def _get_version(fd):
"""Confirm zoneinfo file magic string, and return version number."""
if fd.read(4) != 'TZif':
raise MythTZError(MythTZError.TZ_INVALID_FILE)
version = fd.read(1) # read version number
fd.seek(15, 1) # skip reserved bytes
if version == '\0':
return 1
else:
return int(version) # should be 2
def _get_transition_search(self, dt=None):
if dt is None:
dt = _pydatetime.now()
dt = (dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second)
index = self.__last
direction = 0
while True:
if dt < self._ranges[index][0]:
if direction == 1:
# gap found, use later transition
break
else:
index -= 1
direction = -1
elif dt >= self._ranges[index][1]:
if direction == -1:
# gap found, use later transition
index += 1
break
else:
index += 1
direction = 1
else:
break
if index >= len(self._ranges):
# out of bounds future, use final transition
index = len(self._ranges) - 1
break
elif index < 0:
# out of bounds past, undefined time frame
raise MythTZError(MythTZError.TZ_CONVERSION_ERROR,
self.tzname(), dt)
self.__last = index
return self._transitions[self._ranges[index][2]]
def _process(self, fd, version=1, skip=False):
from struct import unpack, calcsize
if version == 1:
ttmfmt = '!l'
lfmt = '!ll'
elif version == 2:
ttmfmt = '!q'
lfmt = '!ql'
counts = self._Count(*unpack('!llllll', fd.read(24)))
if skip:
fd.seek(counts.transitions * (calcsize(ttmfmt)+1) +\
counts.types * 6 +\
counts.abbrevs +\
counts.leap_seconds * calcsize(lfmt) +\
counts.std_indicators +\
counts.gmt_indicators,\
1)
return
transitions = []
for i in range(counts.transitions): # read in epoch time data
t = unpack(ttmfmt, fd.read(calcsize(ttmfmt)))[0]
tt = time.gmtime(t)
transitions.append([t, tt, None, None, None, None])
# read in transition type indexes
types = [None] * counts.transitions
for i in range(counts.transitions):
types[i] = t = unpack('!b', fd.read(1))[0]
if t >= counts.types:
raise MythTZError(MythTZError.TZ_INVALID_TRANSITION, t,
counts.types - 1)
# read in type definitions
typedefs = []
for i in range(counts.types):
offset, isdst, _ = unpack('!lbB', fd.read(6))
typedefs.append([offset, isdst])
for i in range(counts.transitions):
offset, isdst = typedefs[types[i]]
transitions[i][2] = time.gmtime(transitions[i][0] + offset)
transitions[i][3] = offset
transitions[i][5] = isdst
# read in type names
for i, name in enumerate(fd.read(counts.abbrevs)[:-1].split('\0')):
for j in range(counts.transitions):
if types[j] == i:
transitions[j][4] = name
# skip leap second definitions
fd.seek(counts.leap_seconds + calcsize(lfmt), 1)
# skip std/wall indicators
fd.seek(counts.std_indicators, 1)
# skip utc/local indicators
fd.seek(counts.gmt_indicators, 1)
for i in range(counts.transitions):
transitions[i] = self._Transition(*transitions[i])
self._transitions = tuple(transitions)
def _process(self, fd, version=1, skip=False):
from struct import unpack, calcsize
if version == 1:
ttmfmt = '!l'
lfmt = '!ll'
elif version == 2:
ttmfmt = '!q'
lfmt = '!ql'
counts = self._Count(*unpack('!llllll', fd.read(24)))
if skip:
fd.seek(counts.transitions * (calcsize(ttmfmt)+1) +\
counts.types * 6 +\
counts.abbrevs +\
counts.leap_seconds * calcsize(lfmt) +\
counts.std_indicators +\
counts.gmt_indicators,\
1)
return
transitions = [None] * counts.transitions
# First transition which is in range for gmtime. Some zoneinfo
# files have massively negative leading entries for e.g. the
# big bang which gmtime() cannot cope with.
first_modern_transition = None
i = 0 # assign i, in case the for-loop is not executed:
for i in range(counts.transitions): # read in epoch time data
t = unpack(ttmfmt, fd.read(calcsize(ttmfmt)))[0]
try:
tt = time.gmtime(t)
transitions[i] = ([t, tt, None, None, None, None])
if first_modern_transition is None:
first_modern_transition = i
except (ValueError, OSError) as e:
# ValueError is only accepted until we have seen a modern
# transition.
if first_modern_transition is not None:
raise e
# Special case if there are no modern transitions, like e.g. UTC timezone:
if ((i == 0) and first_modern_transition is None):
first_modern_transition = counts.transitions
# read in transition type indexes
types = [None] * counts.transitions
for i in range(counts.transitions):
types[i] = t = unpack('!b', fd.read(1))[0]
if t >= counts.types:
raise MythTZError(MythTZError.TZ_INVALID_TRANSITION, t,
counts.types - 1)
# read in type definitions
typedefs = []
for i in range(counts.types):
offset, isdst, _ = unpack('!lbB', fd.read(6))
typedefs.append([offset, isdst])
for i in range(first_modern_transition, counts.transitions):
offset, isdst = typedefs[types[i]]
transitions[i][2] = time.gmtime(transitions[i][0] + offset)
transitions[i][3] = offset
transitions[i][5] = isdst
# read in type names
for i, name in enumerate(fd.read(counts.abbrevs)[:-1].split(b'\0')):
for j in range(first_modern_transition, counts.transitions):
if types[j] == i:
transitions[j][4] = name
# skip leap second definitions
fd.seek(counts.leap_seconds + calcsize(lfmt), 1)
# skip std/wall indicators
fd.seek(counts.std_indicators, 1)
# skip utc/local indicators
fd.seek(counts.gmt_indicators, 1)
transitions = [
self._Transition(*x) for x in transitions[first_modern_transition:]
]
self._transitions = tuple(transitions)