Show (git) diff signs in gutter (#3890)

* Show (git) diff signs in gutter (#3890)

Avoid string allocation when git diffing

Incrementally diff using changesets

refactor diffs to be provider indepndent and improve git implementation

remove dependency on zlib-ng

switch to asynchronus diffing with similar

Update helix-vcs/Cargo.toml

fix toml formatting

Co-authored-by: Ivan Tham <pickfire@riseup.net>

fix typo in documentation

use ropey reexpors from helix-core

fix crash when creating new file

remove useless use if io::Cursor

fix spelling mistakes

implement suggested improvement to repository loading

improve git test isolation

remove lefover comments

Co-authored-by: univerz <univerz@fu-solution.com>

fixed spelling mistake

minor cosmetic changes

fix: set self.differ to None if decoding the diff_base fails

fixup formatting

Co-authored-by: Ivan Tham <pickfire@riseup.net>

reload diff_base when file is reloaded from disk

switch to imara-diff

Fixup formatting

Co-authored-by: Blaž Hrastnik <blaz@mxxn.io>

Redraw buffer whenever a diff is updated.

Only store hunks instead of changes for individual lines to easily allow
jumping between them

Update to latest gitoxide version

Change default diff gutter position

Only update gutter after timeout

* update diff gutter synchronously, with a timeout

* Apply suggestions from code review

Co-authored-by: Blaž Hrastnik <blaz@mxxn.io>
Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

* address review comments and ensure lock is always aquired

* remove configuration for redraw timeout

Co-authored-by: Blaž Hrastnik <blaz@mxxn.io>
Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

1 files changed, 56 insertions, 19 deletions

diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 5a1ac6b1..973cf82e 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -9,6 +9,7 @@ use crate::{
     tree::{self, Tree},
     Align, Document, DocumentId, View, ViewId,
 };
+use helix_vcs::DiffProviderRegistry;
 
 use futures_util::stream::select_all::SelectAll;
 use futures_util::{future, StreamExt};
@@ -26,7 +27,10 @@ use std::{
 };
 
 use tokio::{
-    sync::mpsc::{unbounded_channel, UnboundedReceiver, UnboundedSender},
+    sync::{
+        mpsc::{unbounded_channel, UnboundedReceiver, UnboundedSender},
+        Notify, RwLock,
+    },
     time::{sleep, Duration, Instant, Sleep},
 };
 
@@ -454,6 +458,8 @@ pub enum GutterType {
     LineNumbers,
     /// Show one blank space
     Spacer,
+    /// Highlight local changes
+    Diff,
 }
 
 impl std::str::FromStr for GutterType {
@@ -464,6 +470,7 @@ impl std::str::FromStr for GutterType {
             "diagnostics" => Ok(Self::Diagnostics),
             "spacer" => Ok(Self::Spacer),
             "line-numbers" => Ok(Self::LineNumbers),
+            "diff" => Ok(Self::Diff),
             _ => anyhow::bail!("Gutter type can only be `diagnostics` or `line-numbers`."),
         }
     }
@@ -600,6 +607,8 @@ impl Default for Config {
                 GutterType::Diagnostics,
                 GutterType::Spacer,
                 GutterType::LineNumbers,
+                GutterType::Spacer,
+                GutterType::Diff,
             ],
             middle_click_paste: true,
             auto_pairs: AutoPairConfig::default(),
@@ -681,6 +690,7 @@ pub struct Editor {
     pub macro_replaying: Vec<char>,
     pub language_servers: helix_lsp::Registry,
     pub diagnostics: BTreeMap<lsp::Url, Vec<lsp::Diagnostic>>,
+    pub diff_providers: DiffProviderRegistry,
 
     pub debugger: Option<dap::Client>,
     pub debugger_events: SelectAll<UnboundedReceiverStream<dap::Payload>>,
@@ -711,8 +721,15 @@ pub struct Editor {
     pub exit_code: i32,
 
     pub config_events: (UnboundedSender<ConfigEvent>, UnboundedReceiver<ConfigEvent>),
+    /// Allows asynchronous tasks to control the rendering
+    /// The `Notify` allows asynchronous tasks to request the editor to perform a redraw
+    /// The `RwLock` blocks the editor from performing the render until an exclusive lock can be aquired
+    pub redraw_handle: RedrawHandle,
+    pub needs_redraw: bool,
 }
 
+pub type RedrawHandle = (Arc<Notify>, Arc<RwLock<()>>);
+
 #[derive(Debug)]
 pub enum EditorEvent {
     DocumentSaved(DocumentSavedEventResult),
@@ -785,6 +802,7 @@ impl Editor {
             theme: theme_loader.default(),
             language_servers: helix_lsp::Registry::new(),
             diagnostics: BTreeMap::new(),
+            diff_providers: DiffProviderRegistry::default(),
             debugger: None,
             debugger_events: SelectAll::new(),
             breakpoints: HashMap::new(),
@@ -803,6 +821,8 @@ impl Editor {
             auto_pairs,
             exit_code: 0,
             config_events: unbounded_channel(),
+            redraw_handle: Default::default(),
+            needs_redraw: false,
         }
     }
 
@@ -1109,7 +1129,9 @@ impl Editor {
             let mut doc = Document::open(&path, None, Some(self.syn_loader.clone()))?;
 
             let _ = Self::launch_language_server(&mut self.language_servers, &mut doc);
-
+            if let Some(diff_base) = self.diff_providers.get_diff_base(&path) {
+                doc.set_diff_base(diff_base, self.redraw_handle.clone());
+            }
             self.new_document(doc)
         };
 
@@ -1348,24 +1370,39 @@ impl Editor {
     }
 
     pub async fn wait_event(&mut self) -> EditorEvent {
-        tokio::select! {
-            biased;
+        // the loop only runs once or twice and would be better implemented with a recursion + const generic
+        // however due to limitations with async functions that can not be implemented right now
+        loop {
+            tokio::select! {
+                biased;
+
+                Some(event) = self.save_queue.next() => {
+                    self.write_count -= 1;
+                    return EditorEvent::DocumentSaved(event)
+                }
+                Some(config_event) = self.config_events.1.recv() => {
+                    return EditorEvent::ConfigEvent(config_event)
+                }
+                Some(message) = self.language_servers.incoming.next() => {
+                    return EditorEvent::LanguageServerMessage(message)
+                }
+                Some(event) = self.debugger_events.next() => {
+                    return EditorEvent::DebuggerEvent(event)
+                }
 
-            Some(event) = self.save_queue.next() => {
-                self.write_count -= 1;
-                EditorEvent::DocumentSaved(event)
-            }
-            Some(config_event) = self.config_events.1.recv() => {
-                EditorEvent::ConfigEvent(config_event)
-            }
-            Some(message) = self.language_servers.incoming.next() => {
-                EditorEvent::LanguageServerMessage(message)
-            }
-            Some(event) = self.debugger_events.next() => {
-                EditorEvent::DebuggerEvent(event)
-            }
-            _ = &mut self.idle_timer => {
-                EditorEvent::IdleTimer
+                _ = self.redraw_handle.0.notified() => {
+                    if  !self.needs_redraw{
+                        self.needs_redraw = true;
+                        let timeout = Instant::now() + Duration::from_millis(96);
+                        if timeout < self.idle_timer.deadline(){
+                            self.idle_timer.as_mut().reset(timeout)
+                        }
+                    }
+                }
+
+                _ = &mut self.idle_timer  => {
+                    return EditorEvent::IdleTimer
+                }
             }
         }
     }