chore: migrate from git command to gix (#16)

Reviewed-on: https://git.reya.su/reya/signed/pulls/16

crates/signed_git/Cargo.toml

@@ -9,6 +9,8 @@ signed_core = { path = "../signed_core" }
 
 nostr.workspace = true
 gix = { workspace = true, features = ["revision", "blob-diff"] }
+gix-worktree = "0.56"
+gix-worktree-state = "0.34"
 anyhow.workspace = true
 
 [dev-dependencies]

crates/signed_state/src/checkouts.rs

@@ -1,6 +1,5 @@
 use std::collections::{HashMap, HashSet};
 use std::path::{Path, PathBuf};
-use std::process::Command;
 use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
 
 use anyhow::Error;
@@ -617,67 +616,27 @@ fn resolve_associations<'a>(
     out
 }
 
-/// Whether the worktree of `path` has uncommitted changes.
-fn worktree_dirty(path: &Path) -> bool {
-    let output = Command::new("git")
-        .arg("-C")
-        .arg(path)
-        .args(["status", "--porcelain"])
-        .env("GIT_TERMINAL_PROMPT", "0")
-        .output();
-    match output {
-        Ok(output) => !String::from_utf8_lossy(&output.stdout).trim().is_empty(),
-        Err(_) => false,
-    }
-}
-
-/// Commits in `base..branch` of the checkout at `path`.
-fn commits_ahead(path: &Path, base: &str, branch: &str) -> u32 {
-    let output = Command::new("git")
-        .arg("-C")
-        .arg(path)
-        .args(["rev-list", "--count", &format!("{base}..{branch}")])
-        .env("GIT_TERMINAL_PROMPT", "0")
-        .output();
-    match output {
-        Ok(output) => String::from_utf8_lossy(&output.stdout)
-            .trim()
-            .parse()
-            .unwrap_or(0),
-        Err(_) => 0,
-    }
-}
-
-/// The branch checked out at `path`, read via `git branch --show-current`.
-fn current_branch_of(path: &Path) -> Option<String> {
-    let output = Command::new("git")
-        .arg("-C")
-        .arg(path)
-        .args(["branch", "--show-current"])
-        .env("GIT_TERMINAL_PROMPT", "0")
-        .output()
-        .ok()?;
-    let branch = String::from_utf8_lossy(&output.stdout).trim().to_owned();
-    (!branch.is_empty()).then_some(branch)
-}
-
 /// The ready-to-contribute status of one checkout.
 fn checkout_status(path: &Path, announced_head: Option<&str>) -> Option<CheckoutStatus> {
     let branches = signed_git::worktree_branches(path).ok()?;
-    if branches.is_empty() || worktree_dirty(path) {
+
+    if branches.is_empty() || signed_git::worktree_dirty(path) {
         return None;
     }
-    let branch = current_branch_of(path)?;
+
+    let branch = signed_git::worktree_current_branch(path)?;
     let head = signed_git::head_commit_id(path).ok().flatten()?;
     let base = announced_head
         .filter(|name| branches.iter().any(|b| b == name))
         .map(str::to_owned)
         .or_else(|| branches.iter().find(|b| *b == "main").cloned())
         .or_else(|| branches.first().cloned())?;
+
     if base == branch {
         return None;
     }
-    let ahead = commits_ahead(path, &base, &branch);
+
+    let ahead = signed_git::worktree_commits_ahead(path, &base, &branch);
     (ahead > 0).then_some(CheckoutStatus {
         path: path.to_path_buf(),
         branch,
@@ -687,30 +646,17 @@ fn checkout_status(path: &Path, announced_head: Option<&str>) -> Option<Checkout
     })
 }
 
-/// Whether the reference `name` exists in the checkout at `path`.
-///
-/// Example, `refs/remotes/origin/main`.
-fn ref_exists(path: &Path, name: &str) -> bool {
-    let output = Command::new("git")
-        .arg("-C")
-        .arg(path)
-        .args(["rev-parse", "--verify", "--quiet", name])
-        .env("GIT_TERMINAL_PROMPT", "0")
-        .output();
-    matches!(output, Ok(output) if output.status.success())
-}
-
 /// The `ready to push` status of one checkout of the user's own repository.
 ///
 /// `fetch` refreshes the remote heads first, so a full pass sees pushes made
 /// elsewhere; the fast local pass skips it and compares against the tracking
 /// refs left by the last full pass, which is enough to detect local commits.
 fn checkout_push_status(path: &Path, fetch: bool) -> Option<CheckoutStatus> {
-    if worktree_dirty(path) {
+    if signed_git::worktree_dirty(path) {
         return None;
     }
 
-    let branch = current_branch_of(path)?;
+    let branch = signed_git::worktree_current_branch(path)?;
     let head = signed_git::head_commit_id(path).ok().flatten()?;
     let origin = signed_git::origin_url(path).ok().flatten()?;
 
@@ -724,15 +670,15 @@ fn checkout_push_status(path: &Path, fetch: bool) -> Option<CheckoutStatus> {
 
     // A branch never fetched or pushed yet compares against the remote HEAD.
     // The remote HEAD is the fork point in practice.
-    let base = if ref_exists(path, &remote) {
+    let base = if signed_git::worktree_ref_exists(path, &remote) {
         remote
-    } else if ref_exists(path, "refs/remotes/origin/HEAD") {
+    } else if signed_git::worktree_ref_exists(path, "refs/remotes/origin/HEAD") {
         "refs/remotes/origin/HEAD".to_owned()
     } else {
         return None;
     };
 
-    let ahead = commits_ahead(path, &base, &branch);
+    let ahead = signed_git::worktree_commits_ahead(path, &base, &branch);
 
