Allow var lookups to bypass cache with pdict value

src/blockchain_utils.erl

@@ -878,14 +878,20 @@ get_vars(VarList, Ledger) ->
                VarsNonce :: non_neg_integer(),
                Ledger :: blockchain_ledger_v1:ledger()) -> {ok, any()} | {error, any()}.
 get_var_(VarName, HasAux, VarsNonce, Ledger) ->
-    Cache = persistent_term:get(?var_cache),
-    cream:cache(
-      Cache,
-      {HasAux, VarsNonce, VarName},
-      fun() ->
-              get_var_(VarName, Ledger)
-      end
-    ).
+    case get('__speculative_absorb') of
+        true ->
+            %% do not update the cache
+            get_var_(VarName, Ledger);
+        _ ->
+            Cache = persistent_term:get(?var_cache),
+            cream:cache(
+              Cache,
+              {HasAux, VarsNonce, VarName},
+              fun() ->
+                      get_var_(VarName, Ledger)
+              end
+             )
+    end.
 
 -spec get_var(VarName :: atom(), Ledger :: blockchain_ledger_v1:ledger()) -> {ok, any()} | {error, any()}.
 get_var(VarName, Ledger) ->

src/region/blockchain_region_v1.erl

@@ -73,24 +73,31 @@ h3_to_region(H3, Ledger, RegionBins) ->
     Res = polyfill_resolution(Ledger),
     HasAux = blockchain_ledger_v1:has_aux(Ledger),
     Parent = h3:parent(H3, Res),
-    Cache = persistent_term:get(?region_cache),
-    cream:cache(
-        Cache,
-        {HasAux, VarsNonce, Parent},
-        fun() ->
-                MaybeBins =
-                    case RegionBins of
-                        no_prefetch -> get_all_region_bins(Ledger);
-                        {error, _} = Err -> Err;
-                        B -> {ok, B}
-                    end,
-                case MaybeBins of
-                    {ok, Bins} ->
-                        h3_to_region_(Parent, Bins);
-                    {error, _} = Error -> Error
-                end
-        end
-     ).
+    LookupFun = fun() ->
+                        MaybeBins =
+                        case RegionBins of
+                            no_prefetch -> get_all_region_bins(Ledger);
+                            {error, _} = Err -> Err;
+                            B -> {ok, B}
+                        end,
+                        case MaybeBins of
+                            {ok, Bins} ->
+                                h3_to_region_(Parent, Bins);
+                            {error, _} = Error -> Error
+                        end
+                end,
+    %% don't contaminate the cache when doing speculative absorbs
+    case get('__speculative_absorb') of
+        true ->
+            LookupFun();
+        _ ->
+            Cache = persistent_term:get(?region_cache),
+            cream:cache(
+              Cache,
+              {HasAux, VarsNonce, Parent},
+              LookupFun
+             )
+    end.
 
 -spec h3_in_region(
     H3 :: h3:h3_index(),

src/transactions/blockchain_txn_mgr.erl

@@ -206,6 +206,8 @@ init(Args) ->
                                   Tabs
                           end,
     ok = blockchain_event:add_handler(self()),
+    %% indicate this process does speculative absorbs to determine txn validity
+    put('__speculative_absorb', true),
     {ok, #state{txn_cache = TxnCache, rejections_deferred = []}}.
 
 handle_cast({set_chain, Chain}, State=#state{chain = undefined}) ->

src/transactions/v1/blockchain_txn_vars_v1.erl

@@ -616,18 +616,24 @@ delayed_absorb(Txn, Ledger) ->
                     ok = blockchain_ledger_v1:master_key(Key, Ledger)
             end
     end,
-    blockchain_utils:teardown_var_cache(),
-    case blockchain_ledger_v1:mode(Ledger) of
-        active ->
-            %% we've invalidated the region cache, so prewarm it.
-            spawn(fun() ->
-                          timer:sleep(30000),
-                          blockchain_region_v1:prewarm_cache(blockchain_ledger_v1:remove_context(Ledger))
-                  end);
+    case get('__speculative_absorb') of
+        true ->
+            ok;
         _ ->
+            %% arguably this is unnecessary because the var nonce is part of the cache key
+            blockchain_utils:teardown_var_cache(),
+            case blockchain_ledger_v1:mode(Ledger) of
+                active ->
+                    %% we've invalidated the region cache, so prewarm it.
+                    spawn(fun() ->
+                                  timer:sleep(30000),
+                                  blockchain_region_v1:prewarm_cache(blockchain_ledger_v1:remove_context(Ledger))
+                          end);
+                _ ->
+                    ok
+            end,
             ok
-    end,
-    ok.
+    end.
 
 sum_higher(Target, Proplist) ->
     sum_higher(Target, Proplist, 0).