From 04878c5ed9a6c688fe09a11cc342fbfd3a5efd5e Mon Sep 17 00:00:00 2001
From: Ulf Norell <ulf.norell@gmail.com>
Date: Tue, 1 Oct 2019 10:52:09 +0200
Subject: [PATCH 1/2] Add function to compute the byte size of a heap_value

Used to compute store gas cost in AEVM
---
 src/aeb_heap.erl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/aeb_heap.erl b/src/aeb_heap.erl
index e180102..14838a4 100644
--- a/src/aeb_heap.erl
+++ b/src/aeb_heap.erl
@@ -14,6 +14,7 @@
         , heap_value_maps/1
         , heap_value_offset/1
         , heap_value_heap/1
+        , heap_value_byte_size/1
         , heap_fragment_maps/1
         , heap_fragment_offset/1
         , heap_fragment_heap/1
@@ -90,6 +91,25 @@ heap_value_offset({_, Heap}) -> Heap#heap.offset.
                              binary() | #{non_neg_integer() => non_neg_integer()}.
 heap_value_heap({_, Heap}) -> Heap#heap.heap.
 
+%% -- Byte size of a heap value ----------------------------------------------
+
+-spec heap_value_byte_size(heap_value()) -> non_neg_integer().
+heap_value_byte_size({_, Heap}) ->
+    Value = Heap#heap.heap,
+    Maps  = Heap#heap.maps,
+    ValueSize =
+        if is_binary(Value) -> byte_size(Value);
+           true -> 0 end,
+    MapsSize =
+        lists:sum([ pmap_size(Map) || Map <- maps:values(Maps#maps.maps) ]),
+    ValueSize + MapsSize.
+
+pmap_size(#pmap{data = stored}) -> 0;
+pmap_size(#pmap{data = Data}) when is_map(Data) ->
+    lists:sum([ byte_size(Key) + byte_size(Val)
+                || {Key, Val} <- maps:to_list(Data),
+                   Val /= tombstone ]).
+
 %% -- Value to binary --------------------------------------------------------
 
 -spec to_binary(aeb_aevm_data:data()) -> aeb_aevm_data:heap().

From 48cfbd03b0763669680b6ae6385180446cf7b922 Mon Sep 17 00:00:00 2001
From: Ulf Norell <ulf.norell@gmail.com>
Date: Tue, 1 Oct 2019 10:52:54 +0200
Subject: [PATCH 2/2] Recalibrate the store map threshold

Now that we charge gas for store writes the math is changed.
---
 src/aeb_fate_maps.erl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/aeb_fate_maps.erl b/src/aeb_fate_maps.erl
index 2b62f81..e57831d 100644
--- a/src/aeb_fate_maps.erl
+++ b/src/aeb_fate_maps.erl
@@ -25,7 +25,7 @@
 %% Size in bytes of serialization of a map for which we turn it into a store
 %% map. It's not worth turning small maps into store maps.
 %% Under consensus!
--define(STORE_MAP_THRESHOLD, 500).
+-define(STORE_MAP_THRESHOLD, 100).
 
 -type fate_value() :: aeb_fate_data:fate_type().
 -type fate_value_or_tombstone() :: fate_value() | ?FATE_MAP_TOMBSTONE.