class TimezoneDatabase(object):
"""
On demand timezone database cache. This scans a TZdb directory for .ics files matching a
TZID and caches the component data in a calendar from whence the actual component is returned.
"""
sTimezoneDatabase = None
@staticmethod
def createTimezoneDatabase(dbpath):
TimezoneDatabase.sTimezoneDatabase = TimezoneDatabase()
TimezoneDatabase.sTimezoneDatabase.setPath(dbpath)
@staticmethod
def clearTimezoneDatabase():
if TimezoneDatabase.sTimezoneDatabase is not None:
TimezoneDatabase.sTimezoneDatabase.clear()
def __init__(self):
from pycalendar.icalendar.calendar import Calendar
self.dbpath = None
self.calendar = Calendar()
self.tzcache = {}
self.stdtzcache = set()
def setPath(self, dbpath):
self.dbpath = dbpath
def clear(self):
from pycalendar.icalendar.calendar import Calendar
self.calendar = Calendar()
self.tzcache.clear()
self.stdtzcache.clear()
@staticmethod
def getTimezoneDatabase():
if TimezoneDatabase.sTimezoneDatabase is None:
TimezoneDatabase.sTimezoneDatabase = TimezoneDatabase()
return TimezoneDatabase.sTimezoneDatabase
@staticmethod
def getTimezone(tzid):
return TimezoneDatabase.getTimezoneDatabase()._getTimezone(tzid)
@staticmethod
def getTimezoneInCalendar(tzid):
"""
Return a VTIMEZONE inside a valid VCALENDAR
"""
tz = TimezoneDatabase.getTimezone(tzid)
if tz is not None:
from pycalendar.icalendar.calendar import Calendar
cal = Calendar()
cal.addComponent(tz.duplicate(cal))
return cal
else:
return None
@staticmethod
def getTimezoneOffsetSeconds(tzid, dt, relative_to_utc=False):
# Cache it first
tz = TimezoneDatabase.getTimezone(tzid)
if tz is not None:
return tz.getTimezoneOffsetSeconds(dt, relative_to_utc)
else:
return 0
@staticmethod
def getTimezoneDescriptor(tzid, dt):
# Cache it first
tz = TimezoneDatabase.getTimezone(tzid)
if tz is not None:
return tz.getTimezoneDescriptor(dt)
else:
return ""
@staticmethod
def isStandardTimezone(tzid):
return TimezoneDatabase.getTimezoneDatabase()._isStandardTimezone(tzid)
def cacheTimezone(self, tzid):
"""
Load the specified timezone identifier's timezone data from a file and parse it
into the L{Calendar} used to store timezones used by this object.
@param tzid: the timezone identifier to load
@type tzid: L{str}
"""
if self.dbpath is None:
return
tzpath = os.path.join(self.dbpath, "%s.ics" % (tzid,))
tzpath = os.path.normpath(tzpath)
if tzpath.startswith(self.dbpath) and os.path.isfile(tzpath):
try:
with open(tzpath) as f:
self.calendar.parseComponent(f)
except (IOError, InvalidData):
raise NoTimezoneInDatabase(self.dbpath, tzid)
else:
raise NoTimezoneInDatabase(self.dbpath, tzid)
def addTimezone(self, tz):
"""
Add the specified VTIMEZONE component to this object's L{Calendar} cache. This component
is assumed to be a non-standard timezone - i.e., not loaded from the timezone database.
@param tz: the VTIMEZONE component to add
@type tz: L{Component}
"""
copy = tz.duplicate(self.calendar)
self.calendar.addComponent(copy)
self.tzcache[copy.getID()] = copy
def _addStandardTimezone(self, tz):
"""
Same as L{addTimezone} except that the timezone is marked as a standard timezone. This
is only meant to be used for testing which happens int he absence of a real standard
timezone database.
@param tz: the VTIMEZONE component to add
@type tz: L{Component}
"""
if tz.getID() not in self.tzcache:
self.addTimezone(tz)
self.stdtzcache.add(tz.getID())
def _isStandardTimezone(self, tzid):
"""
Add the specified VTIMEZONE component to this object's L{Calendar} cache. This component
is assumed to be a non-standard timezone - i.e., not loaded from the timezone database.
@param tzid: the timezone identifier to lookup
@type tzid: L{str}
"""
return tzid in self.stdtzcache
def _getTimezone(self, tzid):
"""
Get a timezone matching the specified timezone identifier. Use this object's
cache - if not in the cache try to load it from a tz database file and store in
this object's calendar.
@param tzid: the timezone identifier to lookup
@type tzid: L{str}
"""
if tzid not in self.tzcache:
tz = self.calendar.getTimezone(tzid)
if tz is None:
try:
self.cacheTimezone(tzid)
except NoTimezoneInDatabase:
pass
tz = self.calendar.getTimezone(tzid)
self.tzcache[tzid] = tz
if tz is not None and tzid is not None:
self.stdtzcache.add(tzid)
return self.tzcache[tzid]
@staticmethod
def mergeTimezones(cal, tzs):
"""
Merge each timezone from other calendar.
"""
tzdb = TimezoneDatabase.getTimezoneDatabase()
# Not if our own calendar
if cal is tzdb.calendar:
return
# Merge each timezone from other calendar
for tz in tzs:
tzdb.mergeTimezone(tz)
def mergeTimezone(self, tz):
"""
If the supplied VTIMEZONE is not in our cache then store it in memory.
