Pull request: all: get rid of labels

Merge in DNS/adguard-home from rm-labels to master

Squashed commit of the following:

commit 5e3688ed92b0f76a47078a55bc22c401422c914c
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Dec 9 17:46:50 2021 +0300

    all: imp code, docs

commit 123d1ec52d0037315e8de94ab5a26b48cf0bf984
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Dec 9 17:14:05 2021 +0300

    all: get rid of labels

internal/aghnet/hostscontainer.go

@@ -309,21 +309,22 @@ func (hp *hostsParser) parseLine(line string) (ip net.IP, hosts []string) {
 		return nil, nil
 	}
 
-loop:
 	for _, f := range fields[1:] {
 		switch hashIdx := strings.IndexByte(f, '#'); hashIdx {
-		case 0:
-			// The rest of the fields are a part of the comment so skip
-			// immediately.
-			break loop
 		case -1:
 			hosts = append(hosts, f)
+
+			continue
+		case 0:
+			// Go on.
 		default:
 			// Only a part of the field is a comment.
 			hosts = append(hosts, f[:hashIdx])
-
-			break loop
 		}
+
+		// The rest of the fields are a part of the comment so skip
+		// immediately.
+		break
 	}
 
 	return ip, hosts

internal/aghos/os.go

@@ -91,7 +91,7 @@ func PIDByCommand(command string, except ...int) (pid int, err error) {
 	}
 
 	var instNum int
-	pid, instNum, err = parsePSOutput(stdout, command, except...)
+	pid, instNum, err = parsePSOutput(stdout, command, except)
 	if err != nil {
 		return 0, err
 	}
@@ -125,9 +125,8 @@ func PIDByCommand(command string, except ...int) (pid int, err error) {
 //   1230 some/base/path/example-cmd
 //   3210 example-cmd
 //
-func parsePSOutput(r io.Reader, cmdName string, ignore ...int) (largest, instNum int, err error) {
+func parsePSOutput(r io.Reader, cmdName string, ignore []int) (largest, instNum int, err error) {
 	s := bufio.NewScanner(r)
-ScanLoop:
 	for s.Scan() {
 		fields := strings.Fields(s.Text())
 		if len(fields) != 2 || path.Base(fields[1]) != cmdName {
@@ -135,16 +134,10 @@ ScanLoop:
 		}
 
 		cur, aerr := strconv.Atoi(fields[0])
-		if aerr != nil || cur < 0 {
+		if aerr != nil || cur < 0 || intIn(cur, ignore) {
 			continue
 		}
 
-		for _, pid := range ignore {
-			if cur == pid {
-				continue ScanLoop
-			}
-		}
-
 		instNum++
 		if cur > largest {
 			largest = cur
@@ -157,6 +150,17 @@ ScanLoop:
 	return largest, instNum, nil
 }
 
+// intIn returns true if nums contains n.
+func intIn(n int, nums []int) (ok bool) {
+	for _, nn := range nums {
+		if n == nn {
+			return true
+		}
+	}
+
+	return false
+}
+
 // IsOpenWrt returns true if host OS is OpenWrt.
 func IsOpenWrt() (ok bool) {
 	return isOpenWrt()

internal/aghos/os_test.go

@@ -63,7 +63,7 @@ func TestLargestLabeled(t *testing.T) {
 		r := bytes.NewReader(tc.data)
 
 		t.Run(tc.name, func(t *testing.T) {
-			pid, instNum, err := parsePSOutput(r, comm)
+			pid, instNum, err := parsePSOutput(r, comm, nil)
 			require.NoError(t, err)
 
 			assert.Equal(t, tc.wantPID, pid)
@@ -76,7 +76,7 @@ func TestLargestLabeled(t *testing.T) {
 		require.NoError(t, err)
 
 		target := &aghio.LimitReachedError{}
-		_, _, err = parsePSOutput(lr, "")
+		_, _, err = parsePSOutput(lr, "", nil)
 		require.ErrorAs(t, err, &target)
 
 		assert.EqualValues(t, 0, target.Limit)
@@ -89,7 +89,7 @@ func TestLargestLabeled(t *testing.T) {
 			`3` + comm + nl,
 		))
 
-		pid, instances, err := parsePSOutput(r, comm, 1, 3)
+		pid, instances, err := parsePSOutput(r, comm, []int{1, 3})
 		require.NoError(t, err)
 
 		assert.Equal(t, 2, pid)