lint: string concat in loops; token expires

* ref token-expires-in (idiomatic)
* other changes are strictly `perfsprint` linter - notable:
  - cos.JoinWords
  - logerr (backtrace)

Signed-off-by: Alex Aizman <[email protected]>

Author: alex-aizman

ais/htrun.go

@@ -1022,10 +1022,11 @@ func isBrowser(userAgent string) bool {
 
 func (h *htrun) logerr(tag string, v any, err error) {
 	const maxl = 48
-	var efmt, msg string
+	var efmt string
 	if nlog.Stopping() {
 		return
 	}
+
 	if v != nil {
 		efmt = fmt.Sprintf("message: {%+v", v)
 		if len(efmt) > maxl {
@@ -1035,18 +1036,29 @@ func (h *htrun) logerr(tag string, v any, err error) {
 		}
 	}
 	efmt = tag + " response error: %v, " + efmt + " at "
-	msg = fmt.Sprintf(efmt, err)
+
+	// build msg
+	var (
+		sb strings.Builder
+	)
+	sb.Grow(cos.KiB)
+	sb.WriteString(fmt.Sprintf(efmt, err))
+
 	for i := 1; i < 4; i++ {
 		_, file, line, ok := runtime.Caller(i)
 		if !ok {
 			break
 		}
 		if i > 1 {
-			msg += " <- "
+			sb.WriteString(" <- ")
 		}
 		f := filepath.Base(file)
-		msg += fmt.Sprintf("%s:%d", f, line)
+		sb.WriteString(f)
+		sb.WriteByte(':')
+		sb.WriteString(strconv.Itoa(line))
 	}
+	msg := sb.String()
+
 	if cos.IsErrBrokenPipe(err) { // client went away
 		nlog.Infoln("Warning: " + msg)
 	} else {

ais/test/xaction_test.go

@@ -5,6 +5,7 @@
 package integration_test
 
 import (
+	"strings"
 	"testing"
 	"time"
 
@@ -28,6 +29,16 @@ func TestXactionNotFound(t *testing.T) {
 	tools.CheckErrIsNotFound(t, err)
 }
 
+func _string(vec nl.StatusVec) string {
+	var sb strings.Builder
+	for _, ns := range vec {
+		sb.WriteString(ns.String())
+		sb.WriteString(", ")
+	}
+	s := sb.String()
+	return s[:max(0, len(s)-2)]
+}
+
 func TestXactionAllStatus(t *testing.T) {
 	tests := []struct {
 		running bool
@@ -51,7 +62,7 @@ func TestXactionAllStatus(t *testing.T) {
 				continue
 			}
 			if kind != apc.ActList {
-				tlog.Logln(vec.String())
+				tlog.Logln(_string(vec))
 			}
 			for _, ns := range vec {
 				tassert.Errorf(t, ns.Kind == kind, "kind %q vs %q", ns.Kind, kind)

bench/micro/hrw/helpers.go

@@ -61,9 +61,9 @@ func similarFileName(bucketName string, objNum int) string {
 // Duplicated on purpose to avoid dependency on any AIStore code.
 func randNodeID(randGen *rand.Rand) string {
 	randIP := ""
-	for range 3 {
-		randIP += strconv.Itoa(randGen.IntN(255)) + "."
-	}
+	randIP += strconv.Itoa(randGen.IntN(255)) + "."
+	randIP += strconv.Itoa(randGen.IntN(255)) + "."
+	randIP += strconv.Itoa(randGen.IntN(255)) + "."
 	randIP += strconv.Itoa(randGen.IntN(255))
 	cksum := onexxh.Checksum32S(cos.UnsafeB(randIP), xxHashSeed)
 	nodeID := strconv.Itoa(int(cksum & 0xfffff))

cmd/authn/tok/token.go

@@ -319,14 +319,13 @@ func (c *AISClaims) CheckPermissions(clusterID string, bck *cmn.Bck, perms apc.A
 //
 
 func expiresIn(tm time.Time) string {
-	now := time.Now()
-	if now.After(tm) {
+	dur := time.Until(tm)
+	if dur <= 0 {
 		return ErrTokenExpired.Error()
 	}
 	// round up
-	d := tm.Sub(now) / time.Second
-	d *= time.Second
-	return "token expires in " + d.String()
+	dur = dur.Round(time.Second)
+	return "token expires in " + dur.String()
 }
 
 func (c *AISClaims) aclForCluster(clusterID string) (perms apc.AccessAttrs, ok bool) {

