Add google-endpoints to third_party/.

third_party/google-endpoints/strict_rfc3339.py

+# Copyright 2012 (C) Daniel Richman, Adam Greig
+#
+# This file is part of strict_rfc3339.
+#
+# strict_rfc3339 is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# strict_rfc3339 is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with strict_rfc3339.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Super simple lightweight RFC3339 functions
+"""
+
+import re
+import time
+import calendar
+
+__all__ = ["validate_rfc3339",
+           "InvalidRFC3339Error",
+           "rfc3339_to_timestamp",
+           "timestamp_to_rfc3339_utcoffset",
+           "timestamp_to_rfc3339_localoffset",
+           "now_to_rfc3339_utcoffset",
+           "now_to_rfc3339_localoffset"]
+
+rfc3339_regex = re.compile(
+    r"^(\d\d\d\d)\-(\d\d)\-(\d\d)T"
+    r"(\d\d):(\d\d):(\d\d)(\.\d+)?(Z|([+\-])(\d\d):(\d\d))$")
+
+
+def validate_rfc3339(datestring):
+    """Check an RFC3339 string is valid via a regex and some range checks"""
+
+    m = rfc3339_regex.match(datestring)
+    if m is None:
+        return False
+
+    groups = m.groups()
+
+    year, month, day, hour, minute, second = [int(i) for i in groups[:6]]
+
+    if not 1 <= year <= 9999:
+        # Have to reject this, unfortunately (despite it being OK by rfc3339):
+        # calendar.timegm/calendar.monthrange can't cope (since datetime can't)
+        return False
+
+    if not 1 <= month <= 12:
+        return False
+
+    (_, max_day) = calendar.monthrange(year, month)
+    if not 1 <= day <= max_day:
+        return False
+
+    if not (0 <= hour <= 23 and 0 <= minute <= 59 and 0 <= second <= 59):
+        # forbid leap seconds :-(. See README
+        return False
+
+    if groups[7] != "Z":
+        (offset_sign, offset_hours, offset_mins) = groups[8:]
+        if not (0 <= int(offset_hours) <= 23 and 0 <= int(offset_mins) <= 59):
+            return False
+
+    # all OK
+    return True
+
+
+class InvalidRFC3339Error(ValueError):
+    """Subclass of ValueError thrown by rfc3339_to_timestamp"""
+    pass
+
+
+def rfc3339_to_timestamp(datestring):
+    """Convert an RFC3339 date-time string to a UTC UNIX timestamp"""
+
+    if not validate_rfc3339(datestring):
+        raise InvalidRFC3339Error
+
+    groups = rfc3339_regex.match(datestring).groups()
+
+    time_tuple = [int(p) for p in groups[:6]]
+    timestamp = calendar.timegm(time_tuple)
+
+    seconds_part = groups[6]
+    if seconds_part is not None:
+        timestamp += float("0" + seconds_part)
+
+    if groups[7] != "Z":
+        (offset_sign, offset_hours, offset_mins) = groups[8:]
+        offset_seconds = int(offset_hours) * 3600 + int(offset_mins) * 60
+        if offset_sign == '-':
+            offset_seconds = -offset_seconds
+        timestamp -= offset_seconds
+
+    return timestamp
+
+
+def _seconds_and_microseconds(timestamp):
+    """
+    Split a floating point timestamp into an integer number of seconds since
+    the epoch, and an integer number of microseconds (having rounded to the
+    nearest microsecond).
+
+    If `_seconds_and_microseconds(x) = (y, z)` then the following holds (up to
+    the error introduced by floating point operations):
+
+    * `x = y + z / 1_000_000.`
+    * `0 <= z < 1_000_000.`
+    """
+
+    if isinstance(timestamp, int):
+        return (timestamp, 0)
+    else:
+        timestamp_us = int(round(timestamp * 1e6))
+        return divmod(timestamp_us, 1000000)
+
+def _make_datestring_start(time_tuple, microseconds):
+    ds_format = "{0:04d}-{1:02d}-{2:02d}T{3:02d}:{4:02d}:{5:02d}"
+    datestring = ds_format.format(*time_tuple)
+
+    seconds_part_str = "{0:06d}".format(microseconds)
+    # There used to be a bug here where it could be 1000000
+    assert len(seconds_part_str) == 6 and seconds_part_str[0] != '-'
+    seconds_part_str = seconds_part_str.rstrip("0")
+    if seconds_part_str != "":
+        datestring += "." + seconds_part_str
+
+    return datestring
+
+
+def timestamp_to_rfc3339_utcoffset(timestamp):
+    """Convert a UTC UNIX timestamp to RFC3339, with the offset as 'Z'"""
+
+    seconds, microseconds = _seconds_and_microseconds(timestamp)
+
+    time_tuple = time.gmtime(seconds)
+    datestring = _make_datestring_start(time_tuple, microseconds)
+    datestring += "Z"
+
+    assert abs(rfc3339_to_timestamp(datestring) - timestamp) < 0.000001
+    return datestring
+
+
+def timestamp_to_rfc3339_localoffset(timestamp):
+    """
+    Convert a UTC UNIX timestamp to RFC3339, using the local offset.
+
+    localtime() provides the time parts. The difference between gmtime and
+    localtime tells us the offset.
+    """
+
+    seconds, microseconds = _seconds_and_microseconds(timestamp)
+
+    time_tuple = time.localtime(seconds)
+    datestring = _make_datestring_start(time_tuple, microseconds)
+
+    gm_time_tuple = time.gmtime(seconds)
+    offset = calendar.timegm(time_tuple) - calendar.timegm(gm_time_tuple)
+
+    if abs(offset) % 60 != 0:
+        raise ValueError("Your local offset is not a whole minute")
+
+    offset_minutes = abs(offset) // 60
+    offset_hours = offset_minutes // 60
+    offset_minutes %= 60
+
+    offset_string = "{0:02d}:{1:02d}".format(offset_hours, offset_minutes)
+
+    if offset < 0:
+        datestring += "-"
+    else:
+        datestring += "+"
+
+    datestring += offset_string
+    assert abs(rfc3339_to_timestamp(datestring) - timestamp) < 0.000001
+
+    return datestring
+
+
+def now_to_rfc3339_utcoffset(integer=True):
+    """Convert the current time to RFC3339, with the offset as 'Z'"""
+
+    timestamp = time.time()
+    if integer:
+        timestamp = int(timestamp)
+    return timestamp_to_rfc3339_utcoffset(timestamp)
+
+
+def now_to_rfc3339_localoffset(integer=True):
+    """Convert the current time to RFC3339, using the local offset."""
+
+    timestamp = time.time()
+    if integer:
+        timestamp = int(timestamp)
+    return timestamp_to_rfc3339_localoffset(timestamp)