huangyq23 / lilliput

A native Swift framework for working with binary data of varying endianness

Lilliput 1.1.3

####ChangeLog

######1.1.3 Provide accessor for direct access to the buffer's memory.

######1.1.2 Forgot to update README.

######1.1.1 Minor improvements and fixes.

######1.1.0 Updated to support Swift 2.

######1.0.5 Have to check for "arm" also to prevent compile errors on 32-bit devices.

######1.0.4 Missed two more tests that will not compile on 32-bit devices.

######1.0.3 Add compile configuration protection around tests that won't compile on 32-bit devices.

######1.0.2 Attempting to allow building for both iOS and OSX using one project file.

============

Lilliput is a native Swift framework for working with binary data of varying endianness. For example you can use it to do custom loading of PNG files which are written in big endian byte order, or tinker with reverse engineering game data files which is what I use it for.

There are only two types in the framework:

ByteOrder - Handles converting values between little and big endianness

ByteBuffer - A collection of bytes with a specific byte order

ByteOrder and ByteBuffer are loosely based on similar classes found in Java of the same name, so knowledge of them should help you here.

Examples

Putting and getting a big endian 32 bit integer

let buffer = ByteBuffer(order: BigEndian(), capacity: 100)
buffer.putUInt32(1024) // Put this value at the current position of the buffer
buffer.flip() // Reset the position to 0 and set the limit to 4 (the amout of bytes written)
let value = buffer.getUInt32() // Get the value at the current position of the buffer

Rough parsing of a PNG file

let pngBuffer = ByteBuffer(order: BigEndian(), capacity: 4096) // Filled from a file
buffer.flip() // Must flip before reading after you write to a buffer
let signature = buffer.getUInt8(8)

if signature != [UInt8][137, 80, 78, 71, 13, 10, 26, 10] {
    println("Not a PNG file")
    return
}

let chunkLength = buffer.getUInt32()
let chunkType = buffer.getUInt8(4)
let chunkData = buffer.getUInt8(chunkLength)
let chunkCRC = buffer.getUInt32()

Installation

Can install via Carthage, or by dragging and dropping the project file into your project.

Contact

Justin Kolb
@nabobnick

License

Lilliput is available under the MIT license. See the LICENSE file for more info.