Binn

Binn is a computer data serialization format used mainly for application data transfer. It stores primitive data types and data structures in a binary form. For the full spec see http://github.com/liteserver/binn

Elixir Types	Binn
1 # integer	integer
1.0 # float	floating point numbers (IEEE single and double precision)
true # boolean	boolean (true and false)
:atom # atom / symbol	string
"elixir" # string	string
[1, 2, 3] # list	list
{1, 2, 3} # tuple	list
%{:a => 1, :b => 2} # map	object, where all keys are cast to string
%{1 => :a, 2 => :b} # map	map, if the Elixir map's keys are all integer
%{:a => 1, 2 => :b} # map	object, where all keys are cast to string

The Binn format is designed to be compact and fast on readings. The elements are stored with their sizes to increase the read performance. The strings are null terminated so when read the library returns a pointer to them inside the buffer, avoiding memory allocation and data copying, an operation known as zero-copy.

Installation

If available in Hex, the package can be installed by adding binn to your list of dependencies in mix.exs:

def deps do
  [
    {:binn, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/binn.

Encoding

iex(1)> %{hello: "world", number: 123} |> Binn.encode
<<226, 22, 2, 2, 105, 100, 32, 12, 5, 104, 101, 108, 108, 111, 160, 5, 119, 111, 114, 108, 100, 0>>

elixir

iex(3)> data |> Binn.decode
%{hello: "world", number: 123}

Undefined

The undefined value is enconded using the byte 0x03.

It is an extended type derived from the storage type NOBYTES.