onion108 / cplusplus-output-benchmark

A benchmarking for common ways to output used by C++ competitive programmers.

Hi there 👋

Howdy! I'm 27Onion "Wolfys" Nebell.

Here is my personal website: Click Me To Teleport

Analyze

cplusplus-output-benchmark's Issues

More professional output speed comparison

Benchmarks

1. I/O 10M integers

Goal: Print out ten million integers from 0 to 10M to file. Then reopen that file to scan back.

All benchmarks are in benchmarks/0000.10m_size_t/unit.

Notice: I modified libstdc++'s BUFSIZ 1048576 due to BUFSIZ is too small (512 bytes) for MinGW-W64, or it performs horribly.

Platform	Windows	MinGW-W64 GCC 11.0.0	MSVCRT + libstdc++

Method	Output time	Input time	Comment
stdio.h(fprintf/fscanf)	2.412987s	5.607791s
fstream	0.462012s	1.192s
fstream with rdbuf.sputc trick	0.33895s	1.170173s
fast_io::i/obuf_file	0.04903s	0.080996s
fast_io::i/obuf_file_mutex	0.146064s	0.113155s	thread safe
c_locale_i/obuf_file ("C")	0.065988s	0.086012s	imbued with locale, locale "C"
c_locale_i/obuf_file local	0.153995s	❌	imbued with locale, locale ""
fmt::format_int+obuf_file	0.122999s	❌
fmt::format_int+ofstream	0.209055s	❌
fmt::format+ofstream	0.548s	❌	fmt makes things slower
fmt::print	0.663996s	❌	fmt makes things slower
std::to_chars+obuf_file	0.12s	❌
std::to_chars+ofstream	0.192s	❌
fast_io::c_file_unlocked	0.098999s	0.126003s	I hacked MSVCRT's FILE* implementation
fast_io::c_file	0.298988s	0.318001s	Thread Safe. I hacked MSVCRET's FILE* implementation
fast_io::filebuf_file	0.048999s	0.081s	I hacked libstdc++'s streambuf/filebuf implementation
fast_io::iobuf_utf8_file_char16	0.124s	0.112001s	UTF-16=>UTF-8 with SSE
fast_io::iobuf_utf8_file_char32	0.110999s	0.111011s	UTF-32=>UTF-8 with SSE
std::wofstream	2.64s	3.843735s	wofstream with std::locale codecvt. Extremely slow tbh.
fast_io::wfilebuf_io_observer	2.415692s	2.497704s	wofstream with std::locale codecvt. This proves fstream can never get fixed.
Rust language	0.483s	❌	RUST IS SLOW. Also Rust does not deal with locale. Think how bad it is.
Rust itoa library 0.4.6	> 0.165s	❌	I ignored the \n part for it to ensure no bias.

Rust language is 10x slower than fast_io. + binary bloat and itoa library is still extremely slow and usable for me. It is at least 3x slower than fast_io.

Run the same test on MSVC 19.26.28805.

Platform	Windows	MSVC 19.26.28805	Install fmtlib wastes time of my life

Method	Output time	Input time	Comment
stdio.h(fprintf/fscanf)	1.5353597s	1.4157233s
fstream	3.6350262s	3.8420339s
fstream with rdbuf.sputc trick	3.3735902s	3.8145566s
fast_io::i/obuf_file	0.0631433s	0.1030554s
fast_io::i/obuf_file_mutex	0.2190659s	0.2485886s	thread safe
std::to_chars+obuf_file	0.1641641s	❌
std::to_chars+ofstream	0.5461922s	❌
fast_io::c_file_unlocked	0.1102575s	0.2399757s	I hacked Universal CRT's FILE* implementation
fast_io::c_file	0.2034755s	0.2621148s	Thread Safe. I hacked UCRT's FILE* implementation
fast_io::filebuf_file	0.126661s	0.2378803s	I hacked MSVC STL's streambuf/filebuf implementation

