#44 fixes: api signatures and cache version-miss (#48)

* fix: Fix API signatures

* fix: Fix get_snap version_not_found case

src/dmt_client.erl

@@ -68,6 +68,10 @@
 -type object_filter() :: fun((object_type(), domain_object()) -> boolean()).
 -type object_folder(Acc) :: fun((object_type(), domain_object(), Acc) -> Acc).
 -type domain_object() :: dmsl_domain_thrift:'DomainObject'().
+%% HACK: this is type required for checkout_objects_by_type:
+%% domain_object is any object from union, tagged with it's name
+%% yet there's no way to extract typespecs for untagged objects
+-type untagged_domain_object() :: tuple().
 -type versioned_object() :: dmsl_domain_config_thrift:'VersionedObject'().
 -type domain() :: dmsl_domain_thrift:'Domain'().
 -type history() :: dmsl_domain_config_thrift:'History'().
@@ -118,15 +122,15 @@ checkout_versioned_object(Reference, ObjectReference, Opts) ->
     Version = ref_to_version(Reference),
     #'VersionedObject'{version = Version, object = checkout_object(Reference, ObjectReference, Opts)}.
 
--spec checkout_objects_by_type(object_type()) -> [domain_object()] | no_return().
+-spec checkout_objects_by_type(object_type()) -> [untagged_domain_object()] | no_return().
 checkout_objects_by_type(ObjectType) ->
     checkout_objects_by_type(latest, ObjectType).
 
--spec checkout_objects_by_type(version(), object_type()) -> [domain_object()] | no_return().
+-spec checkout_objects_by_type(version(), object_type()) -> [untagged_domain_object()] | no_return().
 checkout_objects_by_type(Reference, ObjectType) ->
     checkout_objects_by_type(Reference, ObjectType, #{}).
 
--spec checkout_objects_by_type(version(), object_type(), opts()) -> [domain_object()] | no_return().
+-spec checkout_objects_by_type(version(), object_type(), opts()) -> [untagged_domain_object()] | no_return().
 checkout_objects_by_type(Reference, ObjectType, Opts) ->
     Version = ref_to_version(Reference),
     unwrap(dmt_client_cache:get_objects_by_type(Version, ObjectType, Opts)).
@@ -162,23 +166,23 @@ checkout_fold_objects(Reference, Folder, Acc, Opts) ->
     Version = ref_to_version(Reference),
     unwrap(dmt_client_cache:fold_objects(Version, Folder, Acc, Opts)).
 
--spec commit(version(), commit()) -> version() | no_return().
+-spec commit(vsn(), commit()) -> vsn() | no_return().
 commit(Version, Commit) ->
     commit(Version, Commit, #{}).
 
--spec commit(version(), commit(), opts()) -> version() | no_return().
+-spec commit(vsn(), commit(), opts()) -> vsn() | no_return().
 commit(Version, Commit, Opts) ->
     dmt_client_backend:commit(Version, Commit, Opts).
 
--spec get_last_version() -> version().
+-spec get_last_version() -> vsn().
 get_last_version() ->
     dmt_client_cache:get_last_version().
 
--spec pull_range(version(), limit()) -> history() | no_return().
+-spec pull_range(vsn(), limit()) -> history() | no_return().
 pull_range(Version, Limit) ->
     pull_range(Version, Limit, #{}).
 
--spec pull_range(version(), limit(), opts()) -> history() | no_return().
+-spec pull_range(vsn(), limit(), opts()) -> history() | no_return().
 pull_range(Version, Limit, Opts) ->
     dmt_client_backend:pull_range(Version, Limit, Opts).
 

src/dmt_client_cache.erl

@@ -216,7 +216,7 @@ ensure_version(Version, Opts) ->
 
 -spec do_get(dmt_client:vsn()) -> {ok, dmt_client:snapshot()} | {error, version_not_found}.
 do_get(Version) ->
-    case get_snap(Version) of
+    case fetch_snap(Version) of
         {ok, Snap} ->
             build_snapshot(Snap);
         {error, version_not_found} = Error ->
@@ -226,8 +226,10 @@ do_get(Version) ->
 -spec do_get_object(dmt_client:vsn(), dmt_client:object_ref()) ->
     {ok, dmt_client:domain_object()} | {error, version_not_found | object_not_found}.
 do_get_object(Version, ObjectRef) ->
-    {ok, #snap{tid = TID}} = get_snap(Version),
+    try
-    try ets:lookup(TID, ObjectRef) of
+        Snap = get_snap(Version),
+        ets:lookup(Snap#snap.tid, ObjectRef)
+    of
         [#object{obj = Object}] ->
             {ok, Object};
         [] ->
@@ -241,11 +243,13 @@ do_get_object(Version, ObjectRef) ->
     end.
 
 do_get_objects_by_type(Version, ObjectType) ->
-    {ok, #snap{tid = TID}} = get_snap(Version),
     MatchSpec = [
         {{object, '_', {ObjectType, '$1'}}, [], ['$1']}
     ],
-    try ets:select(TID, MatchSpec) of
+    try
+        Snap = get_snap(Version),
+        ets:select(Snap#snap.tid, MatchSpec)
+    of
         Result ->
             {ok, Result}
     catch
@@ -255,11 +259,13 @@ do_get_objects_by_type(Version, ObjectType) ->
     end.
 
 do_fold_objects(Version, Folder, Acc) ->
-    {ok, #snap{tid = TID}} = get_snap(Version),
     MappedFolder = fun({object, {Type, _Ref}, {Type, Object}}, AccIn) ->
         Folder(Type, Object, AccIn)
     end,
-    try ets:foldl(MappedFolder, Acc, TID) of
+    try
+        Snap = get_snap(Version),
+        ets:foldl(MappedFolder, Acc, Snap#snap.tid)
+    of
         Result ->
             {ok, Result}
     catch
@@ -270,7 +276,7 @@ do_fold_objects(Version, Folder, Acc) ->
 
 -spec put_snapshot(dmt_client:snapshot()) -> ok.
 put_snapshot(#'Snapshot'{version = Version, domain = Domain}) ->
-    case get_snap(Version) of
+    case fetch_snap(Version) of
         {ok, _Snap} ->
             ok;
         {error, version_not_found} ->
@@ -296,8 +302,15 @@ put_domain_to_table(TID, Domain) ->
         Domain
     ).
 
--spec get_snap(dmt_client:vsn()) -> {ok, snap()} | {error, version_not_found}.
+-spec get_snap(dmt_client:vsn()) -> snap() | no_return().
 get_snap(Version) ->
+    case fetch_snap(Version) of
+        {ok, Snap} -> Snap;
+        {error, version_not_found} -> error(badarg)
+    end.
+
+-spec fetch_snap(dmt_client:vsn()) -> {ok, snap()} | {error, version_not_found}.
+fetch_snap(Version) ->
     case ets:lookup(?TABLE, Version) of
         [Snap] ->
             _ = update_last_access(Version),