@ton/core/src/utils/bitsForNumber.ts

Core TypeScript library that implements low level primitives for TON blockchain.

/**
 * Copyright (c) Whales Corp. 
 * All Rights Reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

export function bitsForNumber(src: bigint | number, mode: 'int' | 'uint'): number {
    let v = BigInt(src);

    // Handle negative values
    if (mode === 'int') {

        // Corner case for zero or -1 value
        if (v === 0n || v === -1n) {
            return 1;
        }

        let v2 = v > 0 ? v : -v;
        return (v2.toString(2).length + 1/* Sign bit */);
    } else if (mode === 'uint') {
        if (v < 0) {
            throw Error(`value is negative. Got ${src}`);
        }
        return (v.toString(2).length);
    } else {
        throw Error(`invalid mode. Got ${mode}`);
    }
}