Skip to content

SPECS.md

Latest commit

 

History

History
187 lines (129 loc) · 4.1 KB

SPECS.md

File metadata and controls

187 lines (129 loc) · 4.1 KB

Simple Structured Binary Format Specification

Overview

The Simple Structured Binary Format is a simple, efficient, structured binary data format. It mimics JSON, with additional types and compression support.

Unit

All sizes and offsets are in basic machine units (bytes).

Endianness

All numbers are stored in little-endian format.

Packing

All fields are tightly packed.

Header

Type Description
uint32 Magic number (default: 0x46425353)
bool Use compression
Node Root node (if compression is enabled, data is compressed with Brotli)

Types

String

Type Description
uint8[] UTF-8 encoded string data
uint8 Null terminator (0x00)

Node

Type Description
uint8 Node type
uint8[] Node data

The following node types are allowed:

Value Node type
0x00 End
0x01 Null
0x02 Object
0x03 Array
0x04 Boolean
0x05 SByte
0x06 Short
0x07 Integer
0x08 Long
0x09 Byte
0x0A UShort
0x0B UInteger
0x0C ULong
0x0D HalfFloat
0x0E Single
0x0F Double
0x10 String
0x11 ByteArray

Node data for each node type

End

No data. The End node is not a value, it is a sentinel used exclusively to terminate Object and Array sequences. An End node must never appear as the root node or as the value of an Object key-node pair; it may only appear where a terminator is expected.

Null

No data.

Object

Type Description
KeyNodePair[] Zero or more key-node pairs, in the order they were written

KeyNodePair

Type Description
String Key
Node Value node

Reading an Object: read a String key, then read the node type byte. If the node type is End (0x00), the object is complete. Otherwise dispatch on the node type as usual, then repeat from the beginning of the next key-node pair.

Array

Type Description
Node[] Zero or more value nodes, in the order they were written

Reading an Array: read the node type byte. If the node type is End (0x00), the array is complete. Otherwise dispatch on the node type as usual, then repeat.

Boolean

Type Description
bool Value

SByte

Type Description
int8 Value

Short

Type Description
int16 Value

Integer

Type Description
int32 Value

Long

Type Description
int64 Value

Byte

Type Description
uint8 Value

UShort

Type Description
uint16 Value

UInteger

Type Description
uint32 Value

ULong

Type Description
uint64 Value

HalfFloat

Type Description
float16 Value

Single

Type Description
float32 Value

Double

Type Description
float64 Value

String

Type Description
String Value

ByteArray

Type Description
uint32 Length
uint8[] Data