refactor: factorization of the reset (#79)

flock.go

@@ -185,3 +185,12 @@ func (f *Flock) ensureFhState() {
 
 	f.fh = nil
 }
+
+func (f *Flock) reset() {
+	f.l = false
+	f.r = false
+
+	_ = f.fh.Close()
+
+	f.fh = nil
+}

flock_unix.go

@@ -56,7 +56,8 @@ func (f *Flock) lock(locked *bool, flag int) error {
 		defer f.ensureFhState()
 	}
 
-	if err := syscall.Flock(int(f.fh.Fd()), flag); err != nil {
+	err := syscall.Flock(int(f.fh.Fd()), flag)
+	if err != nil {
 		shouldRetry, reopenErr := f.reopenFDOnError(err)
 		if reopenErr != nil {
 			return reopenErr
@@ -66,7 +67,8 @@ func (f *Flock) lock(locked *bool, flag int) error {
 			return err
 		}
 
-		if err = syscall.Flock(int(f.fh.Fd()), flag); err != nil {
+		err = syscall.Flock(int(f.fh.Fd()), flag)
+		if err != nil {
 			return err
 		}
 	}
@@ -99,15 +101,12 @@ func (f *Flock) Unlock() error {
 	}
 
 	// Mark the file as unlocked.
-	if err := syscall.Flock(int(f.fh.Fd()), syscall.LOCK_UN); err != nil {
+	err := syscall.Flock(int(f.fh.Fd()), syscall.LOCK_UN)
+	if err != nil {
 		return err
 	}
 
-	_ = f.fh.Close()
-
-	f.l = false
-	f.r = false
-	f.fh = nil
+	f.reset()
 
 	return nil
 }
@@ -167,7 +166,8 @@ retry:
 	}
 
 	if !retried {
-		if shouldRetry, reopenErr := f.reopenFDOnError(err); reopenErr != nil {
+		shouldRetry, reopenErr := f.reopenFDOnError(err)
+		if reopenErr != nil {
 			return false, reopenErr
 		} else if shouldRetry {
 			retried = true
@@ -180,9 +180,8 @@ retry:
 
 // reopenFDOnError determines whether we should reopen the file handle in readwrite mode and try again.
 // This comes from `util-linux/sys-utils/flock.c`:
-//
-//	Since Linux 3.4 (commit 55725513)
-//	Probably NFSv4 where flock() is emulated by fcntl().
+// > Since Linux 3.4 (commit 55725513)
+// > Probably NFSv4 where flock() is emulated by fcntl().
 func (f *Flock) reopenFDOnError(err error) (bool, error) {
 	if !errors.Is(err, syscall.EIO) && !errors.Is(err, syscall.EBADF) {
 		return false, nil

flock_unix_variants.go

@@ -99,7 +99,8 @@ func (f *Flock) lock(locked *bool, flag lockType) error {
 		defer f.ensureFhState()
 	}
 
-	if _, err := f.doLock(waitLock, flag, true); err != nil {
+	_, err := f.doLock(waitLock, flag, true)
+	if err != nil {
 		return err
 	}
 
@@ -137,16 +138,19 @@ func (f *Flock) doLock(cmd cmdType, lt lockType, blocking bool) (bool, error) {
 
 	l := locks[ino]
 
-	if l.owner == f {
+	switch {
+	case l.owner == f:
 		// This file already owns the lock, but the call may change its lock type.
-	} else if l.owner == nil {
+	case l.owner == nil:
 		// No owner: it's ours now.
 		l.owner = f
-	} else if !blocking {
+
+	case !blocking:
 		// Already owned: cannot take the lock.
 		mu.Unlock()
 		return false, nil
-	} else {
+
+	default:
 		// Already owned: add a channel to wait on.
 		wait = make(chan *Flock)
 		l.queue = append(l.queue, wait)
@@ -188,11 +192,7 @@ func (f *Flock) Unlock() error {
 		return err
 	}
 
-	_ = f.fh.Close()
-
-	f.l = false
-	f.r = false
-	f.fh = nil
+	f.reset()
 
 	return nil
 }

flock_windows.go

@@ -6,6 +6,7 @@
 package flock
 
 import (
+	"errors"
 	"syscall"
 )
 
@@ -85,11 +86,7 @@ func (f *Flock) Unlock() error {
 		return errNo
 	}
 
-	_ = f.fh.Close()
-
-	f.l = false
-	f.r = false
-	f.fh = nil
+	f.reset()
 
 	return nil
 }
@@ -137,7 +134,7 @@ func (f *Flock) try(locked *bool, flag uint32) (bool, error) {
 
 	_, errNo := lockFileEx(syscall.Handle(f.fh.Fd()), flag|winLockfileFailImmediately, 0, 1, 0, &syscall.Overlapped{})
 	if errNo > 0 {
-		if errNo == ErrorLockViolation || errNo == syscall.ERROR_IO_PENDING {
+		if errors.Is(errNo, ErrorLockViolation) || errors.Is(errNo, syscall.ERROR_IO_PENDING) {
 			return false, nil
 		}