Agent: durable turn and queue state, visible inbox closure, OpenAI phase; prompt fixes; fetch/bench fixes

examples/fetch/src/main.rs

@@ -2,6 +2,32 @@
 use sausage_actor::{Inbox, Message, json, me, reply};
 use wstd::http::{Body, Client, Request};
 
+fn next_fetch_id() -> Result<u64, String> {
+    let previous = match std::fs::read_to_string("/data/fetch-sequence") {
+        Ok(value) => value.parse::<u64>().map_err(|e| e.to_string())?,
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => existing_fetch_id()?,
+        Err(e) => return Err(e.to_string()),
+    };
+    let next = previous
+        .checked_add(1)
+        .ok_or_else(|| "fetch ID space exhausted".to_string())?;
+    std::fs::write("/data/fetch-sequence", next.to_string()).map_err(|e| e.to_string())?;
+    Ok(next)
+}
+
+fn existing_fetch_id() -> Result<u64, String> {
+    let entries = match std::fs::read_dir("/public/fetch") {
+        Ok(entries) => entries,
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => return Ok(0),
+        Err(e) => return Err(e.to_string()),
+    };
+    Ok(entries
+        .filter_map(Result::ok)
+        .filter_map(|entry| entry.file_name().to_str()?.parse().ok())
+        .max()
+        .unwrap_or(0))
+}
+
 async fn fetch(n: u64, message: Message) {
     let url = message.body["url"].as_str().unwrap_or_default();
     let started = wstd::time::Instant::now();
@@ -41,12 +67,13 @@ async fn fetch(n: u64, message: Message) {
 fn main() {
     wstd::runtime::block_on(async {
         let inbox = Inbox::start();
-        let mut n = 0;
         while let Some(message) = inbox.recv().await {
             match message.kind() {
-                "fetch" => {
-                    n += 1;
-                    wstd::runtime::spawn(fetch(n, message)).detach();
+                "fetch" => match next_fetch_id() {
+                    Ok(n) => wstd::runtime::spawn(fetch(n, message)).detach(),
+                    Err(reason) => {
+                        let _ = reply(&message, json!({"type": "error", "reason": reason}));
+                    }
                 }
                 "ping" => {
                     let _ = reply(&message, json!({"type": "pong"}));