bytebuffer

What is bytebuffer?

The bytebuffer npm package is a utility for working with binary data in JavaScript. It provides a comprehensive API for reading and writing various data types to and from byte buffers, making it useful for tasks such as serialization, deserialization, and network communication.

What are bytebuffer's main functionalities?

Creating a ByteBuffer

This feature allows you to create a new ByteBuffer instance. ByteBuffers are used to manage binary data efficiently.

const ByteBuffer = require('bytebuffer');
const bb = new ByteBuffer();

Writing Data to a ByteBuffer

This feature allows you to write various data types to a ByteBuffer. In this example, an integer and a float are written to the buffer.

const ByteBuffer = require('bytebuffer');
const bb = new ByteBuffer();
bb.writeInt32(123456);
bb.writeFloat32(3.14);

Reading Data from a ByteBuffer

This feature allows you to read various data types from a ByteBuffer. In this example, an integer and a float are read from the buffer after writing.

const ByteBuffer = require('bytebuffer');
const bb = new ByteBuffer();
bb.writeInt32(123456);
bb.writeFloat32(3.14);
bb.flip();
const intVal = bb.readInt32();
const floatVal = bb.readFloat32();

Handling Endianness

This feature allows you to specify the endianness (byte order) of the ByteBuffer. In this example, the buffer is set to little-endian mode.

const ByteBuffer = require('bytebuffer');
const bb = new ByteBuffer(ByteBuffer.LITTLE_ENDIAN);
bb.writeInt32(123456);
bb.flip();
const intVal = bb.readInt32();

Converting ByteBuffer to ArrayBuffer

This feature allows you to convert a ByteBuffer to an ArrayBuffer, which can be useful for interoperability with other APIs that use ArrayBuffers.

const ByteBuffer = require('bytebuffer');
const bb = new ByteBuffer();
bb.writeInt32(123456);
const arrayBuffer = bb.toArrayBuffer();

Other packages similar to bytebuffer

buffer

The buffer package is a Node.js core module that provides a way of handling binary data. It is similar to bytebuffer in that it allows for reading and writing various data types, but it is more integrated into the Node.js ecosystem and is generally more performant.

protobufjs

The protobufjs package is a library for working with Protocol Buffers, a binary serialization format. While it offers more advanced serialization capabilities compared to bytebuffer, it is more complex and specifically designed for Protocol Buffers.

dataview

The dataview package provides a DataView implementation for Node.js, allowing for low-level manipulation of ArrayBuffers. It is similar to bytebuffer in terms of functionality but is more low-level and requires more manual management of buffers.

README

Provides a Java-like, Netty-inspired ByteBuffer implementation using typed arrays. It also tries to abstract a bit of the complexity away by providing convenience methods for those who just want to write stuff without caring about signed, unsigned and the actual bit sizes. It's also used for the cross-platform multiplayer component in eSoccer, an HTML5 game developed at University of Applied Sciences Bonn.

ByteBuffer

• Mimics Java ByteBuffers as close as reasonable while using typed array terms

• Full 64bit support via Long.js (optional)

• Simple allocation (new ByteBuffer(capacity[, littleEndian]) or ByteBuffer.allocate(capacity[, littleEndian]))

• Wrapping of quite everything which is or includes an ArrayBuffer (ByteBuffer.wrap(buffer[, littleEndian]))

• Cloning using the same (ByteBuffer#clone()) and copying using an independent backing buffer (ByteBuffer#copy())

• Slicing using the same (ByteBuffer#slice(begin, end)) and using an indepentent backing buffer (ByteBuffer#sliceAndCompact(begin, end))

• Manual offset (ByteBuffer#offset and ByteBuffer#length) and array manipulation (ByteBuffer#array)

• Remaining readable bytes (ByteBuffer#remaining()) and backing buffer capacity getters (ByteBuffer#capacity())

• Explicit (ByteBuffer#resize(capacity)) and implicit resizing (ByteBuffer#ensureCapacity(capacity))

• Efficient implicit resizing by doubling the current capacity

• Flipping (ByteBuffer#flip()), marking (ByteBuffer#mark([offset])) and resetting (ByteBuffer#reset())

• Compacting of the backing buffer (ByteBuffer#compact())

• Conversion to ArrayBuffer (ByteBuffer#toArrayBuffer([forceCopy])) (i.e. to send data over the wire, e.g. a WebSocket with binaryType="arraybuffer")

• Conversion to Buffer (ByteBuffer#toBuffer()) if running inside of node.js

• Reversing (ByteBuffer#reverse()), appending (ByteBuffer#append(src[, offset])) and prepending (ByteBuffer#prepend(src[, offset])) of other ByteBuffers with implicit capacity management

• Explicit destruction (ByteBuffer#destroy())

• ByteBuffer#writeUint/Int8/16/32/64(value[, offset]) and ByteBuffer#readUint/Int8/16/32/64([offset])

• ByteBuffer#writeVarint32/64(value[, offset]) and ByteBuffer#readVarint32/64([offset]) to write a base 128 variable-length integer as used in protobuf

• ByteBuffer#writeZigZagVarint32/64(value[, offset]) and ByteBuffer#readZigZagVarint32/64([offset]) to write a zig-zag encoded base 128 variable-length integer as used in protobuf for efficient encoding of signed values

• ByteBuffer#writeFloat32/64(value[, offset]) and ByteBuffer#readFloat32/64([offset])

• ByteBuffer#write/readByte, ByteBuffer#write/readShort, ByteBuffer#write/readInt, ByteBuffer#write/readLong (all signed), ByteBuffer#write/readVarint and ByteBuffer#write/readZigZagVarint (both 32bit signed), ByteBuffer#write/readFloat, ByteBuffer#write/readDouble aliases for the above for convenience

