Invalidate all files in the graph when we get a rescan event.

[ci skip-build-wheels]

src/rust/engine/src/context.rs

@@ -399,6 +399,16 @@ impl Invalidatable for InvalidatableGraph {
     );
     cleared + dirtied
   }
+
+  fn invalidate_all(&self, caller: &str) -> usize {
+    let InvalidationResult { cleared, dirtied } =
+      self.invalidate_from_roots(|node| node.fs_subject().is_some());
+    info!(
+      "{} invalidation: cleared {} and dirtied {} nodes for all paths",
+      caller, cleared, dirtied
+    );
+    cleared + dirtied
+  }
 }
 
 impl Deref for InvalidatableGraph {

src/rust/engine/src/scheduler.rs

@@ -15,9 +15,9 @@ use crate::nodes::{Select, Visualizer};
 use crate::session::{ObservedValueResult, Root, Session};
 
 use futures::{future, FutureExt};
-use graph::{InvalidationResult, LastObserved};
+use graph::LastObserved;
 use hashing::{Digest, EMPTY_DIGEST};
-use log::{debug, info, warn};
+use log::{debug, warn};
 use stdio::TryCloneAsFile;
 use tempfile::TempDir;
 use tokio::process;
@@ -109,15 +109,7 @@ impl Scheduler {
   /// Invalidate all filesystem dependencies in the graph.
   ///
   pub fn invalidate_all_paths(&self) -> usize {
-    let InvalidationResult { cleared, dirtied } = self
-      .core
-      .graph
-      .invalidate_from_roots(|node| node.fs_subject().is_some());
-    info!(
-      "invalidation: cleared {} and dirtied {} nodes for all paths",
-      cleared, dirtied
-    );
-    cleared + dirtied
+    self.core.graph.invalidate_all("external")
   }
 
   ///

src/rust/engine/watch/src/lib.rs

@@ -39,6 +39,7 @@ use std::time::Duration;
 use crossbeam_channel::{self, Receiver, RecvTimeoutError, TryRecvError};
 use fs::GitignoreStyleExcludes;
 use log::{debug, trace, warn};
+use notify::event::Flag;
 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
 use parking_lot::Mutex;
 use task_executor::Executor;
@@ -159,6 +160,7 @@ impl InvalidationWatcher {
         };
         match event_res {
           Ok(Ok(ev)) => {
+            let flag = ev.flag();
             let paths: HashSet<_> = ev
               .paths
               .into_iter()
@@ -198,10 +200,13 @@ impl InvalidationWatcher {
               .collect();
 
             // Only invalidate stuff if we have paths that weren't filtered out by gitignore.
-            if !paths.is_empty() {
+            if flag == Some(Flag::Rescan) {
+              debug!("notify queue overflowed: invalidating all paths");
+              invalidatable.invalidate_all("notify");
+            } else if !paths.is_empty() {
               debug!("notify invalidating {:?} because of {:?}", paths, ev.kind);
               invalidatable.invalidate(&paths, "notify");
-            };
+            }
           }
           Ok(Err(err)) => {
             if let notify::ErrorKind::PathNotFound = err.kind {
@@ -282,6 +287,7 @@ impl InvalidationWatcher {
 
 pub trait Invalidatable: Send + Sync + 'static {
   fn invalidate(&self, paths: &HashSet<PathBuf>, caller: &str) -> usize;
+  fn invalidate_all(&self, caller: &str) -> usize;
 }
 
 ///

src/rust/engine/watch/src/tests.rs

@@ -157,4 +157,8 @@ impl Invalidatable for TestInvalidatable {
     calls.push(paths.clone());
     invalidated
   }
+
+  fn invalidate_all(&self, _caller: &str) -> usize {
+    unimplemented!();
+  }
 }