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|
pub mod builder;
mod message_dispatcher;
mod subscriber;
use log::{debug, error};
use serde::{de::DeserializeOwned, Serialize};
use serde_json::json;
use std::{sync::Arc, time::Duration};
use karyon_core::{
async_util::{timeout, TaskGroup, TaskResult},
util::random_32,
};
use karyon_net::Conn;
use crate::{
message::{self, SubscriptionID},
Error, Result,
};
use message_dispatcher::MessageDispatcher;
use subscriber::Subscriber;
pub use subscriber::Subscription;
type RequestID = u32;
/// Represents an RPC client
pub struct Client {
conn: Conn<serde_json::Value>,
timeout: Option<u64>,
message_dispatcher: MessageDispatcher,
task_group: TaskGroup,
subscriber: Subscriber,
}
impl Client {
/// Calls the provided method, waits for the response, and returns the result.
pub async fn call<T: Serialize + DeserializeOwned, V: DeserializeOwned>(
&self,
method: &str,
params: T,
) -> Result<V> {
let response = self.send_request(method, params).await?;
match response.result {
Some(result) => Ok(serde_json::from_value::<V>(result)?),
None => Err(Error::InvalidMsg("Invalid response result")),
}
}
/// Subscribes to the provided method, waits for the response, and returns the result.
///
/// This function sends a subscription request to the specified method
/// with the given parameters. It waits for the response and returns a
/// tuple containing a `SubscriptionID` and a `Subscription` (channel receiver).
pub async fn subscribe<T: Serialize + DeserializeOwned>(
&self,
method: &str,
params: T,
) -> Result<(SubscriptionID, Subscription)> {
let response = self.send_request(method, params).await?;
let sub_id = match response.result {
Some(result) => serde_json::from_value::<SubscriptionID>(result)?,
None => return Err(Error::InvalidMsg("Invalid subscription id")),
};
let rx = self.subscriber.subscribe(sub_id).await;
Ok((sub_id, rx))
}
/// Unsubscribes from the provided method, waits for the response, and returns the result.
///
/// This function sends an unsubscription request for the specified method
/// and subscription ID. It waits for the response to confirm the unsubscription.
pub async fn unsubscribe(&self, method: &str, sub_id: SubscriptionID) -> Result<()> {
let _ = self.send_request(method, sub_id).await?;
self.subscriber.unsubscribe(&sub_id).await;
Ok(())
}
async fn send_request<T: Serialize + DeserializeOwned>(
&self,
method: &str,
params: T,
) -> Result<message::Response> {
let id: RequestID = random_32();
let request = message::Request {
jsonrpc: message::JSONRPC_VERSION.to_string(),
id: json!(id),
method: method.to_string(),
params: Some(json!(params)),
};
let req_json = serde_json::to_value(&request)?;
// Send the json request
self.conn.send(req_json).await?;
debug!("--> {request}");
// Register a new request
let rx = self.message_dispatcher.register(id).await;
// Wait for the message dispatcher to send the response
let result = match self.timeout {
Some(t) => timeout(Duration::from_millis(t), rx.recv()).await?,
None => rx.recv().await,
};
let response = match result {
Ok(r) => r,
Err(err) => {
// Unregister the request if an error occurs
self.message_dispatcher.unregister(&id).await;
return Err(err.into());
}
};
if let Some(error) = response.error {
return Err(Error::SubscribeError(error.code, error.message));
}
// It should be OK to unwrap here, as the message dispatcher checks
// for the response id.
if *response.id.as_ref().unwrap() != request.id {
return Err(Error::InvalidMsg("Invalid response id"));
}
Ok(response)
}
fn start_background_receiving(self: &Arc<Self>) {
let selfc = self.clone();
let on_complete = |result: TaskResult<Result<()>>| async move {
if let TaskResult::Completed(Err(err)) = result {
error!("background receiving stopped: {err}");
}
// Drop all subscription
selfc.subscriber.drop_all().await;
};
let selfc = self.clone();
// Spawn a new task for listing to new coming messages.
self.task_group.spawn(
async move {
loop {
let msg = selfc.conn.recv().await?;
if let Err(err) = selfc.handle_msg(msg).await {
error!(
"Handle a msg from the endpoint {} : {err}",
selfc.conn.peer_endpoint()?
);
}
}
},
on_complete,
);
}
async fn handle_msg(&self, msg: serde_json::Value) -> Result<()> {
// Check if the received message is of type Response
if let Ok(res) = serde_json::from_value::<message::Response>(msg.clone()) {
debug!("<-- {res}");
self.message_dispatcher.dispatch(res).await?;
return Ok(());
}
// Check if the received message is of type Notification
if let Ok(nt) = serde_json::from_value::<message::Notification>(msg.clone()) {
debug!("<-- {nt}");
self.subscriber.notify(nt).await?;
return Ok(());
}
error!("Receive unexpected msg: {msg}");
Err(Error::InvalidMsg("Unexpected msg"))
}
}
|
