Align any given number to the nearest specified amount of bits or bytes

data-align.js

/**
 * Returns a number that is n-bits aligned, where n is the number of bits specified
 * @param x The input number to be aligned
 * @param bits The amount of bits to align the number to
 * @returns `x` aligned to the nearest n-bits, where `n` is the specified amount of bits
 */
function alignToBits(x, bits) {
    return (x + (bits - 1)) & (-1 * bits);
}

/**
 * Returns a number that is n-bytes aligned, where n is the number of bytes specified
 * @param x The input number to be aligned
 * @param bytes The amount of bytes to align the number to
 * @returns `x` aligned to the nearest n-bytes, where `n` is the specified number of bytes
 */
function alignToBytes(x, bytes) {
    return alignToBits(x, bytes * 8);
}

/*

EXAMPLES:
==========

// Align numbers to the nearest 8 bit value
alignToBits( 1,  8) => 8
alignToBits( 2,  8) => 8
alignToBits( 3,  8) => 8
// ...
alignToBits( 8,  8) => 8
alignToBits( 9,  8) => 16
alignToBits(10,  8) => 16

// Align numbers to the nearest 2 byte value
alignToBytes( 1, 2) => 16
alignToBytes( 2, 2) => 16
// ...
alignToBytes(15, 2) => 16
alignToBytes(16, 2) => 16
alignToBytes(17, 2) => 32

*/