feat: --statistics for gix excludes query

With it one gets some insights into the work done to fulfil the query.

gitoxide-core/src/repository/exclude.rs

@@ -14,17 +14,20 @@ pub mod query {
         pub format: OutputFormat,
         pub overrides: Vec<OsString>,
         pub show_ignore_patterns: bool,
+        pub statistics: bool,
     }
 }
 
 pub fn query(
     repo: gix::Repository,
     pathspecs: impl Iterator<Item = gix::path::Spec>,
     mut out: impl io::Write,
+    mut err: impl io::Write,
     query::Options {
         overrides,
         format,
         show_ignore_patterns,
+        statistics,
     }: query::Options,
 ) -> anyhow::Result<()> {
     if format != OutputFormat::Human {
@@ -62,5 +65,10 @@ pub fn query(
             }
         }
     }
+
+    if let Some(stats) = statistics.then(|| cache.take_statistics()) {
+        out.flush()?;
+        writeln!(err, "{:#?}", stats).ok();
+    }
     Ok(())
 }

src/plumbing/main.rs

@@ -862,6 +862,7 @@ pub fn main() -> Result<()> {
         },
         Subcommands::Exclude(cmd) => match cmd {
             exclude::Subcommands::Query {
+                statistics,
                 patterns,
                 pathspecs,
                 show_ignore_patterns,
@@ -871,7 +872,7 @@ pub fn main() -> Result<()> {
                 progress,
                 progress_keep_open,
                 None,
-                move |_progress, out, _err| {
+                move |_progress, out, err| {
                     use gix::bstr::ByteSlice;
                     core::repository::exclude::query(
                         repository(Mode::Strict)?,
@@ -886,10 +887,12 @@ pub fn main() -> Result<()> {
                             Box::new(pathspecs.into_iter())
                         },
                         out,
+                        err,
                         core::repository::exclude::query::Options {
                             format,
                             show_ignore_patterns,
                             overrides: patterns,
+                            statistics,
                         },
                     )
                 },

src/plumbing/options/mod.rs

@@ -469,6 +469,9 @@ pub mod exclude {
     pub enum Subcommands {
         /// Check if path-specs are excluded and print the result similar to `git check-ignore`.
         Query {
+            /// Print various statistics to stderr
+            #[clap(long, short = 's')]
+            statistics: bool,
             /// Show actual ignore patterns instead of un-excluding an entry.
             ///
             /// That way one can understand why an entry might not be excluded.