Patchwork D9203: dirstate-tree: simplify the control flow in the Node.insert method

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Submitter phabricator
Date Oct. 13, 2020, 9:25 p.m.
Message ID <differential-rev-PHID-DREV-pt5v3cfnzmpwdzoapjkg-req@mercurial-scm.org>
Download mbox | patch
Permalink /patch/47452/
State Superseded
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Comments

phabricator - Oct. 13, 2020, 9:25 p.m.
marmoute created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.

REVISION SUMMARY
  But explicitly with the special case early, laying out the various case become
  simpler.
  
  (The initial motivation was to make some future lifetime error simpler).

REPOSITORY
  rHG Mercurial

BRANCH
  default

REVISION DETAIL
  https://phab.mercurial-scm.org/D9203

AFFECTED FILES
  rust/hg-core/src/dirstate/dirstate_tree/node.rs

CHANGE DETAILS




To: marmoute, #hg-reviewers
Cc: mercurial-patches, mercurial-devel

Patch

diff --git a/rust/hg-core/src/dirstate/dirstate_tree/node.rs b/rust/hg-core/src/dirstate/dirstate_tree/node.rs
--- a/rust/hg-core/src/dirstate/dirstate_tree/node.rs
+++ b/rust/hg-core/src/dirstate/dirstate_tree/node.rs
@@ -60,43 +60,46 @@ 
         // Are we're modifying the current file ? Is the the end of the path ?
         let is_current_file = tail.is_empty() && head.is_empty();
 
-        if let NodeKind::File(file) = &mut self.kind {
-            if is_current_file {
-                let new = Self {
-                    kind: NodeKind::File(File {
-                        entry: new_entry,
-                        ..file.clone()
-                    }),
-                };
-                return InsertResult {
-                    did_insert: false,
-                    old_entry: Some(std::mem::replace(self, new)),
-                };
-            } else {
-                match file.entry.state {
-                    // Only replace the current file with a directory if it's
-                    // marked as `Removed`
-                    EntryState::Removed => {
-                        self.kind = NodeKind::Directory(Directory {
-                            was_file: Some(Box::from(file.clone())),
-                            children: Default::default(),
-                        })
-                    }
-                    _ => {
-                        return Node::insert_in_file(
-                            file, new_entry, head, tail,
-                        )
-                    }
+        // Potentially Replace the current file with a directory if it's marked
+        // as `Removed`
+        if !is_current_file {
+            if let NodeKind::File(file) = &mut self.kind {
+                if file.entry.state == EntryState::Removed {
+                    self.kind = NodeKind::Directory(Directory {
+                        was_file: Some(Box::from(file.clone())),
+                        children: Default::default(),
+                    })
                 }
             }
         }
-
         match &mut self.kind {
             NodeKind::Directory(directory) => {
                 Node::insert_in_directory(directory, new_entry, head, tail)
             }
-            NodeKind::File(_) => {
-                unreachable!("The file case has already been handled")
+            NodeKind::File(file) => {
+                if is_current_file {
+                    let new = Self {
+                        kind: NodeKind::File(File {
+                            entry: new_entry,
+                            ..file.clone()
+                        }),
+                    };
+                    InsertResult {
+                        did_insert: false,
+                        old_entry: Some(std::mem::replace(self, new)),
+                    }
+                } else {
+                    match file.entry.state {
+                        EntryState::Removed => {
+                            unreachable!("Removed file turning into a directory was dealt with earlier")
+                        }
+                        _ => {
+                            Node::insert_in_file(
+                                file, new_entry, head, tail,
+                            )
+                        }
+                    }
+                }
             }
         }
     }