feat: Repository::shallow_commits() returns an uptodate list of shallow boundary commits.

Author: Byron

gix/src/diff.rs

@@ -0,0 +1,17 @@
+pub use gix_diff::*;
+
+///
+pub mod rename {
+    /// Determine how to do rename tracking.
+    #[derive(Debug, Copy, Clone, Eq, PartialEq)]
+    pub enum Tracking {
+        /// Do not track renames at all, the fastest option.
+        Disabled,
+        /// Track renames.
+        Renames,
+        /// Track renames and copies.
+        ///
+        /// This is the most expensive option.
+        RenamesAndCopies,
+    }
+}

gix/src/lib.rs

@@ -98,12 +98,7 @@ pub mod interrupt;
 
 mod ext;
 ///
-pub mod prelude {
-    pub use gix_features::parallel::reduce::Finalize;
-    pub use gix_odb::{Find, FindExt, Header, HeaderExt, Write};
-
-    pub use crate::ext::*;
-}
+pub mod prelude;
 
 ///
 pub mod path;
@@ -133,31 +128,10 @@ mod repository;
 pub mod tag;
 
 ///
-pub mod progress {
-    #[cfg(feature = "progress-tree")]
-    pub use gix_features::progress::prodash::tree;
-    pub use gix_features::progress::*;
-}
+pub mod progress;
 
 ///
-pub mod diff {
-    pub use gix_diff::*;
-    ///
-    pub mod rename {
-        /// Determine how to do rename tracking.
-        #[derive(Debug, Copy, Clone, Eq, PartialEq)]
-        pub enum Tracking {
-            /// Do not track renames at all, the fastest option.
-            Disabled,
-            /// Track renames.
-            Renames,
-            /// Track renames and copies.
-            ///
-            /// This is the most expensive option.
-            RenamesAndCopies,
-        }
-    }
-}
+pub mod diff;
 
 /// See [ThreadSafeRepository::discover()], but returns a [`Repository`] instead.
 #[allow(clippy::result_large_err)]
@@ -238,20 +212,10 @@ pub fn open_opts(directory: impl Into<std::path::PathBuf>, options: open::Option
 }
 
 ///
-pub mod permission {
-    ///
-    pub mod env_var {
-        ///
-        pub mod resource {
-            ///
-            pub type Error = gix_sec::permission::Error<std::path::PathBuf>;
-        }
-    }
-}
+pub mod permission;
+
 ///
-pub mod permissions {
-    pub use crate::repository::permissions::{Config, Environment};
-}
+pub mod permissions;
 pub use repository::permissions::Permissions;
 
 ///
@@ -278,33 +242,10 @@ pub mod remote;
 pub mod init;
 
 /// Not to be confused with 'status'.
-pub mod state {
-    /// Tell what operation is currently in progress.
-    #[derive(Debug, PartialEq, Eq)]
-    pub enum InProgress {
-        /// A mailbox is being applied.
-        ApplyMailbox,
-        /// A rebase is happening while a mailbox is being applied.
-        // TODO: test
-        ApplyMailboxRebase,
-        /// A git bisect operation has not yet been concluded.
-        Bisect,
-        /// A cherry pick operation.
-        CherryPick,
-        /// A cherry pick with multiple commits pending.
-        CherryPickSequence,
-        /// A merge operation.
-        Merge,
-        /// A rebase operation.
-        Rebase,
-        /// An interactive rebase operation.
-        RebaseInteractive,
-        /// A revert operation.
-        Revert,
-        /// A revert operation with multiple commits pending.
-        RevertSequence,
-    }
-}
+pub mod state;
+
+///
+pub mod shallow;
 
 ///
 pub mod discover;

gix/src/open/repository.rs

@@ -267,6 +267,7 @@ impl ThreadSafeRepository {
             // used when spawning new repositories off this one when following worktrees
             linked_worktree_options: options,
             index: gix_features::fs::MutableSnapshot::new().into(),
+            shallow_commits: gix_features::fs::MutableSnapshot::new().into(),
         })
     }
 }

gix/src/permission.rs

@@ -0,0 +1,8 @@
+///
+pub mod env_var {
+    ///
+    pub mod resource {
+        ///
+        pub type Error = gix_sec::permission::Error<std::path::PathBuf>;
+    }
+}

gix/src/permissions.rs

@@ -0,0 +1 @@
+pub use crate::repository::permissions::{Config, Environment};

gix/src/prelude.rs

@@ -0,0 +1,4 @@
+pub use gix_features::parallel::reduce::Finalize;
+pub use gix_odb::{Find, FindExt, Header, HeaderExt, Write};
+
+pub use crate::ext::*;

