Add dbname to mango exec stats (#4990)

* WIP: include dbname in mango exec stats

* Don't output dbname in exec stats http response

* Make sure mango nouveau logs reports

* Test that mango reports get the dbname in the stats

* With compliant formatting

* Switch to adding exec stats dbname during create

* Add stats to explain cursor

* Add stats to mango cursor special

* Fix mango special cursor test

src/mango/src/mango_cursor.erl

@@ -424,6 +424,7 @@ create_cursor(Db, {[], Trace0}, Selector, Opts) ->
     Skip = couch_util:get_value(skip, Opts, 0),
     Fields = couch_util:get_value(fields, Opts, all_fields),
     Bookmark = couch_util:get_value(bookmark, Opts),
+    Stats = mango_execution_stats:stats_init(couch_db:name(Db)),
     {ok, #cursor{
         db = Db,
         index = none,
@@ -433,7 +434,8 @@ create_cursor(Db, {[], Trace0}, Selector, Opts) ->
         limit = Limit,
         skip = Skip,
         fields = Fields,
-        bookmark = Bookmark
+        bookmark = Bookmark,
+        execution_stats = Stats
     }};
 create_cursor(Db, {Indexes, Trace0}, Selector, Opts) ->
     Trace1 = maps:merge(Trace0, #{filtered_indexes => sets:from_list(Indexes)}),

src/mango/src/mango_cursor.hrl

@@ -25,7 +25,7 @@
     fields = undefined,
     user_fun,
     user_acc,
-    execution_stats = #execution_stats{},
+    execution_stats,
     bookmark,
     bookmark_docid,
     bookmark_key

src/mango/src/mango_cursor_nouveau.erl

@@ -53,6 +53,8 @@ create(Db, {Indexes, Trace}, Selector, Opts) ->
     Skip = couch_util:get_value(skip, Opts, 0),
     Fields = couch_util:get_value(fields, Opts, all_fields),
 
+    Stats = mango_execution_stats:stats_init(couch_db:name(Db)),
+
     {ok, #cursor{
         db = Db,
         index = Index,
@@ -62,7 +64,8 @@ create(Db, {Indexes, Trace}, Selector, Opts) ->
         opts = Opts,
         limit = Limit,
         skip = Skip,
-        fields = Fields
+        fields = Fields,
+        execution_stats = Stats
     }}.
 
 explain(Cursor) ->
@@ -128,6 +131,8 @@ execute(Cursor, UserFun, UserAcc) ->
             {FinalUserAcc0, Stats1} = mango_execution_stats:maybe_add_stats(
                 Opts, UserFun, Stats0, FinalUserAcc
             ),
+            %% This needs Stats1 as log_end is called in maybe_add_stats
+            mango_execution_stats:log_stats(Stats1),
             FinalUserAcc1 = mango_cursor:maybe_add_warning(UserFun, Cursor, Stats1, FinalUserAcc0),
             {ok, FinalUserAcc1}
     end.

src/mango/src/mango_cursor_special.erl

@@ -45,6 +45,7 @@ create(Db, {Indexes, Trace0}, Selector, Opts) ->
     Skip = couch_util:get_value(skip, Opts, 0),
     Fields = couch_util:get_value(fields, Opts, all_fields),
     Bookmark = couch_util:get_value(bookmark, Opts),
+    Stats = mango_execution_stats:stats_init(couch_db:name(Db)),
 
     IndexRanges1 = mango_cursor:maybe_noop_range(Selector, IndexRanges),
     Trace = maps:merge(Trace0, #{sorted_index_ranges => SortedIndexRanges}),
@@ -59,7 +60,8 @@ create(Db, {Indexes, Trace0}, Selector, Opts) ->
         limit = Limit,
         skip = Skip,
         fields = Fields,
-        bookmark = Bookmark
+        bookmark = Bookmark,
+        execution_stats = Stats
     }}.
 
 explain(Cursor) ->
@@ -74,13 +76,26 @@ handle_message(Msg, Cursor) ->
 -ifdef(TEST).
 -include_lib("couch/include/couch_eunit.hrl").
 
