wttr.in/cmd/peakHandling.go
2020-06-01 14:18:03 +02:00

79 lines
1.6 KiB
Go

package main
import (
"log"
"net/http"
"sync"
"time"
"github.com/robfig/cron"
)
var peakRequest30 sync.Map
var peakRequest60 sync.Map
func initPeakHandling() {
c := cron.New()
// cronTime := fmt.Sprintf("%d,%d * * * *", 30-prefetchInterval/60, 60-prefetchInterval/60)
c.AddFunc("24 * * * *", prefetchPeakRequests30)
c.AddFunc("54 * * * *", prefetchPeakRequests60)
c.Start()
}
func savePeakRequest(cacheDigest string, r *http.Request) {
_, min, _ := time.Now().Clock()
if min == 30 {
peakRequest30.Store(cacheDigest, *r)
} else if min == 0 {
peakRequest60.Store(cacheDigest, *r)
}
}
func prefetchRequest(r *http.Request) {
processRequest(r)
}
func syncMapLen(sm *sync.Map) int {
count := 0
f := func(key, value interface{}) bool {
// Not really certain about this part, don't know for sure
// if this is a good check for an entry's existence
if key == "" {
return false
}
count++
return true
}
sm.Range(f)
return count
}
func prefetchPeakRequests(peakRequestMap *sync.Map) {
peakRequestLen := syncMapLen(peakRequestMap)
log.Printf("PREFETCH: Prefetching %d requests\n", peakRequestLen)
if peakRequestLen == 0 {
return
}
sleepBetweenRequests := time.Duration(prefetchInterval*1000/peakRequestLen) * time.Millisecond
peakRequestMap.Range(func(key interface{}, value interface{}) bool {
go func(r http.Request) {
prefetchRequest(&r)
}(value.(http.Request))
peakRequestMap.Delete(key)
time.Sleep(sleepBetweenRequests)
return true
})
}
func prefetchPeakRequests30() {
prefetchPeakRequests(&peakRequest30)
}
func prefetchPeakRequests60() {
prefetchPeakRequests(&peakRequest60)
}