ruby/lib/time.rb

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Ruby

#
# == Introduction
#
# This library extends the Time class:
# * conversion between date string and time object.
# * date-time defined by RFC 2822
# * HTTP-date defined by RFC 2616
# * dateTime defined by XML Schema Part 2: Datatypes (ISO 8601)
# * various formats handled by Date._parse (string to time only)
#
# == Design Issues
#
# === Specialized interface
#
# This library provides methods dedicated to special purposes:
# * RFC 2822, RFC 2616 and XML Schema.
# * They makes usual life easier.
#
# === Doesn't depend on strftime
#
# This library doesn't use +strftime+. Especially #rfc2822 doesn't depend
# on +strftime+ because:
#
# * %a and %b are locale sensitive
#
# Since they are locale sensitive, they may be replaced to
# invalid weekday/month name in some locales.
# Since ruby-1.6 doesn't invoke setlocale by default,
# the problem doesn't arise until some external library invokes setlocale.
# Ruby/GTK is the example of such library.
#
# * %z is not portable
#
# %z is required to generate zone in date-time of RFC 2822
# but it is not portable.
#
require 'date/format'
#
# Implements the extensions to the Time class that are described in the
# documentation for the time.rb library.
#
class Time
class << Time
ZoneOffset = {
'UTC' => 0,
# ISO 8601
'Z' => 0,
# RFC 822
'UT' => 0, 'GMT' => 0,
'EST' => -5, 'EDT' => -4,
'CST' => -6, 'CDT' => -5,
'MST' => -7, 'MDT' => -6,
'PST' => -8, 'PDT' => -7,
# Following definition of military zones is original one.
# See RFC 1123 and RFC 2822 for the error in RFC 822.
'A' => +1, 'B' => +2, 'C' => +3, 'D' => +4, 'E' => +5, 'F' => +6,
'G' => +7, 'H' => +8, 'I' => +9, 'K' => +10, 'L' => +11, 'M' => +12,
'N' => -1, 'O' => -2, 'P' => -3, 'Q' => -4, 'R' => -5, 'S' => -6,
'T' => -7, 'U' => -8, 'V' => -9, 'W' => -10, 'X' => -11, 'Y' => -12,
}
def zone_offset(zone, year=self.now.year)
off = nil
zone = zone.upcase
if /\A([+-])(\d\d):?(\d\d)\z/ =~ zone
off = ($1 == '-' ? -1 : 1) * ($2.to_i * 60 + $3.to_i) * 60
elsif /\A[+-]\d\d\z/ =~ zone
off = zone.to_i * 3600
elsif ZoneOffset.include?(zone)
off = ZoneOffset[zone] * 3600
elsif ((t = self.local(year, 1, 1)).zone.upcase == zone rescue false)
off = t.utc_offset
elsif ((t = self.local(year, 7, 1)).zone.upcase == zone rescue false)
off = t.utc_offset
end
off
end
def zone_utc?(zone)
# * +0000
# In RFC 2822, +0000 indicate a time zone at Universal Time.
# Europe/London is "a time zone at Universal Time" in Winter.
# Europe/Lisbon is "a time zone at Universal Time" in Winter.
# Atlantic/Reykjavik is "a time zone at Universal Time".
# Africa/Dakar is "a time zone at Universal Time".
# So +0000 is a local time such as Europe/London, etc.
# * GMT
# GMT is used as a time zone abbreviation in Europe/London,
# Africa/Dakar, etc.
# So it is a local time.
#
# * -0000, -00:00
# In RFC 2822, -0000 the date-time contains no information about the
# local time zone.
# In RFC 3339, -00:00 is used for the time in UTC is known,
# but the offset to local time is unknown.
# They are not appropriate for specific time zone such as
# Europe/London because time zone neutral,
# So -00:00 and -0000 are treated as UTC.
if /\A(?:-00:00|-0000|-00|UTC|Z|UT)\z/i =~ zone
true
else
false
end
end
private :zone_utc?
