[ByteBuffer] Reduce ARC traffic when reading

[fabianfett]

In my local testing it seems that the compiler adds a retain and release cycle around the use of map here.

Modifications:

• Replaced the use of .map with a guard let in the byteBuffer read methods.

Result:

Faster reads on ByteBuffer.

[fabianfett]

@swift-nio-bot test perf please

[swift-server-bot]

performance report

build id: 81

timestamp: Thu Oct 21 14:21:39 UTC 2021

results

name	min	max	mean	std
write_http_headers	0.004169956	0.00419325	0.0041795288	7.766251903088347e-06
http_headers_canonical_form	0.088055274	0.088587642	0.0882778209	0.00025034319680366374
http_headers_canonical_form_trimming_whitespace	0.168275028	0.169624616	0.1692467345	0.0004882337811140741
http_headers_canonical_form_trimming_whitespace_from_short_string	0.153795174	0.156386562	0.15484314670000002	0.000743439201082233
http_headers_canonical_form_trimming_whitespace_from_long_string	0.237557188	0.239528825	0.23892181529999998	0.0005725042828614283
bytebuffer_write_12MB_short_string_literals	0.541479508	0.54719041	0.5430489761	0.0017167516237856894
bytebuffer_write_12MB_short_calculated_strings	0.541006557	0.543095481	0.5418912588	0.0005578923293874074
bytebuffer_write_12MB_medium_string_literals	0.182454814	0.185974794	0.18474813029999998	0.0010591400016275326
bytebuffer_write_12MB_medium_calculated_strings	0.229726193	0.233763991	0.23103418950000001	0.0012363111472903992
bytebuffer_write_12MB_large_calculated_strings	0.14716342	0.148505867	0.14779702649999998	0.0003641974028372413
bytebuffer_lots_of_rw	0.47108764	0.475915602	0.4724715663	0.0017907100827541404
bytebuffer_write_http_response_ascii_only_as_string	0.040969405	0.04142388	0.0410970444	0.00017065109840464334
bytebuffer_write_http_response_ascii_only_as_staticstring	0.031699864	0.032273651	0.0318890161	0.0002003290520975978
bytebuffer_write_http_response_some_nonascii_as_string	0.041542704	0.043524175	0.0419298697	0.0005995650532103435
bytebuffer_write_http_response_some_nonascii_as_staticstring	0.032287417	0.032818364	0.0324188661	0.00020020785707273273
no-net_http1_10k_reqs_1_conn	0.109151003	0.115363126	0.11112164760000001	0.0022130553501657282
http1_10k_reqs_1_conn	0.603534636	0.613215139	0.6094643499	0.003042471993141479
http1_10k_reqs_100_conns	0.596938067	0.601148947	0.5989975538000001	0.0013332306436497894
future_whenallsucceed_100k_immediately_succeeded_off_loop	0.078860741	0.080310505	0.0795883566	0.0004380483918080299
future_whenallsucceed_100k_immediately_succeeded_on_loop	0.0781298	0.086177285	0.0793687205	0.0024084819765559703
future_whenallsucceed_100k_deferred_off_loop	0.29794172	0.305158389	0.301420458	0.002478755914605993
future_whenallsucceed_100k_deferred_on_loop	0.135919682	0.139265652	0.1368457608	0.0009255819584314108
future_whenallcomplete_100k_immediately_succeeded_off_loop	0.036776816	0.038440418	0.0378630081	0.000529992511073391
