Struct subspace_farmer::cluster::nats_client::NatsClient

pub struct NatsClient { /* private fields */ }

NATS client wrapper that can be used to interact with other Subspace-specific clients

Implementations

impl NatsClient

pub async fn new<A: ToServerAddrs>( addrs: A, request_retry_backoff_policy: ExponentialBackoff, ) -> Result<Self, Error>

Create new instance by connecting to specified addresses

pub fn from_client( client: Client, request_retry_backoff_policy: ExponentialBackoff, ) -> Result<Self, Error>

Create new client from existing NATS instance

pub fn approximate_max_message_size(&self) -> usize

Approximate max message size (a few more bytes will not hurt), the actual limit is expected to be a bit higher

pub async fn request<Request>( &self, request: &Request, instance: Option<&str>, ) -> Result<Request::Response, RequestError>

where Request: GenericRequest,

Make request and wait for response

pub async fn request_responder<Request, F, OP>( &self, instance: Option<&str>, queue_group: Option<String>, process: OP, ) -> Result<()>

where Request: GenericRequest, F: Future<Output = Option<Request::Response>> + Send, OP: Fn(Request) -> F + Send + Sync,

Responds to requests from the given subject using the provided processing function.

This will create a subscription on the subject for the given instance (if provided) and queue group. Incoming messages will be deserialized as the request type Request and passed to the process function to produce a response of type Request::Response. The response will then be sent back on the reply subject from the original request.

Each request is processed in a newly created async tokio task.

Arguments

• instance - Optional instance name to use in place of the * in the subject
• group - The queue group name for the subscription
• process - The function to call with the decoded request to produce a response

pub async fn stream_request<Request>( &self, request: Request, instance: Option<&str>, ) -> Result<StreamResponseSubscriber<Request::Response>, StreamRequestError>

where Request: GenericStreamRequest,

Make request that expects stream response

pub async fn stream_response<Request, S>( &self, response_subject: String, response_stream: S, )

where Request: GenericStreamRequest, S: Stream<Item = Request::Response> + Unpin,

Helper method to send responses to requests initiated with Self::stream_request

pub async fn notification<Notification>( &self, notification: &Notification, instance: Option<&str>, ) -> Result<(), PublishError>

where Notification: GenericNotification,

Make notification without waiting for response

pub async fn broadcast<Broadcast>( &self, message: &Broadcast, instance: &str, ) -> Result<(), PublishError>

where Broadcast: GenericBroadcast,

Send a broadcast message

pub async fn subscribe_to_stream_requests<Request>( &self, instance: Option<&str>, queue_group: Option<String>, ) -> Result<SubscriberWrapper<StreamRequest<Request>>, SubscribeError>

where Request: GenericStreamRequest,

Simple subscription that will produce decoded stream requests, while skipping messages that fail to decode

pub async fn subscribe_to_notifications<Notification>( &self, instance: Option<&str>, queue_group: Option<String>, ) -> Result<SubscriberWrapper<Notification>, SubscribeError>

where Notification: GenericNotification,

Simple subscription that will produce decoded notifications, while skipping messages that fail to decode

pub async fn subscribe_to_broadcasts<Broadcast>( &self, instance: Option<&str>, queue_group: Option<String>, ) -> Result<SubscriberWrapper<Broadcast>, SubscribeError>

where Broadcast: GenericBroadcast,

Simple subscription that will produce decoded broadcasts, while skipping messages that fail to decode

Methods from Deref<Target = Client>

pub fn server_info(&self) -> ServerInfo

Returns last received info from the server.

Examples

let client = async_nats::connect("demo.nats.io").await?;
println!("info: {:?}", client.server_info());

pub fn is_server_compatible(&self, major: i64, minor: i64, patch: i64) -> bool

Returns true if the server version is compatible with the version components.

Examples

let client = async_nats::connect("demo.nats.io").await?;
assert!(client.is_server_compatible(2, 8, 4));

pub async fn publish<S>( &self, subject: S, payload: Bytes, ) -> Result<(), Error<PublishErrorKind>>

where S: ToSubject,

Publish a [Message] to a given subject.

Examples

let client = async_nats::connect("demo.nats.io").await?;
client.publish("events.data", "payload".into()).await?;

pub async fn publish_with_headers<S>( &self, subject: S, headers: HeaderMap, payload: Bytes, ) -> Result<(), Error<PublishErrorKind>>

where S: ToSubject,

Publish a [Message] with headers to a given subject.

