# Copyright 2016 Google Inc. 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.
[docs]class Duration(object):
"""
A Duration represents a signed, fixed-length span of time represented
as a count of seconds and fractions of seconds at nanosecond
resolution. It is independent of any calendar and concepts like \"day\"
or \"month\". It is related to Timestamp in that the difference between
two Timestamp values is a Duration and it can be added or subtracted
from a Timestamp. Range is approximately +-10,000 years.
Example 1: Compute Duration from two Timestamps in pseudo code.
::
Timestamp start = ...;
Timestamp end = ...;
Duration duration = ...;
duration.seconds = end.seconds - start.seconds;
duration.nanos = end.nanos - start.nanos;
if (duration.seconds < 0 && duration.nanos > 0) {
duration.seconds += 1;
duration.nanos -= 1000000000;
} else if (durations.seconds > 0 && duration.nanos < 0) {
duration.seconds -= 1;
duration.nanos += 1000000000;
}
Example 2: Compute Timestamp from Timestamp + Duration in pseudo code.
::
Timestamp start = ...;
Duration duration = ...;
Timestamp end = ...;
end.seconds = start.seconds + duration.seconds;
end.nanos = start.nanos + duration.nanos;
if (end.nanos < 0) {
end.seconds -= 1;
end.nanos += 1000000000;
} else if (end.nanos >= 1000000000) {
end.seconds += 1;
end.nanos -= 1000000000;
}
Attributes:
seconds (long): Signed seconds of the span of time. Must be from -315,576,000,000
to +315,576,000,000 inclusive.
nanos (int): Signed fractions of a second at nanosecond resolution of the span
of time. Durations less than one second are represented with a 0
``seconds`` field and a positive or negative ``nanos`` field. For durations
of one second or more, a non-zero value for the ``nanos`` field must be
of the same sign as the ``seconds`` field. Must be from -999,999,999
to +999,999,999 inclusive.
"""
pass