vetting and linting and some code restyling

15 files changed, 75 insertions, 45 deletions

diff --git a/internal/io/dlog/dlog.go b/internal/io/dlog/dlog.go
index 28e6882..da67585 100644
--- a/internal/io/dlog/dlog.go
+++ b/internal/io/dlog/dlog.go
@@ -82,7 +82,7 @@ func new(sourceProcess, sourcePackage source.Source) *DLog {
 	if err != nil {
 		panic(err)
 	}
-	strategy := loggers.GetStrategy(config.Common.LogStrategy)
+	strategy := loggers.NewStrategy(config.Common.LogStrategy)
 	loggerName := config.Common.Logger
 	level := newLevel(config.Common.LogLevel)
 
@@ -153,6 +153,7 @@ func (d *DLog) writeArgStrings(sb *strings.Builder, args []interface{}) {
 	}
 }
 
+// FatalPanic terminates the process with a fatal error.
 func (d *DLog) FatalPanic(args ...interface{}) {
 	d.log(Fatal, args)
 	d.Flush()
@@ -162,42 +163,51 @@ func (d *DLog) FatalPanic(args ...interface{}) {
 	panic(sb.String())
 }
 
+// Fatal logs a fatal error.
 func (d *DLog) Fatal(args ...interface{}) string {
 	return d.log(Fatal, args)
 }
 
+// Error logging.
 func (d *DLog) Error(args ...interface{}) string {
 	return d.log(Error, args)
 }
 
+// Warn logs a warning message.
 func (d *DLog) Warn(args ...interface{}) string {
 	return d.log(Warn, args)
 }
 
+// Info logging.
 func (d *DLog) Info(args ...interface{}) string {
 	return d.log(Info, args)
 }
 
+// Verbose logging.
 func (d *DLog) Verbose(args ...interface{}) string {
 	return d.log(Verbose, args)
 }
 
+// Debug logging.
 func (d *DLog) Debug(args ...interface{}) string {
 	return d.log(Debug, args)
 }
 
+// Trace logging.
 func (d *DLog) Trace(args ...interface{}) string {
 	_, file, line, _ := runtime.Caller(1)
 	args = append(args, fmt.Sprintf("at %s:%d", file, line))
 	return d.log(Trace, args)
 }
 
+// Devel used for development purpose only logging (e.g. "print" debugging).
 func (d *DLog) Devel(args ...interface{}) string {
 	_, file, line, _ := runtime.Caller(1)
 	args = append(args, fmt.Sprintf("at %s:%d", file, line))
 	return d.log(Devel, args)
 }
 
+// Raw message logging.
 func (d *DLog) Raw(message string) string {
 	if !config.Client.TermColorsEnable || !d.logger.SupportsColors() {
 		d.logger.Log(time.Now(), message)
@@ -207,6 +217,7 @@ func (d *DLog) Raw(message string) string {
 	return message
 }
 
+// Mapreduce logging.
 func (d *DLog) Mapreduce(table string, data map[string]interface{}) string {
 	args := make([]interface{}, len(data)+1)
 
@@ -251,6 +262,11 @@ func (d *DLog) Mapreduce(table string, data map[string]interface{}) string {
 	return d.log(Info, args)
 }
 
-func (d *DLog) Flush()  { d.logger.Flush() }
-func (d *DLog) Pause()  { d.logger.Pause() }
+// Flush the log buffers.
+func (d *DLog) Flush() { d.logger.Flush() }
+
+// Pause the logging.
+func (d *DLog) Pause() { d.logger.Pause() }
+
+// Resume the logging.
 func (d *DLog) Resume() { d.logger.Resume() }
diff --git a/internal/io/dlog/level.go b/internal/io/dlog/level.go
index 248ad83..0971094 100644
--- a/internal/io/dlog/level.go
+++ b/internal/io/dlog/level.go
@@ -7,6 +7,7 @@ import (
 
 type level int
 
+// Available log levels.
 const (
 	Fatal   level = iota
 	Error   level = iota
@@ -20,7 +21,8 @@ const (
 	All     level = iota
 )
 
