[storm] How can I make my own "store"?

[Jason Baker]

On Wed, Sep 23, 2009 at 10:09 AM, James Henstridge <james at jamesh.id.au>wrote:

> If you're instantiating a new object, then Storm will issue an INSERT to
> add the new row.
>

This is actually what we're trying to prevent.  We want to make an object
that has the same interface as the store, but will save objects to a CSV
file to be loaded by SQL*Loader later instead of having an INSERT statement
generated.

Perhaps some code snippets will help illustrate what we're trying to do
(note that this is just the relevant parts of course):

class BulkStore(object):
    def add(self, entity, has_identity_property=True):
        """
        Add an object to this store.  Will take no action if the object has
        been added since the last flush operation.
        """
        entity_store = Store.of(entity)
        if entity_store is not None and entity_store is not self:
            msg = '%s is part of another store.' % repr(entity)
            raise WrongStoreError, msg

        elif entity_store is None:
            # <snip> - do whatever this store
            # should do on adding an object
            self.set_as_store(entity)

    def set_as_store(self, entity):
        """
        Set this saver as the storm store.
        """
        obj_info = get_obj_info(entity)
        obj_info['store'] = self

    def add_flush_order(self, *args, **kwargs):
        """This is a stub method that is for compatibility with the storm
           store.  Currently, this does nothing."""

The add_flush_order method is just there because it will be called
automatically sometimes.  For the most part, we're ignoring it because we're
determining our own flush ordering (although it would be nice if storm had a
function that we can call to determine flush ordering the same way the store
does).

In my testing thus far, this approach seems to be working flawlessly.
 However, I get the feeling that this is something that you guys hadn't
planned for and may give problems at some point.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://lists.ubuntu.com/archives/storm/attachments/20090925/c4c473a2/attachment-0002.htm