kiwi-schema

Kiwi Message Format

This is a binary encoding format inspired by Google's Protocol Buffer format. It is pretty similar but also includes support for efficient compound messages using the struct keyword.

Native Types

• bool: A value that stores either true or false. Will use 1 byte.
• byte: An unsigned 8-bit integer value. Uses 1 byte, obviously.
• int: A 32-bit value stored using a variable-length encoding optimized for storing numbers with a small magnitude. Will use at most 5 bytes.
• uint: A 32-bit value stored using a variable-length encoding optimized for storing small positive numbers with a small magnitude. Will use at most 5 bytes.
• float: A 32-bit floating-point number. Will always use 4 bytes.
• string: A UTF-8 length-prefixed string. Will use at least 1 byte.

User Types

• enum: An int with a restricted set of values that are identified by name.
• struct: A compound value with a fixed set of fields that are always required and written out in order.
• message: A compound value with optional fields. A field can be made required using the required keyword.
• T[]: Any type can be made into an array using the [] suffix.

Example Schema

enum Type {
  FLAT = 0;
  ROUND = 1;
  POINTED = 2;
}

struct Color {
  byte red;
  byte green;
  byte blue;
  byte alpha;
}

message RootMessage {
  required uint clientID = 1;
  Type type = 2;
  Color[] colors = 3;
}