heat.scaling.scalingutil

Source code for heat.scaling.scalingutil

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import math

ADJUSTMENT_TYPES = (
    EXACT_CAPACITY, CHANGE_IN_CAPACITY, PERCENT_CHANGE_IN_CAPACITY) = (
    'exact_capacity', 'change_in_capacity', 'percent_change_in_capacity')

CFN_ADJUSTMENT_TYPES = (
    CFN_EXACT_CAPACITY, CFN_CHANGE_IN_CAPACITY,
    CFN_PERCENT_CHANGE_IN_CAPACITY) = ('ExactCapacity', 'ChangeInCapacity',
                                       'PercentChangeInCapacity')


[docs]def calculate_new_capacity(current, adjustment, adjustment_type, min_adjustment_step, minimum, maximum): """Calculates new capacity from the given adjustments. Given the current capacity, calculates the new capacity which results from applying the given adjustment of the given adjustment-type. The new capacity will be kept within the maximum and minimum bounds. """ def _get_minimum_adjustment(adjustment, min_adjustment_step): if min_adjustment_step and min_adjustment_step > abs(adjustment): adjustment = (min_adjustment_step if adjustment > 0 else -min_adjustment_step) return adjustment if adjustment_type in (CHANGE_IN_CAPACITY, CFN_CHANGE_IN_CAPACITY): new_capacity = current + adjustment elif adjustment_type in (EXACT_CAPACITY, CFN_EXACT_CAPACITY): new_capacity = adjustment else: # PercentChangeInCapacity delta = current * adjustment / 100.0 if math.fabs(delta) < 1.0: rounded = int(math.ceil(delta) if delta > 0.0 else math.floor(delta)) else: rounded = int(math.floor(delta) if delta > 0.0 else math.ceil(delta)) adjustment = _get_minimum_adjustment(rounded, min_adjustment_step) new_capacity = current + adjustment if new_capacity > maximum: return maximum if new_capacity < minimum: return minimum return new_capacity
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