@jawis/shared-algs/util.js

Data structures for building concurrent programs.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.equal = exports.align32 = exports.readNumber = exports.writeNumber = void 0;
const _jab_1 = require("^jab");
/**
 *
 * - Writes little endian, because that's easiest.
 * - Checks that the number isn't truncated.
 */
const writeNumber = (target, offset, value, numBytes, errorMessage = "Not enough space for value.") => {
    let tmp = value;
    for (let i = 0; i < numBytes; i++) {
        target[offset + i] = tmp & 0xff;
        tmp = tmp >> 8;
    }
    (0, _jab_1.assert)(tmp === 0, errorMessage, {
        value,
        tmp,
        numBytes,
    });
};
exports.writeNumber = writeNumber;
/**
 *
 */
const readNumber = (source, offset, numBytes) => {
    let value = 0;
    let shift = 0;
    for (let i = 0; i < numBytes; i++) {
        value += (0, _jab_1.def)(source[offset + i] << shift);
        shift += 8;
    }
    return value;
};
exports.readNumber = readNumber;
/**
 * Round up to divisible by four.
 *
 * @source https://www.npmjs.com/package/sharedmap
 */
function align32(v) {
    return (v & 0xffffffffffffc) + (v & 0x3 ? 0x4 : 0);
}
exports.align32 = align32;
/**
 * todo: should be able to use 'equal' library.
 */
const equal = (a, b) => {
    if (a.length !== b.length) {
        return false;
    }
    for (let i = 0; i < a.length; i++) {
        if (a[i] !== b[i]) {
            return false;
        }
    }
    return true;
};
exports.equal = equal;