-create_test() ->
+create_test_() ->
+    {
+        foreach,
+        fun() ->
+            meck:expect(couch_db, name, fun(A) when is_atom(A) -> atom_to_binary(A) end)
+        end,
+        fun(_) -> meck:unload() end,
+        [
+            ?TDEF_FE(t_create)
+        ]
+    }.
+
+t_create(_) ->
     Index = #idx{type = <<"special">>, def = all_docs},
     Indexes = [Index],
     Ranges = [{'$gt', null, '$lt', mango_json_max}],
     Trace = #{},
     Selector = {[]},
     Options = [{limit, limit}, {skip, skip}, {fields, fields}, {bookmark, bookmark}],
+    Stats = mango_execution_stats:stats_init(couch_db:name(db)),
     Cursor =
         #cursor{
             db = db,
@@ -92,7 +107,8 @@ create_test() ->
             skip = skip,
             fields = fields,
             bookmark = bookmark,
-            trace = #{sorted_index_ranges => [{Index, Ranges, 0}]}
+            trace = #{sorted_index_ranges => [{Index, Ranges, 0}]},
+            execution_stats = Stats
         },
     ?assertEqual({ok, Cursor}, create(db, {Indexes, Trace}, Selector, Options)).
 

src/mango/src/mango_cursor_text.erl

@@ -50,7 +50,9 @@ create(Db, {Indexes, Trace}, Selector, Opts0) ->
                 ?MANGO_ERROR(multiple_text_indexes)
         end,
 
-    Opts = unpack_bookmark(couch_db:name(Db), Opts0),
+    DbName = couch_db:name(Db),
+    Opts = unpack_bookmark(DbName, Opts0),
+    Stats = mango_execution_stats:stats_init(DbName),
 
     DreyfusLimit = get_dreyfus_limit(),
     Limit = erlang:min(DreyfusLimit, couch_util:get_value(limit, Opts, mango_opts:default_limit())),
@@ -66,7 +68,8 @@ create(Db, {Indexes, Trace}, Selector, Opts0) ->
         opts = Opts,
         limit = Limit,
         skip = Skip,
-        fields = Fields
+        fields = Fields,
+        execution_stats = Stats
     }}.
 
 explain(Cursor) ->
@@ -389,36 +392,42 @@ t_create_regular(_) ->
     Limit = 10,
     Options = [{limit, Limit}, {skip, skip}, {fields, fields}, {bookmark, bookmark}],
     Options1 = [{limit, Limit}, {skip, skip}, {fields, fields}, {bookmark, unpacked_bookmark}],
+    Db = db,
+    Stats = mango_execution_stats:stats_init(couch_db:name(Db)),
     Cursor = #cursor{
-        db = db,
+        db = Db,
         index = Index,
         ranges = null,
         trace = Trace,
         selector = selector,
         opts = Options1,
         limit = Limit,
         skip = skip,
-        fields = fields
+        fields = fields,
+        execution_stats = Stats
     },
     meck:expect(dreyfus_bookmark, unpack, [db_name, bookmark], meck:val(unpacked_bookmark)),
-    ?assertEqual({ok, Cursor}, create(db, {Indexes, Trace}, selector, Options)).
+    ?assertEqual({ok, Cursor}, create(Db, {Indexes, Trace}, selector, Options)).
 
 t_create_no_bookmark(_) ->
     Limit = 99,
     Options = [{limit, Limit}, {skip, skip}, {fields, fields}, {bookmark, nil}],
     Options1 = [{limit, Limit}, {skip, skip}, {fields, fields}, {bookmark, []}],
+    Db = db,
+    Stats = mango_execution_stats:stats_init(couch_db:name(Db)),
     Cursor = #cursor{
-        db = db,
+        db = Db,
         index = index,
         ranges = null,
         trace = trace,
         selector = selector,
         opts = Options1,
         limit = Limit,
         skip = skip,
-        fields = fields
+        fields = fields,
+        execution_stats = Stats
     },
-    ?assertEqual({ok, Cursor}, create(db, {[index], trace}, selector, Options)).
+    ?assertEqual({ok, Cursor}, create(Db, {[index], trace}, selector, Options)).
 
 t_create_invalid_bookmark(_) ->
     Options = [{bookmark, invalid}],