[SDKs] Make arv-copy preserve pipeline template component order
- Add an OrderedJsonModel class to arvados.api. This is a subclass of googleapiclient.model.JsonModel. It overrides the de/serialize methods. When it calls a json load/dump method, it passes in collections.OrderedDict as the object_hook to preserve order (refer to the json module documentation).
- Ensure that whenever arv-copy instantiates an API client, it passes in an OrderedJsonModel instance as the
modelkeyword argument. Refer to the apiclient.discovery PyDoc.
This will make arv-copy do the right thing with pipeline templates, and give us the right API hooks to extend this functionality to other Python clients easily.
We should not make OrderedJsonModel the default model because the space overhead is noticeable, and not necessary for most applications.
6095: Stop demoting OrderedDicts to dicts in arv-copy.
History: first there was 79564b0ac7d03327cc351bbd6df544ab1f776380.
This preserved the order of copied pipeline templates, but that's in
part because it stopped recursing through those templates.
1b8caff3ad598744e4a0379b01fc95ca4838caa0 fixed the recursion, but then
started losing the order again. This retains the order by ensuring we
copy OrderedDicts as OrderedDicts.
#5 Updated by Brett Smith about 4 years ago
6095-arv-copy-preserve-object-order-wip is up for review. A couple of notes:
- If you look at the original JsonModel source, you may wonder about the whole simplejson module business. If you follow the source all the way down, you'll find that it uses the standard json module whenever that's available. Since we're pretty heavily committed to Python 2.7 at this point, I went ahead and hardcoded that for simplicity.
- Suggested test by hand:
arv-copy --src [instance --dst [same] --no-recursive --project-uuid [project uuid] [pipeline template uuid]