fasttime - fast time formatting for go

Getting Started

try on https://go.dev/play/p/wnb6G181qu6

package main

import (
	"time"

	"github.com/phuslu/fasttime"
)

func main() {
	println(fasttime.Strftime("%a %b %d %H:%M:%S %Z %Y", time.Now()))
}

// Thu Dec 17 10:49:04 +08 2020

Benchmarks

// go test -v -cpu=4 -run=none -bench=. -benchmem strftime_test.go
package strftime_test

import (
	"io"
	"testing"
	"time"

	itchyny "github.com/itchyny/timefmt-go"
	lestrrat "github.com/lestrrat-go/strftime"
	fasttime "github.com/phuslu/fasttime"
)

var now = time.Now()

func BenchmarkUnixDateStdTime(b *testing.B) {
	for i := 0; i < b.N; i++ {
		now.Format(time.UnixDate)
	}
}

func BenchmarkUnixDateLestrrat(b *testing.B) {
	p, _ := lestrrat.New("%a %b %e %H:%M:%S %Z %Y")
	for i := 0; i < b.N; i++ {
		p.Format(io.Discard, now)
	}
}

func BenchmarkUnixDateItchyny(b *testing.B) {
	for i := 0; i < b.N; i++ {
		itchyny.Format(now, "%a %b %e %H:%M:%S %Z %Y")
	}
}

func BenchmarkUnixDateFasttime(b *testing.B) {
	for i := 0; i < b.N; i++ {
		fasttime.Strftime("%a %b %e %H:%M:%S %Z %Y", now)
	}
}

func BenchmarkStampMicroStdTime(b *testing.B) {
	for i := 0; i < b.N; i++ {
		now.Format(time.StampMicro)
	}
}

func BenchmarkStampMicroLestrrat(b *testing.B) {
	p, _ := lestrrat.New("%b %e %H:%M:%S.%f", lestrrat.WithMicroseconds('f'))
	for i := 0; i < b.N; i++ {
		p.Format(io.Discard, now)
	}
}

func BenchmarkStampMicroItchyny(b *testing.B) {
	for i := 0; i < b.N; i++ {
		itchyny.Format(now, "%b %e %H:%M:%S.%f")
	}
}

func BenchmarkStampMicroFasttime(b *testing.B) {
	for i := 0; i < b.N; i++ {
		fasttime.Strftime("%b %e %H:%M:%S.%f", now)
	}
}

func BenchmarkRFC3339StdTime(b *testing.B) {
	for i := 0; i < b.N; i++ {
		now.Format(time.RFC3339)
	}
}

func BenchmarkRFC3339Lestrrat(b *testing.B) {
	p, _ := lestrrat.New("%Y-%m-%dT%H:%M:%S%z")
	for i := 0; i < b.N; i++ {
		p.Format(io.Discard, now)
	}
}

func BenchmarkRFC3339Itchyny(b *testing.B) {
	for i := 0; i < b.N; i++ {
		itchyny.Format(now, "%Y-%m-%dT%H:%M:%S%:z")
	}
}

func BenchmarkRFC3339Fasttime(b *testing.B) {
	for i := 0; i < b.N; i++ {
		fasttime.Strftime("%Y-%m-%dT%H:%M:%S%:z", now)
	}
}

A Performance result as below, for daily benchmark results see github actions

BenchmarkUnixDateStdTime-4      	 3134547	       359.0 ns/op	      32 B/op	       1 allocs/op
BenchmarkUnixDateLestrrat-4     	 2445044	       505.8 ns/op	      64 B/op	       1 allocs/op
BenchmarkUnixDateItchyny-4      	 3726554	       316.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkUnixDateFasttime-4     	 4719768	       245.8 ns/op	       0 B/op	       0 allocs/op

BenchmarkStampMicroStdTime-4    	 3793047	       318.8 ns/op	      24 B/op	       1 allocs/op
BenchmarkStampMicroLestrrat-4   	 2409372	       477.2 ns/op	      72 B/op	       2 allocs/op
BenchmarkStampMicroItchyny-4    	 4752626	       242.8 ns/op	       0 B/op	       0 allocs/op
BenchmarkStampMicroFasttime-4   	 7268750	       164.2 ns/op	       0 B/op	       0 allocs/op

