Expand description
zbus
This is the main subcrate of the zbus project, that provides the API to interact with D-Bus. It takes care of the establishment of a connection, the creation, sending and receiving of different kind of D-Bus messages (method calls, signals etc) for you.
Status: Stable.
Getting Started
The best way to get started with zbus is the book, where we start with basic D-Bus concepts and explain with code samples, how zbus makes D-Bus easy.
Example code
Server
A simple service that politely greets whoever calls its SayHello
method:
use std::{error::Error, future::pending};
use zbus::{ConnectionBuilder, dbus_interface};
struct Greeter {
count: u64
}
#[dbus_interface(name = "org.zbus.MyGreeter1")]
impl Greeter {
// Can be `async` as well.
fn say_hello(&mut self, name: &str) -> String {
self.count += 1;
format!("Hello {}! I have been called {} times.", name, self.count)
}
}
// Although we use `async-std` here, you can use any async runtime of choice.
#[async_std::main]
async fn main() -> Result<(), Box<dyn Error>> {
let greeter = Greeter { count: 0 };
let _ = ConnectionBuilder::session()?
.name("org.zbus.MyGreeter")?
.serve_at("/org/zbus/MyGreeter", greeter)?
.build()
.await?;
// Do other things or go to wait forever
pending::<()>().await;
Ok(())
}
You can use the following command to test it:
$ busctl --user call org.zbus.MyGreeter /org/zbus/MyGreeter org.zbus.MyGreeter1 SayHello s "Maria"
s "Hello Maria! I have been called 1 times."
Client
Now let’s write the client-side code for MyGreeter
service:
use zbus::{Connection, Result, dbus_proxy};
#[dbus_proxy(
interface = "org.zbus.MyGreeter1",
default_service = "org.zbus.MyGreeter",
default_path = "/org/zbus/MyGreeter"
)]
trait MyGreeter {
async fn say_hello(&self, name: &str) -> Result<String>;
}
// Although we use `async-std` here, you can use any async runtime of choice.
#[async_std::main]
async fn main() -> Result<()> {
let connection = Connection::session().await?;
// `dbus_proxy` macro creates `MyGreaterProxy` based on `Notifications` trait.
let proxy = MyGreeterProxy::new(&connection).await?;
let reply = proxy.say_hello("Maria").await?;
println!("{reply}");
Ok(())
}
Blocking API
While zbus is primarily asynchronous (since 2.0), blocking wrappers are provided for convenience.
Compatibility with async runtimes
zbus is runtime-agnostic and should work out of the box with different Rust async runtimes. However, in order to achieve that, zbus spawns a thread per connection to handle various internal tasks. If that is something you would like to avoid, you need to:
- Use
ConnectionBuilder
and disable theinternal_executor
flag. - Ensure the internal executor keeps ticking continuously.
Moreover, by default zbus makes use of async-io
for all I/O, which also launches its own thread
to run its own internal executor.
Special tokio support
Since tokio
is the most popular async runtime, zbus provides an easy way to enable tight
integration with it without you having to worry about any of the above: Enabling the tokio
feature:
[dependencies]
zbus = { version = "3", default-features = false, features = ["tokio"] }
That’s it! No threads launched behind your back by zbus (directly or indirectly) now and no need to tick any executors etc. 😼
Note: On Windows, the async-io
feature is currently required for UNIX domain socket support,
see the corresponding tokio issue on GitHub.
Note: On Windows, there is no standard implicit way to connect to a session bus. zbus provides
opt-in compatibility to the GDBus session bus discovery mechanism via the windows-gdbus
feature.
This mechanism uses a machine-wide mutex however, so only one GDBus session bus can run at a time.
Re-exports
pub use zbus_names as names;
pub use zvariant;
Modules
quick-xml
feature)xml
feature)Structs
zbus::Connection
.Interface
type.Interface
type.SignalContext
instance. A reference to the underlying interface may be obtained via
InterfaceRef::get
and InterfaceRef::get_mut
.MatchRule
.Message
MessageField
instances.Message
objects received by a single zbus::Connection
.stream::Stream
implementation that yields Message
items.MatchRule
.stream::Stream
implementation that yields UniqueName
when the bus owner changes.stream::Stream
implementation that yields property change notifications.stream::Stream
implementation that yields signal messages.tcp:
D-Bus address.tcp:
D-Bus address.Enums
Interface
callbacks.zbus
.Proxy::call_with_flags
.tcp:
address family.Constants
Traits
Type Definitions
Result
with the error type zbus::Error
.Attribute Macros
zbus::Proxy
and zbus::blocking::Proxy
).Derive Macros
zbus::DBusError
trait.