     (ahead > 0).then_some(CheckoutStatus {
         path: path.to_path_buf(),
@@ -822,6 +768,8 @@ pub fn pr_proposes_checkout(
 
 #[cfg(test)]
 mod tests {
+    use std::process::Command;
+
     use signed_core::{RepoAddr, repo_addr};
 
     use super::*;

crates/workspace/src/views/repo_detail/mod.rs

@@ -492,16 +492,8 @@ impl RepoDetailView {
                 if refresh_generation != this.ref_generation {
                     return;
                 }
-                if let Ok(Some((moved, branches, tags, current_branch, head_commit))) = refresh {
-                    if moved {
-                        // The mirror caught up with the remote.
-                        // E.g. the push of an owned checkout just landed.
-                        // Rebuild the explorer, previews and commit list from the worktree.
-                        this.reload_worktree(cx);
-                        cx.notify();
-                        return;
-                    }
 
+                if let Ok(Some((moved, branches, tags, current_branch, head_commit))) = refresh {
                     let branches: Vec<SharedString> = branches.iter().map(Into::into).collect();
                     let tags: Vec<SharedString> = tags.iter().map(Into::into).collect();
 
@@ -528,6 +520,10 @@ impl RepoDetailView {
                         this.load_all_commits(cx);
                     }
 
+                    if moved {
+                        this.catch_up_worktree(cx);
+                    }
+
                     cx.notify();
                 }
             })?;
@@ -1225,6 +1221,119 @@ impl RepoDetailView {
         self.tasks.push(task);
     }
 
+    /// Refresh the file explorer, previews and commit list after the mirror
+    /// caught up with the remote.
+    ///
+    /// The checked-out branch fast-forwarded in place, so unlike
+    /// [`Self::reload_worktree`] this keeps the panel's selection and previews:
+    /// it rebuilds the tree, drops previews of files the refresh removed and
+    /// re-renders the README when it is on screen.
+    fn catch_up_worktree(&mut self, cx: &mut Context<Self>) {
+        let Some(worktree) = self.worktree.clone() else {
+            return;
+        };
+
+        let task = cx.spawn(async move |this, cx| {
+            let result = cx
+                .background_spawn(async move {
+                    let snapshot = signed_git::worktree_snapshot(&worktree)?;
+                    let tree = build_tree_items(&snapshot.entries);
+                    Ok::<_, Error>((snapshot, tree))
+                })
+                .await;
+
+            this.update(cx, |this, cx| {
+                match result {
+                    Ok((snapshot, tree)) => {
+                        let head_changed = snapshot.head_commit.as_ref().map(|c| &c.id)
+                            != this.head_commit.as_ref().map(|c| &c.id);
+
+                        this.head_commit = snapshot.head_commit;
+                        this.tree_state.update(cx, |state, cx| {
+                            state.set_items(tree_items(tree, false), cx);
+                        });
+
+                        // Drop previews of files the refresh removed from the  worktree,
+                        // everything else stays put.
+                        let present: HashSet<String> = snapshot
+                            .entries
+                            .iter()
+                            .map(|path| path.to_string_lossy().into_owned())
+                            .collect();
+
+                        let mut previewed: Vec<String> = Vec::new();
+                        previewed.extend(this.files.keys().cloned());
+                        previewed.extend(this.selected_file.clone().map(|p| p.to_string()));
+
+                        if let Some(path) = this.md.as_ref().and_then(|md| md.path.clone()) {
+                            previewed.push(path.to_string());
+                        }
+
+                        if let Some(path) = this.code.as_ref().map(|code| code.path.clone()) {
+                            previewed.push(path.to_string());
+                        }
+
+                        previewed.sort();
+                        previewed.dedup();
+
+                        for path in previewed {
+                            if !present.contains(&path) {
+                                this.drop_preview_of(&path);
+                            }
+                        }
+
+                        // Re-render the README when it is on screen, i.e. when no file preview is open.
+                        if this.selected_file.is_none() {
+                            match snapshot.readme_path.zip(snapshot.readme) {
+                                Some((path, bytes)) => {
+                                    this.readme_name = Some(path.to_string_lossy().into());
+                                    if let Ok(text) = String::from_utf8(bytes) {
+                                        this.set_markdown(None, &text, cx);
+                                    }
+                                }
+                                None => {
+                                    this.md = None;
+                                    this.readme_name = None;
+                                }
+                            }
+                        }
+
+                        if head_changed {
+                            this.all_commits = None;
+                            this.loading_all_commits = false;
+                            this.load_all_commits(cx);
+                        }
+                    }
+                    Err(error) => {
+                        this.error = Some(error.to_string().into());
+                    }
+                }
+                cx.notify();
+            })?;
+
+            Ok(())
+        });
+
+        self.tasks.push(task);
+    }
+
+    /// Drop the cached preview, editor and commit state of `path`.
+    fn drop_preview_of(&mut self, path: &str) {
+        if let Some(FileContent::Text(text)) = self.files.remove(path) {
+            self.preview_bytes -= text.len();
+        }
+        self.commits.remove(path);
+        if self.selected_file.as_deref() == Some(path) {
+            self.selected_file = None;
+        }
+        if self.md.as_ref().and_then(|md| md.path.as_deref()) == Some(path) {
+            self.md = None;
+        }
+        if self.code.as_ref().map(|code| code.path.as_ref()) == Some(path) {
+            self.code = None;
+        }
+    }
+
     /// Drop the oldest previews beyond the cache caps.
     /// Keep the currently selected file.
     /// An evicted file's parsed editor state drops with its entry.