rename src/nepi/ into just nepi/

[nepi.git] / nepi / util / timefuncs.py

diff --git a/nepi/util/timefuncs.py b/nepi/util/timefuncs.py
new file mode 100644 (file)
index 0000000..76d3979
--- /dev/null
+++ b/nepi/util/timefuncs.py
@@ -0,0 +1,122 @@
+#
+#    NEPI, a framework to manage network experiments
+#    Copyright (C) 2013 INRIA
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 2 as
+#    published by the Free Software Foundation;
+#
+#    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Author: Alina Quereilhac <alina.quereilhac@inria.fr>
+
+
+import datetime
+import re
+
+_strf = "%Y%m%d%H%M%S%f"
+_reabs = re.compile("^\d{20}$")
+_rerel = re.compile("^(?P<time>\d+(.\d+)?)(?P<units>h|m|s|ms|us)$")
+
+# Work around to fix "ImportError: Failed to import _strptime because the import lock is held by another thread."
+datetime.datetime.strptime("20120807124732894211", _strf)
+
+def stformat(sdate):
+    """ Constructs a datetime object from a string date with
+    format YYYYMMddHHMMSSffff 
+
+    """
+    return datetime.datetime.strptime(sdate, _strf).date()
+
+def tsformat(date = None):
+    """ Formats a datetime object to a string with format YYYYMMddHHMMSSffff.
+    If no date is given, the current date is used.
+    
+    """
+    if not date:
+        date = tnow()
+
+    return date.strftime(_strf)
+
+def tnow():
+    """ Returns datetime object with the current time """
+    return datetime.datetime.now()
+
+def tdiff(date1, date2):
+    """ Returns difference ( date1 - date2 ) as a datetime object,
+    where date1 and date 2 are datetime objects 
+    
+    """
+    return date1 - date2
+
+def _get_total_seconds(td): 
+    return (td.microseconds + (td.seconds + td.days * 24 * 3600) * 1e6) / 1e6
+
+def tdiffsec(date1, date2):
+    """ Returns the date difference ( date1 - date2 ) in seconds,
+    where date1 and date 2 are datetime objects 
+    
+    """
+    diff = tdiff(date1, date2)
+    return _get_total_seconds(diff)
+
+def stabsformat(sdate, dbase = None):
+    """ Constructs a datetime object from a string date.
+    The string date can be expressed as an absolute date
+    ( i.e. format YYYYMMddHHMMSSffff ) or as a relative time
+    ( e.g. format '5m' or '10s'). 
+    If the date is a relative time and the dbase parameter 
+    is given (dbase must be datetime object), the returned
+    date will be dbase + sdate. If dbase is None, 
+    current time will be used instead as base time.
+
+    :param date : string date  
+    :type date : date 
+
+    """
+
+    # No date given, return current datetime
+    if not sdate:
+        return tnow()
+
+    # Absolute date is given
+    if _reabs.match(sdate):
+        return stformat(sdate)
+
+    # Relative time is given
+    m = _rerel.match(sdate)
+    if m:
+        time = float(m.groupdict()['time'])
+        units = m.groupdict()['units']
+        if units == 'h':
+            delta = datetime.timedelta(hours = time) 
+        elif units == 'm':
+            delta = datetime.timedelta(minutes = time) 
+        elif units == 's':
+            delta = datetime.timedelta(seconds = time) 
+        elif units == 'ms':
+            delta = datetime.timedelta(microseconds = (time*1000)) 
+        else:
+            delta = datetime.timedelta(microseconds = time)
+        
+        if not dbase:
+            dbase = tnow()
+
+        return dbase + delta
+
+    return None
+
+def compute_delay_ms(timestamp2, timestamp1):
+    d1 = datetime.datetime.fromtimestamp(float(timestamp1))
+    d2 = datetime.datetime.fromtimestamp(float(timestamp2))
+    delay = d2 - d1
+
+    # round up resolution - round up to miliseconds
+    return delay.total_seconds() * 1000
+