are actually overriding the built-in .eq to take care of both
// number and BN inputs (no `.eqn` needed) - numbers will be converted
return super.eq(isHex(other)
? hexToBn(other.toString(), { isLe: false, isNegative: !this.isUnsigned })
: bnToBn(other));
}
/**
* @description Returns a breakdown of the hex encoding for this Codec
*/
inspect() {
return {
outer: [this.toU8a()]
};
}
/**
* @description True if this value is the max of the type
*/
isMax() {
const u8a = this.toU8a().filter((b) => b === 0xff);
return u8a.length === (this.__internal__bitLength / 8);
}
/**
* @description Returns a BigInt representation of the number
*/
toBigInt() {
return BigInt(this.toString());
}
/**
* @description Returns the BN representation of the number. (Compatibility)
*/
toBn() {
return this;
}
/**
* @description Returns a hex string representation of the value
*/
toHex(isLe = false) {
// For display/JSON, this is BE, for compare, use isLe
return bnToHex(this, {
bitLength: this.bitLength(),
isLe,
isNegative: !this.isUnsigned
});
}
/**
* @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
*/
toHuman(_isExpanded) {
const rawType = this.toRawType();
if (rawType === 'Balance') {
return this.isMax()
? 'everything'
// FIXME In the case of multiples we need some way of detecting which instance this belongs
// to. as it stands we will always format (incorrectly) against the first token defined
: formatBalance(this, { decimals: this.registry.chainDecimals[0], withSi: true, withUnit: this.registry.chainTokens[0] });
}
const [, divisor] = FORMATTERS.find(([type]) => type === rawType) || [];
return divisor
? toPercentage(this, divisor)
: formatNumber(this);
}
/**
* @description Converts the Object to JSON, typically used for RPC transfers
*/
toJSON(onlyHex = false) {
// FIXME this return type should by string | number, however BN returns string
// Options here are
// - super.bitLength() - the actual used bits, use hex when close to MAX_SAFE_INTEGER
// - this.__internal__bitLength - the max used bits, use hex when larger than native Rust type
return onlyHex || (this.__internal__bitLength > 128) || (super.bitLength() > MAX_NUMBER_BITS)
? this.toHex()
: this.toNumber();
}
/**
* @description Returns the value in a primitive form, either number when <= 52 bits, or string otherwise
*/
toPrimitive() {
return super.bitLength() > MAX_NUMBER_BITS
? this.toString()
: this.toNumber();
}
/**
* @description Returns the base runtime type name for this instance
*/
toRawType() {
// NOTE In the case of balances, which have a special meaning on the UI
// and can be interpreted differently, return a specific value for it so
// underlying it always matches (no matter which length it actually is)
return this instanceof this.registry.createClassUnsafe('Balance')
? 'Balance'
: `${this.isUnsigned ? 'u' : 'i'}${this.bitLength()}`;
}
/**
* @description Returns the string representation of the value
* @param base The base to use for the conversion
*/
toString(base) {
// only included here since we do not inherit docs
return super.toString(base);
}
/**
* @description Encodes the value as a Uint8Array as per the SCALE specifications
*/
toU8a(_isBare) {
return bnToU8a(this, {
bitLength: this.bitLength(),
isLe: true,
isNegative: !this.isUnsigned
});
}
}