generating_timer_cases.md

Generating timer cases

For every timer case a member function must be implemented with the Python code to time.

from performance_analyst import TimerCase


class MyModuleTimings(TimerCase.TimerCase):

    def time_a(self):
        # Statements to time.
        pass

    def time_b(self):
        # Other statements to time.
        pass

If in this example time_a and time_b are very similar, and there are more of these similar timer case member functions, then they should be generated at runtime. Given Python's dynamic nature, this is not a difficult thing to accomplish.

The idea is to add member functions to a TimerCase sub-class at runtime. The implementation of each of these memberfunctions consists of a section of boilerplate statements of which the details are filled in at runtime. The TimerCase base class contains a convenience function TimerCase.add_method to add methods to it programmatically.

In the next example this idea is used in a very silly use-case. These few lines of code do create 1000 timer cases though! Now you can focus on the method's boilerplate implementation instead of copy-paste-adjusting 1000 member functions.

class MyModuleTimings(TimerCase.TimerCase):

    # Empty class, but there could also be handcrafted functions here.
    pass


def create_method(count):

    def method(self):
        math.sqrt(count)  # Very silly example.

    # Format a unique name (within the timer case).
    method.__name__ = "timeSqrt_%d" % (count)

    return method


for count in xrange(1000):
    MyModuleTimings.add_method(create_method(count))