Pull request: all: fix lint and naming issues

Merge in DNS/adguard-home from 2276-fix-lint to master

Updates #2276.

Squashed commit of the following:

commit 433f44cc7b674a20ed60a9d29466ba888b3ef66e
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Dec 7 14:14:28 2020 +0300

    querylog: improve code and documentation

commit 851df97d2a87de5e7180a502055ee6f1a6defdca
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Dec 4 20:36:32 2020 +0300

    all: fix lint and naming issues

internal/querylog/decode.go

@@ -12,7 +12,9 @@ import (
 	"github.com/miekg/dns"
 )
 
-var logEntryHandlers = map[string](func(t json.Token, ent *logEntry) error){
+type logEntryHandler (func(t json.Token, ent *logEntry) error)
+
+var logEntryHandlers = map[string]logEntryHandler{
 	"IP": func(t json.Token, ent *logEntry) error {
 		v, ok := t.(string)
 		if !ok {
@@ -203,16 +205,24 @@ func decodeLogEntry(ent *logEntry, str string) {
 		if _, ok := keyToken.(json.Delim); ok {
 			continue
 		}
-		key := keyToken.(string)
+
+		key, ok := keyToken.(string)
+		if !ok {
+			log.Debug("decodeLogEntry: keyToken is %T and not string", keyToken)
+			return
+		}
+
 		handler, ok := logEntryHandlers[key]
 		if !ok {
 			continue
 		}
+
 		val, err := dec.Token()
 		if err != nil {
 			return
 		}
-		if err := handler(val, ent); err != nil {
+
+		if err = handler(val, ent); err != nil {
 			log.Debug("decodeLogEntry err: %s", err)
 			return
 		}

internal/querylog/qlogfile.go

@@ -53,7 +53,7 @@ func NewQLogFile(path string) (*QLogFile, error) {
 	}, nil
 }
 
-// Seek performs binary search in the query log file looking for a record
+// SeekTS performs binary search in the query log file looking for a record
 // with the specified timestamp. Once the record is found, it sets
 // "position" so that the next ReadNext call returned that record.
 //
@@ -70,7 +70,7 @@ func NewQLogFile(path string) (*QLogFile, error) {
 // so that when we call "ReadNext" this line was returned.
 // * Depth of the search (how many times we compared timestamps).
 // * If we could not find it, it returns one of the errors described above.
-func (q *QLogFile) Seek(timestamp int64) (int64, int, error) {
+func (q *QLogFile) SeekTS(timestamp int64) (int64, int, error) {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 

internal/querylog/qlogfile_test.go

@@ -61,7 +61,7 @@ func TestQLogFileLarge(t *testing.T) {
 		line, err = q.ReadNext()
 		if err == nil {
 			assert.True(t, len(line) > 0)
-			read += 1
+			read++
 		}
 	}
 
@@ -96,12 +96,12 @@ func TestQLogFileSeekLargeFile(t *testing.T) {
 	testSeekLineQLogFile(t, q, count)
 
 	// CASE 5: Seek non-existent (too low)
-	_, _, err = q.Seek(123)
+	_, _, err = q.SeekTS(123)
 	assert.NotNil(t, err)
 
 	// CASE 6: Seek non-existent (too high)
 	ts, _ := time.Parse(time.RFC3339, "2100-01-02T15:04:05Z07:00")
-	_, _, err = q.Seek(ts.UnixNano())
+	_, _, err = q.SeekTS(ts.UnixNano())
 	assert.NotNil(t, err)
 
 	// CASE 7: "Almost" found
@@ -110,7 +110,7 @@ func TestQLogFileSeekLargeFile(t *testing.T) {
 	// ALMOST the record we need
 	timestamp := readQLogTimestamp(line) - 1
 	assert.NotEqual(t, uint64(0), timestamp)
-	_, depth, err := q.Seek(timestamp)
+	_, depth, err := q.SeekTS(timestamp)
 	assert.NotNil(t, err)
 	assert.True(t, depth <= int(math.Log2(float64(count))+3))
 }
@@ -142,12 +142,12 @@ func TestQLogFileSeekSmallFile(t *testing.T) {
 	testSeekLineQLogFile(t, q, count)
 
 	// CASE 5: Seek non-existent (too low)
-	_, _, err = q.Seek(123)
+	_, _, err = q.SeekTS(123)
 	assert.NotNil(t, err)
 
 	// CASE 6: Seek non-existent (too high)
 	ts, _ := time.Parse(time.RFC3339, "2100-01-02T15:04:05Z07:00")
-	_, _, err = q.Seek(ts.UnixNano())
+	_, _, err = q.SeekTS(ts.UnixNano())
 	assert.NotNil(t, err)
 
 	// CASE 7: "Almost" found
@@ -156,7 +156,7 @@ func TestQLogFileSeekSmallFile(t *testing.T) {
 	// ALMOST the record we need
 	timestamp := readQLogTimestamp(line) - 1
 	assert.NotEqual(t, uint64(0), timestamp)
-	_, depth, err := q.Seek(timestamp)
+	_, depth, err := q.SeekTS(timestamp)
 	assert.NotNil(t, err)
 	assert.True(t, depth <= int(math.Log2(float64(count))+3))
 }
@@ -168,7 +168,7 @@ func testSeekLineQLogFile(t *testing.T, q *QLogFile, lineNumber int) {
 	assert.NotEqual(t, uint64(0), ts)
 
