Crate speedy

Expand description

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
`enum`s	`{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.

Endianness