byte-data

byte-data

Pack and unpack binary data.
Copyright (c) 2017-2018 Rafael da Silva Rocha.
https://github.com/rochars/byte-data

byte-data is a JavaScript module for the serialization and deserialization of numbers and strings.

Version 13.x main differences from the latest release:

• Typed Arrays are used to encode/decode 32 and 64-bit floats. This makes this version overall faster than 15.x, but results will depend on the environment implementation of Typed Arrays, wich may differ from one to context to another.
• It only encode and decode ASCII characters; the current version includes support for UTF-8 characters.

This version (13.x) still receive updates and bug fixes.

• No dependencies
• MIT-licensed
• Use it out of the box in the browser
• Use it out of the box in Node
• Use it in little-endian and big-endian hosts
• Write to buffers, option to define start and end index to write
• Read from buffers, option to define start and end index to read
• Use typed arrays or arrays

Pack/unpack:

• Integers, unsigned and signed (two's complement)
• 16-bit IEEE half-precision floating point numbers
• 32-bit IEEE single-precision floating point numbers
• 64-bit IEEE double-precision floating point numbers
• Little-endian and big-endian words
• ASCII Strings (with validation)

Install

npm install byte-data

Use

Node

If you installed via NPM or Yarn, import byteData from byte-data:

import * as byteData from 'byte-data';

// Pack a usigned 8-bit unsigned integer
let packed = byteData.pack(128, {bits: 8});

Or import just what you need:

import {pack} from 'byte-data';
let packed = pack(128, {bits: 8});

Or require:

const byteData = require('byte-data');

// Pack a 32-bit floating point number
let packed = byteData.pack(2.1474836, {bits: 32, float: true});

Browser

Use the compiled file in the /dist folder of this package:

<script src="./dist/byte-data.min.js"></script>
<script>
  // Pack a 32-bit floating point number
  var packed = byteData.pack(2.1474836, {bits: 32, float: true});
</script>

Or get it from the jsDelivr CDN:

<script src="https://cdn.jsdelivr.net/npm/byte-data"></script>

Or get it from unpkg:

<script src="https://unpkg.com/byte-data"></script>

About

Floating-point numbers

Floating-point numbers are IEEE 754 standard.

Signed integers

Signed integers are two's complement.

Strings

Only ASCII characters are supported. Packing and unpacking strings with characters that are not ASCII will throw a 'Bad ASCII code.' error.

Overflow and underflow

Overflow or underflow on integers will throw "Overflow." and "Underflow." errors, respectively.

Browser compatibility

byte-data need IE10+ to run. All moderns browsers should work fine. Cross-browser tests are on the ROADMAP.

API

Strings

/**
 * Read a string of ASCII characters from a byte buffer.
 * @param {!Uint8Array} bytes A byte buffer.
 * @param {number=} index The index to read.
 * @param {?number=} len The number of bytes to read.
 * @return {string}
 * @throws {Error} If a character in the string is not valid ASCII.
 */
function unpackString(bytes, index=0, len=null) {}

/**
 * Write a string of ASCII characters as a byte buffer.
 * @param {string} str The string to pack.
 * @return {!Array<number>} The next index to write on the buffer.
 * @throws {Error} If a character in the string is not valid ASCII.
 */
function packString(str) {}

/**
 * Write a string of ASCII characters to a byte buffer.
 * @param {string} str The string to pack.
 * @param {!Uint8Array|!Array<number>} bytes The output buffer.
 * @param {number=} index The index to write in the buffer.
 * @return {number} The next index to write in the buffer.
 * @throws {Error} If a character in the string is not valid ASCII.
 */
function packStringTo(str, bytes, index=0) {}

Numbers

/**
 * Pack a number as a byte buffer.
 * @param {number} value The number.
 * @param {!Object} theType The type definition.
 * @return {!Array<number>} The packed value.
 * @throws {Error} If the type definition is not valid.
 * @throws {Error} If the value is not valid.
 */
function pack(value, theType) {}

/**
 * Pack an array of numbers as a byte buffer.
 * @param {!Array<number>|!TypedArray} values The values.
 * @param {!Object} theType The type definition.
 * @return {!Array<number>} The packed values.
 * @throws {Error} If the type definition is not valid.
 * @throws {Error} If any of the values are not valid.
 */
function packArray(values, theType) {}

