Add gix log

gitoxide-core/src/repository/log.rs

@@ -0,0 +1,50 @@
+use anyhow::bail;
+use gix::bstr::{BString, ByteSlice};
+
+pub fn log(mut repo: gix::Repository, out: &mut dyn std::io::Write, path: Option<BString>) -> anyhow::Result<()> {
+    repo.object_cache_size_if_unset(repo.compute_object_cache_size_for_tree_diffs(&**repo.index_or_empty()?));
+
+    if let Some(path) = path {
+        log_file(repo, out, path)
+    } else {
+        log_all(repo, out)
+    }
+}
+
+fn log_all(repo: gix::Repository, out: &mut dyn std::io::Write) -> Result<(), anyhow::Error> {
+    let head = repo.head()?.peel_to_commit_in_place()?;
+    let topo = gix::traverse::commit::topo::Builder::from_iters(&repo.objects, [head.id], None::<Vec<gix::ObjectId>>)
+        .build()?;
+
+    for info in topo {
+        let info = info?;
+
+        write_info(&repo, &mut *out, &info)?;
+    }
+
+    Ok(())
+}
+
+fn log_file(_repo: gix::Repository, _out: &mut dyn std::io::Write, _path: BString) -> anyhow::Result<()> {
+    bail!("File-based lookup isn't yet implemented in a way that is competitively fast");
+}
+
+fn write_info(
+    repo: &gix::Repository,
+    mut out: impl std::io::Write,
+    info: &gix::traverse::commit::Info,
+) -> Result<(), std::io::Error> {
+    let commit = repo.find_commit(info.id).unwrap();
+
+    let message = commit.message_raw_sloppy();
+    let title = message.lines().next();
+
+    writeln!(
+        out,
+        "{} {}",
+        info.id.to_hex_with_len(8),
+        title.map_or_else(|| "<no message>".into(), BString::from)
+    )?;
+
+    Ok(())
+}

gitoxide-core/src/repository/mod.rs

@@ -46,6 +46,7 @@ pub mod commitgraph;
 mod fsck;
 pub use fsck::function as fsck;
 pub mod index;
+pub mod log;
 pub mod mailmap;
 mod merge_base;
 pub use merge_base::merge_base;

src/plumbing/main.rs

@@ -269,6 +269,15 @@ pub fn main() -> Result<()> {
                 },
             ),
         },
+        Subcommands::Log(crate::plumbing::options::log::Platform { pathspec }) => prepare_and_run(
+            "log",
+            trace,
+            verbose,
+            progress,
+            progress_keep_open,
+            None,
+            move |_progress, out, _err| core::repository::log::log(repository(Mode::Lenient)?, out, pathspec),
+        ),
         Subcommands::Worktree(crate::plumbing::options::worktree::Platform { cmd }) => match cmd {
             crate::plumbing::options::worktree::SubCommands::List => prepare_and_run(
                 "worktree-list",

src/plumbing/options/mod.rs

@@ -146,6 +146,7 @@ pub enum Subcommands {
     MergeBase(merge_base::Command),
     Merge(merge::Platform),
     Diff(diff::Platform),
+    Log(log::Platform),
     Worktree(worktree::Platform),
     /// Subcommands that need no git repository to run.
     #[clap(subcommand)]
@@ -499,6 +500,18 @@ pub mod diff {
     }
 }
 
+pub mod log {
+    use gix::bstr::BString;
+
+    /// List all commits in a repository, optionally limited to those that change a given path
+    #[derive(Debug, clap::Parser)]
+    pub struct Platform {
+        /// The git path specification to show a log for.
+        #[clap(value_parser = crate::shared::AsBString)]
+        pub pathspec: Option<BString>,
+    }
+}
+
 pub mod config {
     use gix::bstr::BString;