Simplifies median calculation.

This commit is contained in:
James Phillips 2017-03-13 23:29:58 -07:00
parent 43d24b3ba0
commit 1cd3a8a107
No known key found for this signature in database
GPG Key ID: 77183E682AC5FC11
1 changed files with 7 additions and 11 deletions

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@ -240,7 +240,8 @@ func (r *Router) GetDatacentersByDistance() ([]string, error) {
r.RLock()
defer r.RUnlock()
// Calculate a median RTT to the servers in each datacenter, by area.
// Go through each area and aggregate the median RTT from the current
// server to the other servers in each datacenter.
dcs := make(map[string]float64)
for areaID, info := range r.areas {
index := make(map[string][]float64)
@ -275,13 +276,8 @@ func (r *Router) GetDatacentersByDistance() ([]string, error) {
// in the master map, since a given DC might appear in multiple
// areas.
for dc, rtts := range index {
var rtt float64
if len(rtts) > 0 {
sort.Float64s(rtts)
rtt = rtts[len(rtts)/2]
} else {
rtt = lib.ComputeDistance(coord, nil)
}
sort.Float64s(rtts)
rtt := rtts[len(rtts)/2]
current, ok := dcs[dc]
if !ok || (ok && rtt < current) {
@ -298,11 +294,11 @@ func (r *Router) GetDatacentersByDistance() ([]string, error) {
sort.Strings(names)
// Then stable sort by median RTT.
vec := make([]float64, 0, len(dcs))
rtts := make([]float64, 0, len(dcs))
for _, dc := range names {
vec = append(vec, dcs[dc])
rtts = append(rtts, dcs[dc])
}
sort.Stable(&datacenterSorter{names, vec})
sort.Stable(&datacenterSorter{names, rtts})
return names, nil
}