From 5a3ff742218aac32c3af08993f0edb623631fc72 Mon Sep 17 00:00:00 2001
From: Pascal Kuthe
Date: Thu, 1 Dec 2022 09:35:23 +0100
Subject: 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>---
 helix-view/src/document.rs | 52 +++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 44 insertions(+), 8 deletions(-)

(limited to 'helix-view/src/document.rs')

diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index ad47f838..856e5628 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -3,6 +3,8 @@ use futures_util::future::BoxFuture;
 use futures_util::FutureExt;
 use helix_core::auto_pairs::AutoPairs;
 use helix_core::Range;
+use helix_vcs::{DiffHandle, DiffProviderRegistry};
+
 use serde::de::{self, Deserialize, Deserializer};
 use serde::Serialize;
 use std::borrow::Cow;
@@ -24,6 +26,7 @@ use helix_core::{
     DEFAULT_LINE_ENDING,
 };
 
+use crate::editor::RedrawHandle;
 use crate::{apply_transaction, DocumentId, Editor, View, ViewId};
 
 /// 8kB of buffer space for encoding and decoding `Rope`s.
@@ -133,6 +136,8 @@ pub struct Document {
 
     diagnostics: Vec<Diagnostic>,
     language_server: Option<Arc<helix_lsp::Client>>,
+
+    diff_handle: Option<DiffHandle>,
 }
 
 use std::{fmt, mem};
@@ -371,6 +376,7 @@ impl Document {
             last_saved_revision: 0,
             modified_since_accessed: false,
             language_server: None,
+            diff_handle: None,
         }
     }
 
@@ -624,16 +630,20 @@ impl Document {
     }
 
     /// Reload the document from its path.
-    pub fn reload(&mut self, view: &mut View) -> Result<(), Error> {
+    pub fn reload(
+        &mut self,
+        view: &mut View,
+        provider_registry: &DiffProviderRegistry,
+        redraw_handle: RedrawHandle,
+    ) -> Result<(), Error> {
         let encoding = &self.encoding;
-        let path = self.path().filter(|path| path.exists());
-
-        // If there is no path or the path no longer exists.
-        if path.is_none() {
-            bail!("can't find file to reload from");
-        }
+        let path = self
+            .path()
+            .filter(|path| path.exists())
+            .ok_or_else(|| anyhow!("can't find file to reload from"))?
+            .to_owned();
 
-        let mut file = std::fs::File::open(path.unwrap())?;
+        let mut file = std::fs::File::open(&path)?;
         let (rope, ..) = from_reader(&mut file, Some(encoding))?;
 
         // Calculate the difference between the buffer and source text, and apply it.
@@ -646,6 +656,11 @@ impl Document {
 
         self.detect_indent_and_line_ending();
 
+        match provider_registry.get_diff_base(&path) {
+            Some(diff_base) => self.set_diff_base(diff_base, redraw_handle),
+            None => self.diff_handle = None,
+        }
+
         Ok(())
     }
 
@@ -787,6 +802,10 @@ impl Document {
 
         if !transaction.changes().is_empty() {
             self.version += 1;
+            // start computing the diff in parallel
+            if let Some(diff_handle) = &self.diff_handle {
+                diff_handle.update_document(self.text.clone(), false);
+            }
 
             // generate revert to savepoint
             if self.savepoint.is_some() {
@@ -1046,6 +1065,23 @@ impl Document {
         server.is_initialized().then(|| server)
     }
 
+    pub fn diff_handle(&self) -> Option<&DiffHandle> {
+        self.diff_handle.as_ref()
+    }
+
+    /// Intialize/updates the differ for this document with a new base.
+    pub fn set_diff_base(&mut self, diff_base: Vec<u8>, redraw_handle: RedrawHandle) {
+        if let Ok((diff_base, _)) = from_reader(&mut diff_base.as_slice(), Some(self.encoding)) {
+            if let Some(differ) = &self.diff_handle {
+                differ.update_diff_base(diff_base);
+                return;
+            }
+            self.diff_handle = Some(DiffHandle::new(diff_base, self.text.clone(), redraw_handle))
+        } else {
+            self.diff_handle = None;
+        }
+    }
+
     #[inline]
     /// Tree-sitter AST tree
     pub fn syntax(&self) -> Option<&Syntax> {
-- 
cgit v1.2.3-70-g09d2