func (s *Store) getHyperLoglog(siteId int64) (hl *hyperloglog.HyperLogLogPlus, e error) {
var (
bts []byte
isNew bool = true
ok bool
)
key := itob32(siteId)
if ok, e = s.ldb.Has(key, nil); ok {
isNew = false
bts, e = s.ldb.Get(key, nil)
if e != nil {
if leveldb.ErrNotFound == e {
isNew = true
} else {
return
}
}
}
hl, e = hyperloglog.NewPlus(HyperlogPrecision)
if e != nil {
return
}
if !isNew {
e = hl.GobDecode(bts)
if e != nil {
return
}
}
return hl, nil
}
// NewSet generates a new Set and returns it
func NewSet(name string, tags []string) *Set {
// error is only returned if precision is outside the 4-18 range
// TODO: this is the maximum precision, should it be configurable?
hll, _ := hyperloglog.NewPlus(18)
return &Set{
name: name,
tags: tags,
hll: hll,
}
}
func (s *Set) Flush() {
s.HLL.HyperLogLogPlus, _ = hll.NewPlus(configHLLPrecision)
s.Count = 0
}