Basic multi-pack index creation (#279)

Could imagine providing statistics as part of the creation result.

Author: Byron

Diff for: git-hash/src/lib.rs

@@ -7,6 +7,7 @@
 mod borrowed;
 
 use std::convert::TryFrom;
+use std::str::FromStr;
 
 pub use borrowed::oid;
 
@@ -85,6 +86,17 @@ impl TryFrom<u8> for Kind {
     }
 }
 
+impl FromStr for Kind {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "sha1" | "SHA1" => Kind::Sha1,
+            other => return Err(other.into()),
+        })
+    }
+}
+
 impl Kind {
     /// Returns the shortest hash we support
     #[inline]

Diff for: gitoxide-core/src/pack/index.rs

@@ -55,6 +55,7 @@ pub struct Context<'a, W: io::Write> {
     pub format: OutputFormat,
     pub should_interrupt: &'a AtomicBool,
     pub out: W,
+    pub object_hash: git_repository::hash::Kind,
 }
 
 pub fn stream_len(mut s: impl io::Seek) -> io::Result<u64> {
@@ -85,7 +86,7 @@ pub fn from_pack(
         thread_limit: ctx.thread_limit,
         iteration_mode: ctx.iteration_mode.into(),
         index_kind: pack::index::Version::default(),
-        object_hash: git_repository::hash::Kind::Sha1, // TODO: make this configurable via CLI, context
+        object_hash: ctx.object_hash,
     };
     let out = ctx.out;
     let format = ctx.format;

Diff for: gitoxide-core/src/pack/mod.rs

@@ -1,5 +1,6 @@
 pub mod explode;
 pub mod index;
+pub mod multi_index;
 pub mod verify;
 
 #[cfg(any(feature = "async-client", feature = "blocking-client"))]

Diff for: gitoxide-core/src/pack/multi_index.rs

@@ -0,0 +1,31 @@
+use git_repository::Progress;
+use std::io::BufWriter;
+use std::path::PathBuf;
+use std::sync::atomic::AtomicBool;
+
+use git_repository as git;
+
+pub const PROGRESS_RANGE: std::ops::RangeInclusive<u8> = 2..=3;
+
+pub fn create(
+    index_paths: Vec<PathBuf>,
+    output_path: PathBuf,
+    progress: impl Progress,
+    should_interrupt: &AtomicBool,
+    object_hash: git::hash::Kind,
+) -> anyhow::Result<()> {
+    let mut out = BufWriter::new(git::lock::File::acquire_to_update_resource(
+        output_path,
+        git::lock::acquire::Fail::Immediately,
+        None,
+    )?);
+    git::odb::pack::multi_index::File::write_from_index_paths(
+        index_paths,
+        &mut out,
+        progress,
+        should_interrupt,
+        git::odb::pack::multi_index::write::Options { object_hash },
+    )?;
+    out.into_inner()?.commit()?;
+    Ok(())
+}

Diff for: src/plumbing/main.rs

@@ -51,6 +51,7 @@ pub fn main() -> Result<()> {
     let verbose = args.verbose;
     let format = args.format;
     let cmd = args.cmd;
+    let object_hash = args.object_hash;
 
     let progress;
     let progress_keep_open;
@@ -241,13 +242,34 @@ pub fn main() -> Result<()> {
                 },
             )
             .map(|_| ()),
+            pack::Subcommands::MultiIndex(subcommands) => match subcommands {
+                pack::multi_index::Subcommands::Create {
+                    output_path,
+                    index_paths,
+                } => prepare_and_run(
+                    "pack-multi-index-create",
+                    verbose,
+                    progress,
+                    progress_keep_open,
+                    core::pack::multi_index::PROGRESS_RANGE,
+                    move |progress, _out, _err| {
+                        core::pack::multi_index::create(
+                            index_paths,
+                            output_path,
+                            progress,
+                            &git_repository::interrupt::IS_INTERRUPTED,
+                            object_hash,
+                        )
+                    },
+                ),
+            },
             pack::Subcommands::Index(subcommands) => match subcommands {
                 pack::index::Subcommands::Create {
                     iteration_mode,
                     pack_path,
                     directory,
                 } => prepare_and_run(
-                    "pack-index-from-data",
+                    "pack-index-create",
                     verbose,
                     progress,
                     progress_keep_open,
@@ -273,6 +295,7 @@ pub fn main() -> Result<()> {
                                 iteration_mode,
                                 format,
                                 out,
+                                object_hash,
                                 should_interrupt: &git_repository::interrupt::IS_INTERRUPTED,
                             },
                         )
@@ -321,7 +344,7 @@ pub fn main() -> Result<()> {
         },
         Subcommands::Commitgraph(subcommands) => match subcommands {
             commitgraph::Subcommands::Verify { path, statistics } => prepare_and_run(
-                "commit-graph-verify",
+                "commitgraph-verify",
                 verbose,
                 progress,
                 progress_keep_open,

