From ac41f497b4addcb1fd5f13971cc485f18b2028ff Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Fri, 15 Sep 2023 16:04:21 +0200
Subject: [PATCH 1/2] feat: add bytesize rule sql function

---
 apps/emqx_rule_engine/src/emqx_rule_funcs.erl        | 4 ++++
 apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
index edaa5f25f..37797cb4f 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
@@ -89,6 +89,7 @@
     bitsl/2,
     bitsr/2,
     bitsize/1,
+    bytesize/1,
     subbits/2,
     subbits/3,
     subbits/6
@@ -405,6 +406,9 @@ find_topic_filter(Filter, TopicFilters, Func) ->
 null() ->
     undefined.
 
+bytesize(IoList) ->
+    erlang:iolist_size(IoList).
+
 %%------------------------------------------------------------------------------
 %% Arithmetic Funcs
 %%------------------------------------------------------------------------------
diff --git a/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl b/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
index 65be15405..93b35fbc4 100644
--- a/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
+++ b/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
@@ -759,6 +759,10 @@ t_bitsize(_) ->
     ?assertEqual(8, apply_func(bitsize, [<<"a">>])),
     ?assertEqual(4, apply_func(bitsize, [<<15:4>>])).
 
+t_bytesize(_) ->
+    ?assertEqual(1, apply_func(bytesize, [<<"a">>])),
+    ?assertEqual(0, apply_func(bytesize, [<<>>])).
+
 t_subbits(_) ->
     ?assertEqual(1, apply_func(subbits, [<<255:8>>, 1])),
     ?assertEqual(3, apply_func(subbits, [<<255:8>>, 2])),

From 062854eff7cbe4a804a53b8933a16b6dad164732 Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Fri, 15 Sep 2023 16:07:23 +0200
Subject: [PATCH 2/2] docs: add changelog

---
 changes/ce/feat-11620.en.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changes/ce/feat-11620.en.md

diff --git a/changes/ce/feat-11620.en.md b/changes/ce/feat-11620.en.md
new file mode 100644
index 000000000..3953d337b
--- /dev/null
+++ b/changes/ce/feat-11620.en.md
@@ -0,0 +1 @@
+Add a new rule-engine SQL function `bytesize` to get the size of a byte-string. e.g. ``SELECT * FROM "t/#" WHERE bytesize(payload) > 10`