Make gix::Repository extension available in oxidize.

It has minimal dependencies and can be used everywhere.

crates/gitbutler-branch-actions/src/base.rs

@@ -11,10 +11,10 @@ use anyhow::{anyhow, bail, Context, Result};
 use gitbutler_branch::GITBUTLER_WORKSPACE_REFERENCE;
 use gitbutler_command_context::CommandContext;
 use gitbutler_error::error::Marker;
-use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid};
+use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid, GixRepositoryExt};
 use gitbutler_project::FetchResult;
 use gitbutler_reference::{Refname, RemoteRefname};
-use gitbutler_repo::{GixRepositoryExt, LogUntil, RepositoryExt};
+use gitbutler_repo::{LogUntil, RepositoryExt};
 use gitbutler_repo_actions::RepoActionsExt;
 use gitbutler_stack::{BranchOwnershipClaims, Stack, Target, VirtualBranchesHandle};
 use serde::Serialize;

crates/gitbutler-branch-actions/src/branch.rs

@@ -7,11 +7,11 @@ use gitbutler_branch::BranchIdentity;
 use gitbutler_branch::ReferenceExtGix;
 use gitbutler_command_context::CommandContext;
 use gitbutler_diff::DiffByPathMap;
-use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid};
+use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid, GixRepositoryExt};
 use gitbutler_project::access::WorktreeReadPermission;
 use gitbutler_reference::normalize_branch_name;
 use gitbutler_reference::RemoteRefname;
-use gitbutler_repo::{GixRepositoryExt, RepositoryExt as _};
+use gitbutler_repo::RepositoryExt as _;
 use gitbutler_serde::BStringForFrontend;
 use gitbutler_stack::{Stack as GitButlerBranch, StackId, Target};
 use gix::object::tree::diff::Action;

crates/gitbutler-branch-actions/src/branch_manager/branch_creation.rs

@@ -1,14 +1,19 @@
+use super::BranchManager;
 use crate::r#virtual as vbranch;
+use crate::{
+    conflicts::RepoConflictsExt, hunk::VirtualBranchHunk, integration::update_workspace_commit,
+    VirtualBranchesExt,
+};
 use anyhow::{anyhow, bail, Context, Result};
 use gitbutler_branch::BranchCreateRequest;
 use gitbutler_branch::{self, dedup};
 use gitbutler_cherry_pick::RepositoryExt as _;
 use gitbutler_commit::{commit_ext::CommitExt, commit_headers::HasCommitHeaders};
 use gitbutler_error::error::Marker;
 use gitbutler_oplog::SnapshotExt;
+use gitbutler_oxidize::GixRepositoryExt;
 use gitbutler_project::access::WorktreeWritePermission;
 use gitbutler_reference::{Refname, RemoteRefname};
-use gitbutler_repo::GixRepositoryExt;
 use gitbutler_repo::{
     rebase::{cherry_rebase_group, gitbutler_merge_commits},
     LogUntil, RepositoryExt,
@@ -19,12 +24,6 @@ use gitbutler_time::time::now_since_unix_epoch_ms;
 use gitbutler_workspace::checkout_branch_trees;
 use tracing::instrument;
 
-use super::BranchManager;
-use crate::{
-    conflicts::RepoConflictsExt, hunk::VirtualBranchHunk, integration::update_workspace_commit,
-    VirtualBranchesExt,
-};
-
 impl BranchManager<'_> {
     #[instrument(level = tracing::Level::DEBUG, skip(self, perm), err(Debug))]
     pub fn create_virtual_branch(

crates/gitbutler-branch-actions/src/branch_manager/branch_removal.rs

@@ -5,11 +5,10 @@ use git2::Commit;
 use gitbutler_branch::BranchExt;
 use gitbutler_commit::commit_headers::CommitHeadersV2;
 use gitbutler_oplog::SnapshotExt;
-use gitbutler_oxidize::git2_to_gix_object_id;
 use gitbutler_oxidize::gix_to_git2_oid;
+use gitbutler_oxidize::{git2_to_gix_object_id, GixRepositoryExt};
 use gitbutler_project::access::WorktreeWritePermission;
 use gitbutler_reference::{normalize_branch_name, ReferenceName, Refname};
-use gitbutler_repo::GixRepositoryExt;
 use gitbutler_repo::RepositoryExt;
 use gitbutler_repo::SignaturePurpose;
 use gitbutler_repo_actions::RepoActionsExt;

