Split genesis ledger tar creation method in two

The previous generate_tar method did two things:

1. It prepared the data needed to generate a new ledger database tar
   file, given some Ledger.t mask over a ledger database
2. It generated the actual tar files and names given that data

When we generate the tar files for the migrated ledger databases during
the hard fork, we will not have Ledger.t masks available to us. Rather,
we will have known databases of hard fork accounts. In this situation,
it is easier to do (1) separately, and then re-use (2) to generate the
actual files.

The generate_tar method now does (2) alone; a separate
generate_ledger_tar method now does (1) and (2).

Author: cjjdespres

src/app/runtime_genesis_ledger/runtime_genesis_ledger.ml

@@ -34,7 +34,7 @@ let load_ledger ~ignore_missing_fields ~pad_app_state
 let generate_ledger_tarball ~genesis_dir ~ledger_name_prefix ledger =
   let%bind tar_path =
     Deferred.Or_error.ok_exn
-    @@ Genesis_ledger_helper.Ledger.generate_tar ~genesis_dir ~logger
+    @@ Genesis_ledger_helper.Ledger.generate_ledger_tar ~genesis_dir ~logger
          ~ledger_name_prefix ledger
   in
   [%log info] "Generated ledger tar at %s" tar_path ;

src/lib/genesis_ledger_helper/genesis_ledger_helper.ml

@@ -219,35 +219,28 @@ module Ledger = struct
         | _, Some name ->
             search_local_and_s3 name )
 
-  let generate_tar ~genesis_dir ~logger ~ledger_name_prefix ledger =
-    Mina_ledger.Ledger.commit ledger ;
-    let dirname = Option.value_exn (Mina_ledger.Ledger.get_directory ledger) in
-    let root_hash =
-      Ledger_hash.to_base58_check @@ Mina_ledger.Ledger.merkle_root ledger
-    in
-    let%bind () = Unix.mkdir ~p:() genesis_dir in
-    let tar_path = genesis_dir ^/ hash_filename root_hash ~ledger_name_prefix in
+  let generate_tar ~logger ~target_dir ~ledger_name_prefix ~root_hash
+      ~ledger_dirname () =
+    let root_hash = Ledger_hash.to_base58_check root_hash in
+    let%bind.Deferred () = Unix.mkdir ~p:() target_dir in
+    let tar_path = target_dir ^/ hash_filename root_hash ~ledger_name_prefix in
     [%log trace]
       "Creating $ledger tar file for $root_hash at $path from database at $dir"
       ~metadata:
         [ ("ledger", `String ledger_name_prefix)
         ; ("root_hash", `String root_hash)
         ; ("path", `String tar_path)
-        ; ("dir", `String dirname)
+        ; ("dir", `String ledger_dirname)
         ] ;
     (* This sleep for 5s is a hack for rocksdb. It seems like rocksdb would need some
        time to stablize *)
-    let%bind () = after (Time.Span.of_int_sec 5) in
-    match%map Tar.create ~root:dirname ~file:tar_path ~directory:"." () with
+    let%bind.Deferred () = after (Time.Span.of_int_sec 5) in
+    match%map.Deferred
+      Tar.create ~root:ledger_dirname ~file:tar_path ~directory:"." ()
+    with
     | Ok () ->
         Ok tar_path
     | Error err ->
-        let root_hash =
-          Ledger_hash.to_base58_check @@ Mina_ledger.Ledger.merkle_root ledger
-        in
-        let tar_path =
-          genesis_dir ^/ hash_filename root_hash ~ledger_name_prefix
-        in
         [%log error] "Could not generate a $ledger file at $path: $error"
           ~metadata:
             [ ("ledger", `String ledger_name_prefix)
@@ -256,6 +249,13 @@ module Ledger = struct
             ] ;
         Error err
 
+  let generate_ledger_tar ~genesis_dir ~logger ~ledger_name_prefix ledger =
+    Mina_ledger.Ledger.commit ledger ;
+    let dirname = Option.value_exn (Mina_ledger.Ledger.get_directory ledger) in
+    let root_hash = Mina_ledger.Ledger.merkle_root ledger in
+    generate_tar ~logger ~target_dir:genesis_dir ~ledger_name_prefix ~root_hash
+      ~ledger_dirname:dirname ()
+
   let padded_accounts_from_runtime_config_opt ~logger ~proof_level
       ~ledger_name_prefix ?overwrite_version (config : Runtime_config.Ledger.t)
       =
@@ -454,7 +454,7 @@ module Ledger = struct
         in
         let ledger = Lazy.force (Genesis_ledger.Packed.t packed) in
         let%bind.Deferred.Or_error tar_path =
-          generate_tar ~genesis_dir ~logger ~ledger_name_prefix ledger
+          generate_ledger_tar ~genesis_dir ~logger ~ledger_name_prefix ledger
         in
         let config =
           { config with
@@ -531,7 +531,7 @@ module Ledger = struct
         in
         let ledger = Lazy.force (Genesis_ledger.Packed.t packed) in
         let%map.Deferred.Or_error tar_file =
-          generate_tar ~genesis_dir ~logger ~ledger_name_prefix ledger
+          generate_ledger_tar ~genesis_dir ~logger ~ledger_name_prefix ledger
         in
         (packed, config, tar_file)
     | Tar { tar_file; extracted_path } ->