Differential

Complexity

Total Complexity

4

Size/Duplication

Total Lines	27
Duplicated Lines	0 %

Importance

Changes	1
Bugs	1	Features	0

2 Methods

Rating	Name	Duplication	Size	Complexity
A	__init__()	0	2	1
A	per_second()	0	21	3

# -*- coding: utf-8 -*-
"""
.. moduleauthor:: Kenny Freeman <kenny.freeman@gmail.com>

"""

__author__ = 'Kenny Freeman'
__email__ = 'kenny.freeman@gmail.com'
__version__ = '0.3.3'
__license__     = "ISCL"
__docformat__   = 'reStructuredText'


class Differential(object):
    """Computes the rate of change of a set of metrics."""

    def __init__(self):
        self.metrics = {}

    def per_second(self, name, val, ts):
        """Records and returns the rate of change of a metric in units/second.

        :param name: The name of a metric
        :type name: str
        :param val: The value of a metric
        :type val: int or float
        :rtype: int or float
        """
        ret = type(val)(0)
        if name not in self.metrics:
            self.metrics[name] = (val, ts)
        else:
            pval, ptime = self.metrics[name]
            dval = val - pval
            dtime = ts - ptime
            if dtime > 0:
                ret = dval / dtime
            else:
                ret = 0
        return ret