@btc-vision/transaction/src/utils/BufferHelper.ts

OPNet transaction library allows you to create and sign transactions for the OPNet network.

import { U256_BYTE_LENGTH } from './lengths.js';
import { MemorySlotPointer } from './types.js';

export class BufferHelper {
    public static readonly EXPECTED_BUFFER_LENGTH: number = 32;

    public static bufferToUint8Array(buffer: Buffer | Uint8Array): Uint8Array {
        if (Buffer.isBuffer(buffer)) {
            const length: number = buffer.byteLength;
            const arrayBuffer: ArrayBuffer = new ArrayBuffer(length);

            const view: Uint8Array = new Uint8Array(arrayBuffer);
            for (let i = 0; i < length; ++i) {
                view[i] = buffer[i];
            }

            return view;
        }

        return buffer;
    }

    public static uint8ArrayToHex(input: Uint8Array): string {
        return Buffer.from(input.buffer, 0, input.byteLength).toString('hex');
    }

    public static hexToUint8Array(input: string): Uint8Array {
        if (input.startsWith('0x')) {
            input = input.substring(2); // Remove the '0x' prefix
        }

        if (input.length % 2 !== 0) {
            input = '0' + input; // Pad with a leading zero if the length is odd
        }

        const lengthS = input.length / 2;
        const buffer = new Uint8Array(lengthS);

        for (let i = 0; i < lengthS; i++) {
            buffer[i] = parseInt(input.substring(i * 2, i * 2 + 2), 16);
        }

        return buffer;
    }

    public static pointerToUint8Array(pointer: MemorySlotPointer): Uint8Array {
        const pointerHex = pointer.toString(16).padStart(64, '0');

        return BufferHelper.hexToUint8Array(pointerHex);
    }

    public static uint8ArrayToPointer(input: Uint8Array): MemorySlotPointer {
        const hex = BufferHelper.uint8ArrayToHex(input);

        return BigInt('0x' + hex);
    }

    public static valueToUint8Array(value: bigint, length: number = U256_BYTE_LENGTH): Uint8Array {
        const valueHex = value.toString(16).padStart(length * 2, '0');

        return BufferHelper.hexToUint8Array(valueHex);
    }

    public static uint8ArrayToValue(input: Uint8Array): bigint {
        const hex = BufferHelper.uint8ArrayToHex(input);

        if (!hex) return BigInt(0);

        return BigInt('0x' + hex);
    }
}