StreamingFast binary

Binary Encoder and Decoder library

Usage

Struct Field Tags

• _ will skip the field when encoding & deocode a struc
• sizeof= indicates this field is a number used to track the length of a another field.
• little indicates this field will be encoded as little endian
• big indicates this field will be encoded as big endian
• optional indicates this field is optional. An optional field will have an initial byte either 0x00 or 0x01 indicating whether the field is present. If the field is present it will be followed by the value.
• Bare values will be parsed as type and little endian when necessary

Supported Types

• int8, int16, int32, int64, Int128
• uint8, uint16,uint32,uint64, Uint128
• float32, float64, Float128
• string, bool
• Varint16, Varint32
• Varuint16, Varuint32

Custom Types

To implement custom types, your types would need to implement the MarshalerBinary & UnmarshalerBinary interfaces

Example

Basic Implementation

type Example struct {
    Var      uint32 `bin:"_"`
    Str      string
    IntCount uint32 `bin:"sizeof=Var"`
    Weird    [8]byte
    Var      []int
}

Custom Implementation

type Example struct {
	Prefix byte
	Value  uint32
}

func (e *Example) UnmarshalBinary(decoder *Decoder) (err error) {
	if e.Prefix, err = decoder.ReadByte(); err != nil {
		return err
	}
	if e.Value, err = decoder.ReadUint32(BE()); err != nil {
		return err
	}
	return nil
}

func (e *Example) MarshalBinary(encoder *Encoder) error {
	if err := encoder.WriteByte(e.Prefix); err != nil {
		return err
	}
	return encoder.WriteUint32(e.Value, BE())
}

Contributing

Issues and PR in this repo related strictly to the binary library

Report any protocol-specific issues in their respective repositories

Please first refer to the general StreamingFast contribution guide, if you wish to contribute to this code base.

This codebase uses unit tests extensively, please write and run tests.

License

Apache 2.0