feat: gix free index from-list and gix index from-tree gain --skip-hash.

This flag can be derived from options, but thus far we have no higher-level
writing of the index so this has to do to see the difference in performance.

Author: Byron

Diff for: gitoxide-core/src/repository/index/mod.rs

@@ -1,19 +1,23 @@
 use std::{ffi::OsString, path::PathBuf};
 
 use anyhow::bail;
-use gix::prelude::FindExt;
 
 pub fn from_tree(
+    repo: gix::Repository,
     mut spec: OsString,
     index_path: Option<PathBuf>,
     force: bool,
-    repo: gix::Repository,
+    skip_hash: bool,
 ) -> anyhow::Result<()> {
     spec.push("^{tree}");
     let spec = gix::path::os_str_into_bstr(&spec)?;
     let tree = repo.rev_parse_single(spec)?;
-    let index = gix::index::State::from_tree(&tree, |oid, buf| repo.objects.find_tree_iter(oid, buf).ok())?;
-    let options = gix::index::write::Options::default();
+
+    let mut index = repo.index_from_tree(&tree)?;
+    let options = gix::index::write::Options {
+        skip_hash,
+        ..Default::default()
+    };
 
     match index_path {
         Some(index_path) => {
@@ -23,11 +27,10 @@ pub fn from_tree(
                     index_path.display()
                 );
             }
-            let mut index = gix::index::File::from_state(index, index_path);
+            index.set_path(index_path);
             index.write(options)?;
         }
         None => {
-            let index = gix::index::File::from_state(index, std::path::PathBuf::new());
             let mut out = Vec::with_capacity(512 * 1024);
             index.write_to(&mut out, options)?;
         }
@@ -36,7 +39,12 @@ pub fn from_tree(
     Ok(())
 }
 
-pub fn from_list(entries_file: PathBuf, index_path: Option<PathBuf>, force: bool) -> anyhow::Result<()> {
+pub fn from_list(
+    entries_file: PathBuf,
+    index_path: Option<PathBuf>,
+    force: bool,
+    skip_hash: bool,
+) -> anyhow::Result<()> {
     use std::io::BufRead;
     let object_hash = gix::hash::Kind::Sha1;
 
@@ -57,7 +65,10 @@ pub fn from_list(entries_file: PathBuf, index_path: Option<PathBuf>, force: bool
     }
     index.sort_entries();
 
-    let options = gix::index::write::Options::default();
+    let options = gix::index::write::Options {
+        skip_hash,
+        ..Default::default()
+    };
     match index_path {
         Some(index_path) => {
             if index_path.is_file() && !force {

Diff for: src/plumbing/main.rs

@@ -447,6 +447,7 @@ pub fn main() -> Result<()> {
                 free::index::Subcommands::FromList {
                     force,
                     index_output_path,
+                    skip_hash,
                     file,
                 } => prepare_and_run(
                     "index-from-list",
@@ -455,7 +456,9 @@ pub fn main() -> Result<()> {
                     progress,
                     progress_keep_open,
                     None,
-                    move |_progress, _out, _err| core::repository::index::from_list(file, index_output_path, force),
+                    move |_progress, _out, _err| {
+                        core::repository::index::from_list(file, index_output_path, force, skip_hash)
+                    },
                 ),
                 free::index::Subcommands::CheckoutExclusive {
                     directory,
@@ -1164,6 +1167,7 @@ pub fn main() -> Result<()> {
             index::Subcommands::FromTree {
                 force,
                 index_output_path,
+                skip_hash,
                 spec,
             } => prepare_and_run(
                 "index-from-tree",
@@ -1173,7 +1177,13 @@ pub fn main() -> Result<()> {
                 progress_keep_open,
                 None,
                 move |_progress, _out, _err| {
-                    core::repository::index::from_tree(spec, index_output_path, force, repository(Mode::Strict)?)
+                    core::repository::index::from_tree(
+                        repository(Mode::Strict)?,
+                        spec,
+                        index_output_path,
+                        force,
+                        skip_hash,
+                    )
                 },
             ),
         },

Diff for: src/plumbing/options/free.rs

@@ -63,6 +63,9 @@ pub mod index {
             /// back by default, but that requires us to write more of the index to work.
             #[clap(long, short = 'i')]
             index_output_path: Option<PathBuf>,
+            /// Don't write the trailing hash for a performance gain.
+            #[clap(long, short = 's')]
+            skip_hash: bool,
             /// The file to read the index entries from, one path per line.
             file: PathBuf,
         },

Diff for: src/plumbing/options/mod.rs

@@ -705,6 +705,9 @@ pub mod index {
             /// back by default, but that requires us to write more of the index to work.
             #[clap(long, short = 'i')]
             index_output_path: Option<PathBuf>,
+            /// Don't write the trailing hash for a performance gain.
+            #[clap(long, short = 's')]
+            skip_hash: bool,
             /// A revspec that points to the to generate the index from.
             spec: std::ffi::OsString,
         },