Check() will check if it exists with the specified version number. If you give it -1 it won't compare the version number. So that's a basic Exists() call. Does that make sense?
On Thu, Mar 1, 2012 at 6:13 PM, Shelley, Ryan <[email protected]>wrote: > I don't see an Op.exists() method. Check, Create, Delete and SetData. I'm > on 3.4.3, if that makes a difference. > > On 2/29/12 7:16 PM, "Ted Dunning" <[email protected]> wrote: > > >On Wed, Feb 29, 2012 at 7:04 PM, Marshall McMullen < > >[email protected]> wrote: > > > >> Yes, Ted's right. The multi has to fail as that's part of the contract > >>it > >> guarantees. > >> > >> The only thing you could do, which will significantly narrow the race > >> condition, is as you're *building *the multi, check if the path already > >> exists. If so, then don't add the create op for that path into the > >>multi. > >> Of course this may not work in every situation, but we use that > >>approach in > >> many code paths and it works well. > >> > > > >Another approach is to compose one multi with Op.exists() for each level > >so > >that you find everything you need, then create another with the correct > >Op.create() operations. That gets the problem down to two server > >round-trips but still has the race condition. > >