Diff for: src/plumbing/options.rs

@@ -36,6 +36,10 @@ pub struct Args {
     )]
     pub format: core::OutputFormat,
 
+    /// The object format to assume when reading files that don't inherently know about it, or when writing files.
+    #[clap(long, default_value = "sha1", possible_values(&["sha1"]))]
+    pub object_hash: git_repository::hash::Kind,
+
     #[clap(subcommand)]
     pub cmd: Subcommands,
 }
@@ -63,6 +67,12 @@ pub mod pack {
 
     #[derive(Debug, clap::Parser)]
     pub enum Subcommands {
+        /// Subcommands for interacting with pack indices (.idx)
+        #[clap(subcommand)]
+        Index(index::Subcommands),
+        /// Subcommands for interacting with multi-pack indices (named "multi-pack-index")
+        #[clap(subcommand)]
+        MultiIndex(multi_index::Subcommands),
         /// Create a new pack with a set of objects.
         #[clap(setting = AppSettings::DisableVersionFlag)]
         Create {
@@ -153,9 +163,6 @@ pub mod pack {
             /// If unset, they will be discarded.
             directory: Option<PathBuf>,
         },
-        /// Subcommands for interacting with pack indices (.idx)
-        #[clap(subcommand)]
-        Index(index::Subcommands),
         /// Dissolve a pack into its loose objects.
         ///
         /// Note that this effectively removes delta compression for an average compression of 2x, creating one file per object in the process.
@@ -234,6 +241,29 @@ pub mod pack {
         },
     }
 
+    ///
+    pub mod multi_index {
+        use clap::AppSettings;
+        use std::path::PathBuf;
+
+        #[derive(Debug, clap::Parser)]
+        pub enum Subcommands {
+            /// create a multi-pack index from one or more pack index files
+            #[clap(setting = AppSettings::DisableVersionFlag)]
+            Create {
+                /// The path to which the multi-index file should be written, overwriting any possibly existing file.
+                ///
+                /// Note for the multi-index to be useful, it should be side-by-side with the supplied `.idx` files.
+                #[clap(long, short = 'o')]
+                output_path: PathBuf,
+
+                /// Paths to the pack index files to read (with .idx extension).
+                #[clap(required = true)]
+                index_paths: Vec<PathBuf>,
+            },
+        }
+    }
+
     ///
     pub mod index {
         use clap::AppSettings;

Diff for: tests/journey/gix.sh

@@ -42,7 +42,7 @@ title "git-tempfile crate"
 title "gix pack"
 (when "running 'pack'"
   snapshot="$snapshot/pack"
-  
+
   title "gix pack receive"
   (with "the 'receive' sub-command"
     snapshot="$snapshot/receive"
@@ -265,7 +265,18 @@ title "gix pack"
 
   title "gix pack multi-index"
   (with "the 'multi-index' sub-command"
-
+      snapshot="$snapshot/multi-index"
+      title "gix pack multi-index create"
+      (with "the 'create' sub-command"
+          snapshot="$snapshot/create"
+          (with 'multiple pack indices'
+            (sandbox
+              it "creates a multi-index successfully" && {
+                expect_run $SUCCESSFULLY "$exe_plumbing" pack multi-index create $fixtures/packs/pack-*.idx -o multi-pack-index
+              }
+            )
+          )
+      )
   )
 
   title "gix pack explode"