Remove worktree and project notifies (#26244)

This reduces the number of multibuffer syncs from 100,000 to 20,000.
Before this change each editor individually observed the project, so
literally any project change was amplified by the number of editors you
had open.

Now editors listen to their buffers instead of the project, and other
users of `cx.observe` on the project have been updated to use specific
events to reduce churn.

Follow up to #26237


Release Notes:

- Improved performance of Zed in large repos with lots of file system
events.

---------

Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>

crates/project/src/project.rs

@@ -22,7 +22,7 @@ mod project_tests;
 mod direnv;
 mod environment;
 use buffer_diff::BufferDiff;
-pub use environment::EnvironmentErrorMessage;
+pub use environment::{EnvironmentErrorMessage, ProjectEnvironmentEvent};
 use git::Repository;
 pub mod search_history;
 mod yarn;
@@ -886,7 +886,6 @@ impl Project {
             });
 
             cx.subscribe(&ssh, Self::on_ssh_event).detach();
-            cx.observe(&ssh, |_, _, cx| cx.notify()).detach();
 
             let this = Self {
                 buffer_ordered_messages_tx: tx,
@@ -1371,9 +1370,9 @@ impl Project {
         self.environment.read(cx).environment_errors()
     }
 
-    pub fn remove_environment_error(&mut self, cx: &mut Context<Self>, worktree_id: WorktreeId) {
-        self.environment.update(cx, |environment, _| {
-            environment.remove_environment_error(worktree_id);
+    pub fn remove_environment_error(&mut self, worktree_id: WorktreeId, cx: &mut Context<Self>) {
+        self.environment.update(cx, |environment, cx| {
+            environment.remove_environment_error(worktree_id, cx);
         });
     }
 
@@ -1764,7 +1763,6 @@ impl Project {
         };
 
         cx.emit(Event::RemoteIdChanged(Some(project_id)));
-        cx.notify();
         Ok(())
     }
 
@@ -1780,7 +1778,6 @@ impl Project {
         self.worktree_store.update(cx, |worktree_store, cx| {
             worktree_store.send_project_updates(cx);
         });
-        cx.notify();
         cx.emit(Event::Reshared);
         Ok(())
     }
@@ -1810,13 +1807,12 @@ impl Project {
         self.enqueue_buffer_ordered_message(BufferOrderedMessage::Resync)
             .unwrap();
         cx.emit(Event::Rejoined);
-        cx.notify();
         Ok(())
     }
 
     pub fn unshare(&mut self, cx: &mut Context<Self>) -> Result<()> {
         self.unshare_internal(cx)?;
-        cx.notify();
+        cx.emit(Event::RemoteIdChanged(None));
         Ok(())
     }
 
@@ -1860,7 +1856,6 @@ impl Project {
         }
         self.disconnected_from_host_internal(cx);
         cx.emit(Event::DisconnectedFromHost);
-        cx.notify();
     }
 
     pub fn set_role(&mut self, role: proto::ChannelRole, cx: &mut Context<Self>) {
@@ -2509,15 +2504,11 @@ impl Project {
         }
     }
 
-    fn on_worktree_added(&mut self, worktree: &Entity<Worktree>, cx: &mut Context<Self>) {
-        {
-            let mut remotely_created_models = self.remotely_created_models.lock();
-            if remotely_created_models.retain_count > 0 {
-                remotely_created_models.worktrees.push(worktree.clone())
-            }
+    fn on_worktree_added(&mut self, worktree: &Entity<Worktree>, _: &mut Context<Self>) {
+        let mut remotely_created_models = self.remotely_created_models.lock();
+        if remotely_created_models.retain_count > 0 {
+            remotely_created_models.worktrees.push(worktree.clone())
         }
-        cx.observe(worktree, |_, _, cx| cx.notify()).detach();
-        cx.notify();
     }
 
     fn on_worktree_released(&mut self, id_to_remove: WorktreeId, cx: &mut Context<Self>) {
@@ -2529,8 +2520,6 @@ impl Project {
                 })
                 .log_err();
         }
-
-        cx.notify();
     }
 
     fn on_buffer_event(
@@ -3804,7 +3793,6 @@ impl Project {
             cx.emit(Event::CollaboratorJoined(collaborator.peer_id));
             this.collaborators
                 .insert(collaborator.peer_id, collaborator);
-            cx.notify();
         })?;
 
         Ok(())
@@ -3848,7 +3836,6 @@ impl Project {
                 old_peer_id,
                 new_peer_id,
             });
-            cx.notify();
             Ok(())
         })?
     }
@@ -3876,7 +3863,6 @@ impl Project {
             });
 
             cx.emit(Event::CollaboratorLeft(peer_id));
-            cx.notify();
             Ok(())
         })?
     }
@@ -4292,7 +4278,6 @@ impl Project {
         worktrees: Vec<proto::WorktreeMetadata>,
         cx: &mut Context<Project>,
     ) -> Result<()> {
-        cx.notify();
         self.worktree_store.update(cx, |worktree_store, cx| {
             worktree_store.set_worktrees_from_proto(worktrees, self.replica_id(), cx)
         })