Optimized memory usage; Reducing memory fragmentation

main.go

@@ -3,6 +3,9 @@ package main
 import (
 	"os"
 	"os/signal"
+	"runtime"
+	"runtime/debug"
+	"time"
 
 	"net/http"
 	_ "net/http/pprof"
@@ -13,6 +16,20 @@ const version = "2.1.5"
 type ctxKey string
 
 func main() {
+	go func() {
+		var logMemStats = len(os.Getenv("IMGPROXY_LOG_MEM_STATS")) > 0
+
+		for range time.Tick(time.Duration(conf.FreeMemoryInterval) * time.Second) {
+			debug.FreeOSMemory()
+
+			if logMemStats {
+				var m runtime.MemStats
+				runtime.ReadMemStats(&m)
+				logNotice("[MEMORY USAGE] Sys: %d; HeapIdle: %d; HeapInuse: %d", m.Sys/1024/1024, m.HeapIdle/1024/1024, m.HeapInuse/1024/1024)
+			}
+		}
+	}()
+
 	if len(os.Getenv("IMGPROXY_PPROF_BIND")) > 0 {
 		go func() {
 			http.ListenAndServe(os.Getenv("IMGPROXY_PPROF_BIND"), nil)