EBON (efficient binary object notation)

EBON is a binary data representation format for network transfer and data storage. It was designed to represent graphs of simple DTO-like objects (much like BSON but without MongoDb stuff).

EBON specification:

Terminals
    byte        1 byte (8-bits)
    int32       4 bytes (32-bit signed integer) big-endian
    int64       8 bytes (64-bit signed integer) big-endian
    double64	8 bytes (64-bit IEEE 754 floating point)

Non-terminals
    entity       ::= null | boolean | int | long | double | enum | string  | list | map | object | byte_array | ref
    null         ::= \x00                               Null
    boolean      ::= \x01 \x01 | \x01 \x00              Boolean (1 for 'true' and 0 for 'false')
    int          ::= \x02 int32                         Integer
    long         ::= \x03 int64                         Long integer
    double       ::= \x04 double64                      Double precision floating point value
    enum         ::= \x10 string string                 Enum value (first string - class name, second - name of enum value)
    string       ::= ref | \x05 id size (byte*)         UTF-8 encoded string (size - number of bytes in array)
    byte_array   ::= ref | \x08 id size (byte*)         Array of bytes (size - length of array in bytes)
    list         ::= ref | \x06 id size (entity*)       List (size - number of elements)
    map          ::= ref | \x09 id size (key_value*)    Map (size - number of key-value pairs)
    object       ::= ref | \x07 id string size (field*) Object (string - class name, size - number of fields)
    key_value    ::= entity entity                      Entity-key and entity-value
    field        ::= string entity                      Name of field and its value
    ref          ::= \x11 id                            Reference to already serialized object
    size         ::= int32                              Size
    id           ::= int32                              Entity's identifier

This is very early draft. Specification is subject to change with no backward compatibility.

This project is a java library for serializing/deserializing object graphs in EBON format. Library is released under apache-2.0 license.

To use this lib in maven project:

<repository>
   <id>ebon-repo</id>
   <url>https://github.com/mkulak/ebon/raw/master/releases</url>
</repository>

<dependency>
    <groupId>com.xap4o</groupId>
    <artifactId>ebon</artifactId>
    <version>0.7</version>
</dependency>

Serialization/deserialization is that simple:

class MyObjectTree {
    public int a;
    private boolean b;
    private Map<String, List<MyCustomClass>> foo;
    @Skip
    private String secretField;

    @Getter("calculated-field-name")
    public int calcBar() { .... }

    @Setter("some-other-name")
    public void setBaz(long value) { .... }
}

MyObjectTree obj = ...
byte[] bytes = EBON.serialize(obj);
MyObjectTree newObj = EBON.deserialize(bytes);

Features:

• dead simple spec and API
• no external dependencies
• can serialize graphs
• java/actionscript support
• no dinosaur legacy code
• no Serializable or any other mandatory interface
• no need to declare default constructors

Limitations: All serialized objects should contain only fields of type boolean, int, long, double, String, List, Map, byte[], enum and can contain objects of custom classes which themselves comply with same restrictions. So byte, char, short, float, Set and arrays of any type are not supported. This is purely design decision in order to make lib more simple, clean and cross-language. Also current version depends on sun.reflect.ReflectionFactory which is internal class of Oracle JVM and may not be available on other JVMs.

Actionscript 3 implementation is here.