A fast binary serialization framework

The goal of this crate is to provide fast, simple and easy binary serialization.

Benchmarks

See rust_serialization_benchmark for benchmarks.

Example

use std::borrow::Cow;
use speedy::{Readable, Writable, Endianness};

#[derive(PartialEq, Debug, Readable, Writable)]
enum Enum {
    A,
    B,
    C,
}

#[derive(PartialEq, Debug, Readable, Writable)]
struct Struct< 'a > {
    number: u64,
    string: String,
    vector: Vec< u8 >,
    cow: Cow< 'a, [i64] >,
    float: f32,
    enumeration: Enum
}

fn main() {
    let original = Struct {
        number: 0x12345678ABCDEF00,
        string: "A totally pointless string".to_owned(),
        vector: vec![ 1, 2, 3 ],
        cow: Cow::Borrowed( &[ 4, 5, 6 ] ),
        float: 3.1415,
        enumeration: Enum::C
    };

    let bytes = original.write_to_vec().unwrap();
    let deserialized: Struct =
        Struct::read_from_buffer( &bytes ).unwrap();

    assert_eq!( original, deserialized );
}

Supported types

Out-of-box the following types are supported:

Type	Serialized as
u8	as-is
u16	as-is
u32	as-is
u64	as-is
usize	u64
i8	as-is
i16	as-is
i32	as-is
i64	as-is
f32	as-is
f64	as-is
bool	u8, either 0 or 1
char	u32
String	{length: u32, bytes: [u8]}
Cow<'a, str>	{length: u32, bytes: [u8]}
Vec<T>	{length: u32, values: [T]}
Cow<'a, [T]>	{length: u32, values: [T]}
HashMap<K, V>	{length: u32, values: [K, V]}
BTreeMap<K, V>	{length: u32, values: [K, V]}
HashSet<T>	{length: u32, values: [T]}
BTreeSet<T>	{length: u32, values: [T]}
Range<T>	(T, T)
RangeInclusive<T>	(T, T)
Option<T>	(1_u8, T) or 0_u8
Result<T, E>	(1_u8, T) or (0_u8, E)
()	nothing
(T)	as-is
(T, T)	as-is
(T, .., T)	as-is
enums	{tag: u32, variant: T}
AtomicU8	u8
AtomicI8	i8
AtomicU16	u16
AtomicI16	i16
AtomicU32	u32
AtomicI32	i32
AtomicU64	u64
AtomicI64	i64
NonZeroU32	u32
std::net::Ipv4Addr	u32
std::net::Ipv6Addr	u128
std::net::IpAddr	{is_ipv4: u8, value: {u32 or u128}}
std::time::Duration	{secs: u64, subsec_nanos: u32}
std::time::SystemTime	std::time::Duration since UNIX_EPOCH
uuid::Uuid	[u8; 16]

These are stable and will not change in the future.

Field attributes

#[speedy(length = $expr)]

Can be used on most standard containers to specify the field's length. Can refer to any of the previous fields.

For example:

use speedy::{Readable, Writable};

#[derive(Readable, Writable)]
struct Struct {
    byte_count: u8,
    #[speedy(length = byte_count / 4)]
    data: Vec< u32 >
}

Before serializing you need to make sure that whatever is set as length is equal to the .len() of the field; if it's not then you will get an error when trying to serialize it.

Setting this attribute changes the serialization format as follows:

Type	Serialized as
Vec<T>	[T]
Cow<'a, [T]>	[T]
String	[u8]
Cow<'a, str>	[u8]
HashMap<K, V>	[K, V]
BTreeMap<K, V>	[K, V]
HashSet<T>	[T]
BTreeSet<T>	[T]

#[speedy(length_type = $ty)]

Can be used to specify the exact size of the implicit length field of a container as it is read or written.

Possible values:

• u7 (same as u8, but restricted to 7 bits for u64_varint compatibility)
• u8
• u16
• u32 (default)
• u64_varint

#[speedy(varint)]

Can be used only on u64 fields. Forces the field to be serialized as a varint.

#[speedy(skip)]

Skips a given field when reading and writing.

#[speedy(default_on_eof)]

If an EOF is encountered when reading this field its value will be set to the default value for its type and the EOF will be ignored.

#[speedy(constant_prefix = $expr)]

Specifies a static string of bytes which will be written or has to be present when reading before a given field.

Enum attributes

#[speedy(tag_type = $ty)]

Can be used to specify the exact size of the enum's tag as it is read or written.

Possible values:

• u7 (same as u8, but restricted to 7 bits for u64_varint compatibility)
• u8
• u16
• u32 (default)
• u64_varint

#[speedy(peek_tag)]

An enum marked with this attribute will not consume its tag value when reading from a stream, nor will it write its own tag when writing.

Enum variant attributes

#[speedy(tag = $expr)]

Specifies a preset tag value to be used for a given enum variant.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.