future_whenallcomplete_100k_immediately_succeeded_on_loop	0.036233749	0.037457102	0.0367684395	0.0004175333296868504
future_whenallcomplete_100k_deferred_off_loop	0.221114073	0.225355666	0.2228828944	0.0015060956533410213
future_whenallcomplete_100k_deferred_on_loop	0.072958725	0.079199835	0.0739254677	0.0018853156049431698
future_reduce_10k_futures	0.03832076	0.039375941	0.0386847819	0.00031046723969435614
future_reduce_into_10k_futures	0.038530985	0.039488932	0.0389915629	0.00029453830262914066
channel_pipeline_1m_events	0.097142373	0.09731771	0.09721936719999999	6.730169132231618e-05
websocket_encode_50b_space_at_front_1m_frames_cow	0.515673586	0.520921327	0.516471733	0.0015766917713478546
websocket_encode_50b_space_at_front_1m_frames_cow_masking	0.067899326	0.068369067	0.06805335180000001	0.0002114663834018727
websocket_encode_1kb_space_at_front_100k_frames_cow	0.054371187	0.054822104	0.054467691	0.00017908688503690738
websocket_encode_50b_no_space_at_front_1m_frames_cow	0.515659588	0.516209981	0.5159911945	0.00021541721841696981
websocket_encode_1kb_no_space_at_front_100k_frames_cow	0.054346354	0.054782316	0.054494673800000004	0.00019221477404761982
websocket_encode_50b_space_at_front_10k_frames	0.006773438	0.006788569	0.0067806718000000005	5.3915513908338085e-06
websocket_encode_50b_space_at_front_10k_frames_masking	0.083597739	0.084283576	0.08385275480000001	0.0002514137424082724
websocket_encode_1kb_space_at_front_1k_frames	0.000800629	0.000810076	0.0008058901	2.527154853893122e-06
websocket_encode_50b_no_space_at_front_10k_frames	0.006711524	0.006741929	0.0067203561999999994	9.273534443062423e-06
websocket_encode_1kb_no_space_at_front_1k_frames	0.000716539	0.000725509	0.0007205386	2.970895719775087e-06
websocket_decode_125b_100k_frames	0.113300821	0.113899097	0.11361955409999999	0.00026156412002772506
websocket_decode_125b_with_a_masking_key_100k_frames	0.116529743	0.117321292	0.116867138	0.00027744140644307143
websocket_decode_64kb_100k_frames	0.117149372	0.117855565	0.1174712706	0.00026469819010177444
websocket_decode_64kb_with_a_masking_key_100k_frames	0.120513076	0.12149612	0.12113974729999999	0.000293264263531509
websocket_decode_64kb_+1_100k_frames	0.116055353	0.116678255	0.11637806710000001	0.00023951466780389562
websocket_decode_64kb_+1_with_a_masking_key_100k_frames	0.11943286	0.120195038	0.1197772104	0.00024792255236540594
circular_buffer_into_byte_buffer_1kb	0.041226056	0.041659248	0.041335674899999994	0.00014950777100981264
circular_buffer_into_byte_buffer_1mb	0.082269057	0.082755151	0.0824666681	0.00021936225923265562
byte_buffer_view_iterator_1mb	0.020487769	0.020909135	0.0205405942	0.00013004639736374394
byte_to_message_decoder_decode_many_small	0.181182936	0.181855663	0.18167033159999998	0.00018210606918936327
generate_10k_random_request_keys	0.091555963	0.091818431	0.09170850230000001	9.227365683305332e-05

