Bincode v0.3.0 Bincode View Source
Module defining the functionalities of Bincode.
Bincode allows you to share data between Elixir and Rust using Rust's Bincode binary format.
You can implement your custom serialization manually, but for most use cases
you can simply declare the Rust structs and enums using Bincode.Structs.declare_struct/3 and
Bincode.Structs.declare_enum/3
Supported types
Most Rust types are supported, plus user defined structs and enums.
| Rust | Bincode notation | Elixir typespec |
|---|---|---|
u8 | :u8 | non_neg_integer |
| ... | ... | ... |
u128 | :u128 | non_neg_integer |
i8 | :i8 | integer |
| ... | ... | ... |
i128 | :i128 | integer |
f32 | :f32 | float |
f64 | :f64 | float |
bool | :bool | boolean |
String | :string | binary |
(u32, String) | {:u32, :string} | {non_neg_integer, binary} |
Option<f32> | {:option, :f32} | float | nil |
Vec<String> | {:list, :string} | [binary] |
HashMap<i64, String> | {:map, {:i64, :string}} | %{required(integer) => binary} |
HashSet<u8> | {:set, :u8} | MapSet.t(non_neg_integer) |
User defined types such as structs and enums can be nested, in this case the type is
the fully qualified module name. See Bincode.Structs.declare_struct/3.
The endianness is little since that's the default used by Bincode.
Tuples are implemented for a max size of 12 by default. That should be enough for
most practical cases but if you need to serialize tuples with more elements, you can
set max_tuple_size in the mix config, like so:
config :bincode, max_tuple_size: 23Examples
Consider the typical example where we want to send data structures across the network. Here with a Rust client and Elixir server:
#[derive(Serialize, Deserialize)]
pub struct PacketSendMessage {
pub from: u64,
pub to: u64,
pub content: String,
}
pub fn send_message(sender_id: u64, receiver_id: u64) {
let message = PacketSendMessage {
from: sender_id,
to: receiver_id,
content: "hello!".to_owned()
};
let encoded: Vec<u8> = bincode::serialize(&message).unwrap();
// now send "encoded" to Elixir app
}On the Elixir side you can simply declare the same packet struct and deserialize the received bytes:
defmodule Packets do
import Bincode.Structs
declare_struct(PacketSendMessage,
from: :u64,
to: :u64,
content: :string
)
end
alias Packets.PacketSendMessage
# Receive "data" from the network
{:ok, {%PacketSendMessage{} = message, rest}} = PacketSendMessage.deserialize(data)
Logger.info("Received message packet #{inspect(message)}")Link to this section Summary
Functions
Deserializes the given binary data into an Elixir term according to the
given type.
Same as deserialize/3 but raises an ArgumentError when the
given value cannot be encoded according to type.
Serializes the given term in binary representation according to the
given type.
Same as serialize/3 but raises an ArgumentError when the
given value cannot be encoded according to type.
Link to this section Types
Specs
bincode_type() :: primitive() | collection() | user_defined()
Specs
collection() ::
{:list, bincode_type()} | {:map, bincode_type()} | {:set, bincode_type()}
Specs
floating_point() :: :f32 | :f64
Specs
option() :: {:varint, boolean()}
Specs
options() :: [option()]
Specs
primitive() :: unsigned() | signed() | floating_point() | :bool | :string | tuple() | {:option, bincode_type()}
Specs
signed() :: :i8 | :i16 | :i32 | :i64 | :i128
Specs
unsigned() :: :u8 | :u16 | :u32 | :u64 | :u128
Specs
user_defined() :: module()
Link to this section Functions
Specs
deserialize(binary(), bincode_type(), options()) :: {:ok, {term(), binary()}} | {:error, String.t()}
Deserializes the given binary data into an Elixir term according to the
given type.
Returns {:ok, {term, rest}} when successful or {:error, error_message}
otherwise. The remaining binary data is returned.
