@polkadot/types-codec
Version:
Implementation of the SCALE codec
47 lines (46 loc) • 1.6 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.U8aFixed = void 0;
const util_1 = require("@polkadot/util");
const Raw_js_1 = require("../native/Raw.js");
/** @internal */
function decodeU8aFixed(value, bitLength) {
const u8a = (0, util_1.u8aToU8a)(value);
const byteLength = bitLength / 8;
if (!u8a.length) {
return [new Uint8Array(byteLength), 0];
}
if ((0, util_1.isU8a)(value) ? u8a.length < byteLength : u8a.length !== byteLength) {
throw new Error(`Expected input with ${byteLength} bytes (${bitLength} bits), found ${u8a.length} bytes`);
}
return [u8a.subarray(0, byteLength), byteLength];
}
/**
* @name U8aFixed
* @description
* A U8a that manages a a sequence of bytes up to the specified bitLength. Not meant
* to be used directly, rather is should be subclassed with the specific lengths.
*/
class U8aFixed extends Raw_js_1.Raw {
constructor(registry, value = new Uint8Array(), bitLength = 256) {
const [u8a, decodedLength] = decodeU8aFixed(value, bitLength);
super(registry, u8a, decodedLength);
}
static with(bitLength, typeName) {
return class extends U8aFixed {
constructor(registry, value) {
super(registry, value, bitLength);
}
toRawType() {
return typeName || super.toRawType();
}
};
}
/**
* @description Returns the base runtime type name for this instance
*/
toRawType() {
return `[u8;${this.length}]`;
}
}
exports.U8aFixed = U8aFixed;