-var allLevels = []level{Fatal, Error, Warn, Info, Default, Verbose, Debug, Devel, Trace, All}
+var allLevels = []level{Fatal, Error, Warn, Info, Default, Verbose, Debug,
+	Devel, Trace, All}
 
 func newLevel(l string) level {
 	switch strings.ToLower(l) {
@@ -73,6 +75,5 @@ func (l level) String() string {
 	case All:
 		return "ALL"
 	}
-
 	panic("Unknown log level " + fmt.Sprintf("%d", l))
 }
diff --git a/internal/io/dlog/loggers/factory.go b/internal/io/dlog/loggers/factory.go
index dda3ee6..415d7fb 100644
--- a/internal/io/dlog/loggers/factory.go
+++ b/internal/io/dlog/loggers/factory.go
@@ -9,11 +9,13 @@ import (
 var factoryMap map[string]Logger
 var factoryMutex sync.Mutex
 
+// Factory is there to retrieve a logger based on various settings.
 func Factory(sourceName, loggerName string, rotationStrategy Strategy) Logger {
 	factoryMutex.Lock()
 	defer factoryMutex.Unlock()
 
-	id := fmt.Sprintf("sourceName:%s,fileBase:%s,loggerName:%s", sourceName, rotationStrategy.FileBase, loggerName)
+	id := fmt.Sprintf("sourceName:%s,fileBase:%s,loggerName:%s", sourceName,
+		rotationStrategy.FileBase, loggerName)
 	if factoryMap == nil {
 		factoryMap = make(map[string]Logger)
 	}
@@ -36,10 +38,10 @@ func Factory(sourceName, loggerName string, rotationStrategy Strategy) Logger {
 			panic(fmt.Sprintf("Unsupported logger type '%s'", loggerName))
 		}
 	}
-
 	return singleton
 }
 
+// FactoryRotate invokes a log rotation of all loggers.
 func FactoryRotate() {
 	factoryMutex.Lock()
 	defer factoryMutex.Unlock()
diff --git a/internal/io/dlog/loggers/file.go b/internal/io/dlog/loggers/file.go
index 87280fd..94824fe 100644
--- a/internal/io/dlog/loggers/file.go
+++ b/internal/io/dlog/loggers/file.go
@@ -12,8 +12,7 @@ import (
 	"github.com/mimecast/dtail/internal/config"
 )
 
-type fileWriter struct {
-}
+type fileWriter struct{}
 
 type fileMessageBuf struct {
 	now     time.Time
@@ -35,7 +34,7 @@ type file struct {
 }
 
 func newFile(strategy Strategy) *file {
-	f := file{
+	return &file{
 		bufferCh: make(chan *fileMessageBuf, runtime.NumCPU()*100),
 		pauseCh:  make(chan struct{}),
 		resumeCh: make(chan struct{}),
@@ -43,16 +42,17 @@ func newFile(strategy Strategy) *file {
 		flushCh:  make(chan struct{}),
 		strategy: strategy,
 	}
-
-	return &f
 }
 
 func (f *file) Start(ctx context.Context, wg *sync.WaitGroup) {
 	f.mutex.Lock()
-	defer f.mutex.Unlock()
+	defer func() {
+		f.started = true
+		f.mutex.Unlock()
+	}()
 
-	// Logger already started from another Goroutine.
 	if f.started {
+		// Logger already started from another Goroutine.
 		wg.Done()
 		return
 	}
@@ -68,7 +68,6 @@ func (f *file) Start(ctx context.Context, wg *sync.WaitGroup) {
 
 	go func() {
 		defer wg.Done()
-
 		for {
 			select {
 			case m := <-f.bufferCh:
@@ -84,8 +83,6 @@ func (f *file) Start(ctx context.Context, wg *sync.WaitGroup) {
 			}
 		}
 	}()
-
-	f.started = true
 }
 
 func (f *file) Log(now time.Time, message string) {
diff --git a/internal/io/dlog/loggers/logger.go b/internal/io/dlog/loggers/logger.go
index c88900d..d4e85de 100644
--- a/internal/io/dlog/loggers/logger.go
+++ b/internal/io/dlog/loggers/logger.go
@@ -6,6 +6,7 @@ import (
 	"time"
 )
 
