A decorator for limiting the call-rate of a function. This is achieved by returning None instead of calling the function when it is called beyond a given threshold.
The usage is as follows:
from limiter import *
@calls_per_sec(calls=1, seconds=1) # These are the default values
def foo():
...
@calls_per_sec(1) # One call per second
def foo():
...This limits the foo() function to one call every second starting from the first function call.
Limiter also works with fractions of seconds:
from limiter import *
@calls_per_sec(calls=5, seconds=0.25)
def foo():
...This limits the foo() function to ten calls every quarter second.
Note that @calls_per_sec(5, 0.25) is not the same as @calls_per_sec(20, 1).
Consider the case when a function is called 20 times in 0.5 seconds:
- If we use
@calls_per_sec(5, 0.25), we drop 10 function calls. - If we use
@calls_per_sec(20, 1), we drop none of the function calls, but every subsequent call for the next 0.5 seconds will be dropped.
This is because the call allowance is reset every X seconds.