This crate provides API for serialization/deserialization of data to/from D-Bus wire format. This binary wire format is simple and very efficient and hence useful outside of D-Bus context as well. A modified form of this format, GVariant is very commonly used for efficient storage of arbitrary data and is also supported by this crate.
Since version 2.0, the API is serde-based and hence you'll find it very intuitive if you're already familiar with serde. If you're not familiar with serde, you may want to first read its tutorial before learning further about this crate.
Serialization and deserialization is achieved through the toplevel functions:
use HashMap;
use LE;
use ;
use EncodingContext as Context;
// All serialization and deserialization API, needs a context.
let ctxt = new_dbus;
// You can also use the more efficient GVariant format:
// let ctxt = Context::<LE>::new_gvariant(0);
// i16
let encoded = to_bytes.unwrap;
let decoded: i16 = from_slice.unwrap;
assert_eq!;
// strings
let encoded = to_bytes.unwrap;
let decoded: &str = from_slice.unwrap;
assert_eq!;
// tuples
let t = ;
let encoded = to_bytes.unwrap;
let decoded: = from_slice.unwrap;
assert_eq!;
// Vec
let v = vec!;
let encoded = to_bytes.unwrap;
let decoded: = from_slice.unwrap;
assert_eq!;
// Dictionary
let mut map: = new;
map.insert;
map.insert;
let encoded = to_bytes.unwrap;
let decoded: = from_slice.unwrap;
assert_eq!;
assert_eq!;
Apart from the obvious requirement of EncodingContext
instance by the main serialization and
deserialization API, the type being serialized or deserialized must also implement Type
trait in addition to Serialize
or Deserialize
, respectively. Please refer to Type
module documentation for more details.
Most of the basic types of D-Bus match 1-1 with all the primitive Rust types. The only two
exceptions being, Signature
and ObjectPath
, which are really just strings. These types
are covered by the Basic
trait.
Similarly, most of the container types also map nicely to the usual Rust types and
collections (as can be seen in the example code above). The only note worthy exception being
ARRAY type. As arrays in Rust are fixed-sized, serde treats them as tuples and so does this
crate. This means they are encoded as STRUCT type of D-Bus. If you need to serialize to, or
deserialize from a D-Bus array, you'll need to use a slice (array can easily be converted to a
slice), a Vec
or an arrayvec::ArrayVec
.
D-Bus string types, including Signature
and ObjectPath
, require one additional
restriction that strings in Rust do not. They must not contain any interior null bytes ('\0'
).
Encoding/Decoding strings that contain this character will return an error.
The generic D-Bus type, VARIANT
is represented by Value
, an enum that holds exactly one
value of any of the other types. Please refer to Value
module documentation for examples.
no-std
While std
is currently a hard requirement, optional no-std
support is planned in the future.
On the other hand, noalloc
support is not planned as it will be extremely difficult to
accomplish. However, community contribution can change that. 😊
Optional features
Feature | Description |
---|---|
arrayvec | Implement Type for arrayvec::ArrayVec and arrayvec::ArrayString |
enumflags2 | Implement Type for [struct@enumflags2::BitFlags<F> ] |
Portability
zvariant is currently Unix-only and will fail to build on non-unix. This is hopefully a temporary limitation.