rochars / byte-data

 * Copyright (c) 2017-2018 Rafael da Silva Rocha.

 * https://github.com/rochars/byte-data

 *

 */

/**

 * @type {!Object}

 * @private

 */

const packer = require("./lib/packer");

/**

 * Write a number or fixed-length string to a byte buffer.

 * @param {number|string} value The value.

 * @param {!Object} theType The type definition.

 * @return {!Array<number|string>}

 * @throws {Error} If the type definition is not valid.

 */

function pack(value, theType) {

    packer.setUp(theType);

    return packer.toBytes(

        [packer.fixBadString(value, theType)], theType);

}

/**

 * Read a number or a fixed-length string from a byte buffer.

 * @param {!Array<number|string>|!Uint8Array} buffer An array of bytes.

 * @param {!Object} theType The type definition.

 * @return {number|string|null}

 * @throws {Error} If the type definition is not valid.

 */

function unpack(buffer, theType) {

    packer.setUp(theType);

    let values = packer.fromBytes(

        buffer.slice(0, theType["offset"]), theType);

    return values ? values[0] : theType["char"] ? "" : null;

}

/**

 * Write an array of numbers or a string to a byte buffer.

 * @param {!Array<number|string>} values The values.

 * @param {!Object} theType The type definition.

 * @return {!Array<number|string>}

 * @throws {Error} If the type definition is not valid.

 */

function packArray(values, theType) {

    packer.setUp(theType);

    // Fix strings with bad length in the array

    if (theType["char"]) {

        let len = values.length;

        for (let i=0; i<len; i++) {

            values[i] = packer.fixBadString(values[i], theType);

        }

    }

    return packer.toBytes(values, theType);

}

/**

 * Read an array of numbers or a string from a byte buffer.

 * @param {!Array<number|string>|!Uint8Array} buffer The byte array.

 * @param {!Object} theType The type definition.

 * @return {!Array<number|string>|number}

 * @throws {Error} If the type definition is not valid.

 */

function unpackArray(buffer, theType) {

    packer.setUp(theType);

    return packer.fromBytes(buffer, theType);

}

// Methods

module.exports.pack = pack;

module.exports.unpack = unpack;

module.exports.packArray = packArray;

module.exports.unpackArray = unpackArray;

module.exports.types = require("./lib/types");