Run the same test on GCC 11. glibc + libstdc++

Platform	Linux	GCC 11.0.0	glibc + libstdc++

Method	Output time	Input time	Comment
stdio.h(fprintf/fscanf)	0.532792935s	0.591907111s
fstream with rdbuf.sputc trick	0.318896068s	0.429406415s
fast_io::i/obuf_file	0.050300857s	0.065372395s
fast_io::i/obuf_file_mutex	0.05290654s	0.083040518s	thread safe
c_locale_i/obuf_file ("C")	0.051939052s	0.065820056s	imbued with locale, locale "C"
c_locale_i/obuf_file local	0.162406082s	❌	imbued with locale, locale ""
std::to_chars+obuf_file	0.115453587s	❌
fmt::format_int+obuf_file	0.1183587s	❌
fmt::format_int+ofstream	0.195914384s	❌
fmt::format+ofstream	0.633590975s	❌	fmt makes things slower
fmt::print	0.495270371s	❌	fmt makes things slower
boost::iostreams	0.400906063s	0.444717051s	Using boost iostreams does not make your code faster
fast_io::c_file_unlocked	0.060076723s	0.073299716s	I hacked glibc's FILE* implementation
fast_io::c_file	0.092490191s	0.104545535s	Thread Safe. I hacked glibc's FILE* implementation
fast_io::filebuf_file	0.052251608s	0.06655806s	I hacked libstdc++'s streambuf/filebuf implementation

You can see fast_io can also boost the performance of existing facilities for 10x! Yes, it can even improve FILE* and fstream's performance for 10x depending on platforms since I use concepts to abstract them all. fmtlib actually slows down I/O performance.

1. Output 10M double in round-trip mode with Ryu algorithm

We only perform this test for MSVC since only msvc's charconv implements it. Yes. fast_io defeats msvc's charconv for over 20% for running the same algorithm.

All benchmarks are in benchmarks/0001.10m_double/charconv.

Run the same test on MSVC 19.26.28805.

Platform	Windows	MSVC 19.26.28805

Method	Output time	Comment
i/obuf_file	0.4653818s
charconv + obuf_file	0.6011s

1. Raw I/O Performance

All benchmarks are in benchmarks/0014.file_io/file_io.

Output 100000000x "Hello World\n"

Notice: I modified libstdc++'s std::filebuf's BUFSIZ to 1048576 due to BUFSIZ is too small (512 bytes) for MinGW-W64 or it performs horribly.

Platform	Windows	MinGW-W64 GCC 11.0.0	MSVCRT + libstdc++

Method	Output time	Comment
fwrite	2.524001s
fstream	1.013001s
fast_io::obuf_file	0.437998s
fast_io::obuf_file_mutex	1.371s	Thread safe
fast_io::c_file_unlocked	1.164997s	I hacked MSVCRT's FILE* implementation
fast_io::c_file	3.337945s	Thread Safe. I hacked MSVCRT's FILE* implementation. Need further optimization
fast_io::filebuf_file	0.467001s	I hacked libstdc++'s std::filebuf implementation

Platform	Linux	GCC 11.0.0	glibc + libstdc++

Method	Output time	Comment
fwrite	1.457288317s
fstream	1.249783346s
fast_io::obuf_file	0.494827134s
fast_io::obuf_file_mutex	0.497138826s	Thread safe
fast_io::c_file_unlocked	0.687976666s	I hacked glibc's FILE* implementation
fast_io::c_file	0.910792697s	Thread Safe. I hacked glibc's FILE* implementation
fast_io::filebuf_file	0.526955039s	I hacked libstdc++'s std::filebuf implementation

Platform	Windows	MSVC 19.26.28805	UCRT + MSVC STL

Method	Output time	Comment
fwrite	3.3139122s
fstream	1.7184119s
fast_io::obuf_file	0.7996034s
fast_io::obuf_file_mutex	2.2949221s	Thread safe. It looks like std::mutex is horribly slow for MSVC STL.
fast_io::c_file_unlocked	1.2103924s	I hacked UCRT's FILE* implementation
fast_io::c_file	2.3604295s	Thread Safe. I hacked UCRT's FILE* implementation
fast_io::filebuf_file	1.2805368s	I hacked MSVC STL's std::filebuf implementation

1. Binary Size Just use the benchmark in benchmarks/0014.file_io/file_io. Dude, you should avoid stream as plague tbh. It is not healthy.

Platform	Windows	MinGW-W64 GCC 11.0.0	MSVCRT + libstdc++ + static compile

Method	Binary Size	Comment
fstream	925KB	Use fstream is not good for your health since std::locale bloats your binary.
fast_io::obuf_file	155KB
fast_io::c_file_unlocked	157KB	I hacked MSVCRT's FILE* implementation
fast_io::c_file	157KB	Thread Safe. I hacked MSVCRT's FILE* implementation