+// Logger is there to plug in your own log implementation.
 type Logger interface {
 	Log(now time.Time, message string)
 	LogWithColors(now time.Time, message, messageWithColors string)
diff --git a/internal/io/dlog/loggers/strategy.go b/internal/io/dlog/loggers/strategy.go
index a1b9355..25d10f0 100644
--- a/internal/io/dlog/loggers/strategy.go
+++ b/internal/io/dlog/loggers/strategy.go
@@ -5,19 +5,26 @@ import (
 	"path/filepath"
 )
 
+// Rotation is the actual strategy used for log rotation..
 type Rotation int
 
 const (
-	DailyRotation  Rotation = iota
+	// DailyRotation tells DTail to rotate its logs on a daily basis or on SIGHUP.
+	DailyRotation Rotation = iota
+	// SignalRotation tells DTail to rotate its logs only on SIGHUP.
 	SignalRotation Rotation = iota
 )
 
+// Strategy is a pair of the rotation and the file base.
 type Strategy struct {
+	// Rotation is the actual rotation strategy used.
 	Rotation Rotation
+	// FileBase can be a name (e.g. "dserver", "dmap") when signal rotation is used.
 	FileBase string
 }
 
-func GetStrategy(name string) Strategy {
+// NewStrategy returns the stratey based on its name.
+func NewStrategy(name string) Strategy {
 	switch name {
 	case "daily":
 		return Strategy{DailyRotation, ""}
diff --git a/internal/io/fs/catfile.go b/internal/io/fs/catfile.go
index 7f387bc..01c15ba 100644
--- a/internal/io/fs/catfile.go
+++ b/internal/io/fs/catfile.go
@@ -6,7 +6,9 @@ type CatFile struct {
 }
 
 // NewCatFile returns a new file catter.
-func NewCatFile(filePath string, globID string, serverMessages chan<- string, limiter chan struct{}) CatFile {
+func NewCatFile(filePath string, globID string, serverMessages chan<- string,
+	limiter chan struct{}) CatFile {
+
 	return CatFile{
 		readFile: readFile{
 			filePath:       filePath,
diff --git a/internal/io/fs/filereader.go b/internal/io/fs/filereader.go
index 0774837..7773142 100644
--- a/internal/io/fs/filereader.go
+++ b/internal/io/fs/filereader.go
@@ -7,7 +7,8 @@ import (
 	"github.com/mimecast/dtail/internal/regex"
 )
 
-// FileReader is the interface used on the dtail server to read/cat/grep/mapr... a file.
+// FileReader is the interface used on the dtail server to read/cat/grep/mapr...
+// a file.
 type FileReader interface {
 	Start(ctx context.Context, lines chan<- line.Line, re regex.Regex) error
 	FilePath() string
diff --git a/internal/io/fs/permissions/permission_linuxacl.go b/internal/io/fs/permissions/permission_linuxacl.go
index 7d2d7ca..904b90f 100644
--- a/internal/io/fs/permissions/permission_linuxacl.go
+++ b/internal/io/fs/permissions/permission_linuxacl.go
@@ -13,7 +13,7 @@ import (
 	"unsafe"
 )
 
-// ToRead checks whether user has Linux file system permissions to read a given file.
+// ToRead checks whether user has Linux file system permissions to read a file.
 func ToRead(user, filePath string) (bool, error) {
 	cUser := C.CString(user)
 	cFilePath := C.CString(filePath)
diff --git a/internal/io/fs/readfile.go b/internal/io/fs/readfile.go
index f128c07..92f85b6 100644
--- a/internal/io/fs/readfile.go
+++ b/internal/io/fs/readfile.go
@@ -42,7 +42,8 @@ type readFile struct {
 
 // String returns the string representation of the readFile
 func (f readFile) String() string {
-	return fmt.Sprintf("readFile(filePath:%s,globID:%s,retry:%v,canSkipLines:%v,seekEOF:%v)",
+	return fmt.Sprintf(
+		"readFile(filePath:%s,globID:%s,retry:%v,canSkipLines:%v,seekEOF:%v)",
 		f.filePath,
 		f.globID,
 		f.retry,
@@ -61,7 +62,9 @@ func (f readFile) Retry() bool {
 }
 
