hyperstream/tools/clock/2016-07-11T1209Z_v0.0.1.py
# The MIT License (MIT) # Copyright (c) 2014-2017 University of Bristol
#
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# copies of the Software, and to permit persons to whom the Software is
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# The above copyright notice and this permission notice shall be included in all
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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from hyperstream import TimeInterval
from hyperstream.stream import StreamInstance
from hyperstream.tool import Tool, check_input_stream_count
from hyperstream.utils import MIN_DATE
from datetime import timedelta
import logging
class Clock(Tool):
def __init__(self, first=MIN_DATE, stride=timedelta(seconds=1)):
"""
Simple clock ticker tool
:param first: Start of the clock
:param stride: Tick stride as timedelta
"""
super(Clock, self).__init__(first=first, stride=stride)
# TODO: type checking
self.first = first
if isinstance(stride, float):
stride = timedelta(seconds=stride)
assert isinstance(stride, timedelta)
self.stride = stride
def message(self, interval):
return '{} running from {} to {} with stride {}'.format(
self.__class__.__name__, str(interval.start), str(interval.end), str(self.stride))
@check_input_stream_count(0)
def _execute(self, sources, alignment_stream, interval):
if interval.start < self.first:
interval.start = self.first
n_strides = int((interval.start - self.first).total_seconds() // self.stride.total_seconds())
t = self.first + n_strides * self.stride
while t <= interval.end:
if t > interval.start:
yield StreamInstance(t, t)
t += self.stride