Source Code for Module pike.nttime

  1  # 
  2  # Copyright (c) 2013, EMC Corporation 
  3  # All rights reserved. 
  4  # 
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  9  # this list of conditions and the following disclaimer. 
 10  # 2. Redistributions in binary form must reproduce the above copyright notice, 
 11  # this list of conditions and the following disclaimer in the documentation 
 12  # and/or other materials provided with the distribution. 
 13  # 
 14  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 15  # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 16  # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 17  # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
 18  # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 19  # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 20  # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 21  # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 22  # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 23  # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 24  # POSSIBILITY OF SUCH DAMAGE. 
 25  # 
 26  # Module Name: 
 27  # 
 28  #        nttime.py 
 29  # 
 30  # Abstract: 
 31  # 
 32  #        NT time format utility class 
 33  # 
 34  # Authors: Rafal Szczesniak (rafal.szczesniak@isilon.com) 
 35  #          Masen Furer (masen.furer@dell.com) 
 36  # 
 37   
 38  from datetime import datetime, timedelta 
 39  import math 
 40  import time 
 41   
 42  _unix_time_offset = 11644473600L 
 43  _unix_epoch = datetime.fromtimestamp(0) + timedelta(hours=time.localtime().tm_isdst) 
 44  _intervals_per_second = 10000000L 
 45   
 46 -def _unix_time_to_nt_time(t): 
 47      return (t + _unix_time_offset) * _intervals_per_second 
 48   
 49 -def _datetime_to_unix_time(t): 
 50      td = (t - _unix_epoch) 
 51      return td.seconds + (td.days * 24 * 3600) 
 52   
 53 -def _datetime_to_nt_time(t): 
 54      return _unix_time_to_nt_time(_datetime_to_unix_time(t)) 
 55   
 56 -def _nt_time_to_unix_time(t): 
 57      """ 
 58      Converts "FILETIME" to Python's time library format. 
 59   
 60      routine borrowed from dist_shell: sys_ex/windows/file.py 
 61      """ 
 62   
 63      # This calculation below might seem rather complex for such time 
 64      # conversions, however, due to issues with floating point 
 65      # arithmetics precision, this HACK is required to compute the time 
 66      # in Python's time library format such that times like "12:59.59.1" 
 67      # don't turn into "01:00:00.0" when converted back. This 
 68      # calculation below makes use of Python's bigint capabilities. 
 69      py_time = (t << 32) / _intervals_per_second 
 70      py_time -= _unix_time_offset << 32 
 71      py_time_parts = divmod(py_time, 2**32) 
 72      py_time = float(py_time_parts[0]) 
 73      py_time += math.copysign(py_time_parts[1], py_time) / 2**32 
 74      return py_time 
 75   
 76 -def GMT_to_datetime(gmt_token): 
 77      dt_obj = datetime.strptime( 
 78              gmt_token, 
 79              "@GMT-%Y.%m.%d-%H.%M.%S") 
 80      # apply timezone conversion 
 81      dt_obj -= timedelta(seconds=time.timezone) 
 82      return dt_obj 
 83   
 84 -class NtTime(long): 
 85      """ 
 86      NtTime may be initialized with any of the following values 
 87        * string in ISO format or @GMT- format (timewarp) 
 88        * datetime 
 89        * int/long indicating number of 100-nanosecond intervals since 1601-01-01 
 90      """ 
 91 -    def __new__(cls, value): 
 92          if isinstance(value, basestring): 
 93              if value.startswith("@GMT-"): 
 94                  dt = GMT_to_datetime(value) 
 95              else: 
 96                  dt = datetime.strptime(value, "%Y-%m-%d %H:%M:%S") 
 97              value = _datetime_to_nt_time(dt) 
 98          elif isinstance(value, datetime): 
 99              value = _datetime_to_nt_time(value) 
100   
101          return super(NtTime, cls).__new__(cls, long(value)) 
102   
103 -    def __repr__(self): 
104          return str(self) 
105   
106 -    def __str__(self): 
107          return self.to_datetime().isoformat(" ") 
108   
109 -    def to_datetime(self): 
110          return datetime.fromtimestamp(_nt_time_to_unix_time(self)) 
111   
112 -    def to_pytime(self): 
113          return _nt_time_to_unix_time(self) 
114   
115 -    def to_unixtime(self): 
116          return long(self.to_pytime()) 
117