kamma 0.0.4

kamma is a very simplified Task File Queue

kamma is a very simplified task file queue that persists tasks and its needed data. It also has a worker that process all pending tasks.

Motivation

Nowadays local disk access is an undervalued resource for many reasons, however stored data is always available even after power outage. By contrast, network resources or remote third parties are not always ready. Is for this reason I developed the kamma in order to isolate dependent tasks from the miseries of remote services. kamma would try process all pending tasks forever respecting the queue order.

Limitations

Up to (sys.maxint - FileQue.max_head_index) items can hold the queue. Not recommended for high performance scenarios.

Install

As simple as:

pip install kamma

Example

import kamma
from kamma.worker import KammaWorker

try:
   input = raw_input
except NameError:
   pass

# task callback
def task_fib(data):
    def fibonacci(n):
        if n < 0:
            raise Exception("Value must be >= 0")
        if n <= 1:
            return 1
        return fibonacci(n - 1) + fibonacci(n - 2)
    try:
        n = data['n']
        print("computing fibonacci({})".format(n))
        result = fibonacci(n)
        print("*** fibonacci({}): {} ***".format(n, result))
    except Exception as e:
        raise kamma.AbortTask(str(e))


if __name__ == "__main__":
    # kamma worker, we define the TaskCallback
    worker = KammaWorker(queue_path="task_queue",
                         task_callbacks=[kamma.TaskCallback(id='fibonacci', callback=task_fib)])
    # start listening for incoming tasks
    worker.run_async()
    print("ctrl+c to exit")
    try:
        while True:
            n = int(input("Fibonacci of: "))
            # add new fibonacci task
            worker.push_task(kamma.Task(id='fibonacci', data={'n': n}))
    except KeyboardInterrupt:
        pass
    worker.wait_empty_event()
    worker.stop()