kamma 0.0.10

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) tasks can be queued as maximum.

• All task’s arguments should be serializable by json

• Not recommended for high performance scenarios.

Install

As simple as:

pip install kamma

Example

import kamma

# python 2 and 3 compatibility issue
try:
   input = raw_input
except NameError:
   pass

# kamma worker
app = kamma.Worker()

# registering fibonacci callback in kamma app
@app.task_callback(timeout=5, retry_wait=kamma.wait_fixed(1),
                   retry_stop=kamma.stop_after_attempt(1))
def fibonacci(n, level=0):
    result = 1
    if n < 0 or n > 100:
        raise kamma.AbortTask("n has to be 0 <= n <= 100")
    if n > 1:
        result = fibonacci(n - 1, level=level + 1) + fibonacci(n - 2, level=level + 1)
    if level == 0:
        print("*** RESULT: fibonacci of '{}' is '{}' ***".format(n, result))
    return result


if __name__ == "__main__":
    # start listening for incoming tasks
    app.run_async()
    print("Enter the value of the fibonacci you want to compute, 0 to exit")
    n = 1
    while True:
        n = int(input(""))
        if n == 0:
            break
        # add new fibonacci task
        app.push_task(fibonacci, n=n)
    app.stop()

The complete example here: examples/example.py