Nameserver batch api

[jcorwin]

An API to execute a batch of commands as an atomic unit.
Also tracks a nameserver state version, which is updated on any state change.

union BatchedCommand {
1: optional ShardInfo create_shard
2: optional ShardId delete_shard
3: optional AddLinkRequest add_link
4: optional RemoveLinkRequest remove_link
5: optional Forwarding set_forwarding
6: optional Forwarding remove_forwarding
}

service Manager {
...
void batch_execute(1: list commands) throws (1: GizzardException ex)
...
void increment_state_version() throws(1: GizzardException ex)
i64 get_current_state_version() throws(1: GizzardException ex)
i64 get_master_state_version() throws(1: GizzardException ex)
...
}

[xeno-by]

Thank you for your contribution! Twitter has decided to stop supporting Gizzard as an open source project. Sorry that your pull requests was not reviewed earlier.
We're now formally archiving this project but please feel free to fork and resurrect.