From 2243cacf70046aff615242b0a6a0f569cca3289d Mon Sep 17 00:00:00 2001
From: Bryan Stitt <bryan@satoshiandkin.com>
Date: Sun, 5 Jun 2022 22:39:44 +0000
Subject: [PATCH] new heads subscription works

---
 web3-proxy/src/app.rs               | 13 ++++++++-----
 web3-proxy/src/config.rs            |  2 +-
 web3-proxy/src/frontend/errors.rs   |  6 ++----
 web3-proxy/src/frontend/ws_proxy.rs |  2 +-
 web3-proxy/src/jsonrpc.rs           |  4 +++-
 5 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/web3-proxy/src/app.rs b/web3-proxy/src/app.rs
index 1bd1eb72..c7d898d3 100644
--- a/web3-proxy/src/app.rs
+++ b/web3-proxy/src/app.rs
@@ -158,13 +158,12 @@ impl Web3ProxyApp {
         let f = {
             let subscription_id = subscription_id.clone();
 
-            let id = payload.id;
             let params = payload.params.as_deref().unwrap().get();
 
             if params == r#"["newHeads"]"# {
                 let head_block_receiver = self.head_block_receiver.clone();
 
-                info!("received new heads subscription");
+                trace!(?subscription_id, "new heads subscription");
                 async move {
                     let mut head_block_receiver = Abortable::new(
                         WatchStream::new(head_block_receiver),
@@ -172,9 +171,8 @@ impl Web3ProxyApp {
                     );
 
                     while let Some(new_head) = head_block_receiver.next().await {
-                        // TODO: make a struct for this? using JsonRpcForwardedResponse
+                        // TODO: make a struct for this? using JsonRpcForwardedResponse won't work because it needs an id
                         let msg = json!({
-                            "id": id,
                             "jsonrpc": "2.0",
                             "method":"eth_subscription",
                             "params": {
@@ -185,8 +183,13 @@ impl Web3ProxyApp {
 
                         let msg = Message::Text(serde_json::to_string(&msg).unwrap());
 
-                        subscription_tx.send_async(msg).await.unwrap();
+                        if subscription_tx.send_async(msg).await.is_err() {
+                            // TODO: cancel this subscription earlier? select on head_block_receiver.next() and an abort handle?
+                            break;
+                        };
                     }
+
+                    trace!(?subscription_id, "closed new heads subscription");
                 }
             } else {
                 return Err(anyhow::anyhow!("unimplemented"));
diff --git a/web3-proxy/src/config.rs b/web3-proxy/src/config.rs
index a2415d30..e08be760 100644
--- a/web3-proxy/src/config.rs
+++ b/web3-proxy/src/config.rs
@@ -13,7 +13,7 @@ pub struct CliConfig {
     #[argh(option, default = "8544")]
     pub port: u16,
 
-    /// number of worker threads
+    /// number of worker threads. Defaults to the number of logical processors
     #[argh(option, default = "0")]
     pub workers: usize,
 
diff --git a/web3-proxy/src/frontend/errors.rs b/web3-proxy/src/frontend/errors.rs
index 2fe25d6d..6ac9353c 100644
--- a/web3-proxy/src/frontend/errors.rs
+++ b/web3-proxy/src/frontend/errors.rs
@@ -12,12 +12,12 @@ pub async fn handler_404() -> impl IntoResponse {
 
 /// handle errors by converting them into something that implements `IntoResponse`
 /// TODO: use this. i can't get https://docs.rs/axum/latest/axum/error_handling/index.html to work
+/// TODO: i think we want a custom result type instead. put the anyhow result inside. then `impl IntoResponse for CustomResult`
 pub async fn handle_anyhow_error(
     err: anyhow::Error,
     code: Option<StatusCode>,
 ) -> impl IntoResponse {
-    // TODO: what id can we use? how do we make sure the incoming id gets attached to this?
-    let id = RawValue::from_string("0".to_string()).unwrap();
+    let id = RawValue::from_string("null".to_string()).unwrap();
 
     let err = JsonRpcForwardedResponse::from_anyhow_error(err, id);
 
@@ -27,5 +27,3 @@ pub async fn handle_anyhow_error(
 
     (code, Json(err))
 }
-
-// i think we want a custom result type. it has an anyhow result inside. if it impl IntoResponse I think we'll get this for free
diff --git a/web3-proxy/src/frontend/ws_proxy.rs b/web3-proxy/src/frontend/ws_proxy.rs
index 1f842cdf..6d2eb356 100644
--- a/web3-proxy/src/frontend/ws_proxy.rs
+++ b/web3-proxy/src/frontend/ws_proxy.rs
@@ -83,7 +83,7 @@ async fn handle_socket_payload(
         }
         Err(err) => {
             // TODO: what should this id be?
-            let id = RawValue::from_string("0".to_string()).unwrap();
+            let id = RawValue::from_string("null".to_string()).unwrap();
             (id, Err(err.into()))
         }
     };
diff --git a/web3-proxy/src/jsonrpc.rs b/web3-proxy/src/jsonrpc.rs
index f3809c1b..e0d82d49 100644
--- a/web3-proxy/src/jsonrpc.rs
+++ b/web3-proxy/src/jsonrpc.rs
@@ -193,7 +193,9 @@ impl JsonRpcForwardedResponse {
 
     pub fn from_string(partial_response: String, id: Box<RawValue>) -> Self {
         trace!("partial_response: {}", partial_response);
-        let partial_response = RawValue::from_string(partial_response).unwrap();
+        // TODO: anyhow result on this
+        // TODO: proper escaping. this feels wrong. probably refactor to not need this at all
+        let partial_response = RawValue::from_string(format!(r#""{}""#, partial_response)).unwrap();
 
         Self::from_response(partial_response, id)
     }