 // Start tailing a log file.
-func (f readFile) Start(ctx context.Context, lines chan<- line.Line, re regex.Regex) error {
+func (f readFile) Start(ctx context.Context, lines chan<- line.Line,
+	re regex.Regex) error {
+
 	dlog.Common.Debug("readFile", f)
 	defer func() {
 		select {
@@ -74,7 +77,8 @@ func (f readFile) Start(ctx context.Context, lines chan<- line.Line, re regex.Re
 	case f.limiter <- struct{}{}:
 	default:
 		select {
-		case f.serverMessages <- dlog.Common.Warn(f.filePath, f.globID, "Server limit reached. Queuing file..."):
+		case f.serverMessages <- dlog.Common.Warn(f.filePath, f.globID,
+			"Server limit reached. Queuing file..."):
 		case <-ctx.Done():
 			return nil
 		}
@@ -139,13 +143,11 @@ func (f readFile) makeReader(fd *os.File) (reader *bufio.Reader, err error) {
 	default:
 		reader = bufio.NewReader(fd)
 	}
-
 	return
 }
 
 func (f readFile) read(ctx context.Context, fd *os.File, rawLines chan *bytes.Buffer, truncate <-chan struct{}) error {
 	var offset uint64
-
 	reader, err := f.makeReader(fd)
 	if err != nil {
 		return err
@@ -193,7 +195,8 @@ func (f readFile) read(ctx context.Context, fd *os.File, rawLines chan *bytes.Bu
 		default:
 			if message.Len() >= lineLengthThreshold {
 				if !warnedAboutLongLine {
-					f.serverMessages <- dlog.Common.Warn(f.filePath, "Long log line, splitting into multiple lines")
+					f.serverMessages <- dlog.Common.Warn(f.filePath,
+						"Long log line, splitting into multiple lines")
 					warnedAboutLongLine = true
 				}
 				message.WriteString("\n")
@@ -210,9 +213,10 @@ func (f readFile) read(ctx context.Context, fd *os.File, rawLines chan *bytes.Bu
 }
 
 // Filter log lines matching a given regular expression.
-func (f readFile) filter(ctx context.Context, wg *sync.WaitGroup, rawLines <-chan *bytes.Buffer, lines chan<- line.Line, re regex.Regex) {
-	defer wg.Done()
+func (f readFile) filter(ctx context.Context, wg *sync.WaitGroup,
+	rawLines <-chan *bytes.Buffer, lines chan<- line.Line, re regex.Regex) {
 
+	defer wg.Done()
 	for {
 		select {
 		case line, ok := <-rawLines:
@@ -231,9 +235,10 @@ func (f readFile) filter(ctx context.Context, wg *sync.WaitGroup, rawLines <-cha
 	}
 }
 
-func (f readFile) transmittable(lineBytes *bytes.Buffer, length, capacity int, re regex.Regex) (line.Line, bool) {
-	var read line.Line
+func (f readFile) transmittable(lineBytes *bytes.Buffer, length, capacity int,
+	re regex.Regex) (line.Line, bool) {
 
+	var read line.Line
 	if !re.Match(lineBytes.Bytes()) {
 		f.updateLineNotMatched()
 		f.updateLineNotTransmitted()
@@ -254,7 +259,6 @@ func (f readFile) transmittable(lineBytes *bytes.Buffer, length, capacity int, r
 		Count:           f.totalLineCount(),
 		TransmittedPerc: f.transmittedPerc(),
 	}
-
 	return read, true
 }
 
@@ -267,7 +271,6 @@ func (f readFile) truncated(fd *os.File) (bool, error) {
 	if err != nil {
 		return true, err
 	}
-
 	// Can not open file at original path.
 	pathFd, err := os.Open(f.filePath)
 	if err != nil {
@@ -280,10 +283,8 @@ func (f readFile) truncated(fd *os.File) (bool, error) {
 	if err != nil {
 		return true, err
 	}
-
 	if curPos > pathPos {
 		return true, errors.New("File got truncated")
 	}
-
 	return false, nil
 }
diff --git a/internal/io/fs/tailfile.go b/internal/io/fs/tailfile.go
index 14994e5..b03b45d 100644
--- a/internal/io/fs/tailfile.go
+++ b/internal/io/fs/tailfile.go
@@ -6,7 +6,9 @@ type TailFile struct {
 }
 
