JarCastingbit-manip
Library for bitwise manipulations over arrays
Examples
Cyclic Shifter
//Given an array or (buffer) of bytes:
byte[] bytes =new byte[]{0b10000001,0b00011000,0b00000111};//100000010001100000000111
//Then invoking a bitwise cyclic right shift 2
Bitwise.CyclicShifter.Using.aByteArray(bytes,2);
//the contents of bytes is now
//{0b11100000,0b010001100,0b0000000} 111000000100011000000001
//Invoking a bitwise cyclic left shift 2
Bitwise.CyclicShifter.Using.aByteArray(bytes,-2);
//bytes is back to {0b10000001,0b00011000,0b0000111}; 100000010001100000000111
//Then invoking a bitwise cyclic right shift 9
Bitwise.CyclicShifter.Using.aByteArray(bytes,9);
//the contents of bytes will be
//{0b00000011,0b11000000,0b10001100} 000000111100000010001100
There is also the method Bitwise.CyclicShifter.Using.aByteBuffer implemented for you as well as a generic constructor new CyclicShifter<T>(ToIntFunction<T> lengthGetter, ObjIntToByteFunction<T> getAtIndex, ObjIntByteConsumer<T> setAtIndex) to easily use whatever kind of byte container you please.
At the core all of the shifting and carrying is done using bitwise operators, therefore it runs pretty darn fast. It could be faster using concrete object interaction instead of method references.
Boundless buffer operations
Another object you may find useful is a CyclicByteBuffer which can be used to do operations over arrays smaller or larger than itself. A use of this object can be found in the Bitwise.Util.doOperation(byte[],IntBinaryOperator,byte...) method.
byte[] bytes =new byte[]{0b10000001,0b00011000,0b00000111};//100000010001100000000111
//Let's XOR these bytes with {0b11111111,0b00000000}
Util.doOperation(bytes, (a, b)->(a^b),(byte)-1,(byte)0);
//the contents of bytes will now be
//{0b01111110,0b00011000,0b11111000} 011111100001100011111000