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v/vlib/time/parse.v
2021-01-18 13:20:06 +01:00

144 lines
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V

// Copyright (c) 2019-2021 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))
}
// ----- iso8601 -----
const (
err_invalid_8601 = error('Invalid 8601 Format')
)
fn parse_iso8601_date(s string) ?(int, int, int) {
year, month, day, dummy := 0, 0, 0, byte(0)
count := unsafe { C.sscanf(charptr(s.str), '%4d-%2d-%2d%c', &year, &month, &day, &dummy) }
if count != 3 {
return err_invalid_8601
}
return year, month, day
}
fn parse_iso8601_time(s string) ?(int, int, int, int, i64, bool) {
hour := 0
minute := 0
second := 0
microsecond := 0
plus_min_z := `a`
offset_hour := 0
offset_minute := 0
mut count := unsafe {
C.sscanf(charptr(s.str), '%2d:%2d:%2d.%6d%c%2d:%2d', &hour, &minute, &second,
&microsecond, charptr(&plus_min_z), &offset_hour, &offset_minute)
}
// Missread microsecond ([Sec Hour Minute].len == 3 < 4)
if count < 4 {
count = unsafe {
C.sscanf(charptr(s.str), '%2d:%2d:%2d%c%2d:%2d', &hour, &minute, &second,
charptr(&plus_min_z), &offset_hour, &offset_minute)
}
count++ // Increment count because skipped microsecond
}
if count < 4 {
return err_invalid_8601
}
is_local_time := plus_min_z == `a` && count == 4
is_utc := plus_min_z == `Z` && count == 5
if !(count == 7 || is_local_time || is_utc) {
return err_invalid_8601
}
if plus_min_z != `+` && plus_min_z != `-` && !is_utc && !is_local_time {
return error('Invalid 8601 format, expected `Z` or `+` or `-` as time separator')
}
mut unix_offset := 0
if offset_hour > 0 {
unix_offset += 3600 * offset_hour
}
if offset_minute > 0 {
unix_offset += 60 * offset_minute
}
if plus_min_z == `+` {
unix_offset *= -1
}
return hour, minute, second, microsecond, unix_offset, is_local_time
}
// 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 {
t_i := s.index('T') or { -1 }
parts := if t_i != -1 { [s[..t_i], s[t_i + 1..]] } else { s.split(' ') }
if !(parts.len == 1 || parts.len == 2) {
return err_invalid_8601
}
year, month, day := parse_iso8601_date(parts[0]) ?
mut hour, mut minute, mut second, mut microsecond, mut unix_offset, mut is_local_time := 0, 0, 0, 0, i64(0), true
if parts.len == 2 {
hour, minute, second, microsecond, unix_offset, is_local_time = parse_iso8601_time(parts[1]) ?
}
mut t := new_time(Time{
year: year
month: month
day: day
hour: hour
minute: minute
second: second
microsecond: microsecond
})
if is_local_time {
return t // Time already local time
}
mut unix_time := t.unix
if unix_offset < 0 {
unix_time -= u64(-unix_offset)
} else if unix_offset > 0 {
unix_time += u64(unix_offset)
}
t = unix2(int(unix_time), t.microsecond)
return t
}