cmd/cli/teb/mountpath.go

@@ -188,15 +188,20 @@ func _capStatus(tcdf fs.Tcdf) (s string) {
 }
 
 func _fmtMpathDisks(cdfs map[string]*fs.CDF, idx int) (s string) {
-	var next bool
+	var (
+		prefix = "\n" + strings.Repeat("\t", idx) + " "
+		sb     strings.Builder
+		next   bool
+	)
+	sb.Grow(len(cdfs) * 64) // estimate per CDF entry
 	for _, cdf := range cdfs {
 		if next {
-			s += "\n" + strings.Repeat("\t", idx) + " "
+			sb.WriteString(prefix)
 		}
-		s += cdf.FS.String()
+		sb.WriteString(cdf.FS.String())
 		next = true
 	}
-	return
+	return sb.String()
 }
 
 func _inclStatus(st StstMap) bool {

cmd/cli/teb/performance.go

@@ -343,9 +343,14 @@ func _metricToPrintedColName(mname string, cols []*header, metrics, n2n cos.StrK
 	if parts[l] == "total" { // latency; see related: `stats.LatencyToCounter`
 		l--
 	}
+	var sb strings.Builder
+	sb.Grow(32)
+	sb.WriteString(printedName)
 	for j := 1; j < l; j++ {
-		printedName += "-" + strings.ToUpper(parts[j])
+		sb.WriteByte('-')
+		sb.WriteString(strings.ToUpper(parts[j]))
 	}
+	printedName = sb.String()
 
 	// suffix
 	switch kind {

cmn/cos/log_module.go

@@ -7,6 +7,7 @@ package cos
 import (
 	"fmt"
 	"strconv"
+	"strings"
 
 	"github.com/NVIDIA/aistore/cmn/debug"
 )
@@ -80,21 +81,25 @@ func (l LogLevel) Validate() (err error) {
 
 func (l LogLevel) String() (s string) {
 	var (
-		ms             string
 		n              int
 		level, modules = l.Parse()
 	)
 	s = strconv.Itoa(level)
 	if modules == 0 {
 		return
 	}
+
+	var sb strings.Builder
+	sb.Grow(len(Mods) * 16)
 	for i, sm := range Mods {
 		if modules&(1<<i) != 0 {
-			ms += "," + sm
+			sb.WriteByte(',')
+			sb.WriteString(sm)
 			n++
 		}
 	}
+
 	debug.Assert(n > 0, fmt.Sprintf(ferl, string(l), level, modules))
-	s += " (module" + Plural(n) + ": " + ms[1:] + ")"
+	s += " (module" + Plural(n) + ": " + sb.String()[1:] + ")"
 	return
 }

cmn/cos/quantity.go

@@ -41,11 +41,14 @@ func ParseQuantity(quantity string) (ParsedQuantity, error) {
 		idx     int
 		number  string
 		parsedQ ParsedQuantity
+		sb      strings.Builder
 	)
 	quantity = strings.ReplaceAll(quantity, " ", "")
+	sb.Grow(len(quantity)) // at most all digits
 	for ; idx < len(quantity) && unicode.IsDigit(rune(quantity[idx])); idx++ {
-		number += string(quantity[idx])
+		sb.WriteByte(quantity[idx])
 	}
+	number = sb.String()
 
 	value, err := strconv.Atoi(number)
 	if err != nil {

cmn/cos/template.go

@@ -378,14 +378,16 @@ func ParseAtTemplate(template string) (pt ParsedTemplate, _ error) {
 			err    error
 			tr     = TemplateRange{}
 			left   = strings.IndexByte(template, '@')
+			sb     strings.Builder
 			number string
 		)
 		if left == -1 {
 			break
 		}
 		for left++; len(template) > left && unicode.IsDigit(rune(template[left])); left++ {
-			number += string(template[left])
+			sb.WriteByte(template[left])
 		}
+		number = sb.String()
 
 		tr.Start = 0
 		if tr.End, err = strconv.ParseInt(number, 10, 64); err != nil {

cmn/cos/url.go

@@ -72,17 +72,25 @@ func ReparseQuery(r *http.Request) {
 	r.URL.RawQuery = q.Encode()
 }
 
-// JoinWords uses forward slash to join any number of words into a single path.
-// Returned path is prefixed with a slash.
-func JoinWords(w string, words ...string) (path string) {
-	path = w
-	if path[0] != '/' {
-		path = "/" + path
+func JoinWords(w0 string, words ...string) (path string) {
+	debug.Assert(w0 != "")
+	var l = len(w0)
+	if w0[0] != '/' {
+		l++
 	}
-	for _, s := range words {
-		path += "/" + s
+	for _, w := range words {
+		l += 1 + len(w)
 	}
-	return
+	b := make([]byte, 0, l)
+	if w0[0] != '/' {
+		b = append(b, '/')
+	}
+	b = append(b, w0...)
+	for _, w := range words {
+		b = append(b, '/')
+		b = append(b, w...)
+	}
+	return UnsafeS(b)
 }
 
 // JoinPath joins two path elements that may (or may not) be prefixed/suffixed with a slash.