LeapYearMonthDays = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
CommonYearMonthDays = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
def month_days(y, m)
if ((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)
LeapYearMonthDays[m-1]
else
CommonYearMonthDays[m-1]
end
end
private :month_days
def apply_offset(year, mon, day, hour, min, sec, off)
if off < 0
off = -off
off, o = off.divmod(60)
if o != 0 then sec += o; o, sec = sec.divmod(60); off += o end
off, o = off.divmod(60)
if o != 0 then min += o; o, min = min.divmod(60); off += o end
off, o = off.divmod(24)
if o != 0 then hour += o; o, hour = hour.divmod(24); off += o end
if off != 0
day += off
if month_days(year, mon) < day
mon += 1
if 12 < mon
mon = 1
year += 1
end
day = 1
end
end
elsif 0 < off
off, o = off.divmod(60)
if o != 0 then sec -= o; o, sec = sec.divmod(60); off -= o end
off, o = off.divmod(60)
if o != 0 then min -= o; o, min = min.divmod(60); off -= o end
off, o = off.divmod(24)
if o != 0 then hour -= o; o, hour = hour.divmod(24); off -= o end
if off != 0 then
day -= off
if day < 1
mon -= 1
if mon < 1
year -= 1
mon = 12
end
day = month_days(year, mon)
end
end
end
return year, mon, day, hour, min, sec
end
private :apply_offset
def make_time(year, mon, day, hour, min, sec, sec_fraction, zone, now)
usec = nil
usec = sec_fraction * 1000000 if sec_fraction
if now
begin
break if year; year = now.year
break if mon; mon = now.mon
break if day; day = now.day
break if hour; hour = now.hour
break if min; min = now.min
break if sec; sec = now.sec
break if sec_fraction; usec = now.tv_usec
end until true
end
year ||= 1970
mon ||= 1
day ||= 1
hour ||= 0
min ||= 0
sec ||= 0
usec ||= 0
off = nil
off = zone_offset(zone, year) if zone
if off
year, mon, day, hour, min, sec =
apply_offset(year, mon, day, hour, min, sec, off)
t = self.utc(year, mon, day, hour, min, sec, usec)
t.localtime if !zone_utc?(zone)
t
else
self.local(year, mon, day, hour, min, sec, usec)
