Summary:
Once we start moving the bookmark across the imported commits (D22598159 (c5e880c239)), we need to check dependent systems to avoid overloading them when parsing the commits. In this diff we added the functionality to check Phabricator. We use an external service (jf graphql - find discussion here: https://fburl.com/nr1f19gs) to fetch commits from Phabricator. Each commit id starts with "r", followed by a call sign (e.g FBS for fbsource) and the commit hash (https://fburl.com/qa/9pf0vtkk). If we try to fetch an invalid commit id (e.g not having a call sign), we should receive an error. Otherwise, we should receive a JSON.
An imported commit should have the following query result: https://fburl.com/graphiql/20txxvsn - nodes has one result with the imported field true.
If the commit hasn't been recognised by Phabricator yet, the nodes array will be empty.
If the commit has been recognised, but not yet parsed, the imported field will be false.
If we haven't parsed the batch, we will try to check Phabricator again after sleeping for a couple of seconds.
If it has parsed the batch of commits, we move the bookmark to the next batch.
Reviewed By: krallin
Differential Revision: D22762800
fbshipit-source-id: 5c02262923524793f364743e3e1b3f46c921db8d
f1ef619284