What's is Gobuf?

Gobuf is a binary serialization format like protobuf.

But it didn't need any DSL file to define messages.

It just needs you write down data format by Go structs.

It can analize Go struct and generate marshaller and unmarshaller code automaticlly.

And it not only supports generate Go code but also C#.

It has a good plugin mechanism, let you can add different programming language generation easily.

Pipeline

 +-----------+           +-----------------+        +----------+          +-------------------+
 |  Go code  <-----------+  Gobuf Command  +-------->  Plugin  +---------->  Target Language  |
 +-----------+  analyze  +-----------------+  JSON  +----------+  output  +-------------------+

1. Gobuf command line tool analyze a Go source file.
2. Gobuf output type informations to command line standard output.
3. Plugin use type informations to generate target language source code.

Example:

gobuf protocol.go | gobuf-cs > protocol.gb.cs

Types

Gobuf supports almost all kinds of Go data type, but it has some limits.

This is all the data types that Gobuf supports:

• Type = Scalar | Composite
• Scalar = Numberic | "string" | "bool"
• Numeric = "int" | "uint" | "int8" | "uint8" | "int16" | "uint16" | "int32" | "uint32" | "int64" | "uint64" | "float32" | "float64"
• Composite = Pointer | Array | Map | Bytes | Struct
• Pointer = "*" ( Scalar | Struct )
• Array = "[" "]" Type
• Bytes = "[" "]" "byte"
• Map = "map" "[" Scalar "]" Type
• Struct = "type" Name "struct" "{" Name Type [";" Name Type] "}"

Type Maping

Gobuf maping Go type to different programming languages.

This is the type maping rule:

Go	C#
int	long
uint	ulong
int8	sbyte
uint8	byte
int16	short
uint16	ushort
int32	int
uint32	uint
int64	long
uint64	ulong
float32	float
float64	double
bool	bool
string	utf8 string
[]byte	byte[]
[]Type	List<Type>
map[Scalar]Type	Dictionary<Scalar, Type>
*Scalar	Nullable<Scalar>
*Struct	Class
Struct	Class

Wired Format

Type	Format
int	base128 varint + zig-zag
uint	base128 varint
int8, uint8, bool	1byte
int16, uint16	2byte little-endian
int32, uint32	4byte little-endian
int64, uint64	8byte little-endian
float32	convert to uint32 bits
float64	convert to uint64 bits
string	uint(utf8_length) + utf8_length
[]byte	uint(length) + length
[]Type	uint(count) + items
map[Scalar]Type	uint(count) + items(key + value)
*Scalar	is_null ? uint8(0) : uint8(1) + element
*Struct	is_null ? uint8(0) : uint8(1) + fields
Struct	fields