Add a global option to print memory usage

This option, -print-memory-usage, will print memory usage every second while
the program is running.

duplicacy/duplicacy_main.go

@@ -147,6 +147,10 @@ func setGlobalOptions(context *cli.Context) {
 		duplicacy.SetLoggingLevel(duplicacy.DEBUG)
 	}
 
+	if context.GlobalBool("print-memory-usage") {
+		go duplicacy.PrintMemoryUsage()
+	}
+
 	ScriptEnabled = true
 	if context.GlobalBool("no-script") {
 		ScriptEnabled = false
@@ -2180,6 +2184,10 @@ func main() {
 			Usage: "suppress logs with the specified id",
 			Argument: "<id>",
 		},
+		cli.BoolFlag{
+			Name:  "print-memory-usage",
+			Usage: "print memory usage every second",
+		},
 	}
 
 	app.HideVersion = true

src/duplicacy_utils.go

@@ -14,6 +14,7 @@ import (
 	"strconv"
 	"strings"
 	"time"
+        "runtime"
 
 	"github.com/gilbertchen/gopass"
 	"golang.org/x/crypto/pbkdf2"
@@ -460,3 +461,16 @@ func AtoSize(sizeString string) int {
 
 	return size
 }
+
+func PrintMemoryUsage() {
+
+	for {
+		var m runtime.MemStats
+		runtime.ReadMemStats(&m)
+
+		LOG_INFO("MEMORY_STATS", "Currently allocated: %s, total allocated: %s, system memory: %s, number of GCs: %d",
+		         PrettySize(int64(m.Alloc)), PrettySize(int64(m.TotalAlloc)), PrettySize(int64(m.Sys)), m.NumGC)
+
+		time.Sleep(time.Second)
+	}
+}