comparison

name	current	previous	winner	diff
write_http_headers	0.004169956	0.004173768	current	0%
http_headers_canonical_form	0.088055274	0.087810981	previous	0%
http_headers_canonical_form_trimming_whitespace	0.168275028	0.167407024	previous	0%
http_headers_canonical_form_trimming_whitespace_from_short_string	0.153795174	0.153040553	previous	0%
http_headers_canonical_form_trimming_whitespace_from_long_string	0.237557188	0.237190983	previous	0%
bytebuffer_write_12MB_short_string_literals	0.541479508	0.534323642	previous	1%
bytebuffer_write_12MB_short_calculated_strings	0.541006557	0.532762593	previous	1%
bytebuffer_write_12MB_medium_string_literals	0.182454814	0.178170728	previous	2%
bytebuffer_write_12MB_medium_calculated_strings	0.229726193	0.22884603	previous	0%
bytebuffer_write_12MB_large_calculated_strings	0.14716342	0.147709601	current	0%
bytebuffer_lots_of_rw	0.47108764	0.529788832	current	-11%
bytebuffer_write_http_response_ascii_only_as_string	0.040969405	0.040653462	previous	0%
bytebuffer_write_http_response_ascii_only_as_staticstring	0.031699864	0.031083966	previous	1%
bytebuffer_write_http_response_some_nonascii_as_string	0.041542704	0.041689994	current	0%
bytebuffer_write_http_response_some_nonascii_as_staticstring	0.032287417	0.032483179	current	0%
no-net_http1_10k_reqs_1_conn	0.109151003	0.107796223	previous	1%
http1_10k_reqs_1_conn	0.603534636	0.608815231	current	0%
http1_10k_reqs_100_conns	0.596938067	0.599726853	current	0%
future_whenallsucceed_100k_immediately_succeeded_off_loop	0.078860741	0.077595126	previous	1%
future_whenallsucceed_100k_immediately_succeeded_on_loop	0.0781298	0.078733979	current	0%
future_whenallsucceed_100k_deferred_off_loop	0.29794172	0.287749749	previous	3%
future_whenallsucceed_100k_deferred_on_loop	0.135919682	0.13355893	previous	1%
future_whenallcomplete_100k_immediately_succeeded_off_loop	0.036776816	0.035950449	previous	2%
future_whenallcomplete_100k_immediately_succeeded_on_loop	0.036233749	0.035990379	previous	0%
future_whenallcomplete_100k_deferred_off_loop	0.221114073	0.212803552	previous	3%
future_whenallcomplete_100k_deferred_on_loop	0.072958725	0.070250905	previous	3%
future_reduce_10k_futures	0.03832076	0.038230662	previous	0%
future_reduce_into_10k_futures	0.038530985	0.037234258	previous	3%
channel_pipeline_1m_events	0.097142373	0.097675333	current	0%
websocket_encode_50b_space_at_front_1m_frames_cow	0.515673586	0.517624033	current	0%
websocket_encode_50b_space_at_front_1m_frames_cow_masking	0.067899326	0.065880294	previous	3%
websocket_encode_1kb_space_at_front_100k_frames_cow	0.054371187	0.054261527	previous	0%
websocket_encode_50b_no_space_at_front_1m_frames_cow	0.515659588	0.517575663	current	0%
websocket_encode_1kb_no_space_at_front_100k_frames_cow	0.054346354	0.054403566	current	0%
websocket_encode_50b_space_at_front_10k_frames	0.006773438	0.006794661	current	0%
websocket_encode_50b_space_at_front_10k_frames_masking	0.083597739	0.081286349	previous	2%
websocket_encode_1kb_space_at_front_1k_frames	0.000800629	0.000788918	previous	1%
websocket_encode_50b_no_space_at_front_10k_frames	0.006711524	0.006752694	current	0%
websocket_encode_1kb_no_space_at_front_1k_frames	0.000716539	0.000716036	previous	0%
websocket_decode_125b_100k_frames	0.113300821	0.116987663	current	-3%
websocket_decode_125b_with_a_masking_key_100k_frames	0.116529743	0.119994401	current	-2%
websocket_decode_64kb_100k_frames	0.117149372	0.12104027	current	-3%
websocket_decode_64kb_with_a_masking_key_100k_frames	0.120513076	0.124047064	current	-2%
websocket_decode_64kb_+1_100k_frames	0.116055353	0.120446876	current	-3%
websocket_decode_64kb_+1_with_a_masking_key_100k_frames	0.11943286	0.123589328	current	-3%
circular_buffer_into_byte_buffer_1kb	0.041226056	0.041295048	current	0%
circular_buffer_into_byte_buffer_1mb	0.082269057	0.082280352	current	0%
byte_buffer_view_iterator_1mb	0.020487769	0.020486943	previous	0%
byte_to_message_decoder_decode_many_small	0.181182936	0.197320356	current	-8%
generate_10k_random_request_keys	0.091555963	0.089960851	previous	1%

significant differences found