Add ability to configure atomic saving (#13656)

Co-authored-by: Łukasz Langa <lukasz@langa.pl>

book/src/editor.md

@@ -53,6 +53,7 @@
 | `workspace-lsp-roots` | Directories relative to the workspace root that are treated as LSP roots. Should only be set in `.helix/config.toml` | `[]` |
 | `default-line-ending` | The line ending to use for new documents. Can be `native`, `lf`, `crlf`, `ff`, `cr` or `nel`. `native` uses the platform's native line ending (`crlf` on Windows, otherwise `lf`). | `native` |
 | `insert-final-newline` | Whether to automatically insert a trailing line-ending on write if missing | `true` |
+| `atomic-save` | Whether to use atomic operations to write documents to disk. This prevents data loss if the editor is interrupted while writing the file, but may confuse some file watching/hot reloading programs. | `true` |
 | `trim-final-newlines` | Whether to automatically remove line-endings after the final one on write | `false` |
 | `trim-trailing-whitespace` | Whether to automatically remove whitespace preceding line endings on write | `false` |
 | `popup-border` | Draw border around `popup`, `menu`, `all`, or `none` | `none` |

helix-view/src/document.rs

@@ -980,6 +980,7 @@ impl Document {
         // mark changes up to now as saved
         let current_rev = self.get_current_revision();
         let doc_id = self.id();
+        let atomic_save = self.config.load().atomic_save;
 
         let encoding_with_bom_info = (self.encoding, self.has_bom);
         let last_saved_time = self.last_saved_time;
@@ -1029,7 +1030,7 @@ impl Document {
 
             // Assume it is a hardlink to prevent data loss if the metadata cant be read (e.g. on certain Windows configurations)
             let is_hardlink = helix_stdx::faccess::hardlink_count(&write_path).unwrap_or(2) > 1;
-            let backup = if path.exists() {
+            let backup = if path.exists() && atomic_save {
                 let path_ = write_path.clone();
                 // hacks: we use tempfile to handle the complex task of creating
                 // non clobbered temporary path for us we don't want

helix-view/src/editor.rs

@@ -345,6 +345,10 @@ pub struct Config {
     pub default_line_ending: LineEndingConfig,
     /// Whether to automatically insert a trailing line-ending on write if missing. Defaults to `true`.
     pub insert_final_newline: bool,
+    /// Whether to use atomic operations to write documents to disk.
+    /// This prevents data loss if the editor is interrupted while writing the file, but may
+    /// confuse some file watching/hot reloading programs. Defaults to `true`.
+    pub atomic_save: bool,
     /// Whether to automatically remove all trailing line-endings after the final one on write.
     /// Defaults to `false`.
     pub trim_final_newlines: bool,
@@ -1020,6 +1024,7 @@ impl Default for Config {
             workspace_lsp_roots: Vec::new(),
             default_line_ending: LineEndingConfig::default(),
             insert_final_newline: true,
+            atomic_save: true,
             trim_final_newlines: false,
             trim_trailing_whitespace: false,
             smart_tab: Some(SmartTabConfig::default()),