Techcable / bare-jvm

baremessage encoding/decoding for the JVM

bare-jvm

This is a bare messages implementation for the JVM.

Features

• Zero external dependencies and small, well structured code base
• Parsing of bare schemas
• Code generation for data structures, encoding and decoding methods out ouf bare schemas
• Decoding primitive data types from InputStream
• Decoding aggregate data types from InputStream
• Encoding primitive data types to OutputStream
• Encoding aggregate data types to OutputStream
• Reflective decoding of data types from InputStream

Type mappings

Primitive type mappings

bare-jvm	bare spec
String	string
byte	byte
boolean	bool
byte[]	data
byte[]	data<length>
float	f32
double	f64
@Int(Int.Type.i64) long	i64
@Int(Int.Type.u64) BigInteger	u64
@Int(Int.Type.i32) int	i32
@Int(Int.Type.u32) long	u32
@Int(Int.Type.i16) short	i16
@Int(Int.Type.u16) int	i16
@Int(Int.Type.u8) byte	u8
@Int(Int.Type.i8) byte	i8
@Int(Int.Type.i) long	int
@Int(Int.Type.ui) BigInteger	uint

Aggregate types

bare-jvm	bare spec
List<T>	[]type
Array<T>	[length]type
Map<K,V>	map[type A]type B
Optional<T>	optional<type>
class Person {public String name;}	struct
Union u = new Union(Person.class, Account.class)	tagged union

Usage

• Simply copy the required classes from org.nobloat.bare or add the dependency via

• Generate the data structures, encoding and decoding structures with

  • java -jar bare-jvm.jar schema.bare org.example.Messages
  • This will create all data types in a class Messages under org/example/Messages.java

Limitations

• Java has no concept of unsigned primitive data types, hence double the amount of memory is required to safely use unsigned types:
  • u64 becomes BigInteger
  • u32 becomes long
  • u16 becomes int
  • u8 becomes short
• Anonymous structs are not supported by the code generator.