query tracing

Cargo.toml

@@ -34,7 +34,15 @@ bs58 = "0.5.1"
 chrono = "0.4.38"
 clap = { version = "4.5.4", features = ["derive", "env"] }
 derivative = "2.2.0"
-diesel = { version = "2.2.4", features = ["postgres", "serde_json", "numeric", "r2d2", "chrono", "uuid", "i-implement-a-third-party-backend-and-opt-into-breaking-changes"] }
+diesel = { version = "2.2.4", features = [
+    "postgres",
+    "serde_json",
+    "numeric",
+    "r2d2",
+    "chrono",
+    "uuid",
+    "i-implement-a-third-party-backend-and-opt-into-breaking-changes",
+] }
 diesel-derive-enum = { version = "2.1.0", features = ["postgres"] }
 diesel-dynamic-schema = { version = "0.2.1", features = ["postgres"] }
 diesel_derives = "2.1.4"
@@ -56,7 +64,10 @@ serde_derive = "1.0.125"
 serde_json = { version = "1.0", features = ["arbitrary_precision"] }
 serde_regex = "1.1.0"
 serde_yaml = "0.9.21"
-slog = { version = "2.7.0", features = ["release_max_level_trace", "max_level_trace"] }
+slog = { version = "2.7.0", features = [
+    "release_max_level_trace",
+    "max_level_trace",
+] }
 sqlparser = "0.46.0"
 strum = { version = "0.26", features = ["derive"] }
 syn = { version = "2.0.66", features = ["full"] }

graph/build.rs

@@ -25,4 +25,10 @@ fn main() {
         .out_dir("src/substreams_rpc")
         .compile(&["proto/substreams-rpc.proto"], &["proto"])
         .expect("Failed to compile Substreams RPC proto(s)");
+
+    tonic_build::configure()
+        .out_dir("src/grpc/pb")
+        .include_file("mod.rs")
+        .compile(&["proto/tracing.proto"], &["proto"])
+        .expect("Failed to compile Tracing proto(s)");
 }

graph/proto/tracing.proto

@@ -0,0 +1,17 @@
+syntax = "proto3";
+
+package graph.tracing.v1;
+
+service Stream {
+  rpc QueryTrace(Request) returns (stream Trace);
+}
+
+message Request {
+    int32 deployment_id = 1;
+}
+
+message Trace {
+    int32 deployment_id = 1;
+    string query = 2;
+    uint64 duration_millis = 3;
+}

graph/src/components/mod.rs

@@ -60,6 +60,8 @@ pub mod metrics;
 /// Components dealing with versioning
 pub mod versions;
 
+pub mod tracing;
+
 /// A component that receives events of type `T`.
 pub trait EventConsumer<E> {
     /// Get the event sink.