 // NewTailFile returns a new file tailer.
-func NewTailFile(filePath string, globID string, serverMessages chan<- string, limiter chan struct{}) TailFile {
+func NewTailFile(filePath string, globID string, serverMessages chan<- string,
+	limiter chan struct{}) TailFile {
+
 	return TailFile{
 		readFile: readFile{
 			filePath:       filePath,
diff --git a/internal/io/pool/builder.go b/internal/io/pool/builder.go
index c9dc221..89fcf81 100644
--- a/internal/io/pool/builder.go
+++ b/internal/io/pool/builder.go
@@ -5,6 +5,8 @@ import (
 	"sync"
 )
 
+// BuilderBuffer is there to optimize memory allocations (DTail allocates a lot
+// of memory while reading log data otherwise)
 var BuilderBuffer = sync.Pool{
 	New: func() interface{} {
 		sb := strings.Builder{}
@@ -12,6 +14,7 @@ var BuilderBuffer = sync.Pool{
 	},
 }
 
+// RecycleBuilderBuffer recycles the buffer again.
 func RecycleBuilderBuffer(sb *strings.Builder) {
 	sb.Reset()
 	BuilderBuffer.Put(sb)
diff --git a/internal/io/pool/bytesbuffer.go b/internal/io/pool/bytesbuffer.go
index 0a159f5..3d48f2c 100644
--- a/internal/io/pool/bytesbuffer.go
+++ b/internal/io/pool/bytesbuffer.go
@@ -5,6 +5,8 @@ import (
 	"sync"
 )
 
+// BytesBuffer is there to optimize memory allocations. DTail otherwise allocates
+// a lot of memory while reading logs.
 var BytesBuffer = sync.Pool{
 	New: func() interface{} {
 		b := bytes.Buffer{}
@@ -13,6 +15,7 @@ var BytesBuffer = sync.Pool{
 	},
 }
 
+// RecycleBytesBuffer recycles the buffer again.
 func RecycleBytesBuffer(b *bytes.Buffer) {
 	b.Reset()
 	BytesBuffer.Put(b)
diff --git a/internal/io/prompt/prompt.go b/internal/io/prompt/prompt.go
index 7c3cdb5..e82132d 100644
--- a/internal/io/prompt/prompt.go
+++ b/internal/io/prompt/prompt.go
@@ -19,7 +19,8 @@ type Answer struct {
 	Callback func()
 	// Runs after Callback and after logging resumes
 	EndCallback func()
-	AskAgain    bool
+	// AskAgain can be used to not to ask again about the question.
+	AskAgain bool
 }
 
 // Prompt used for interactive user input.
@@ -30,7 +31,6 @@ type Prompt struct {
 
 func (p *Prompt) askString() string {
 	var sb strings.Builder
-
 	sb.WriteString(p.question)
 	sb.WriteString("? (")
 
@@ -41,7 +41,6 @@ func (p *Prompt) askString() string {
 
 	sb.WriteString(strings.Join(ax, ","))
 	sb.WriteString("): ")
-
 	return sb.String()
 }
 
@@ -68,7 +67,6 @@ func (p *Prompt) Ask() {
 			if a.Callback != nil {
 				a.Callback()
 			}
-
 			if !a.AskAgain {
 				dlog.Common.Resume()
 				if a.EndCallback != nil {
@@ -90,6 +88,5 @@ func (p *Prompt) answer(answerStr string) (*Answer, bool) {
 		default:
 		}
 	}
-
 	return nil, false
 }
diff --git a/internal/io/signal/signal.go b/internal/io/signal/signal.go
index 14056c4..584b59c 100644
--- a/internal/io/signal/signal.go
+++ b/internal/io/signal/signal.go
@@ -14,10 +14,8 @@ import (
 func InterruptCh(ctx context.Context) <-chan string {
 	sigIntCh := make(chan os.Signal)
 	gosignal.Notify(sigIntCh, os.Interrupt)
-
 	sigOtherCh := make(chan os.Signal)
 	gosignal.Notify(sigOtherCh, syscall.SIGHUP, syscall.SIGTERM, syscall.SIGQUIT)
-
 	statsCh := make(chan string)
 
 	go func() {
@@ -41,7 +39,6 @@ func InterruptCh(ctx context.Context) <-chan string {
 			}
 		}
 	}()
-
 	return statsCh
 }