end
end
private :make_time
#
# Parses +date+ using Date._parse and converts it to a Time object.
#
# If a block is given, the year described in +date+ is converted by the
# block. For example:
#
# Time.parse(...) {|y| y < 100 ? (y >= 69 ? y + 1900 : y + 2000) : y}
#
# If the upper components of the given time are broken or missing, they are
# supplied with those of +now+. For the lower components, the minimum
# values (1 or 0) are assumed if broken or missing. For example:
#
# # Suppose it is "Thu Nov 29 14:33:20 GMT 2001" now and
# # your timezone is GMT:
# now = Time.parse("Thu Nov 29 14:33:20 GMT 2001")
# Time.parse("16:30", now) #=> 2001-11-29 16:30:00 +0900
# Time.parse("7/23", now) #=> 2001-07-23 00:00:00 +0900
# Time.parse("Aug 31", now) #=> 2001-08-31 00:00:00 +0900
# Time.parse("Aug 2000", now) #=> 2000-08-01 00:00:00 +0900
#
# Since there are numerous conflicts among locally defined timezone
# abbreviations all over the world, this method is not made to
# understand all of them. For example, the abbreviation "CST" is
# used variously as:
#
# -06:00 in America/Chicago,
# -05:00 in America/Havana,
# +08:00 in Asia/Harbin,
# +09:30 in Australia/Darwin,
# +10:30 in Australia/Adelaide,
# etc.
#
# Based on the fact, this method only understands the timezone
# abbreviations described in RFC 822 and the system timezone, in the
# order named. (i.e. a definition in RFC 822 overrides the system
# timezone definition.) The system timezone is taken from
# <tt>Time.local(year, 1, 1).zone</tt> and
# <tt>Time.local(year, 7, 1).zone</tt>.
# If the extracted timezone abbreviation does not match any of them,
# it is ignored and the given time is regarded as a local time.
#
# ArgumentError is raised if Date._parse cannot extract information from
# +date+ or Time class cannot represent specified date.
#
# This method can be used as fail-safe for other parsing methods as:
#
# Time.rfc2822(date) rescue Time.parse(date)
# Time.httpdate(date) rescue Time.parse(date)
# Time.xmlschema(date) rescue Time.parse(date)
#
# A failure for Time.parse should be checked, though.
#
def parse(date, now=self.now)
d = Date._parse(date, false)
if !d[:year] && !d[:mon] && !d[:mday] && !d[:hour] && !d[:min] && !d[:sec] && !d[:sec_fraction]
raise ArgumentError, "no time information in #{date.inspect}"
end
year = d[:year]
year = yield(year) if year && block_given?
make_time(year, d[:mon], d[:mday], d[:hour], d[:min], d[:sec], d[:sec_fraction], d[:zone], now)
end
#
# Parses +date+ using Date._strptime and converts it to a Time object.
#
# If a block is given, the year described in +date+ is converted by the
# block. For example:
#
# Time.strptime(...) {|y| y < 100 ? (y >= 69 ? y + 1900 : y + 2000) : y}
def strptime(date, format, now=self.now)
d = Date._strptime(date, format)
raise ArgumentError, "invalid strptime format - `#{format}'" unless d
year = d[:year]
year = yield(year) if year && block_given?
make_time(year, d[:mon], d[:mday], d[:hour], d[:min], d[:sec], d[:sec_fraction], d[:zone], now)
end
MonthValue = {
'JAN' => 1, 'FEB' => 2, 'MAR' => 3, 'APR' => 4, 'MAY' => 5, 'JUN' => 6,
'JUL' => 7, 'AUG' => 8, 'SEP' => 9, 'OCT' =>10, 'NOV' =>11, 'DEC' =>12
}
#
# Parses +date+ as date-time defined by RFC 2822 and converts it to a Time
# object. The format is identical to the date format defined by RFC 822 and
# updated by RFC 1123.
#
# ArgumentError is raised if +date+ is not compliant with RFC 2822
# or Time class cannot represent specified date.
#
# See #rfc2822 for more information on this format.
#
def rfc2822(date)
if /\A\s*
(?:(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun)\s*,\s*)?
(\d{1,2})\s+
(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s+
(\d{2,})\s+
(\d{2})\s*
:\s*(\d{2})\s*
(?::\s*(\d{2}))?\s+
([+-]\d{4}|
UT|GMT|EST|EDT|CST|CDT|MST|MDT|PST|PDT|[A-IK-Z])/ix =~ date
# Since RFC 2822 permit comments, the regexp has no right anchor.
day = $1.to_i
mon = MonthValue[$2.upcase]
year = $3.to_i
hour = $4.to_i
min = $5.to_i
sec = $6 ? $6.to_i : 0
zone = $7
# following year completion is compliant with RFC 2822.
year = if year < 50
2000 + year
elsif year < 1000
1900 + year
else
year
end
year, mon, day, hour, min, sec =
apply_offset(year, mon, day, hour, min, sec, zone_offset(zone))
t = self.utc(year, mon, day, hour, min, sec)
t.localtime if !zone_utc?(zone)
t
else
raise ArgumentError.new("not RFC 2822 compliant date: #{date.inspect}")
