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|
pub mod builder;
use std::{collections::HashMap, sync::Arc, time::Duration};
use log::{debug, error, warn};
use serde::{de::DeserializeOwned, Serialize};
use serde_json::json;
use karyon_core::{
async_runtime::lock::Mutex,
async_util::{timeout, TaskGroup, TaskResult},
util::random_32,
};
use karyon_net::Conn;
use crate::{
message::{self, SubscriptionID},
Error, Result,
};
const CHANNEL_CAP: usize = 10;
/// Type alias for a subscription to receive notifications.
///
/// The receiver channel is returned by the `subscribe` method to receive
/// notifications from the server.
pub type Subscription = async_channel::Receiver<serde_json::Value>;
/// Represents an RPC client
pub struct Client {
conn: Conn<serde_json::Value>,
timeout: Option<u64>,
chans: Mutex<HashMap<u32, async_channel::Sender<message::Response>>>,
subscriptions: Mutex<HashMap<SubscriptionID, async_channel::Sender<serde_json::Value>>>,
task_group: TaskGroup,
}
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 (ch_tx, ch_rx) = async_channel::bounded(CHANNEL_CAP);
self.subscriptions.lock().await.insert(sub_id, ch_tx);
Ok((sub_id, ch_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.subscriptions.lock().await.remove(&sub_id);
Ok(())
}
async fn send_request<T: Serialize + DeserializeOwned>(
&self,
method: &str,
params: T,
) -> Result<message::Response> {
let id = 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)?;
self.conn.send(req_json).await?;
let (tx, rx) = async_channel::bounded(CHANNEL_CAP);
self.chans.lock().await.insert(id, tx);
let response = match self.wait_for_response(rx).await {
Ok(r) => r,
Err(err) => {
self.chans.lock().await.remove(&id);
return Err(err);
}
};
if let Some(error) = response.error {
return Err(Error::SubscribeError(error.code, error.message));
}
if *response.id.as_ref().unwrap() != request.id {
return Err(Error::InvalidMsg("Invalid response id"));
}
debug!("--> {request}");
Ok(response)
}
async fn wait_for_response(
&self,
rx: async_channel::Receiver<message::Response>,
) -> Result<message::Response> {
match self.timeout {
Some(t) => timeout(Duration::from_millis(t), rx.recv())
.await?
.map_err(Error::from),
None => rx.recv().await.map_err(Error::from),
}
}
fn start_background_receiving(self: &Arc<Self>) {
let selfc = self.clone();
let on_failure = |result: TaskResult<Result<()>>| async move {
if let TaskResult::Completed(Err(err)) = result {
error!("background receiving stopped: {err}");
}
// drop all subscription channels
selfc.subscriptions.lock().await.clear();
};
let selfc = self.clone();
self.task_group.spawn(
async move {
loop {
let msg = selfc.conn.recv().await?;
if let Err(err) = selfc.handle_msg(msg).await {
error!(
"Failed to handle a new received msg from the connection {} : {err}",
selfc.conn.peer_endpoint()?
);
}
}
},
on_failure,
);
}
async fn handle_msg(&self, msg: serde_json::Value) -> Result<()> {
if let Ok(res) = serde_json::from_value::<message::Response>(msg.clone()) {
debug!("<-- {res}");
if res.id.is_none() {
return Err(Error::InvalidMsg("Response id is none"));
}
let id: u32 = serde_json::from_value(res.id.clone().unwrap())?;
match self.chans.lock().await.remove(&id) {
Some(tx) => tx.send(res).await?,
None => return Err(Error::InvalidMsg("Receive unkown message")),
}
return Ok(());
}
if let Ok(nt) = serde_json::from_value::<message::Notification>(msg.clone()) {
debug!("<-- {nt}");
let sub_result: message::NotificationResult = match nt.params {
Some(ref p) => serde_json::from_value(p.clone())?,
None => return Err(Error::InvalidMsg("Invalid notification msg")),
};
match self
.subscriptions
.lock()
.await
.get(&sub_result.subscription)
{
Some(s) => {
s.send(sub_result.result.unwrap_or(json!(""))).await?;
return Ok(());
}
None => {
warn!("Receive unknown notification {}", sub_result.subscription);
return Ok(());
}
}
}
error!("Receive unexpected msg: {msg}");
Err(Error::InvalidMsg("Unexpected msg"))
}
}
|
