IRC-SPHERE/HyperStream

# The MIT License (MIT) # Copyright (c) 2014-2017 University of Bristol
#
#  Permission is hereby granted, free of charge, to any person obtaining a copy
#  of this software and associated documentation files (the "Software"), to deal
#  in the Software without restriction, including without limitation the rights
#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#  copies of the Software, and to permit persons to whom the Software is
#  furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included in all
#  copies or substantial portions of the Software.
#
#  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.
#  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
#  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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from hyperstream.stream import StreamInstance
from hyperstream.tool import Tool, check_input_stream_count
from hyperstream.utils import MIN_DATE, get_timedelta
from datetime import datetime


class Clock(Tool):
    def __init__(self, first=MIN_DATE, stride=1.0):
        """
        Simple clock ticker tool
        :param first: Start of the clock
        :param stride: Tick stride as timedelta
        """
        super(Clock, self).__init__(first=first, stride=stride)

        if not isinstance(first, datetime):
            raise ValueError("Expected datetime.datetime, got {}".format(first.__type__.__name__))

        self._stride = get_timedelta(stride)

    def message(self, interval):
        return '{} running from {} to {} with stride {}s'.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