@polkadot/types
Version:
Implementation of the Parity codec
111 lines (110 loc) • 3.55 kB
JavaScript
import { u32 } from '@polkadot/types-codec';
import { BN, bnToBn, isBigInt, isBn, isHex, isNumber, isU8a } from '@polkadot/util';
import { decodeAddress, encodeAddress } from '@polkadot/util-crypto';
const PREFIX_1BYTE = 0xef;
const PREFIX_2BYTE = 0xfc;
const PREFIX_4BYTE = 0xfd;
const PREFIX_8BYTE = 0xfe;
const MAX_1BYTE = new BN(PREFIX_1BYTE);
const MAX_2BYTE = new BN(1).shln(16);
const MAX_4BYTE = new BN(1).shln(32);
/** @internal */
function decodeAccountIndex(value) {
// eslint-disable-next-line @typescript-eslint/no-use-before-define
if (value instanceof GenericAccountIndex) {
// `value.toBn()` on AccountIndex returns a pure BN (i.e. not an
// AccountIndex), which has the initial `toString()` implementation.
return value.toBn();
}
else if (isBn(value) || isNumber(value) || isHex(value) || isU8a(value) || isBigInt(value)) {
return value;
}
return decodeAccountIndex(decodeAddress(value));
}
/**
* @name GenericAccountIndex
* @description
* A wrapper around an AccountIndex, which is a shortened, variable-length encoding
* for an Account. We extends from [[U32]] to provide the number-like properties.
*/
export class GenericAccountIndex extends u32 {
constructor(registry, value = new BN(0)) {
super(registry, decodeAccountIndex(value));
}
static calcLength(_value) {
const value = bnToBn(_value);
if (value.lte(MAX_1BYTE)) {
return 1;
}
else if (value.lt(MAX_2BYTE)) {
return 2;
}
else if (value.lt(MAX_4BYTE)) {
return 4;
}
return 8;
}
static readLength(input) {
const first = input[0];
if (first === PREFIX_2BYTE) {
return [1, 2];
}
else if (first === PREFIX_4BYTE) {
return [1, 4];
}
else if (first === PREFIX_8BYTE) {
return [1, 8];
}
return [0, 1];
}
static writeLength(input) {
switch (input.length) {
case 2: return new Uint8Array([PREFIX_2BYTE]);
case 4: return new Uint8Array([PREFIX_4BYTE]);
case 8: return new Uint8Array([PREFIX_8BYTE]);
default: return new Uint8Array([]);
}
}
/**
* @description Compares the value of the input to see if there is a match
*/
eq(other) {
// shortcut for BN or Number, don't create an object
if (isBn(other) || isNumber(other)) {
return super.eq(other);
}
// convert and compare
return super.eq(this.registry.createTypeUnsafe('AccountIndex', [other]));
}
/**
* @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
*/
toHuman() {
return this.toJSON();
}
/**
* @description Converts the Object to JSON, typically used for RPC transfers
*/
toJSON() {
return this.toString();
}
/**
* @description Converts the value in a best-fit primitive form
*/
toPrimitive() {
return this.toJSON();
}
/**
* @description Returns the string representation of the value
*/
toString() {
const length = GenericAccountIndex.calcLength(this);
return encodeAddress(this.toU8a().subarray(0, length), this.registry.chainSS58);
}
/**
* @description Returns the base runtime type name for this instance
*/
toRawType() {
return 'AccountIndex';
}
}