Import processutils from oslo-incubator.

1 files changed, 210 insertions, 0 deletions

diff --git a/os_net_config/openstack/common/timeutils.py b/os_net_config/openstack/common/timeutils.py
new file mode 100644
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+++ b/os_net_config/openstack/common/timeutils.py
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+# Copyright 2011 OpenStack Foundation.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+Time related utilities and helper functions.
+"""
+
+import calendar
+import datetime
+import time
+
+import iso8601
+import six
+
+
+# ISO 8601 extended time format with microseconds
+_ISO8601_TIME_FORMAT_SUBSECOND = '%Y-%m-%dT%H:%M:%S.%f'
+_ISO8601_TIME_FORMAT = '%Y-%m-%dT%H:%M:%S'
+PERFECT_TIME_FORMAT = _ISO8601_TIME_FORMAT_SUBSECOND
+
+
+def isotime(at=None, subsecond=False):
+    """Stringify time in ISO 8601 format."""
+    if not at:
+        at = utcnow()
+    st = at.strftime(_ISO8601_TIME_FORMAT
+                     if not subsecond
+                     else _ISO8601_TIME_FORMAT_SUBSECOND)
+    tz = at.tzinfo.tzname(None) if at.tzinfo else 'UTC'
+    st += ('Z' if tz == 'UTC' else tz)
+    return st
+
+
+def parse_isotime(timestr):
+    """Parse time from ISO 8601 format."""
+    try:
+        return iso8601.parse_date(timestr)
+    except iso8601.ParseError as e:
+        raise ValueError(six.text_type(e))
+    except TypeError as e:
+        raise ValueError(six.text_type(e))
+
+
+def strtime(at=None, fmt=PERFECT_TIME_FORMAT):
+    """Returns formatted utcnow."""
+    if not at:
+        at = utcnow()
+    return at.strftime(fmt)
+
+
+def parse_strtime(timestr, fmt=PERFECT_TIME_FORMAT):
+    """Turn a formatted time back into a datetime."""
+    return datetime.datetime.strptime(timestr, fmt)
+
+
+def normalize_time(timestamp):
+    """Normalize time in arbitrary timezone to UTC naive object."""
+    offset = timestamp.utcoffset()
+    if offset is None:
+        return timestamp
+    return timestamp.replace(tzinfo=None) - offset
+
+
+def is_older_than(before, seconds):
+    """Return True if before is older than seconds."""
+    if isinstance(before, six.string_types):
+        before = parse_strtime(before).replace(tzinfo=None)
+    else:
+        before = before.replace(tzinfo=None)
+
+    return utcnow() - before > datetime.timedelta(seconds=seconds)
+
+
+def is_newer_than(after, seconds):
+    """Return True if after is newer than seconds."""
+    if isinstance(after, six.string_types):
+        after = parse_strtime(after).replace(tzinfo=None)
+    else:
+        after = after.replace(tzinfo=None)
+
+    return after - utcnow() > datetime.timedelta(seconds=seconds)
+
+
+def utcnow_ts():
+    """Timestamp version of our utcnow function."""
+    if utcnow.override_time is None:
+        # NOTE(kgriffs): This is several times faster
+        # than going through calendar.timegm(...)
+        return int(time.time())
+
+    return calendar.timegm(utcnow().timetuple())
+
+
+def utcnow():
+    """Overridable version of utils.utcnow."""
+    if utcnow.override_time:
+        try:
+            return utcnow.override_time.pop(0)
+        except AttributeError:
+            return utcnow.override_time
+    return datetime.datetime.utcnow()
+
+
+def iso8601_from_timestamp(timestamp):
+    """Returns a iso8601 formatted date from timestamp."""
+    return isotime(datetime.datetime.utcfromtimestamp(timestamp))
+
+
+utcnow.override_time = None
+
+
+def set_time_override(override_time=None):
+    """Overrides utils.utcnow.
+
+    Make it return a constant time or a list thereof, one at a time.
+
+    :param override_time: datetime instance or list thereof. If not
+                          given, defaults to the current UTC time.
+    """
+    utcnow.override_time = override_time or datetime.datetime.utcnow()
+
+
+def advance_time_delta(timedelta):
+    """Advance overridden time using a datetime.timedelta."""
+    assert(not utcnow.override_time is None)
+    try:
+        for dt in utcnow.override_time:
+            dt += timedelta
+    except TypeError:
+        utcnow.override_time += timedelta
+
+
+def advance_time_seconds(seconds):
+    """Advance overridden time by seconds."""
+    advance_time_delta(datetime.timedelta(0, seconds))
+
+
+def clear_time_override():
+    """Remove the overridden time."""
+    utcnow.override_time = None
+
+
+def marshall_now(now=None):
+    """Make an rpc-safe datetime with microseconds.
+
+    Note: tzinfo is stripped, but not required for relative times.
+    """
+    if not now:
+        now = utcnow()
+    return dict(day=now.day, month=now.month, year=now.year, hour=now.hour,
+                minute=now.minute, second=now.second,
+                microsecond=now.microsecond)
+
+
+def unmarshall_time(tyme):
+    """Unmarshall a datetime dict."""
+    return datetime.datetime(day=tyme['day'],
+                             month=tyme['month'],
+                             year=tyme['year'],
+                             hour=tyme['hour'],
+                             minute=tyme['minute'],
+                             second=tyme['second'],
+                             microsecond=tyme['microsecond'])
+
+
+def delta_seconds(before, after):
+    """Return the difference between two timing objects.
+
+    Compute the difference in seconds between two date, time, or
+    datetime objects (as a float, to microsecond resolution).
+    """
+    delta = after - before
+    return total_seconds(delta)
+
+
+def total_seconds(delta):
+    """Return the total seconds of datetime.timedelta object.
+
+    Compute total seconds of datetime.timedelta, datetime.timedelta
+    doesn't have method total_seconds in Python2.6, calculate it manually.
+    """
+    try:
+        return delta.total_seconds()
+    except AttributeError:
+        return ((delta.days * 24 * 3600) + delta.seconds +
+                float(delta.microseconds) / (10 ** 6))
+
+
+def is_soon(dt, window):
+    """Determines if time is going to happen in the next window seconds.
+
+    :param dt: the time
+    :param window: minimum seconds to remain to consider the time not soon
+
+    :return: True if expiration is within the given duration
+    """
+    soon = (utcnow() + datetime.timedelta(seconds=window))
+    return normalize_time(dt) <= soon