File 0311-erts-Display-large-maps-similarly-to-small-maps.patch of Package erlang
From f8a11c5c5fb67875bd4769ebfbd57a07be76349a Mon Sep 17 00:00:00 2001
From: Magnus Thoang <magnusthoang@gmail.com>
Date: Tue, 22 Nov 2022 22:55:56 +0100
Subject: [PATCH] [erts] Display large maps similarly to small maps
The formatting of large maps done by erlang:display/1 used to reveal
interesting information about the map internals, but was difficult to
read, compared to the formatting of small maps, and did not represent a
map in proper erlang syntax. This commit aims at a formatting that is
proper erlang syntax, still without any sorting of elements.
---
erts/emulator/beam/erl_printf_term.c | 58 +++++++++++++++-------
erts/emulator/test/map_SUITE.erl | 72 ++++++++++++++++++++++++++--
2 files changed, 111 insertions(+), 19 deletions(-)
diff --git a/erts/emulator/beam/erl_printf_term.c b/erts/emulator/beam/erl_printf_term.c
index 24d6032012..bc87f99a2a 100644
--- a/erts/emulator/beam/erl_printf_term.c
+++ b/erts/emulator/beam/erl_printf_term.c
@@ -726,41 +726,67 @@ print_term(fmtfn_t fn, void* arg, Eterm obj, long *dcount) {
switch (MAP_HEADER_TYPE(*head)) {
case MAP_HEADER_TAG_HAMT_HEAD_ARRAY:
case MAP_HEADER_TAG_HAMT_HEAD_BITMAP:
- PRINT_STRING(res, fn, arg, "#<");
- PRINT_UWORD(res, fn, arg, 'x', 0, 1, mapval);
- PRINT_STRING(res, fn, arg, ">{");
- WSTACK_PUSH(s,PRT_CLOSE_TUPLE);
+ PRINT_STRING(res, fn, arg, "#{");
+ WSTACK_PUSH(s, PRT_CLOSE_TUPLE);
n = hashmap_bitcount(mapval);
ASSERT(n < 17);
head += 2;
if (n > 0) {
+ Eterm* assoc;
+ Eterm key, val;
n--;
- WSTACK_PUSH(s, head[n]);
- WSTACK_PUSH(s, PRT_TERM);
- while (n--) {
- WSTACK_PUSH(s, PRT_COMMA);
+ if (is_list(head[n])) {
+ assoc = list_val(head[n]);
+ key = CAR(assoc);
+ val = CDR(assoc);
+ WSTACK_PUSH5(s, val, PRT_TERM, PRT_ASSOC, key, PRT_TERM);
+ } else {
WSTACK_PUSH(s, head[n]);
WSTACK_PUSH(s, PRT_TERM);
+ }
+ while (n--) {
+ if (is_list(head[n])) {
+ assoc = list_val(head[n]);
+ key = CAR(assoc);
+ val = CDR(assoc);
+ WSTACK_PUSH6(s, PRT_COMMA, val, PRT_TERM, PRT_ASSOC, key, PRT_TERM);
+ } else {
+ WSTACK_PUSH(s, PRT_COMMA);
+ WSTACK_PUSH(s, head[n]);
+ WSTACK_PUSH(s, PRT_TERM);
+ }
}
}
break;
case MAP_HEADER_TAG_HAMT_NODE_BITMAP:
n = hashmap_bitcount(mapval);
head++;
- PRINT_CHAR(res, fn, arg, '<');
- PRINT_UWORD(res, fn, arg, 'x', 0, 1, mapval);
- PRINT_STRING(res, fn, arg, ">{");
- WSTACK_PUSH(s,PRT_CLOSE_TUPLE);
ASSERT(n < 17);
if (n > 0) {
+ Eterm* assoc;
+ Eterm key, val;
n--;
- WSTACK_PUSH(s, head[n]);
- WSTACK_PUSH(s, PRT_TERM);
- while (n--) {
- WSTACK_PUSH(s, PRT_COMMA);
+ if (is_list(head[n])) {
+ assoc = list_val(head[n]);