• ByteBuffer#writeUTF8String(str[, offset]), ByteBuffer#readUTF8String(chars[, offset]) and ByteBuffer#readUTF8StringBytes(length[, offset]) using the included UTF8 en-/decoder (full 6 bytes, ref)

• ByteBuffer#writeLString(str[, offset])) and ByteBuffer#readLString([offset]) to write respectively read a length-prepended (number of characters as UTF8 char) string

• ByteBuffer#writeVString(str[, offset])) and ByteBuffer#readVString([offset]) to write respectively read a length-prepended (number of bytes as base 128 variable-length 32bit integer) string

• ByteBuffer#writeCString(str[, offset]) and ByteBuffer#readCString([offset]) to write respectively read a NULL-terminated (Uint8 0x00) string

• ByteBuffer#writeJSON(data[, offset[, stringify]]) and ByteBuffer#readJSON([offset[, parse]]) to write respectively read arbitraty object data. Allows overriding the default stringify (default: JSON.stringify) and parse (default: JSON.parse) implementations.

• All with implicit offset advance if the offset parameter is omitted or without, if specified

• Chaining of all operations that allow this (i.e. do not return some specific value like in read operations), e.g.

  var bb = new ByteBuffer();
  ...
  bb.reset().writeInt(1).writeLString("Hello world!").flip().compact()...
  

• Switching between little endian and big endian byte order through ByteBuffer#LE() and ByteBuffer#BE(), e.g.

  var bb = new ByteBuffer(8).LE().writeInt(1).BE().writeInt(2).flip(); // toHex: <01 00 00 00 00 00 00 02>
  

• ByteBuffer#toString(), ByteBuffer#toHex([wrap]), ByteBuffer#toASCII([wrap]) and ByteBuffer#printDebug() (emits hex + ASCII + offsets to console, looks like your favourite hex editor) for pain-free debugging

Features

• CommonJS compatible
• RequireJS/AMD compatible
• Browser compatible (include the script, then use var ByteBuffer = dcodeIO.ByteBuffer;)
• node.js compatible, also available via npm
• Closure Compiler ADVANCED_OPTIMIZATIONS compatible (fully annotated, ByteBuffer.min.js has been compiled this way, ByteBuffer.min.map is the source map)
• Fully documented using jsdoc3
• Well tested through nodeunit
• Zero production dependencies (Long.js is optional)
• Small footprint

Usage

Node.js / CommonJS

• Install: npm install bytebuffer

var ByteBuffer = require("bytebuffer");
var bb = new ByteBuffer();
bb.writeLString("Hello world!");
bb.flip();
console.log(bb.readLString()+" from ByteBuffer.js");

Browser

Optionally depends on Long.js for long (int64) support. If you do not require long support, you can skip the Long.js include.

<script src="//raw.github.com/dcodeIO/Long.js/master/Long.min.js"></script>
<script src="//raw.github.com/dcodeIO/ByteBuffer.js/master/ByteBuffer.min.js"></script>

var ByteBuffer = dcodeIO.ByteBuffer;
var bb = new ByteBuffer();
bb.writeLString("Hello world!");
bb.flip();
alert(bb.readLString()+" from ByteBuffer.js");

Require.js / AMD

Optionally depends on Long.js for long (int64) support. If you do not require long support, you can skip the Long.js config. Require.js example:

require.config({
    "paths": {
        "Long": "/path/to/Long.js"
        "ByteBuffer": "/path/to/ByteBuffer.js"
    }
});
require(["ByteBuffer"], function(ByteBuffer) {
    var bb = new ByteBuffer();
    bb.writeLString("Hello world!");
    bb.flip();
    alert(bb.readLString()+" from ByteBuffer.js");
});

On long (int64) support

As of the ECMAScript specification, number types have a maximum value of 2^53. Beyond that, behaviour might be unexpected. However, real long support requires the full 64 bits with the possibility to perform bitwise operations on the value for varint en-/decoding. So, to enable true long support in ByteBuffer.js, it optionally depends on Long.js, which actually utilizes two 32 bit numbers internally. If you do not require long support at all, you can skip it and save the additional bandwidth. On node, long support is available by default through the long dependency.

Downloads

• ZIP-Archive
• Tarball

Documentation

• View documentation

Tests (& Examples)

• View source
• View report

Prerequisites to run it against IE<10, FF<15, Chrome<9 etc.

• Working ArrayBuffer & DataView implementations (i.e. use a polyfill)

Usage with Closure Compiler's advanced optimizations

You basically have the following three options:

ByteBuffer.js as external dependency

If you compile your code but want to use ByteBuffer.js as an external dependency that's not actually compiled "into" your project, add the provided externs file to your compilation step (which usually excludes compilation of ByteBuffer.js).

ByteBuffer.js compiled into your project and exposed

Use ByteBuffer.js if you want the ByteBuffer class to be exposed to the outside world (of JavaScript) so it can be called by external scripts. This also removes the requirement of using externs but the compiler will also keep possibly unused code.

ByteBuffer.js fully compiled into your project

Use ByteBuffer.noexpose.js if you want the ByteBuffer class to be fully integrated into your (single file) project. Of course no external scripts will be able to call it or its method (trivially) because quite everything will become renamed, some parts inlined and moved around. This will also allow the compiler to actually remove unused code.

Contributors

Dretch (IE8 comp.)

License

Apache License, Version 2.0 - http://www.apache.org/licenses/LICENSE-2.0.html