tree 7c684be0af1ebffa9e88126555c1421b6a2b9c39
parent 9d075b9f9b3be65ad40703b832fc5feb2ff93552
author Alex Fandrianto <alexfandrianto@google.com> 1462242302 -0700
committer Alex Fandrianto <alexfandrianto@google.com> 1462242302 -0700

TODOs: Userdata collection

This sets up the userdata syncgroup among the same user's devices.
When the user creates a new todo list, the other devices will also
join that todo list collection.

We currently shard by email address and use a common cloud.

Caveats:
- Since we can only create syncgroups underneath an existing syncbase,
  and merging is not supported, the same user must be sure to start
  one device a bit before the other to avoid a creation race.
- Discovery between syncbases has occasional errors saying that ads
  are too large on both the creator and joiner sides.
  This is expected, but we need a hack to syncbase to ensure that
  the cloud is published too.
  https://vanadium-review.googlesource.com/22043
- Similarly, the aforementioned CL is used to improve stability
  after a user's 2nd device joins the todo list. It won't crash if
  a local publish of Vanadium uses that patch.
  https://github.com/vanadium/issues/issues/1314

- If you run with vlog, the app runs out of memory eventually and
  crashes. This bug already existed though, IIRC.
- There are occasional errors in go-jni.
  "Error while importing keypair: -1
   panic: Reference 42975 doesn't exist"
  as well as
  "panic: runtime error: cgo argument has Go pointer to Go pointer"
  https://github.com/vanadium/issues/issues/1315

  This only starts to happen after syncing and seemingly occurs randomly.

Change-Id: If0c76ec52546f93fd1ab56e9ef0d8aeef06201f8