Merge pull request #13 from toudi/support_for_lambda_job_name

Support for lambda GEARMAN_JOB_NAME.

README.md

@@ -46,6 +46,40 @@ the task name by specifying `name` parameter of the decorator. Here's how:
     def my_task_function(foo):
         pass
         
+### ``GEARMAN_JOB_NAME`` method
+GEARMAN_JOB_NAME is the lambda function which takes original task name as
+an argument, and returns altered version of the task name. Very important thing
+to note here is that this changes the internal naming only! So you submit your job
+like you would normally do, only it has a different internal name.
+
+The default behaviour of this method is as follows:
+
+    new_task_name = crc32(getcwd()) + '.' + task_name
+
+This may seem like a very strange idea, but it is there for a reason. Namely, the
+task name uniqueness.
+
+Let's imagine you have two instances of the same project on the same machine.
+Typical situation would be one instance being the test/development instance and
+the other one being the production one. So naturally you submit a job like you normally
+would do:
+
+    client.submit_job('send_mail', ...)
+
+Only now, gearman wouldn't know which worker should process the task. Should it be
+the production one? Or the testing? hash of getcwd() solves this issue, because the
+production environment is located in different location than the testing, and your
+call is transparently renamed to
+
+    client.submit_job('some-hash.send_mail', ...)
+
+If you would like to change this behaviour, simply define GEARMAN_JOB_NAME function
+in the settings:
+
+    GEARMAN_JOB_NAME = lambda name: name
+
+which would leave the internal task name unchanged.
+
 ### Task parameters
 The gearman docs specify that the job function can accept only one parameter
 (usually refered to as the ``data`` parameter). Additionally, that parameter

django_gearman/models.py

@@ -1,9 +1,16 @@
 import pickle
-
+from zlib import adler32
+from os import getcwd
 import gearman
 from django.conf import settings
 
 
+def default_taskname_decorator(task_name):
+    return "%s.%s" % (str(adler32(getcwd()) & 0xffffffff), task_name)
+
+task_name_decorator = getattr(settings, 'GEARMAN_JOB_NAME', default_taskname_decorator)
+
+
 class PickleDataEncoder(gearman.DataEncoder):
     @classmethod
     def encode(cls, encodable_object):
@@ -53,11 +60,14 @@ def parse_data(self, arg, args=None, kwargs=None, *arguments, **karguments):
     def submit_job(
         self, task, orig_data = None, unique=None, priority=None,
         background=False, wait_until_complete=True, max_retries=0,
-        poll_timeout=None, args=None, kwargs=None, *arguments, **karguments):
+        poll_timeout=None, args=None, kwargs=None, *arguments, **karguments):        
         """
         Handle *args and **kwargs before passing it on to GearmanClient's
         submit_job function.
         """
+        if callable(task_name_decorator):
+            task = task_name_decorator(task)
+
         data = self.parse_data(orig_data, args, kwargs, *arguments, **karguments)
 
         return super(DjangoGearmanClient, self).submit_job(
@@ -91,3 +101,8 @@ def __init__(self, **kwargs):
         """Instantiate Gearman worker with servers from settings file."""
         return super(DjangoGearmanWorker, self).__init__(
                 settings.GEARMAN_SERVERS, **kwargs)
+
+    def register_task(self, task_name, task):
+        if callable(task_name_decorator):
+            task_name = task_name_decorator(task_name)
+        return super(DjangoGearmanWorker, self).register_task(task_name, task)