Remove single-string API boundary

collector/src/api.rs

@@ -22,3 +22,10 @@ pub mod collected {
         // nothing
     }
 }
+
+pub mod next_commit {
+    #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+    pub struct Response {
+        pub commit: Option<String>,
+    }
+}

collector/src/main.rs

@@ -171,13 +171,14 @@ fn bench_next(
 ) -> anyhow::Result<()> {
     println!("processing commits");
     let client = reqwest::blocking::Client::new();
-    let commit: Option<String> = client
+    let response: collector::api::next_commit::Response = client
         .get(&format!("{}/perf/next_commit", site_url))
         .send()?
         .json()?;
-    let commit = if let Some(c) = commit {
+    let commit = if let Some(c) = response.commit {
         c
     } else {
+        println!("no commit to benchmark");
         // no missing commits
         return Ok(());
     };

site/src/server.rs

@@ -288,12 +288,15 @@ pub async fn handle_status_page(data: Arc<InputData>) -> status::Response {
     }
 }
 
-pub async fn handle_next_commit(data: Arc<InputData>) -> Option<String> {
-    data.missing_commits()
+pub async fn handle_next_commit(data: Arc<InputData>) -> collector::api::next_commit::Response {
+    let commit = data
+        .missing_commits()
         .await
         .iter()
         .next()
-        .map(|c| c.0.sha.to_string())
+        .map(|c| c.0.sha.to_string());
+
+    collector::api::next_commit::Response { commit }
 }
 
 struct CommitIdxCache {