// Handler of /api/2/pings/{origin}/{time} GET requests to retrieve the average
// `transfer_time_ms` for a specific `origin`, aggregated by hours. The first
// date is {time + 1 day} if way is set to "next" or {time - 1 day} if way is
// set to "prev".
func HandlerGetAvgPerHourDayShift(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
origin := vars["origin"]
start, err := time.Parse("2006-01-02 15:04:05 +0000 UTC", vars["time"])
way := vars["way"]
avgCollection := utils_json.NewAvgCollection(0)
if err == nil {
if way == "prev" {
start = start.AddDate(0, 0, -1)
avgCollection = connector.GetAverages(origin, start, time.Hour, 24)
} else if way == "next" {
start = start.AddDate(0, 0, +1)
avgCollection = connector.GetAverages(origin, start, time.Hour, 24)
}
}
utils_json.WriteAverages(w, avgCollection)
}
func (connector *InfluxConnector) GetAverages(
origin string,
start time.Time,
step time.Duration,
count int) *utils_json.AvgCollection {
avgCollection := utils_json.NewAvgCollection(count)
startUnix := start.Unix() * 1000000000
stepUnix := int64(step.Seconds()) * 1000000000
for i := 0; i < count; i++ {
query := fmt.Sprintf(
"SELECT MEAN(transfer_time_ms) FROM ping WHERE origin = '%s' AND time > %d AND time < %d",
origin,
startUnix,
startUnix+stepUnix,
)
res, err := connector.query(query)
if err != nil || len(res) == 0 {
log.Println("Cannot query an average transfer time from InfluxDB.")
}
avgCollection.Averages[i] = 0
avgCollection.Times[i] = start.String()
if len(res[0].Series) != 0 {
if meanItf := res[0].Series[0].Values[0][1]; meanItf != nil {
if f, err := meanItf.(json.Number).Float64(); err == nil {
avgCollection.Averages[i] = f
}
}
}
start = start.Add(step)
startUnix = startUnix + stepUnix
}
return avgCollection
}