 	// try seeking to that line now
-	pos, _, err := q.Seek(ts)
+	pos, _, err := q.SeekTS(ts)
 	assert.Nil(t, err)
 	assert.NotEqual(t, int64(0), pos)
 
@@ -249,7 +249,7 @@ func prepareTestFiles(dir string, filesCount, linesCount int) []string {
 		files[filesCount-j-1] = f.Name()
 
 		for i := 0; i < linesCount; i++ {
-			lineIP += 1
+			lineIP++
 			lineTime = lineTime.Add(time.Second)
 
 			ip := make(net.IP, 4)
@@ -284,7 +284,7 @@ func TestQLogSeek(t *testing.T) {
 
 	target, _ := time.Parse(time.RFC3339, "2020-08-31T18:44:25.376690873+03:00")
 
-	_, depth, err := q.Seek(target.UnixNano())
+	_, depth, err := q.SeekTS(target.UnixNano())
 	assert.Nil(t, err)
 	assert.Equal(t, 1, depth)
 }
@@ -313,7 +313,7 @@ func TestQLogSeek_ErrTSTooLate(t *testing.T) {
 	target, err := time.Parse(time.RFC3339, "2020-08-31T18:44:25.382540454+03:00")
 	assert.Nil(t, err)
 
-	_, depth, err := q.Seek(target.UnixNano() + int64(time.Second))
+	_, depth, err := q.SeekTS(target.UnixNano() + int64(time.Second))
 	assert.Equal(t, ErrTSTooLate, err)
 	assert.Equal(t, 2, depth)
 }
@@ -342,7 +342,7 @@ func TestQLogSeek_ErrTSTooEarly(t *testing.T) {
 	target, err := time.Parse(time.RFC3339, "2020-08-31T18:44:23.911246629+03:00")
 	assert.Nil(t, err)
 
-	_, depth, err := q.Seek(target.UnixNano() - int64(time.Second))
+	_, depth, err := q.SeekTS(target.UnixNano() - int64(time.Second))
 	assert.Equal(t, ErrTSTooEarly, err)
 	assert.Equal(t, 1, depth)
 }

internal/querylog/qlogreader.go

@@ -44,16 +44,13 @@ func NewQLogReader(files []string) (*QLogReader, error) {
 	}, nil
 }
 
-// Seek performs binary search of a query log record with the specified timestamp.
+// SeekTS performs binary search of a query log record with the specified
-// If the record is found, it sets QLogReader's position to point to that line,
+// timestamp.  If the record is found, it sets QLogReader's position to point to
-// so that the next ReadNext call returned this line.
+// that line, so that the next ReadNext call returned this line.
-//
+func (r *QLogReader) SeekTS(timestamp int64) (err error) {
-// Returns nil if the record is successfully found.
-// Returns an error if for some reason we could not find a record with the specified timestamp.
-func (r *QLogReader) Seek(timestamp int64) (err error) {
 	for i := len(r.qFiles) - 1; i >= 0; i-- {
 		q := r.qFiles[i]
-		_, _, err = q.Seek(timestamp)
+		_, _, err = q.SeekTS(timestamp)
 		if err == nil {
 			// Search is finished, and the searched element have
 			// been found. Update currentFile only, position is

internal/querylog/qlogreader_test.go

@@ -50,7 +50,7 @@ func TestQLogReaderOneFile(t *testing.T) {
 		line, err = r.ReadNext()
 		if err == nil {
 			assert.True(t, len(line) > 0)
-			read += 1
+			read++
 		}
 	}
 
@@ -83,7 +83,7 @@ func TestQLogReaderMultipleFiles(t *testing.T) {
 		line, err = r.ReadNext()
 		if err == nil {
 			assert.True(t, len(line) > 0)
-			read += 1
+			read++
 		}
 	}
 
@@ -147,7 +147,7 @@ func TestQLogReader_Seek(t *testing.T) {
 			timestamp, err := time.Parse(time.RFC3339Nano, tc.time)
 			assert.Nil(t, err)
 
-			err = r.Seek(timestamp.UnixNano())
+			err = r.SeekTS(timestamp.UnixNano())
 			assert.True(t, errors.Is(err, tc.want), err)
 		})
 	}
@@ -228,12 +228,12 @@ func TestQLogReaderSeek(t *testing.T) {
 	testSeekLineQLogReader(t, r, count)
 
 	// CASE 5: Seek non-existent (too low)
-	err = r.Seek(123)
+	err = r.SeekTS(123)
 	assert.NotNil(t, err)
 
 	// CASE 6: Seek non-existent (too high)
 	ts, _ := time.Parse(time.RFC3339, "2100-01-02T15:04:05Z07:00")
-	err = r.Seek(ts.UnixNano())
+	err = r.SeekTS(ts.UnixNano())
 	assert.NotNil(t, err)
 }
 