crates/gitbutler-branch-actions/src/integration.rs

@@ -9,9 +9,9 @@ use gitbutler_command_context::CommandContext;
 use gitbutler_commit::commit_ext::CommitExt;
 use gitbutler_error::error::Marker;
 use gitbutler_operating_modes::OPEN_WORKSPACE_REFS;
-use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid};
+use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid, GixRepositoryExt};
 use gitbutler_project::access::WorktreeWritePermission;
-use gitbutler_repo::{GixRepositoryExt, SignaturePurpose};
+use gitbutler_repo::SignaturePurpose;
 use gitbutler_repo::{LogUntil, RepositoryExt};
 use gitbutler_stack::{Stack, VirtualBranchesHandle};
 use tracing::instrument;

crates/gitbutler-branch-actions/src/upstream_integration.rs

@@ -4,12 +4,12 @@ use anyhow::{anyhow, bail, Result};
 use gitbutler_cherry_pick::RepositoryExt;
 use gitbutler_command_context::CommandContext;
 use gitbutler_commit::commit_ext::CommitExt as _;
-use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid};
+use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid, GixRepositoryExt};
 use gitbutler_project::access::WorktreeWritePermission;
 use gitbutler_repo::RepositoryExt as _;
 use gitbutler_repo::{
     rebase::{cherry_rebase_group, gitbutler_merge_commits},
-    GixRepositoryExt, LogUntil,
+    LogUntil,
 };
 use gitbutler_repo_actions::RepoActionsExt as _;
 use gitbutler_stack::stack_context::StackContext;

crates/gitbutler-branch-actions/src/virtual.rs

@@ -21,12 +21,14 @@ use gitbutler_commit::{commit_ext::CommitExt, commit_headers::HasCommitHeaders};
 use gitbutler_diff::{trees, GitHunk, Hunk};
 use gitbutler_error::error::Code;
 use gitbutler_operating_modes::assure_open_workspace_mode;
-use gitbutler_oxidize::{git2_signature_to_gix_signature, git2_to_gix_object_id, gix_to_git2_oid};
+use gitbutler_oxidize::{
+    git2_signature_to_gix_signature, git2_to_gix_object_id, gix_to_git2_oid, GixRepositoryExt,
+};
 use gitbutler_project::access::WorktreeWritePermission;
 use gitbutler_reference::{normalize_branch_name, Refname, RemoteRefname};
 use gitbutler_repo::{
     rebase::{cherry_rebase, cherry_rebase_group},
-    GixRepositoryExt, LogUntil, RepositoryExt,
+    LogUntil, RepositoryExt,
 };
 use gitbutler_repo_actions::RepoActionsExt;
 use gitbutler_stack::{

crates/gitbutler-cherry-pick/src/lib.rs

@@ -108,18 +108,13 @@ impl GixRepositoryExt for gix::Repository {
             ConflictedTreeKey::Theirs,
         )?;
 
+        use gitbutler_oxidize::GixRepositoryExt;
         self.merge_trees(
             base,
             ours,
             theirs,
-            gix::merge::blob::builtin_driver::text::Labels {
-                ancestor: Some("base".into()),
-                current: Some("ours".into()),
-                other: Some("theirs".into()),
-            },
-            self.tree_merge_options()?
-                .with_tree_favor(Some(gix::merge::tree::TreeFavor::Ours))
-                .with_file_favor(Some(gix::merge::tree::FileFavor::Ours)),
+            self.default_merge_labels(),
+            self.merge_options_force_ours()?,
         )
         .context("failed to merge trees for cherry pick")
     }