BenchmarkRFC3339StdTime-4       	 3563881	       336.0 ns/op	      24 B/op	       1 allocs/op
BenchmarkRFC3339Lestrrat-4      	 2520579	       480.9 ns/op	      64 B/op	       1 allocs/op
BenchmarkRFC3339Itchyny-4       	 4386028	       273.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkRFC3339Fasttime-4      	 6393230	       189.1 ns/op	       0 B/op	       0 allocs/op

Supported formats:

code	Description
%a	The abbreviated name of the day of the week according to the current locale.
%A	The full name of the day of the week according to the current locale.
%b	The abbreviated month name according to the current locale.
%B	The full month name according to the current locale.
%c	The preferred date and time representation for the current locale.
%C	The century number (year/100) as a 2-digit integer.
%d	The day of the month as a decimal number (range 01 to 31).
%D	Equivalent to %m/%d/%y. (Yecch—for Americans only.)
%e	Like %d, the day of the month as a decimal number, but a leading zero is replaced by a space.
%f	Microsecond as a decimal number, zero-padded on the left.
%F	Equivalent to %Y-%m-%d (the ISO 8601 date format).
%G	The ISO 8601 week-based year (see NOTES) with century as a decimal number. The 4-digit year corresponding to the ISO week number (see %V). This has the same format and value as %Y, except that if the ISO week number belongs to the previous or next year, that year is used instead.
%g	Like %G, but without century, that is, with a 2-digit year (00-99).
%h	Equivalent to %b.
%H	The hour as a decimal number using a 24-hour clock (range 00 to 23).
%I	The hour as a decimal number using a 12-hour clock (range 01 to 12).
%j	The day of the year as a decimal number (range 001 to 366).
%k	The hour (24-hour clock) as a decimal number (range 0 to 23); single digits are preceded by a blank. (See also %H.)
%l	The hour (12-hour clock) as a decimal number (range 1 to 12); single digits are preceded by a blank. (See also %I.)
%m	The month as a decimal number (range 01 to 12).
%M	The minute as a decimal number (range 00 to 59).
%n	A newline character.
%N	Nanosecond as a decimal number, zero-padded on the left.
%p	Either "AM" or "PM" according to the given time value, or the corresponding strings for the current locale. Noon is treated as "PM" and midnight as "AM".
%P	Like %p but in lowercase: "am" or "pm" or a corresponding string for the current locale.
%Q	Millisecond as a decimal number, zero-padded on the left.
%r	The time in a.m. or p.m. notation. In the POSIX locale this is equivalent to %I:%M:%S %p.
%R	The time in 24-hour notation (%H:%M). For a version including the seconds, see %T below.
%s	The number of seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC).
%S	The second as a decimal number (range 00 to 60). (The range is up to 60 to allow for occasional leap seconds.)
%t	A tab character.
%T	The time in 24-hour notation (%H:%M:%S).
%u	The day of the week as a decimal, range 1 to 7, Monday being 1. See also %w.
%U	The week number of the current year as a decimal number, range 00 to 53, starting with the first Sunday as the first day of week 01. See also %V and %W.
%v	Equivalent to %e-%b-%Y.
%V	The ISO 8601 week number (see NOTES) of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the new year. See also %U and %W.
%w	The day of the week as a decimal, range 0 to 6, Sunday being 0. See also %u.
%W	The week number of the current year as a decimal number, range 00 to 53, starting with the first Monday as the first day of week 01.
%x	The preferred date representation for the current locale without the time.
%X	The preferred time representation for the current locale without the date.
%y	The year as a decimal number without a century (range 00 to 99).
%Y	The year as a decimal number including the century.
%z	The +hhmm or -hhmm numeric timezone (that is, the hour and minute offset from UTC).
%Z	The timezone name or abbreviation.
%+	The date and time in date(1) format.
%%	A literal '%' character.