end
end
alias rfc822 rfc2822
#
# Parses +date+ as HTTP-date defined by RFC 2616 and converts it to a Time
# object.
#
# ArgumentError is raised if +date+ is not compliant with RFC 2616 or Time
# class cannot represent specified date.
#
# See #httpdate for more information on this format.
#
def httpdate(date)
if /\A\s*
(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun),\x20
(\d{2})\x20
(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\x20
(\d{4})\x20
(\d{2}):(\d{2}):(\d{2})\x20
GMT
\s*\z/ix =~ date
self.rfc2822(date)
elsif /\A\s*
(?:Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday),\x20
(\d\d)-(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)-(\d\d)\x20
(\d\d):(\d\d):(\d\d)\x20
GMT
\s*\z/ix =~ date
year = $3.to_i
if year < 50
year += 2000
else
year += 1900
end
self.utc(year, $2, $1.to_i, $4.to_i, $5.to_i, $6.to_i)
elsif /\A\s*
(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun)\x20
(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\x20
(\d\d|\x20\d)\x20
(\d\d):(\d\d):(\d\d)\x20
(\d{4})
\s*\z/ix =~ date
self.utc($6.to_i, MonthValue[$1.upcase], $2.to_i,
$3.to_i, $4.to_i, $5.to_i)
else
raise ArgumentError.new("not RFC 2616 compliant date: #{date.inspect}")
end
end
#
# Parses +date+ as dateTime defined by XML Schema and converts it to a Time
# object. The format is restricted version of the format defined by ISO
# 8601.
#
# ArgumentError is raised if +date+ is not compliant with the format or Time
# class cannot represent specified date.
#
# See #xmlschema for more information on this format.
#
def xmlschema(date)
if /\A\s*
(-?\d+)-(\d\d)-(\d\d)
T
(\d\d):(\d\d):(\d\d)
(\.\d+)?
(Z|[+-]\d\d:\d\d)?
\s*\z/ix =~ date
year = $1.to_i
mon = $2.to_i
day = $3.to_i
hour = $4.to_i
min = $5.to_i
sec = $6.to_i
usec = 0
if $7
usec = Rational($7) * 1000000
end
if $8
zone = $8
year, mon, day, hour, min, sec =
apply_offset(year, mon, day, hour, min, sec, zone_offset(zone))
self.utc(year, mon, day, hour, min, sec, usec)
else
self.local(year, mon, day, hour, min, sec, usec)
end
else
raise ArgumentError.new("invalid date: #{date.inspect}")
end
end
alias iso8601 xmlschema
end # class << self
#
# Returns a string which represents the time as date-time defined by RFC 2822:
#
# day-of-week, DD month-name CCYY hh:mm:ss zone
#
# where zone is [+-]hhmm.
#
# If +self+ is a UTC time, -0000 is used as zone.
#
def rfc2822
sprintf('%s, %02d %s %d %02d:%02d:%02d ',
RFC2822_DAY_NAME[wday],
day, RFC2822_MONTH_NAME[mon-1], year,
hour, min, sec) +
if utc?
'-0000'
else
off = utc_offset
sign = off < 0 ? '-' : '+'
sprintf('%s%02d%02d', sign, *(off.abs / 60).divmod(60))
end
end
alias rfc822 rfc2822
RFC2822_DAY_NAME = [
'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'
]
RFC2822_MONTH_NAME = [
'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'
]
#
# Returns a string which represents the time as rfc1123-date of HTTP-date
# defined by RFC 2616:
#
# day-of-week, DD month-name CCYY hh:mm:ss GMT
#
# Note that the result is always UTC (GMT).
#
def httpdate
t = dup.utc
sprintf('%s, %02d %s %d %02d:%02d:%02d GMT',
RFC2822_DAY_NAME[t.wday],
t.day, RFC2822_MONTH_NAME[t.mon-1], t.year,
t.hour, t.min, t.sec)
end
#
# Returns a string which represents the time as dateTime defined by XML
# Schema:
#
# CCYY-MM-DDThh:mm:ssTZD
# CCYY-MM-DDThh:mm:ss.sssTZD
#
# where TZD is Z or [+-]hh:mm.
#
# If self is a UTC time, Z is used as TZD. [+-]hh:mm is used otherwise.
#
# +fractional_seconds+ specifies a number of digits of fractional seconds.
# Its default value is 0.
#
def xmlschema(fraction_digits=0)
sprintf('%d-%02d-%02dT%02d:%02d:%02d',
year, mon, day, hour, min, sec) +
if fraction_digits == 0
''
elsif fraction_digits <= 9
'.' + sprintf('%09d', nsec)[0, fraction_digits]
else
'.' + sprintf('%09d', nsec) + '0' * (fraction_digits - 9)
end +
if utc?
'Z'
else
off = utc_offset
sign = off < 0 ? '-' : '+'
sprintf('%s%02d:%02d', sign, *(off.abs / 60).divmod(60))
end
end
alias iso8601 xmlschema
end