graph/src/components/tracing.rs

@@ -0,0 +1,123 @@
+use std::{collections::HashMap, sync::atomic::AtomicBool};
+
+use tokio::sync::{mpsc, RwLock};
+
+use super::store::DeploymentId;
+
+const DEFAULT_BUFFER_SIZE: usize = 100;
+
+#[derive(Debug)]
+pub struct Subscriptions<T> {
+    inner: RwLock<HashMap<DeploymentId, mpsc::Sender<T>>>,
+}
+
+/// A control structure for managing tracing subscriptions.
+#[derive(Debug)]
+pub struct TracingControl<T> {
+    enabled: AtomicBool,
+    subscriptions: Subscriptions<T>,
+    default_buffer_size: usize,
+}
+
+impl<T> Default for TracingControl<T> {
+    fn default() -> Self {
+        Self {
+            enabled: AtomicBool::new(false),
+            subscriptions: Subscriptions {
+                inner: RwLock::new(HashMap::new()),
+            },
+            default_buffer_size: DEFAULT_BUFFER_SIZE,
+        }
+    }
+}
+
+impl<T> TracingControl<T> {
+    pub fn new(default_buffer_size: Option<usize>) -> Self {
+        Self {
+            enabled: AtomicBool::new(false),
+            subscriptions: Subscriptions {
+                inner: RwLock::new(HashMap::new()),
+            },
+            default_buffer_size: default_buffer_size.unwrap_or(DEFAULT_BUFFER_SIZE),
+        }
+    }
+
+    /// Creates a channel sender for the given deployment ID. Only one subscription
+    /// can exist for a given deployment ID. If tracing is disabled or no subscription
+    /// exists, it will return None. Calling producer when a dead subscription exists
+    /// will incur a cleanup cost.
+    pub async fn producer(&self, key: DeploymentId) -> Option<mpsc::Sender<T>> {
+        if !self.enabled.load(std::sync::atomic::Ordering::Relaxed) {
+            return None;
+        }
+
+        let subs = self.subscriptions.inner.read().await;
+        let tx = subs.get(&key);
+
+        match tx {
+            Some(tx) if tx.is_closed() => {
+                drop(subs);
+                let mut subs = self.subscriptions.inner.write().await;
+                subs.remove(&key);
+
+                if subs.is_empty() {
+                    self.enabled
+                        .store(false, std::sync::atomic::Ordering::Relaxed);
+                }
+
+                None
+            }
+            None => None,
+            tx => tx.cloned(),
+        }
+    }
+    pub async fn subscribe_with_chan_size(
+        &self,
+        key: DeploymentId,
+        buffer_size: usize,
+    ) -> mpsc::Receiver<T> {
+        let (tx, rx) = mpsc::channel(buffer_size);
+        let mut guard = self.subscriptions.inner.write().await;
+        guard.insert(key, tx);
+        self.enabled
+            .store(true, std::sync::atomic::Ordering::Relaxed);
+
+        rx
+    }
+
+    /// Creates a new subscription for a given deployment ID. If a subscription already
+    /// exists, it will be replaced.
+    pub async fn subscribe(&self, key: DeploymentId) -> mpsc::Receiver<T> {
+        self.subscribe_with_chan_size(key, self.default_buffer_size)
+            .await
+    }
+}
+
+#[cfg(test)]
+mod test {
+
+    use super::*;
+    use std::sync::atomic::Ordering::Relaxed;
+    use std::sync::Arc;
+
+    #[tokio::test]
+    async fn test_tracing_control() {
+        let control: TracingControl<()> = TracingControl::default();
+        let control = Arc::new(control);
+        assert_eq!(false, control.enabled.load(Relaxed));
+
+        let tx = control.producer(DeploymentId(123)).await;
+        assert!(tx.is_none());
+
+        let rx = control.subscribe(DeploymentId(123)).await;
+        assert_eq!(true, control.enabled.load(Relaxed));
+
+        drop(rx);
+        let tx = control.producer(DeploymentId(123)).await;
+        assert!(tx.is_none());
+        assert_eq!(false, control.enabled.load(Relaxed));
+
+        _ = control.subscribe(DeploymentId(123)).await;
+        assert_eq!(true, control.enabled.load(Relaxed));
+    }
+}

graph/src/data/query/trace.rs

@@ -14,7 +14,7 @@ lazy_static! {
     pub static ref TRACE_NONE: Arc<Trace> = Arc::new(Trace::None);
 }
 
-#[derive(Debug, CacheWeight)]
+#[derive(Debug, CacheWeight, Clone)]
 pub struct TraceWithCacheStatus {
     pub trace: Arc<Trace>,
     pub cache_status: CacheStatus,
@@ -35,7 +35,7 @@ impl HttpTrace {
     }
 }
 
-#[derive(Debug, CacheWeight)]
+#[derive(Debug, CacheWeight, Clone)]
 pub enum Trace {
     None,
     Root {

graph/src/grpc/mod.rs

@@ -0,0 +1,4 @@
+use pb::graph::tracing::v1::{Request, Trace};
+use tonic::async_trait;
+
+pub mod pb;