terom@50: """
terom@50:     Miscellaneous things
terom@50: """
terom@50: 
terom@72: import datetime, calendar, pytz
terom@95: import os, errno
terom@50: 
terom@51: from qmsk.web.urltree import URLType
terom@51: 
terom@51: class URLChannelName (URLType) :
terom@50:     """
terom@51:         Handle LogChannel names in URLs. Deals with instances of LogChannel
terom@50:     """
terom@50: 
terom@51:     def __init__ (self, channels) :
terom@50:         """
terom@51:             Use the given { name -> LogChannel } dict
terom@51:         """
terom@51: 
terom@51:         self.channels = channels
terom@51:     
terom@51:     def parse (self, chan_name) :
terom@51:         """
terom@51:             chan_name -> LogChannel
terom@51:         """
terom@51: 
terom@51:         return self.channels[chan_name]
terom@51: 
terom@51:     def build (self, chan) :
terom@51:         """
terom@51:             LogChannel -> chan_name
terom@51:         """
terom@51: 
terom@51:         return chan.id
terom@51: 
terom@51: class URLDateType (URLType) :
terom@51:     """
terom@117:         Handle dates in URLs as naive datetime objects (with indeterminate time info)
terom@51:     """
terom@51: 
terom@73:     def __init__ (self, date_fmt) :
terom@51:         """
terom@51:             Format/parse dates using the given format
terom@51:         """
terom@51: 
terom@51:         self.date_fmt = date_fmt
terom@51:     
terom@117:     def parse (self, date_str) :
terom@51:         """
terom@117:             date_str -> naive datetime.datetime
terom@50:         """
terom@50:         
terom@117:         return datetime.datetime.strptime(date_str, self.date_fmt)
terom@50:     
terom@117:     def build (self, date) :
terom@51:         """
terom@117:             datetime.date -> date_str
terom@51:         """
terom@50: 
terom@117:         return date.strftime(self.date_fmt)
terom@50: 
terom@72: class URLTimestampType (URLType) :
terom@72:     """
terom@72:         Handles an integer UNIX timestamp as an UTC datetime
terom@72:     """
terom@72: 
terom@72:     def parse (self, timestamp_str) :
terom@72:         """
terom@72:             timestamp_str -> pytz.utc datetime.datetime
terom@72:         """
terom@89:         
terom@89:         return from_utc_timestamp(int(timestamp_str))
terom@72:     
terom@72:     def build (self, dtz) :
terom@72:         """
terom@72:             pytz.utc datetime.datetime -> timestamp_str
terom@72:         """
terom@89:         
terom@89:         return str(to_utc_timestamp(dtz))
terom@72: 
terom@89: def from_utc_timestamp (timestamp) :
terom@89:     """
terom@89:         Converts a UNIX timestamp into a datetime.datetime
terom@89:     """
terom@72: 
terom@89:     return datetime.datetime.utcfromtimestamp(timestamp).replace(tzinfo=pytz.utc)
terom@89: 
terom@89: def to_utc_timestamp (dt) :
terom@89:     """
terom@89:         Converts a datetime.datetime into a UNIX timestamp
terom@89:     """
terom@89: 
terom@89:     return calendar.timegm(dt.utctimetuple())
terom@89: 
terom@95: def mtime (path, ignore_missing=False) :
terom@95:     """
terom@95:         Gets the mtime for the given path as an UTC datetime, or None, if the file doesn't exist and ignore_missing
terom@95:     """
terom@95: 
terom@95:     try :
terom@95:         # stat
terom@95:         st = os.stat(path)
terom@95:     
terom@95:     # trap IOError
terom@95:     except os.error, e :
terom@95:         # ENOENT?
terom@95:         if ignore_missing and e.errno == errno.ENOENT :
terom@95:             return None
terom@95: 
terom@95:         else :
terom@95:             raise
terom@95: 
terom@95:     else :
terom@95:         # decode
terom@95:         return from_utc_timestamp(st.st_mtime)
terom@95: 
terom@129: class FixedOffsetTimezone (pytz._FixedOffset) :
terom@129:     """
terom@129:         A Fixed-offset timezone with no DST info, compatible with pytz.
terom@129: 
terom@129:         This is based on pytz._FixedOffset, but overrides dst() to return timedelta(0)
terom@129:     """
terom@129: 
terom@129:     def __init__ (self, minutes) :
terom@129:         """
terom@129:             Minutes is simply the offset from UTC in minutes, positive or negative, at most 24h.
terom@129:         """
terom@129: 
terom@129:         pytz._FixedOffset.__init__(self, minutes)
terom@129: 
terom@129:     def dst (self, dt) :
terom@129:         """
terom@129:             No DST info
terom@129:         """
terom@129: 
terom@129:         return datetime.timedelta(0)
terom@129: