func (ch Chg) applyData(lfs zx.RWTree, rfs zx.Tree) error {
nd := ch.D.UsrAttrs()
for _, k := range ignoredPutAttrs {
delete(nd, k)
}
datc := rfs.Get(ch.D["path"], 0, zx.All, "")
dc := lfs.Put(ch.D["path"], nd, 0, datc, "")
<-dc
return cerror(dc)
}
// returns true if the caller must poll itself rfs for changes
func newInvalQ(tag string, dbgf *bool, rfs zx.Tree) (*invalQ, bool) {
iq := &invalQ{
Tag: tag,
Dbg: dbgf,
cchgc: make(chan bool, 1),
rfs: rfs,
invalsc: make(chan bool, 1),
}
go iq.postinvalproc()
if rfs == nil {
return iq, false
}
// Use /Chg from rfs or poll rfs it if there's no other way.
dc := rfs.Get("/Chg", 0, zx.All, "")
msg := <-dc
if len(msg) == 0 {
dbg.Warn("no invalidations: %s", cerror(dc))
return iq, true
}
go iq.getinvalproc(dc)
return iq, false
}