crates/gitbutler-oplog/src/oplog.rs

@@ -15,13 +15,15 @@ use anyhow::{anyhow, bail, Context, Result};
 use git2::FileMode;
 use gitbutler_command_context::RepositoryExtLite;
 use gitbutler_diff::{hunks_by_filepath, FileDiff};
-use gitbutler_oxidize::{git2_to_gix_object_id, gix_time_to_git2, gix_to_git2_oid};
+use gitbutler_oxidize::{
+    git2_to_gix_object_id, gix_time_to_git2, gix_to_git2_oid, GixRepositoryExt,
+};
 use gitbutler_project::{
     access::{WorktreeReadPermission, WorktreeWritePermission},
     Project,
 };
+use gitbutler_repo::RepositoryExt;
 use gitbutler_repo::SignaturePurpose;
-use gitbutler_repo::{GixRepositoryExt, RepositoryExt};
 use gitbutler_stack::{Stack, VirtualBranchesHandle, VirtualBranchesState};
 use gix::bstr::ByteSlice;
 use gix::object::tree::diff::Change;

crates/gitbutler-oxidize/src/ext.rs

@@ -0,0 +1,123 @@
+use crate::git2_to_gix_object_id;
+use anyhow::{Context, Result};
+use gix::merge::tree::{Options, TreatAsUnresolved};
+
+pub trait GixRepositoryExt: Sized {
+    /// Configure the repository for diff operations between trees.
+    /// This means it needs an object cache relative to the amount of files in the repository.
+    fn for_tree_diffing(self) -> Result<Self>;
+
+    /// Returns `true` if the merge between `our_tree` and `their_tree` is free of conflicts.
+    /// Conflicts entail content merges with conflict markers, or anything else that doesn't merge cleanly in the tree.
+    ///
+    /// # Important
+    ///
+    /// Make sure the repository is configured [`with_object_memory()`](gix::Repository::with_object_memory()).
+    fn merges_cleanly_compat(
+        &self,
+        ancestor_tree: git2::Oid,
+        our_tree: git2::Oid,
+        their_tree: git2::Oid,
+    ) -> Result<bool>;
+
+    /// Just like the above, but with `gix` types.
+    fn merges_cleanly(
+        &self,
+        ancestor_tree: gix::ObjectId,
+        our_tree: gix::ObjectId,
+        their_tree: gix::ObjectId,
+    ) -> Result<bool>;
+
+    /// Return default label names when merging trees.
+    ///
+    /// Note that these should probably rather be branch names, but that's for another day.
+    fn default_merge_labels(&self) -> gix::merge::blob::builtin_driver::text::Labels<'static> {
+        gix::merge::blob::builtin_driver::text::Labels {
+            ancestor: Some("base".into()),
+            current: Some("ours".into()),
+            other: Some("theirs".into()),
+        }
+    }
+
+    /// Tree merge options that enforce undecidable conflicts to be forcefully resolved
+    /// to favor ours, both when dealing with content merges and with tree merges.
+    fn merge_options_force_ours(&self) -> Result<gix::merge::tree::Options>;
+
+    /// Return options suitable for merging so that the merge stops immediately after the first conflict.
+    /// It also returns the conflict kind to use when checking for unresolved conflicts.
+    fn merge_options_fail_fast(
+        &self,
+    ) -> Result<(
+        gix::merge::tree::Options,
+        gix::merge::tree::TreatAsUnresolved,
+    )>;
+
+    /// Just like [`Self::merge_options_fail_fast()`], but additionally don't perform rename tracking.
+    /// This is useful if the merge result isn't going to be used, and we are only interested in knowing
+    /// if a merge would succeed.
+    fn merge_options_no_rewrites_fail_fast(
+        &self,
+    ) -> Result<(gix::merge::tree::Options, TreatAsUnresolved)>;
+}
+
+impl GixRepositoryExt for gix::Repository {
+    fn for_tree_diffing(mut self) -> anyhow::Result<Self> {
+        let bytes = self.compute_object_cache_size_for_tree_diffs(&***self.index_or_empty()?);
+        self.object_cache_size_if_unset(bytes);
+        Ok(self)
+    }
+
+    fn merges_cleanly_compat(
+        &self,
+        ancestor_tree: git2::Oid,
+        our_tree: git2::Oid,
+        their_tree: git2::Oid,
+    ) -> Result<bool> {
+        self.merges_cleanly(
+            git2_to_gix_object_id(ancestor_tree),
+            git2_to_gix_object_id(our_tree),
+            git2_to_gix_object_id(their_tree),
+        )
+    }
+
+    fn merges_cleanly(
+        &self,
+        ancestor_tree: gix::ObjectId,
+        our_tree: gix::ObjectId,
+        their_tree: gix::ObjectId,
+    ) -> Result<bool> {
+        let (options, conflict_kind) = self.merge_options_no_rewrites_fail_fast()?;
+        let merge_outcome = self
+            .merge_trees(
+                ancestor_tree,
+                our_tree,
+                their_tree,
+                Default::default(),
+                options,
+            )
+            .context("failed to merge trees")?;
+        Ok(!merge_outcome.has_unresolved_conflicts(conflict_kind))
+    }
+
+    fn merge_options_force_ours(&self) -> Result<Options> {
+        Ok(self
+            .tree_merge_options()?
+            .with_tree_favor(Some(gix::merge::tree::TreeFavor::Ours))
+            .with_file_favor(Some(gix::merge::tree::FileFavor::Ours)))
+    }
+
+    fn merge_options_fail_fast(&self) -> Result<(gix::merge::tree::Options, TreatAsUnresolved)> {
+        let conflict_kind = TreatAsUnresolved::forced_resolution();
+        let options = self
+            .tree_merge_options()?
+            .with_fail_on_conflict(Some(conflict_kind));
+        Ok((options, conflict_kind))
+    }
+
+    fn merge_options_no_rewrites_fail_fast(
+        &self,
+    ) -> Result<(gix::merge::tree::Options, TreatAsUnresolved)> {
+        let (options, conflict_kind) = self.merge_options_fail_fast()?;
+        Ok((options.with_rewrites(None), conflict_kind))
+    }
+}

