Sub::Throttle - a tiny module for throttling down an operation

Sub::Throttle is a tiny module that is useful for throttling down the load of a certain operation. For example, it can be used to limit the speed of a batch operation against a database so that other operations (such as requests from the web application) would not slow down too much.

It is easy to modify an existing operation (a for-loop in the case of the example below) to use Sub::Throttle. The example limits the load factor 0.1, i.e. the loop will be delayed 9x the time it took for performing a single operation, effectively limiting the load of the operation to 1/10.

# BEFORE

for (...) {
    # the operation
    ...
}

# AFTER

use Sub::Throttle qw(throttle);

my $load = 0.1;

for (...) {
    throttle($load, sub {
        # the operation
        ...
    });
}