Options
varint- When set to true, enables variable-size integer encoding. It applies to signed and unsigned integers except for:u8and:i8. Signed integers are first mapped to unsigned integers using ZigZag encoding. Variable-size encoding will result in saved bytes the closer to 0 the value is. This is especially true for collections length and enum variants which for a lot of cases fit in a single byte instead of the usual:u64and:u32.
Examples
iex> Bincode.deserialize(<<255>>, :u8)
{:ok, {255, ""}}
iex> Bincode.deserialize(<<12, 0, 0, 0, 0, 0, 0, 0>>, :u64)
{:ok, {12, ""}}
iex> Bincode.deserialize(<<12>>, :u64, varint: true)
{:ok, {12, ""}}
iex> Bincode.deserialize(<<7, 0, 0, 0, 0, 0, 0, 0, 66, 105, 110, 99, 111, 100, 101>>, :string)
{:ok, {"Bincode", ""}}
iex> Bincode.deserialize(<<144, 0, 0>>, {:u16, :bool})
{:ok, {{144, false}, ""}}
iex> Bincode.deserialize(<<4, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4>>, {:list, :u8})
{:ok, {[1, 2, 3, 4], ""}}
iex> Bincode.deserialize(<<1, 0, 0, 0, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 0, 115, 111, 109, 101, 32, 115, 116, 114, 105, 110, 103, 32, 107, 101, 121, 4, 171, 161, 22, 100, 0, 0, 0>>, {:map, {:string, :u64}})
{:ok, {%{"some string key" => 429876423428}, ""}}
iex> Bincode.deserialize([], :bool)
{:error, "Cannot deserialize value [] into type :bool"}Same as deserialize/3 but raises an ArgumentError when the
given value cannot be encoded according to type.
Examples
iex> Bincode.deserialize!(<<1, 54, 23>>, {:option, :u16})
{5942, ""}
iex> Bincode.deserialize!(<<>>, {:list, :string})
** (ArgumentError) Cannot deserialize value "" into type :listSpecs
serialize(term(), bincode_type(), options()) :: {:ok, binary()} | {:error, String.t()}
Serializes the given term in binary representation according to the
given type.
Returns {:ok, serialized_term} when successful or {:error, error_message}
otherwise.
Options
varint- When set to true, enables variable-size integer encoding. It applies to signed and unsigned integers except for:u8and:i8. Signed integers are first mapped to unsigned integers using ZigZag encoding. Variable-size encoding will result in saved bytes the closer to 0 the value is. This is especially true for collections length and enum variants which for a lot of cases fit in a single byte instead of the usual:u64and:u32.
Examples
iex> Bincode.serialize(255, :u8)
{:ok, <<255>>}
iex> Bincode.serialize(12, :u64)
{:ok, <<12, 0, 0, 0, 0, 0, 0, 0>>}
iex> Bincode.serialize(12, :u64, varint: true)
{:ok, <<12>>}
iex> Bincode.serialize("Bincode", :string)
{:ok, <<7, 0, 0, 0, 0, 0, 0, 0, 66, 105, 110, 99, 111, 100, 101>>}
iex> Bincode.serialize({144, false}, {:u16, :bool})
{:ok, <<144, 0, 0>>}
iex> Bincode.serialize([1, 2, 3, 4], {:list, :u8})
{:ok, <<4, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4>>}
iex> Bincode.serialize(%{"some string key" => 429876423428}, {:map, {:string, :u64}})
{:ok, <<1, 0, 0, 0, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 0, 115, 111, 109, 101, 32, 115, 116, 114, 105, 110, 103, 32, 107, 101, 121, 4, 171, 161, 22, 100, 0, 0, 0>>}
iex> Bincode.serialize(%{}, :bool)
{:error, "Cannot serialize value %{} into type :bool"}Same as serialize/3 but raises an ArgumentError when the
given value cannot be encoded according to type.
Examples
iex> Bincode.serialize!([111], {:list, :u16})
<<1, 0, 0, 0, 0, 0, 0, 0, 111, 0>>
iex> Bincode.serialize!(<<>>, {:option, :bool})
** (ArgumentError) Cannot serialize value "" into type :bool