"""
if self._getTimezone(tz.getID()) is None:
self.addTimezone(tz)
class TimezoneDatabase(object):
"""
On demand timezone database cache. This scans a TZdb directory for .ics files matching a
TZID and caches the component data in a calendar from whence the actual component is returned.
"""
sTimezoneDatabase = None
@staticmethod
def createTimezoneDatabase(dbpath):
TimezoneDatabase.sTimezoneDatabase = TimezoneDatabase()
TimezoneDatabase.sTimezoneDatabase.setPath(dbpath)
@staticmethod
def clearTimezoneDatabase():
if TimezoneDatabase.sTimezoneDatabase is not None:
TimezoneDatabase.sTimezoneDatabase.clear()
def __init__(self):
from pycalendar.icalendar.calendar import Calendar
self.dbpath = None
self.calendar = Calendar()
self.tzcache = {}
self.stdtzcache = set()
def setPath(self, dbpath):
self.dbpath = dbpath
def clear(self):
from pycalendar.icalendar.calendar import Calendar
self.calendar = Calendar()
self.tzcache.clear()
self.stdtzcache.clear()
@staticmethod
def getTimezoneDatabase():
if TimezoneDatabase.sTimezoneDatabase is None:
TimezoneDatabase.sTimezoneDatabase = TimezoneDatabase()
return TimezoneDatabase.sTimezoneDatabase
@staticmethod
def getTimezone(tzid):
return TimezoneDatabase.getTimezoneDatabase()._getTimezone(tzid)
@staticmethod
def getTimezoneInCalendar(tzid):
"""
Return a VTIMEZONE inside a valid VCALENDAR
"""
tz = TimezoneDatabase.getTimezone(tzid)
if tz is not None:
from pycalendar.icalendar.calendar import Calendar
cal = Calendar()
cal.addComponent(tz.duplicate(cal))
return cal
else:
return None
@staticmethod
def getTimezoneOffsetSeconds(tzid, dt, relative_to_utc=False):
# Cache it first
tz = TimezoneDatabase.getTimezone(tzid)
if tz is not None:
return tz.getTimezoneOffsetSeconds(dt, relative_to_utc)
else:
return 0
@staticmethod
def getTimezoneDescriptor(tzid, dt):
# Cache it first
tz = TimezoneDatabase.getTimezone(tzid)
if tz is not None:
return tz.getTimezoneDescriptor(dt)
else:
return ""
@staticmethod
def isStandardTimezone(tzid):
return TimezoneDatabase.getTimezoneDatabase()._isStandardTimezone(tzid)
def cacheTimezone(self, tzid):
"""
Load the specified timezone identifier's timezone data from a file and parse it
into the L{Calendar} used to store timezones used by this object.
@param tzid: the timezone identifier to load
@type tzid: L{str}
"""
if self.dbpath is None:
return
tzpath = os.path.join(self.dbpath, "%s.ics" % (tzid, ))
tzpath = os.path.normpath(tzpath)
if tzpath.startswith(self.dbpath) and os.path.isfile(tzpath):
try:
with open(tzpath) as f:
self.calendar.parseComponent(f)
except (IOError, InvalidData):
raise NoTimezoneInDatabase(self.dbpath, tzid)
else:
raise NoTimezoneInDatabase(self.dbpath, tzid)
def addTimezone(self, tz):
"""
Add the specified VTIMEZONE component to this object's L{Calendar} cache. This component
is assumed to be a non-standard timezone - i.e., not loaded from the timezone database.
@param tz: the VTIMEZONE component to add
@type tz: L{Component}
"""
copy = tz.duplicate(self.calendar)
self.calendar.addComponent(copy)
self.tzcache[copy.getID()] = copy
def _addStandardTimezone(self, tz):
"""
Same as L{addTimezone} except that the timezone is marked as a standard timezone. This
is only meant to be used for testing which happens int he absence of a real standard
timezone database.
@param tz: the VTIMEZONE component to add
@type tz: L{Component}
"""
if tz.getID() not in self.tzcache:
self.addTimezone(tz)
self.stdtzcache.add(tz.getID())
def _isStandardTimezone(self, tzid):
"""
Add the specified VTIMEZONE component to this object's L{Calendar} cache. This component
is assumed to be a non-standard timezone - i.e., not loaded from the timezone database.
@param tzid: the timezone identifier to lookup
@type tzid: L{str}
"""
return tzid in self.stdtzcache
def _getTimezone(self, tzid):
"""
Get a timezone matching the specified timezone identifier. Use this object's
cache - if not in the cache try to load it from a tz database file and store in
this object's calendar.
@param tzid: the timezone identifier to lookup
@type tzid: L{str}
"""
if tzid not in self.tzcache:
tz = self.calendar.getTimezone(tzid)
if tz is None:
try:
self.cacheTimezone(tzid)
except NoTimezoneInDatabase:
pass
tz = self.calendar.getTimezone(tzid)
self.tzcache[tzid] = tz
if tz is not None and tzid is not None:
self.stdtzcache.add(tzid)
return self.tzcache[tzid]
@staticmethod
def mergeTimezones(cal, tzs):
"""
Merge each timezone from other calendar.
"""
tzdb = TimezoneDatabase.getTimezoneDatabase()
# Not if our own calendar
if cal is tzdb.calendar:
return
# Merge each timezone from other calendar
for tz in tzs:
tzdb.mergeTimezone(tz)
def mergeTimezone(self, tz):
"""
If the supplied VTIMEZONE is not in our cache then store it in memory.
"""
if self._getTimezone(tz.getID()) is None:
self.addTimezone(tz)
