wip

src/irmin-pack/unix/ext.ml

@@ -364,7 +364,7 @@ module Maker (Config : Conf.S) = struct
             let* _suffix_start_offset, _prefix_commit_offset =
               match t.running_gc with
               | None -> assert false
-              | Some { gc; _ } -> Gc.finalise_snap_exn gc
+              | Some { gc; _ } -> Gc.finalise_snap_exn gc path
             in
             Lwt.return_unit
         end

src/irmin-pack/unix/file_manager.ml

@@ -596,6 +596,10 @@ struct
             else open_rw_no_control_file config
         | `Directory | `Other -> Error `Invalid_layout)
 
+  let open_rw_from_snapshot config ~generation ~suffix_start_offset
+      ~prefix_commit_offset =
+
+
   let open_rw_from_snapshot config ~generation ~suffix_start_offset
       ~prefix_commit_offset =
     let open Result_syntax in

src/irmin-pack/unix/gc.ml

@@ -315,39 +315,45 @@ module Make (Args : Gc_args.S) = struct
           | `Running -> Lwt.return_ok `Running
           | #Async.outcome as status -> go status)
 
-  let finalise_snap_exn t =
+  let create_new_suffix ~root ~generation =
+    let open Result_syntax in
+    let path = Irmin_pack.Layout.V4.suffix_chunk ~root ~chunk_idx:generation in
+    let ao =
+      Ao.create_rw ~path ~overwrite:true ~auto_flush_threshold:1_000_000
+        ~auto_flush_procedure:`Internal
+      |> Errs.raise_if_error
+    in
+    Ao.close ao |> Errs.raise_if_error
+
+  let finalise_snap_exn t snapshot_root =
     let* status = Async.await t.task in
     match status with
     | `Success ->
         let root = t.root in
-        let snap_root = Filename.concat t.root "snap" in
-        let () = Io.mkdir snap_root |> Errs.raise_if_error in
+        let () = Io.mkdir snapshot_root |> Errs.raise_if_error in
         let generation = t.generation in
-        let src_prefix = Irmin_pack.Layout.V4.prefix ~root ~generation in
-        let dst_prefix =
-          Irmin_pack.Layout.V4.prefix ~root:snap_root ~generation
-        in
-        let src_mapping = Irmin_pack.Layout.V4.mapping ~root ~generation in
-        let dst_mapping =
-          Irmin_pack.Layout.V4.mapping ~root:snap_root ~generation
-        in
+        (* let src_prefix = Irmin_pack.Layout.V4.prefix ~root ~generation in
+         * let dst_prefix =
+         *   Irmin_pack.Layout.V4.prefix ~root:snap_root ~generation
+         * in
+         * let src_mapping = Irmin_pack.Layout.V4.mapping ~root ~generation in
+         * let dst_mapping =
+         *   Irmin_pack.Layout.V4.mapping ~root:snap_root ~generation
+         * in
+         * let () =
+         *   Io.move_file ~src:src_prefix ~dst:dst_prefix |> Errs.raise_if_error
+         * in
+         * let () =
+         *   Io.move_file ~src:src_mapping ~dst:dst_mapping |> Errs.raise_if_error
+         * in *)
         let src_dict = Irmin_pack.Layout.V4.dict ~root in
-        let dst_dict = Irmin_pack.Layout.V4.dict ~root:snap_root in
-        let () =
-          Io.move_file ~src:src_prefix ~dst:dst_prefix |> Errs.raise_if_error
-        in
-        let () =
-          Io.move_file ~src:src_mapping ~dst:dst_mapping |> Errs.raise_if_error
-        in
+        let dst_dict = Irmin_pack.Layout.V4.dict ~root:snapshot_root in
         let () =
           Io.cp_file ~src:src_dict ~dst:dst_dict |> Errs.raise_if_error
         in
-        (*TODO there is no new suffix with chunks. *)
-        let suffix =
-          Irmin_pack.Layout.V4.suffix_chunk ~root ~chunk_idx:generation
-        in
-        let () = Io.unlink suffix |> Errs.raise_if_error in
-        Lwt.return (t.offset, t.latest_gc_target_offset)
+        let () = create_new_suffix ~root:snapshot_root ~generation in
+        let latest_gc_target_offset = t.latest_gc_target_offset in
+        Lwt.return_unit
     | _ ->
         let gc_output = read_gc_output ~root:t.root ~generation:t.generation in
         let r = gc_errors status gc_output |> Errs.raise_if_error in

src/irmin-pack/unix/gc_worker.ml

@@ -167,7 +167,7 @@ module Make (Args : Gc_args.S) = struct
         stats := Gc_stats.Worker.add_file_size !stats "mapping" mapping_size
       in
       (fun f ->
-        Mapping_file.create ~report_file_sizes ~root ~generation
+        Mapping_file.create ~report_file_sizes ~root:path_new_files ~generation
           ~register_entries:f ()
         |> Errs.raise_if_error)
       @@ fun ~register_entry ->
@@ -218,7 +218,9 @@ module Make (Args : Gc_args.S) = struct
       (* Step 4. Create the new prefix. *)
       stats := Gc_stats.Worker.finish_current_step !stats "prefix: start";
       let prefix =
-        let path = Irmin_pack.Layout.V4.prefix ~root ~generation in
+        let path =
+          Irmin_pack.Layout.V4.prefix ~root:path_new_files ~generation
+        in
         Ao.create_rw_exn ~path
       in
       let () =
@@ -252,7 +254,9 @@ module Make (Args : Gc_args.S) = struct
         Dispatcher.read_exn dispatcher accessor buf
       in
       let prefix =
-        let path = Irmin_pack.Layout.V4.prefix ~root ~generation in
+        let path =
+          Irmin_pack.Layout.V4.prefix ~root:path_new_files ~generation
+        in
         Io.open_ ~path ~readonly:false |> Errs.raise_if_error
       in
       Errors.finalise_exn (fun _outcome ->
@@ -330,10 +334,11 @@ module Make (Args : Gc_args.S) = struct
 
   (* No one catches errors when this function terminates. Write the result in a
      file and terminate. *)
-  let run_and_output_result ~generation root commit_key new_prefix_end_offset =
+  let run_and_output_result ~generation ~path_new_files root commit_key
+      new_prefix_end_offset =
     let result =
       Errs.catch (fun () ->
-          run ~generation root commit_key new_prefix_end_offset)
+          run ~generation ~path_new_files root commit_key new_prefix_end_offset)
     in
     let write_result = write_gc_output ~root ~generation result in
     write_result |> Errs.log_if_error "writing gc output"