@metaplex-foundation/umi-serializers-core/src/bytes.ts

Core types and helpers for UMI serializers

/**
 * Concatenates an array of `Uint8Array`s into a single `Uint8Array`.
 * @category Utils
 */
export const mergeBytes = (bytesArr: Uint8Array[]): Uint8Array => {
  const totalLength = bytesArr.reduce((total, arr) => total + arr.length, 0);
  const result = new Uint8Array(totalLength);
  let offset = 0;
  bytesArr.forEach((arr) => {
    result.set(arr, offset);
    offset += arr.length;
  });
  return result;
};

/**
 * Pads a `Uint8Array` with zeroes to the specified length.
 * If the array is longer than the specified length, it is returned as-is.
 * @category Utils
 */
export const padBytes = (bytes: Uint8Array, length: number): Uint8Array => {
  if (bytes.length >= length) return bytes;
  const paddedBytes = new Uint8Array(length).fill(0);
  paddedBytes.set(bytes);
  return paddedBytes;
};

/**
 * Fixes a `Uint8Array` to the specified length.
 * If the array is longer than the specified length, it is truncated.
 * If the array is shorter than the specified length, it is padded with zeroes.
 * @category Utils
 */
export const fixBytes = (bytes: Uint8Array, length: number): Uint8Array =>
  padBytes(bytes.slice(0, length), length);