// returns an operation filter which uses a consistent hash to determine
// if the operation will be accepted for processing. can be used to distribute work.
// name: the name of the worker creating this filter. e.g. "Harry"
// workers: a slice of strings representing the available worker names
func ConsistentHashFilter(name string, workers []string) (gtm.OpFilter, error) {
if len(workers) == 0 {
return nil, EmptyWorkers
}
found := false
ring := hashring.New(workers)
for _, worker := range workers {
if worker == name {
found = true
}
}
if !found {
return nil, WorkerMissing
}
return func(op *gtm.Op) bool {
if op.Id != nil {
var idStr string
switch op.Id.(type) {
case bson.ObjectId:
idStr = op.Id.(bson.ObjectId).Hex()
default:
idStr = fmt.Sprintf("%v", op.Id)
}
who, ok := ring.GetNode(idStr)
if ok {
return name == who
} else {
return false
}
} else {
return true
}
}, nil
}
func NewTcpCli(bsCb BaseCliCb, enableHash bool, maxOutgo int, outGoBuf int, heartBeatSecond int) *TcpCli {
tcp := &TcpCli{
cb: bsCb,
enableHash: enableHash,
}
if tcp.enableHash {
tcp.hashRing = hashring.New([]string{})
}
tcp.initData(maxOutgo, outGoBuf, heartBeatSecond, false)
return tcp
}