gix/src/progress.rs

@@ -0,0 +1,3 @@
+#[cfg(feature = "progress-tree")]
+pub use gix_features::progress::prodash::tree;
+pub use gix_features::progress::*;

gix/src/repository/impls.rs

@@ -8,6 +8,7 @@ impl Clone for crate::Repository {
             self.config.clone(),
             self.options.clone(),
             self.index.clone(),
+            self.shallow_commits.clone(),
         )
     }
 }
@@ -40,6 +41,7 @@ impl From<&crate::ThreadSafeRepository> for crate::Repository {
             repo.config.clone(),
             repo.linked_worktree_options.clone(),
             repo.index.clone(),
+            repo.shallow_commits.clone(),
         )
     }
 }
@@ -54,6 +56,7 @@ impl From<crate::ThreadSafeRepository> for crate::Repository {
             repo.config,
             repo.linked_worktree_options,
             repo.index,
+            repo.shallow_commits,
         )
     }
 }
@@ -68,6 +71,7 @@ impl From<crate::Repository> for crate::ThreadSafeRepository {
             config: r.config,
             linked_worktree_options: r.options,
             index: r.index,
+            shallow_commits: r.shallow_commits,
         }
     }
 }

gix/src/repository/init.rs

@@ -1,6 +1,7 @@
 use std::cell::RefCell;
 
 impl crate::Repository {
+    #[allow(clippy::too_many_arguments)]
     pub(crate) fn from_refs_and_objects(
         refs: crate::RefStore,
         objects: crate::OdbHandle,
@@ -9,6 +10,7 @@ impl crate::Repository {
         config: crate::config::Cache,
         linked_worktree_options: crate::open::Options,
         index: crate::worktree::IndexStorage,
+        shallow_commits: crate::shallow::CommitsStorage,
     ) -> Self {
         let objects = setup_objects(objects, &config);
         crate::Repository {
@@ -20,6 +22,7 @@ impl crate::Repository {
             config,
             options: linked_worktree_options,
             index,
+            shallow_commits,
         }
     }
 

gix/src/repository/location.rs

@@ -1,7 +1,5 @@
-use std::borrow::Cow;
 use std::path::PathBuf;
 
-use crate::config::tree::{gitoxide, Key};
 use gix_path::realpath::MAX_SYMLINKS;
 
 impl crate::Repository {
@@ -43,20 +41,6 @@ impl crate::Repository {
         crate::path::install_dir()
     }
 
-    /// Return the path to the `shallow` file which contains hashes, one per line, that describe commits that don't have their
-    /// parents within this repository.
-    pub fn shallow_file(&self) -> PathBuf {
-        let shallow_name = self
-            .config
-            .resolved
-            .string_filter_by_key(
-                gitoxide::Core::SHALLOW_FILE.logical_name().as_str(),
-                &mut self.filter_config_section(),
-            )
-            .unwrap_or(Cow::Borrowed("shallow".into()));
-        self.common_dir().join(gix_path::from_bstr(shallow_name))
-    }
-
     /// Returns the relative path which is the components between the working tree and the current working dir (CWD).
     /// Note that there may be `None` if there is no work tree, even though the `PathBuf` will be empty
     /// if the CWD is at the root of the work tree.

gix/src/repository/mod.rs

@@ -30,6 +30,7 @@ pub(crate) mod permissions;
 mod reference;
 mod remote;
 mod revision;
+mod shallow;
 mod snapshots;
 mod state;
 mod thread_safe;