+ key = CAR(assoc);
+ val = CDR(assoc);
+ WSTACK_PUSH5(s, val, PRT_TERM, PRT_ASSOC, key, PRT_TERM);
+ } else {
WSTACK_PUSH(s, head[n]);
WSTACK_PUSH(s, PRT_TERM);
}
+ while (n--) {
+ if (is_list(head[n])) {
+ assoc = list_val(head[n]);
+ key = CAR(assoc);
+ val = CDR(assoc);
+ WSTACK_PUSH6(s, PRT_COMMA, val, PRT_TERM, PRT_ASSOC, key, PRT_TERM);
+ } else {
+ WSTACK_PUSH(s, PRT_COMMA);
+ WSTACK_PUSH(s, head[n]);
+ WSTACK_PUSH(s, PRT_TERM);
+ }
+ }
}
break;
}
diff --git a/erts/emulator/test/map_SUITE.erl b/erts/emulator/test/map_SUITE.erl
index 8769dea81f..7fb2961cad 100644
--- a/erts/emulator/test/map_SUITE.erl
+++ b/erts/emulator/test/map_SUITE.erl
@@ -88,8 +88,11 @@
t_get_map_elements/1,
y_regs/1,
- %%Bugs
- t_large_unequal_bins_same_hash_bug/1]).
+ %% Bugs
+ t_large_unequal_bins_same_hash_bug/1,
+
+ %% Display
+ t_map_display/1]).
%% Benchmarks
-export([benchmarks/1]).
@@ -168,7 +171,10 @@ groups() ->
y_regs,
%% Bugs
- t_large_unequal_bins_same_hash_bug]},
+ t_large_unequal_bins_same_hash_bug,
+
+ %% Display
+ t_map_display]},
{benchmarks, [{repeat,10}], [benchmarks]}].
run_once() ->
@@ -3498,6 +3504,8 @@ t_large_unequal_bins_same_hash_bug(Config) when is_list(Config) ->
io:format("~p ~p~n", [erlang:phash2(Map3), maps:size(Map3)])
end).
+
+
make_map(0) ->
#{};
make_map(Size) ->
@@ -3542,6 +3550,64 @@ total_memory() ->
undefined
end.
+%% This test case checks that maps larger than 32 elements are readable
+%% when displayed.
+t_map_display(Config) when is_list(Config) ->
+ verify_map_term(make_nontrivial_map(33)),
+ verify_map_term(make_nontrivial_map(253)),
+ verify_map_term({a, make_nontrivial_map(77)}),
+ verify_map_term([make_nontrivial_map(42),
+ {a,make_nontrivial_map(99)},
+ make_nontrivial_map(77)]),
+
+ ok.
+
+make_nontrivial_map(N) ->
+ make_nontrivial_map(N, 32).
+
+make_nontrivial_map(N, Effort) ->
+ L = [begin
+ Key = case I rem 64 of
+ 33 when Effort > 16 ->
+ make_nontrivial_map(I, Effort div 2);
+ _ ->
+ I
+ end,
+ Value = case I rem 5 of
+ 0 ->
+ I * I;
+ 1 ->
+ if
+ Effort > 16 ->
+ make_nontrivial_map(33, Effort div 2);
+ true ->
+ make_map(Effort)
+ end;
+ 2 ->
+ lists:seq(0, I rem 16);
+ 3 ->
+ list_to_tuple(lists:seq(0, I rem 16));
+ 4 ->
+ float(I)
+ end,
+ {Key, Value}
+ end || I <- lists:seq(1, N)],
+ maps:from_list(L).
+
+verify_map_term(Term) ->
+ Printed = string:chomp(erts_debug:display(Term)),
+ {ok,Tokens,1} = erl_scan:string(Printed ++ "."),
+ {ok,ParsedTerm} = erl_parse:parse_term(Tokens),
+
+ case ParsedTerm of
+ Term ->
+ ok;
+ Other ->
+ io:format("Expected:\n~p\n", [Term]),
+ io:format("Got:\n~p", [Other]),
+ ct:fail(failed)
+ end.
+
%%%
%%% Benchmarks
%%%
--
2.35.3
