refactor: use strings.Builder to improve performance

backend/s3/providers.go

@@ -178,7 +178,7 @@ func constructProviders(options fs.Options, providerMap map[string]*Provider) st
 		}
 	}
 
-	var providerList string
+	var providerList strings.Builder
 
 	for _, p := range providers {
 		for i := range options {
@@ -189,7 +189,7 @@ func constructProviders(options fs.Options, providerMap map[string]*Provider) st
 					Value: p.Name,
 					Help:  p.Description,
 				})
-				providerList += p.Name + ", "
+				providerList.WriteString(p.Name + ", ")
 			case "region":
 				addExample(opt, p, p.Region, defaults.Region)
 			case "endpoint":
@@ -232,5 +232,5 @@ func constructProviders(options fs.Options, providerMap map[string]*Provider) st
 		}
 	}
 
-	return strings.TrimSuffix(providerList, ", ")
+	return strings.TrimSuffix(providerList.String(), ", ")
 }

fs/asyncreader/asyncreader_test.go

@@ -150,13 +150,13 @@ func TestAsyncReaderSizes(t *testing.T) {
 
 	var texts [31]string
 	str := ""
-	all := ""
+	var all strings.Builder
 	for i := range len(texts) - 1 {
 		texts[i] = str + "\n"
-		all += texts[i]
+		all.WriteString(texts[i])
 		str += string(rune(i)%26 + 'a')
 	}
-	texts[len(texts)-1] = all
+	texts[len(texts)-1] = all.String()
 
 	for h := range len(texts) {
 		text := texts[h]
@@ -191,13 +191,13 @@ func TestAsyncReaderWriteTo(t *testing.T) {
 
 	var texts [31]string
 	str := ""
-	all := ""
+	var all strings.Builder
 	for i := range len(texts) - 1 {
 		texts[i] = str + "\n"
-		all += texts[i]
+		all.WriteString(texts[i])
 		str += string(rune(i)%26 + 'a')
 	}
-	texts[len(texts)-1] = all
+	texts[len(texts)-1] = all.String()
 
 	for h := range len(texts) {
 		text := texts[h]

fs/parseduration.go

@@ -158,11 +158,11 @@ func (d Duration) readableString(maxNumberOfUnits int) string {
 		return "0s"
 	}
 
-	readableString := ""
+	var readableString strings.Builder
 
 	// Check for minus durations.
 	if d < 0 {
-		readableString += "-"
+		readableString.WriteString("-")
 	}
 
 	duration := time.Duration(math.Abs(float64(d)))
@@ -205,14 +205,14 @@ func (d Duration) readableString(maxNumberOfUnits int) string {
 		if v == 0 {
 			continue
 		}
-		readableString += strval + u
+		readableString.WriteString(strval + u)
 		numberOfUnits++
 		if maxNumberOfUnits > 0 && numberOfUnits >= maxNumberOfUnits {
 			break
 		}
 	}
 
-	return readableString
+	return readableString.String()
 }
 
 // Set a Duration