gix/src/repository/shallow.rs

@@ -0,0 +1,58 @@
+use crate::bstr::ByteSlice;
+use crate::config::tree::{gitoxide, Key};
+use crate::Repository;
+use std::borrow::Cow;
+use std::path::PathBuf;
+
+impl Repository {
+    /// Return `true` if the repository is a shallow clone, i.e. contains history only up to a certain depth.
+    pub fn is_shallow(&self) -> bool {
+        self.shallow_file()
+            .metadata()
+            .map_or(false, |m| m.is_file() && m.len() > 0)
+    }
+
+    /// Return a shared list of shallow commits which is updated automatically if the in-memory snapshot has become stale as the underlying file
+    /// on disk has changed.
+    ///
+    /// The shared list is shared across all clones of this repository.
+    pub fn shallow_commits(&self) -> Result<Option<crate::shallow::Commits>, crate::shallow::open::Error> {
+        self.shallow_commits.recent_snapshot(
+            || self.shallow_file().metadata().ok().and_then(|m| m.modified().ok()),
+            || {
+                let buf = match std::fs::read(self.shallow_file()) {
+                    Ok(buf) => buf,
+                    Err(err) if err.kind() == std::io::ErrorKind::NotFound => return Ok(None),
+                    Err(err) => return Err(err.into()),
+                };
+
+                let commits = buf
+                    .lines()
+                    .map(gix_hash::ObjectId::from_hex)
+                    .collect::<Result<Vec<_>, _>>()?;
+
+                if commits.is_empty() {
+                    Ok(None)
+                } else {
+                    Ok(Some(commits))
+                }
+            },
+        )
+    }
+
+    /// Return the path to the `shallow` file which contains hashes, one per line, that describe commits that don't have their
+    /// parents within this repository.
+    ///
+    /// Note that it may not exist if the repository isn't actually shallow.
+    pub fn shallow_file(&self) -> PathBuf {
+        let shallow_name = self
+            .config
+            .resolved
+            .string_filter_by_key(
+                gitoxide::Core::SHALLOW_FILE.logical_name().as_str(),
+                &mut self.filter_config_section(),
+            )
+            .unwrap_or_else(|| Cow::Borrowed("shallow".into()));
+        self.common_dir().join(gix_path::from_bstr(shallow_name))
+    }
+}

gix/src/repository/state.rs

@@ -41,11 +41,4 @@ impl crate::Repository {
             None
         }
     }
-
-    /// Return `true` if the repository is a shallow clone, i.e. contains history only up to a certain depth.
-    pub fn is_shallow(&self) -> bool {
-        self.shallow_file()
-            .metadata()
-            .map_or(false, |m| m.is_file() && m.len() > 0)
-    }
 }

gix/src/shallow.rs

@@ -0,0 +1,18 @@
+pub(crate) type CommitsStorage =
+    gix_features::threading::OwnShared<gix_features::fs::MutableSnapshot<Vec<gix_hash::ObjectId>>>;
+/// A lazily loaded and auto-updated list of commits which are at the shallow boundary (behind which there are no commits available),
+/// sorted to allow bisecting.
+pub type Commits = gix_features::fs::SharedSnapshot<Vec<gix_hash::ObjectId>>;
+
+///
+pub mod open {
+    /// The error returned by [`Repository::shallow_commits()`][crate::Repository::shallow_commits()].
+    #[derive(Debug, thiserror::Error)]
+    #[allow(missing_docs)]
+    pub enum Error {
+        #[error("Could not open shallow file for reading")]
+        Io(#[from] std::io::Error),
+        #[error("Could not decode a line in shallow file as hex-encoded object hash")]
+        DecodeHash(#[from] gix_hash::decode::Error),
+    }
+}

gix/src/state.rs

@@ -0,0 +1,25 @@
+/// Tell what operation is currently in progress.
+#[derive(Debug, PartialEq, Eq)]
+pub enum InProgress {
+    /// A mailbox is being applied.
+    ApplyMailbox,
+    /// A rebase is happening while a mailbox is being applied.
+    // TODO: test
+    ApplyMailboxRebase,
+    /// A git bisect operation has not yet been concluded.
+    Bisect,
+    /// A cherry pick operation.
+    CherryPick,
+    /// A cherry pick with multiple commits pending.
+    CherryPickSequence,
+    /// A merge operation.
+    Merge,
+    /// A rebase operation.
+    Rebase,
+    /// An interactive rebase operation.
+    RebaseInteractive,
+    /// A revert operation.
+    Revert,
+    /// A revert operation with multiple commits pending.
+    RevertSequence,
+}

gix/src/types.rs

@@ -152,6 +152,7 @@ pub struct Repository {
     /// Particularly useful when following linked worktrees and instantiating new equally configured worktree repositories.
     pub(crate) options: crate::open::Options,
     pub(crate) index: crate::worktree::IndexStorage,
+    pub(crate) shallow_commits: crate::shallow::CommitsStorage,
 }
 
 /// An instance with access to everything a git repository entails, best imagined as container implementing `Sync + Send` for _most_
@@ -175,6 +176,7 @@ pub struct ThreadSafeRepository {
     pub(crate) linked_worktree_options: crate::open::Options,
     /// The index of this instances worktree.
     pub(crate) index: crate::worktree::IndexStorage,
+    pub(crate) shallow_commits: crate::shallow::CommitsStorage,
 }
 
 /// A remote which represents a way to interact with hosts for remote clones of the parent repository.

gix/tests/repository/mod.rs

@@ -5,6 +5,7 @@ mod object;
 mod open;
 mod reference;
 mod remote;
+mod shallow;
 mod state;
 mod worktree;