Yatta!
—Hiro Nakamura
The hiro.Timeline context manager hijacks a few commonly used time functions
to allow time manipulation within its context. Specifically time.sleep, time.time,
time.time_ns, time.monotonic, time.monotonic_ns, time.localtime, time.gmtime,
datetime.now, datetime.utcnow and datetime.today behave according the configuration of the context.
The context provides the following manipulation options:
rewind: accepts seconds as an integer or atimedeltaobject.forward: accepts seconds as an integer or atimedeltaobject.freeze: accepts a floating point time since epoch ordatetimeordateobject to freeze the time at.unfreeze: resumes time from the point it was frozen at.scale: accepts a floating point to accelerate/decelerate time by.> 1 = acceleration, < 1 = decelerationreset: resets all time alterations.
import hiro
from datetime import timedelta, datetime
import time
datetime.now().isoformat()
# OUT: '2013-12-01T06:55:41.706060'
with hiro.Timeline() as timeline:
# forward by an hour
timeline.forward(60*60)
datetime.now().isoformat()
# OUT: '2013-12-01T07:55:41.707383'
# jump forward by 10 minutes
timeline.forward(timedelta(minutes=10))
datetime.now().isoformat()
# OUT: '2013-12-01T08:05:41.707425'
# jump to yesterday and freeze
timeline.freeze(datetime.now() - timedelta(hours=24))
datetime.now().isoformat()
# OUT: '2013-11-30T09:15:41'
timeline.scale(5) # scale time by 5x
time.sleep(5) # this will effectively only sleep for 1 second
# since time is frozen the sleep has no effect
datetime.now().isoformat()
# OUT: '2013-11-30T09:15:41'
timeline.rewind(timedelta(days=365))
datetime.now().isoformat()
# OUT: '2012-11-30T09:15:41'To reduce the amount of statements inside the context, certain timeline setup tasks can be done via the constructor and/or by using the fluent interface.
import hiro
import time
from datetime import timedelta, datetime
start_point = datetime(2012,12,12,0,0,0)
my_timeline = hiro.Timeline(scale=5).forward(60*60).freeze()
with my_timeline as timeline:
print datetime.now()
# OUT: '2012-12-12 01:00:00.000315'
time.sleep(5) # effectively 1 second
# no effect as time is frozen
datetime.now()
# OUT: '2012-12-12 01:00:00.000315'
timeline.unfreeze()
# back to starting point
datetime.now()
# OUT: '2012-12-12 01:00:00.000317'
time.sleep(5) # effectively 1 second
# takes effect (+5 seconds)
datetime.now()
# OUT: '2012-12-12 01:00:05.003100'Timeline can additionally be used as a decorator
import hiro
import time, datetime
@hiro.Timeline(scale=50000)
def sleeper():
datetime.datetime.now()
# OUT: '2013-11-30 14:27:43.409291'
time.sleep(60*60) # effectively 72 ms
datetime.datetime.now()
# OUT: '2013-11-30 15:28:36.240675'
@hiro.Timeline()
def sleeper_aware(timeline):
datetime.datetime.now()
# OUT: '2013-11-30 14:27:43.409291'
timeline.forward(60*60)
datetime.datetime.now()
# OUT: '2013-11-30 15:28:36.240675'In order to execute certain callables within a Timeline context, two
shortcut functions are provided.
run_sync(factor=1, callable, *args, **kwargs)run_async(factor=1, callable, *args, **kwargs)
Both functions return a ScaledRunner object which provides the following methods
get_execution_time: The actual execution time of thecallableget_response(will either return the actual return value ofcallableor raise the exception that was thrown)
run_async returns a derived class of ScaledRunner that additionally provides the following methods
is_running:True/Falsedepending on whether the callable has completed executionjoin: blocks until thecallablecompletes execution
import hiro
import time
def _slow_function(n):
time.sleep(n)
if n > 10:
raise RuntimeError()
return n
runner = hiro.run_sync(10, _slow_function, 10)
runner.get_response()
# OUT: 10
# due to the scale factor 10 it only took 1s to execute
runner.get_execution_time()
# OUT: 1.1052658557891846
runner = hiro.run_async(10, _slow_function, 11)
runner.is_running()
# OUT: True
runner.join()
runner.get_execution_time()
# OUT: 1.1052658557891846
runner.get_response()
# OUT: Traceback (most recent call last):
# ....
# OUT: File "<input>", line 4, in _slow_function
# OUT: RuntimeError