Move Git discovery into DiscoveryEngine
Summary:
Ref T4327. Consolidates and simplifies infrastructure:
- Moves Git discovery into DiscoveryEngine.
- Collapses a bunch of the Git and Mercurial code related to stream discovery.
- Removes all cach code from PullLocal daemon (it's no longer called).
- Adds basic unit tests for Git and Mercurial discovery.
Various cleanup:
- Makes GitStream and MercurialStream extend a common base.
- Improves performance of MercurialStream in some cases, by requiring fewer commits be output and parsed.
- Makes mirroring exceptions easier to debug.
- Fixes discovery of Mercurial repositories with multiple branch heads.
- Adds some missing pht().
Test Plan:
I tested this fairly throughly because I think this phase is complete:
- Made new repositories in multiple VCSes and did full imports.
- Particularly, I reimported Arcanist to make sure that TODO was resolved. I think it was related to the toposort stuff.
- Pushed commits to multiple VCSes.
- Pushed commits to a non-close branch, then pushed a merge commit. Observed commits import initially as non-close, then get flagged for close.
- Started full daemons and resolved various minor issues that showed up in the daemon log until everything ran cleanly.
- Basically spent about 30 minutes banging on this in every way I could think of to try to break it. I found and fixed some minor stuff, but it seems solid.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T4327
Differential Revision: https://secure.phabricator.com/D7987