v/vlib/time/parse.v

116 lines
3.4 KiB
V

// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module time
// parse returns time from a date string in "YYYY-MM-DD HH:MM:SS" format.
pub fn parse(s string) ?Time {
pos := s.index(' ') or { return error('Invalid time format: $s') }
symd := s[..pos]
ymd := symd.split('-')
if ymd.len != 3 {
return error('Invalid time format: $s')
}
shms := s[pos..]
hms := shms.split(':')
hour := hms[0][1..]
minute := hms[1]
second := hms[2]
res := new_time(Time{
year: ymd[0].int()
month: ymd[1].int()
day: ymd[2].int()
hour: hour.int()
minute: minute.int()
second: second.int()
})
return res
}
// parse_rfc2822 returns time from a date string in RFC 2822 datetime format.
pub fn parse_rfc2822(s string) ?Time {
fields := s.split(' ')
if fields.len < 5 {
return error('Invalid time format: $s')
}
pos := months_string.index(fields[2]) or { return error('Invalid time format: $s') }
mm := pos / 3 + 1
mut tmstr := byteptr(0)
unsafe {
tmstr = malloc(s.len * 2)
}
count := unsafe {C.snprintf(charptr(tmstr), (s.len * 2), '%s-%02d-%s %s', fields[3].str,
mm, fields[1].str, fields[4].str)}
return parse(tos(tmstr, count))
}
// parse_iso8601 parses rfc8601 time format yyyy-MM-ddTHH:mm:ss.dddddd+dd:dd as local time
// the fraction part is difference in milli seconds and the last part is offset
// from UTC time and can be both +/- HH:mm
// remarks: not all iso8601 is supported
// also checks and support for leapseconds should be added in future PR
pub fn parse_iso8601(s string) ?Time {
year := 0
month := 0
day := 0
hour := 0
minute := 0
second := 0
mic_second := 0
time_char := `a`
plus_min_z := `a`
offset_hour := 0
offset_min := 0
mut count := unsafe {C.sscanf(charptr(s.str), '%4d-%2d-%2d%c%2d:%2d:%2d.%6d%c%2d:%2d',
&year, &month, &day, charptr(&time_char), &hour, &minute, &second, &mic_second, charptr(&plus_min_z),
&offset_hour, &offset_min)}
// Missread microsec ([Year Month Day T Sec Hour Minute].len == 7 < 8)
if count < 8 {
count = unsafe {C.sscanf(charptr(s.str), '%4d-%2d-%2d%c%2d:%2d:%2d%c%2d:%2d',
&year, &month, &day, charptr(&time_char), &hour, &minute, &second, charptr(&plus_min_z),
&offset_hour, &offset_min)}
count++ // Increment count because skipped microsec
}
is_local_time := plus_min_z == `a` && count == 8
is_utc := plus_min_z == `Z` && count == 9
if count != 11 && !is_local_time && !is_utc {
return error('Invalid 8601 format')
}
if time_char != `T` && time_char != ` ` {
return error('Invalid 8601 format, expected space or `T` as time separator')
}
if plus_min_z != `+` && plus_min_z != `-` && plus_min_z != `Z` && !is_local_time {
return error('Invalid 8601 format, expected `Z` or `+` or `-` as time separator')
}
mut t := new_time(Time{
year: year
month: month
day: day
hour: hour
minute: minute
second: second
microsecond: mic_second
})
if is_local_time {
return t // Time already local time
}
mut unix_time := t.unix
mut unix_offset := int(0)
if offset_hour > 0 {
unix_offset += 3600 * offset_hour
}
if offset_min > 0 {
unix_offset += 60 * offset_min
}
if unix_offset != 0 {
if plus_min_z == `+` {
unix_time -= u64(unix_offset)
} else {
unix_time += u64(unix_offset)
}
t = unix2(int(unix_time), t.microsecond)
}
// Convert the time to local time
return t.to_local_time()
}