JarCastingDisIO
DisIO is a lightweight standalone library which allows you to perform I/O operations on byte level, like Java's ByteBuffer class. However, there are a few problems I have with Java's ByteBuffer class which is why I created this library. Java's ByteBuffer class has a private constructor and two package private abstract methods. Meaning you can't inherit the class and create your own implementation.
Of course, with Kotlin, this is not a problem since you can create extension methods. Nonetheless, it remains a problem in Java.
The goal of this library is not alone to take away the limitations of Java's ByteBuffer class, but also to provide more I/O features on bit/byte level.
Features:
- Basic I/O operations
- Array operations
- Signed and unsigned operations
- Bit operations
- LSB (least significant bit) and MSB (most significant bit) support
- XTEA encryption and decryption
- RSA cryption
Gradle
implementation 'com.displee:disio:2.2'
Initialization
//Set capacity for best performance
val outputBuffer = OutputBuffer(10)
...
val inputBuffer = InputBuffer(outputBuffer.array())
val array = byteArrayOf(...)
val inputBuffer = InputBuffer(array)
LSB mode (least significant bit)
val outputBuffer = OutputBuffer(5)
outputBuffer.lsb()
outputBuffer.writeShort(67)
val inputBuffer = InputBuffer(outputBuffer.array())
inputBuffer.lsb()
val value = inputBuffer.readShort()
...
MSB mode (most significant bit, this is also the default operation mode)
val outputBuffer = OutputBuffer(4)
outputBuffer.msb()
outputBuffer.writeInt(61263)
val inputBuffer = InputBuffer(outputBuffer.array())
inputBuffer.msb()
val value = inputBuffer.readInt()
...
Switch to different buffer type
val outputBuffer = OutputBuffer(0)
outputBuffer.writeInt(4)
val inputBuffer = outputBuffer.toInputBuffer(copyOffset = false)
val value = inputBuffer.readInt()
val inputBuffer = InputBuffer(byteArrayOf(1, 3, 3, 7))
val value = inputBuffer.readInt()
val outputBuffer = inputBuffer.toOutputBuffer()
outputBuffer.writeShort(256)
//now outputBuffer.raw() results in [1, 3, 3, 7, 1, 0]
XTEA encryption and decryption
val value1 = 12 //random
val value2 = 19238 //random
val value3 = 99 //random
val data = byteArrayOf(1, 3, 3, 4, 5, 6, 7, 8, 7, 6, 5)
val keys = intArrayOf(9, 5, 6, 4)
val outputBuffer = OutputBuffer(0)
outputBuffer.write(value1)
outputBuffer.writeInt(value2)
val startOffset = outputBuffer.offset
outputBuffer.write(data)
outputBuffer.encodeXTEA(keys, startOffset, outputBuffer.offset)
outputBuffer.write(value3)
val inputBuffer = outputBuffer.toInputBuffer(false)
assert(inputBuffer.read().toInt() == value1)
assert(inputBuffer.readInt() == value2)
inputBuffer.decodeXTEA(keys, startOffset, inputBuffer.raw().size)
val decryptedData = inputBuffer.read(data.size)
assert(decryptedData.contentEquals(data))
assert(inputBuffer.read().toInt() == value3)