crates/gitbutler-oxidize/src/lib.rs

@@ -4,6 +4,9 @@ use anyhow::Context;
 use gix::bstr::ByteSlice;
 use std::borrow::Borrow;
 
+mod ext;
+pub use ext::GixRepositoryExt;
+
 pub fn gix_time_to_git2(time: gix::date::Time) -> git2::Time {
     git2::Time::new(time.seconds, time.offset)
 }

crates/gitbutler-repo/src/lib.rs

@@ -5,7 +5,7 @@ pub use commands::{FileInfo, RepoCommands};
 pub use remote::GitRemote;
 
 mod repository_ext;
-pub use repository_ext::{GixRepositoryExt, LogUntil, RepositoryExt};
+pub use repository_ext::{LogUntil, RepositoryExt};
 
 pub mod credentials;
 

crates/gitbutler-repo/src/rebase.rs

@@ -9,7 +9,7 @@ use gitbutler_commit::{
     commit_ext::CommitExt,
     commit_headers::{CommitHeadersV2, HasCommitHeaders},
 };
-use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid};
+use gitbutler_oxidize::{git2_to_gix_object_id, gix_to_git2_oid, GixRepositoryExt as _};
 use serde::{Deserialize, Serialize};
 
 /// cherry-pick based rebase, which handles empty commits
@@ -325,15 +325,8 @@ pub fn gitbutler_merge_commits<'repository>(
         git2_to_gix_object_id(base_tree.id()),
         git2_to_gix_object_id(incoming_merge_tree.id()),
         git2_to_gix_object_id(target_merge_tree.id()),
-        gix::merge::blob::builtin_driver::text::Labels {
-            ancestor: Some("base".into()),
-            current: Some("ours".into()),
-            other: Some("theirs".into()),
-        },
-        gix_repo
-            .tree_merge_options()?
-            .with_tree_favor(Some(gix::merge::tree::TreeFavor::Ours))
-            .with_file_favor(Some(gix::merge::tree::FileFavor::Ours)),
+        gix_repo.default_merge_labels(),
+        gix_repo.merge_options_force_ours()?,
     )?;
     let merged_tree_id = merge_result.tree.write()?;