Examples

use std::str::FromStr;
let client = async_nats::connect("demo.nats.io").await?;
let mut headers = async_nats::HeaderMap::new();
headers.insert(
    "X-Header",
    async_nats::HeaderValue::from_str("Value").unwrap(),
);
client
    .publish_with_headers("events.data", headers, "payload".into())
    .await?;

pub async fn publish_with_reply<S, R>( &self, subject: S, reply: R, payload: Bytes, ) -> Result<(), Error<PublishErrorKind>>

where S: ToSubject, R: ToSubject,

Publish a [Message] to a given subject, with specified response subject to which the subscriber can respond. This method does not await for the response.

Examples

let client = async_nats::connect("demo.nats.io").await?;
client
    .publish_with_reply("events.data", "reply_subject", "payload".into())
    .await?;

pub async fn publish_with_reply_and_headers<S, R>( &self, subject: S, reply: R, headers: HeaderMap, payload: Bytes, ) -> Result<(), Error<PublishErrorKind>>

where S: ToSubject, R: ToSubject,

Publish a [Message] to a given subject with headers and specified response subject to which the subscriber can respond. This method does not await for the response.

Examples

use std::str::FromStr;
let client = async_nats::connect("demo.nats.io").await?;
let mut headers = async_nats::HeaderMap::new();
client
    .publish_with_reply_and_headers("events.data", "reply_subject", headers, "payload".into())
    .await?;

pub async fn request<S>( &self, subject: S, payload: Bytes, ) -> Result<Message, Error<RequestErrorKind>>

where S: ToSubject,

Sends the request with headers.

Examples

let client = async_nats::connect("demo.nats.io").await?;
let response = client.request("service", "data".into()).await?;

pub async fn request_with_headers<S>( &self, subject: S, headers: HeaderMap, payload: Bytes, ) -> Result<Message, Error<RequestErrorKind>>

where S: ToSubject,

Sends the request with headers.

Examples

let client = async_nats::connect("demo.nats.io").await?;
let mut headers = async_nats::HeaderMap::new();
headers.insert("Key", "Value");
let response = client
    .request_with_headers("service", headers, "data".into())
    .await?;

pub async fn send_request<S>( &self, subject: S, request: Request, ) -> Result<Message, Error<RequestErrorKind>>

where S: ToSubject,

Sends the request created by the [Request].

Examples

let client = async_nats::connect("demo.nats.io").await?;
let request = async_nats::Request::new().payload("data".into());
let response = client.send_request("service", request).await?;

pub fn new_inbox(&self) -> String

Create a new globally unique inbox which can be used for replies.

Examples

let reply = nc.new_inbox();
let rsub = nc.subscribe(reply).await?;

pub async fn subscribe<S>( &self, subject: S, ) -> Result<Subscriber, SubscribeError>

where S: ToSubject,

Subscribes to a subject to receive [messages][Message].

Examples

use futures::StreamExt;
let client = async_nats::connect("demo.nats.io").await?;
let mut subscription = client.subscribe("events.>").await?;
while let Some(message) = subscription.next().await {
    println!("received message: {:?}", message);
}

pub async fn queue_subscribe<S>( &self, subject: S, queue_group: String, ) -> Result<Subscriber, SubscribeError>

where S: ToSubject,

Subscribes to a subject with a queue group to receive [messages][Message].

Examples

use futures::StreamExt;
let client = async_nats::connect("demo.nats.io").await?;
let mut subscription = client.queue_subscribe("events.>", "queue".into()).await?;
while let Some(message) = subscription.next().await {
    println!("received message: {:?}", message);
}

pub async fn flush(&self) -> Result<(), Error<FlushErrorKind>>

Flushes the internal buffer ensuring that all messages are sent.

Examples

let client = async_nats::connect("demo.nats.io").await?;
client.flush().await?;

pub fn connection_state(&self) -> State

Returns the current state of the connection.

Examples

let client = async_nats::connect("demo.nats.io").await?;
println!("connection state: {}", client.connection_state());

pub async fn force_reconnect(&self) -> Result<(), ReconnectError>

Forces the client to reconnect. Keep in mind that client will reconnect automatically if the connection is lost and this method does not have to be used in normal circumstances. However, if you want to force the client to reconnect, for example to re-trigger the auth-callback, or manually rebalance connections, this method can be useful. This method does not wait for connection to be re-established.

Examples

let client = async_nats::connect("demo.nats.io").await?;
client.force_reconnect().await?;

Trait Implementations

impl Clone for NatsClient

fn clone(&self) -> NatsClient

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NatsClient

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for NatsClient

type Target = Client

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.