Hi folks,
Simple question here. Based on the python client documentation, I'm unclear on
the canonical means to perform in python a read-modify-write cycle on an object
stored in Riak.
What seems intuitive to me:
obj = kv.bucket(b).get(name)
if f.exists():
data = f.get_data()
# todo: check for siblings, and resolve
else:
data = {'my_list': []}
data['my_list'].append(something)
obj.set_data(data)
obj.store()
My assumption here is that the RiakObject 'obj' has internally kept the vector
clock for this key, and when this update gets stored, it will do the right
thing. However, the documentation doesn't say that's what will happen. In fact,
I can't find anything in the documentation that makes it clear how to do this
read-modify-write.
There is this piece of documentation for the python client API:
| populate(self, Result)
| Populate the object based on the return from get.
|
| If None returned, then object is not found
| If a tuple of vclock, contents then one or more
| whole revisions of the key were found
| If a list of vtags is returned there are multiple
| sibling that need to be retrieved with get.
This is obviously not very clear. This sounds like it has something to do with
read-modify-write, but who knows.
So, is my intuition in the code above correct? Or should we write back a
modified object through some other means like populate()?
Thanks for the guidance,
Dave
--
Dave Lowell
d...@connectv.com
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