Add tagged VFS undo journal, host API, and world CLI

host/src/process/mod.rs

@@ -83,6 +83,7 @@ struct Entry {
     command: u32,
     group: u32,
     cancelled: Arc<AtomicBool>,
+    tag: sausage_vfs::journal::Tag,
     abort: AbortHandle,
 }
 /// One runtime keeps compiled components warm and shares the world's namespace across stores.
@@ -191,6 +192,7 @@ impl Runtime {
                 "http://localhost:8081",
             )?),
         };
+        router.attach_journal(world.root.journal());
         let network = Arc::new(net::NetPolicy::open(&world.host_dir)?);
         let engine = compiler.engine.clone();
         let alive = Arc::new(AtomicBool::new(true));
@@ -313,6 +315,7 @@ impl Runtime {
         self.kill_group(group);
         Ok(())
     }
+    #[allow(clippy::too_many_arguments)]
     async fn start(
         self: &Arc<Self>,
         mut request: Request,
@@ -321,6 +324,7 @@ impl Runtime {
         inherited_group: u32,
         conversations: Vec<String>,
         inherited_io: Option<Io>,
+        tool_call: Option<String>,
     ) -> anyhow::Result<Started> {
         anyhow::ensure!(!request.argv.is_empty(), "empty argv");
         let cancelled = if parent == 0 {
@@ -361,6 +365,27 @@ impl Runtime {
         let pre = self.compiler.get(bytes.clone()).await?;
         self.cache.lock().unwrap().insert(bytes);
         let pid = self.next.fetch_add(1, Ordering::Relaxed);
+        let tag = if parent == 0 {
+            let mut tag =
+                sausage_vfs::journal::Tag::process(pid, executable.clone(), conversations.clone())?;
+            if let Some(id) = tool_call {
+                tag.id = id;
+            }
+            tag
+        } else {
+            self.entries
+                .lock()
+                .unwrap()
+                .get(&parent)
+                .ok_or_else(|| anyhow::anyhow!("parent exited"))?
+                .tag
+                .clone()
+        };
+        let root = self
+            .world
+            .root
+            .tagged(tag.clone())
+            .unwrap_or_else(|| self.world.root.clone());
         let command = if command == 0 { pid } else { command };
         let group = match request.group {
             Some(0) => pid,
@@ -384,7 +409,7 @@ impl Runtime {
         };
         let preview1 = if matches!(pre, Compiled::Module(_)) {
             Some(sausage_vfs::preview1::State::new(
-                self.world.root.clone(),
+                root.clone(),
                 &request.cwd,
                 request.argv.clone(),
                 request.env.clone(),
@@ -396,7 +421,7 @@ impl Runtime {
             None
         };
         let mut mounts = Mounts::default();
-        mounts.mount("/", self.world.root.clone(), false);
+        mounts.mount("/", root, false);
         let mut wasi = WasiCtxBuilder::new();
         wasi.args(&request.argv)
             .envs(&request.env)
@@ -499,6 +524,7 @@ impl Runtime {
                     command,
                     group,
                     cancelled: cancelled.clone(),
+                    tag,
                     abort: task.abort_handle(),
                 },
             );
@@ -552,6 +578,7 @@ impl Host for State {
                 self.group,
                 self.conversations.clone(),
                 Some(self.stdio.clone()),
+                None,
             )
             .await
         {
@@ -706,6 +733,7 @@ impl Exec for Arc<Runtime> {
             0,
             options.conversations,
             None,
+            options.tool_call,
         );
         let mut child = if let Some(deadline) = deadline {
             tokio::time::timeout_at(deadline, start)
@@ -737,13 +765,17 @@ impl Exec for Arc<Runtime> {
                 child.code.changed().await?;
             }
         };
-        if let Some(deadline) = deadline {
+        let result = if let Some(deadline) = deadline {
             tokio::time::timeout_at(deadline, run)
                 .await
                 .map_err(|_| anyhow::anyhow!("command timed out"))?
         } else {
             run.await
+        };
+        if let Some(journal) = self.world.root.journal() {
+            journal.retain().await?;
         }
+        result
     }
 }
 /// Construct the harness's shared executor over the same open world.

host/src/process/services.rs

@@ -33,6 +33,7 @@ pub fn supervise(runtime: Arc<Runtime>) -> Supervisor {
                 0,
                 Vec::new(),
                 None,
+                None,
             );
             let child = tokio::select! { _ = &mut stop => return, child = start => child };
             if let Ok(mut child) = child {