/**
 * Pack a number to a byte buffer.
 * @param {number} value The value.
 * @param {!Object} theType The type definition.
 * @param {!Uint8Array|!Array<number>} buffer The output buffer.
 * @param {number=} index The index to write.
 * @return {number} The next index to write.
 * @throws {Error} If the type definition is not valid.
 * @throws {Error} If the value is not valid.
 */
function packTo(value, theType, buffer, index=0) {}

/**
 * Pack a array of numbers to a byte buffer.
 * @param {!Array<number>|!TypedArray} values The value.
 * @param {!Object} theType The type definition.
 * @param {!Uint8Array|!Array<number>} buffer The output buffer.
 * @param {number=} index The buffer index to write.
 * @return {number} The next index to write.
 * @throws {Error} If the type definition is not valid.
 * @throws {Error} If the value is not valid.
 */
function packArrayTo(values, theType, buffer, index=0) {}

/**
 * Unpack a number from a byte buffer.
 * @param {!Uint8Array} buffer The byte buffer.
 * @param {!Object} theType The type definition.
 * @return {number}
 * @throws {Error} If the type definition is not valid
 */
function unpack(buffer, theType) {}

/**
 * Unpack an array of numbers from a byte buffer.
 * @param {!Uint8Array} buffer The byte buffer.
 * @param {!Object} theType The type definition.
 * @return {!Array<number>}
 * @throws {Error} If the type definition is not valid.
 */
function unpackArray(buffer, theType) {}

/**
 * Unpack a number from a byte buffer by index.
 * @param {!Uint8Array} buffer The byte buffer.
 * @param {!Object} theType The type definition.
 * @param {number=} index The buffer index to read.
 * @return {number}
 * @throws {Error} If the type definition is not valid
 */
function unpackFrom(buffer, theType, index=0) {}

/**
 * Unpack a array of numbers from a byte buffer by index.
 * @param {!Uint8Array} buffer The byte buffer.
 * @param {!Object} theType The type definition.
 * @param {number=} start The start index. Assumes 0.
 * @param {?number=} end The end index. Assumes the buffer length.
 * @return {!Array<number>}
 * @throws {Error} If the type definition is not valid
 */
function unpackArrayFrom(buffer, theType, start=0, end=null) {}

/**
 * Unpack a array of numbers to a typed array.
 * @param {!Uint8Array} buffer The byte buffer.
 * @param {!Object} theType The type definition.
 * @param {!TypedArray} output The output array.
 * @throws {Error} If the type definition is not valid
 */
function unpackArrayTo(buffer, theType, output) {}

Types

Types are user-defined objects like this:

const float32 = {
  bits: 32, // required
  signed: true, // optional, defaults to false
  float: true, // optional, defaults to false
  be: false // optional, defaults to false, true for big-endian
}

There is a standard set of types that can be installed:

npm install binary-data-types

All types in binary-data-types are supported by byte-data. They are:

• int2
• uInt2
• int4
• uInt4
• int8
• uInt8

little-endian

• int16
• uInt16
• float16
• int24
• uInt24
• int32
• uInt32
• float32
• int40
• uInt40
• int48
• uInt48
• float64

big-endian:

• int16BE
• uInt16BE
• float16BE
• int24BE
• uInt24BE
• int32BE
• uInt32BE
• float32BE
• int40BE
• uInt40BE
• int48BE
• uInt48BE
• float64BE

Tests on big-endian systems

Use QEMU with this PowerPC/Debian image:
https://people.debian.org/~aurel32/qemu/powerpc/

Contributing

byte-data welcomes all contributions from anyone willing to work in good faith with other contributors and the community. No contribution is too small and all contributions are valued.

See CONTRIBUTING.md for details.

Style guide

byte-data code should follow the Google JavaScript Style Guide:
https://google.github.io/styleguide/jsguide.html

Code of conduct

This project is bound by a code of conduct: The Contributor Covenant, version 1.4, also available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html

Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting [e-mail].

Legal

LICENSE

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

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.