@@ -244,7 +244,7 @@ func testSeekLineQLogReader(t *testing.T, r *QLogReader, lineNumber int) {
 	assert.NotEqual(t, uint64(0), ts)
 
 	// try seeking to that line now
-	err = r.Seek(ts)
+	err = r.SeekTS(ts)
 	assert.Nil(t, err)
 
 	testLine, err := r.ReadNext()

internal/querylog/search.go

@@ -97,7 +97,7 @@ func (l *queryLog) searchFiles(params *searchParams) ([]*logEntry, time.Time, in
 	if params.olderThan.IsZero() {
 		err = r.SeekStart()
 	} else {
-		err = r.Seek(params.olderThan.UnixNano())
+		err = r.SeekTS(params.olderThan.UnixNano())
 		if err == nil {
 			// Read to the next record right away
 			// The one that was specified in the "oldest" param is not needed,
@@ -107,7 +107,7 @@ func (l *queryLog) searchFiles(params *searchParams) ([]*logEntry, time.Time, in
 	}
 
 	if err != nil {
-		log.Debug("Cannot Seek() to %v: %v", params.olderThan, err)
+		log.Debug("Cannot SeekTS() to %v: %v", params.olderThan, err)
 		return entries, oldest, 0
 	}
 

internal/stats/http.go

@@ -37,7 +37,13 @@ func (s *statsCtx) handleStats(w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.Header().Set("Content-Type", "application/json")
-	w.Write(data)
+
+	_, err = w.Write(data)
+	if err != nil {
+		httpError(r, w, http.StatusInternalServerError, "json encode: %s", err)
+
+		return
+	}
 }
 
 type config struct {

internal/stats/stats.go

@@ -1,5 +1,5 @@
-// Module for managing statistics for DNS filtering server
+// Package stats provides units for managing statistics of the filtering DNS
-
+// server.
 package stats
 
 import (

internal/update/update_test.go

@@ -88,16 +88,16 @@ func TestUpdateGetVersion(t *testing.T) {
 }
 
 func TestUpdate(t *testing.T) {
-	_ = os.Mkdir("aghtest", 0755)
+	_ = os.Mkdir("aghtest", 0o755)
 	defer func() {
 		_ = os.RemoveAll("aghtest")
 	}()
 
 	// create "current" files
-	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome", []byte("AdGuardHome"), 0755))
+	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome", []byte("AdGuardHome"), 0o755))
-	assert.Nil(t, ioutil.WriteFile("aghtest/README.md", []byte("README.md"), 0644))
+	assert.Nil(t, ioutil.WriteFile("aghtest/README.md", []byte("README.md"), 0o644))
-	assert.Nil(t, ioutil.WriteFile("aghtest/LICENSE.txt", []byte("LICENSE.txt"), 0644))
+	assert.Nil(t, ioutil.WriteFile("aghtest/LICENSE.txt", []byte("LICENSE.txt"), 0o644))
-	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome.yaml", []byte("AdGuardHome.yaml"), 0644))
+	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome.yaml", []byte("AdGuardHome.yaml"), 0o644))
 
 	// start server for returning package file
 	pkgData, err := ioutil.ReadFile("test/AdGuardHome.tar.gz")
@@ -151,16 +151,16 @@ func TestUpdate(t *testing.T) {
 }
 
 func TestUpdateWindows(t *testing.T) {
-	_ = os.Mkdir("aghtest", 0755)
+	_ = os.Mkdir("aghtest", 0o755)
 	defer func() {
 		_ = os.RemoveAll("aghtest")
 	}()
 
 	// create "current" files
-	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome.exe", []byte("AdGuardHome.exe"), 0755))
+	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome.exe", []byte("AdGuardHome.exe"), 0o755))
-	assert.Nil(t, ioutil.WriteFile("aghtest/README.md", []byte("README.md"), 0644))
+	assert.Nil(t, ioutil.WriteFile("aghtest/README.md", []byte("README.md"), 0o644))
-	assert.Nil(t, ioutil.WriteFile("aghtest/LICENSE.txt", []byte("LICENSE.txt"), 0644))
+	assert.Nil(t, ioutil.WriteFile("aghtest/LICENSE.txt", []byte("LICENSE.txt"), 0o644))
-	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome.yaml", []byte("AdGuardHome.yaml"), 0644))
+	assert.Nil(t, ioutil.WriteFile("aghtest/AdGuardHome.yaml", []byte("AdGuardHome.yaml"), 0o644))
 
 	// start server for returning package file
 	pkgData, err := ioutil.ReadFile("test/AdGuardHome.zip")

internal/update/updater.go

@@ -1,3 +1,4 @@
+// Package update provides an updater for AdGuardHome.
 package update
 
 import (
@@ -224,7 +225,7 @@ func (u *Updater) clean() {
 const MaxPackageFileSize = 32 * 1024 * 1024
 
 // Download package file and save it to disk
-func (u *Updater) downloadPackageFile(url string, filename string) error {
+func (u *Updater) downloadPackageFile(url, filename string) error {
 	resp, err := u.Client.Get(url)
 	if err != nil {
 		return fmt.Errorf("http request failed: %w", err)