Move backup & save related stuff from Buffer to SharedBuffer

Various methods of Buffer should be rather methods of SharedBuffer. This
commit doesn't move all of them to SharedBuffer yet, only those that
need to be moved to SharedBuffer in order to be able to request creating
or removing backups in other SharedBuffer methods.

Author: dmaluka

internal/buffer/backup.go

@@ -34,13 +34,13 @@ Options: [r]ecover, [i]gnore, [a]bort: `
 
 const backupSeconds = 8
 
-var BackupCompleteChan chan *Buffer
+var BackupCompleteChan chan *SharedBuffer
 
 func init() {
-	BackupCompleteChan = make(chan *Buffer, 10)
+	BackupCompleteChan = make(chan *SharedBuffer, 10)
 }
 
-func (b *Buffer) RequestBackup() {
+func (b *SharedBuffer) RequestBackup() {
 	if !b.RequestedBackup {
 		select {
 		case backupRequestChan <- b:
@@ -51,20 +51,20 @@ func (b *Buffer) RequestBackup() {
 	}
 }
 
-func (b *Buffer) backupDir() string {
+func (b *SharedBuffer) backupDir() string {
 	backupdir, err := util.ReplaceHome(b.Settings["backupdir"].(string))
 	if backupdir == "" || err != nil {
 		backupdir = filepath.Join(config.ConfigDir, "backups")
 	}
 	return backupdir
 }
 
-func (b *Buffer) keepBackup() bool {
+func (b *SharedBuffer) keepBackup() bool {
 	return b.forceKeepBackup || b.Settings["permbackup"].(bool)
 }
 
 // Backup saves the current buffer to the backups directory
-func (b *Buffer) Backup() error {
+func (b *SharedBuffer) Backup() error {
 	if !b.Settings["backup"].(bool) || b.Path == "" || b.Type != BTDefault {
 		return nil
 	}
@@ -101,7 +101,7 @@ func (b *Buffer) Backup() error {
 }
 
 // RemoveBackup removes any backup file associated with this buffer
-func (b *Buffer) RemoveBackup() {
+func (b *SharedBuffer) RemoveBackup() {
 	if !b.Settings["backup"].(bool) || b.keepBackup() || b.Path == "" || b.Type != BTDefault {
 		return
 	}
@@ -111,7 +111,7 @@ func (b *Buffer) RemoveBackup() {
 
 // ApplyBackup applies the corresponding backup file to this buffer (if one exists)
 // Returns true if a backup was applied
-func (b *Buffer) ApplyBackup(fsize int64) (bool, bool) {
+func (b *SharedBuffer) ApplyBackup(fsize int64) (bool, bool) {
 	if b.Settings["backup"].(bool) && !b.Settings["permbackup"].(bool) && len(b.Path) > 0 && b.Type == BTDefault {
 		backupfile := util.DetermineEscapePath(b.backupDir(), b.AbsPath)
 		if info, err := os.Stat(backupfile); err == nil {

internal/buffer/buffer.go

@@ -123,6 +123,8 @@ type SharedBuffer struct {
 
 	// Hash of the original buffer -- empty if fastdirty is on
 	origHash [md5.Size]byte
+
+	fini int32
 }
 
 func (b *SharedBuffer) insert(pos Loc, value []byte) {
@@ -223,7 +225,6 @@ type Buffer struct {
 	*EventHandler
 	*SharedBuffer
 
-	fini        int32
 	cursors     []*Cursor
 	curCursor   int
 	StartCursor Loc

internal/buffer/save.go

@@ -47,11 +47,11 @@ type saveRequest struct {
 }
 
 var saveRequestChan chan saveRequest
-var backupRequestChan chan *Buffer
+var backupRequestChan chan *SharedBuffer
 
 func init() {
 	saveRequestChan = make(chan saveRequest, 10)
-	backupRequestChan = make(chan *Buffer, 10)
+	backupRequestChan = make(chan *SharedBuffer, 10)
 
 	go func() {
 		duration := backupSeconds * float64(time.Second)
@@ -116,7 +116,7 @@ func openFile(name string, withSudo bool) (wrappedFile, error) {
 	return wrappedFile{writeCloser, withSudo, screenb, cmd, sigChan}, nil
 }
 
-func (wf wrappedFile) Write(b *Buffer) (int, error) {
+func (wf wrappedFile) Write(b *SharedBuffer) (int, error) {
 	file := bufio.NewWriter(transform.NewWriter(wf.writeCloser, b.encoding.NewEncoder()))
 
 	b.Lock()
@@ -184,7 +184,7 @@ func (wf wrappedFile) Close() error {
 	return err
 }
 
-func (b *Buffer) overwriteFile(name string) (int, error) {
+func (b *SharedBuffer) overwriteFile(name string) (int, error) {
 	file, err := openFile(name, false)
 	if err != nil {
 		return 0, err
@@ -335,7 +335,7 @@ func (b *Buffer) saveToFile(filename string, withSudo bool, autoSave bool) error
 	return err
 }
 
-func (b *Buffer) writeBackup(path string) (string, error) {
+func (b *SharedBuffer) writeBackup(path string) (string, error) {
 	backupDir := b.backupDir()
 	if _, err := os.Stat(backupDir); err != nil {
 		if !errors.Is(err, fs.ErrNotExist) {
@@ -360,7 +360,7 @@ func (b *Buffer) writeBackup(path string) (string, error) {
 // contents of the file if it fails to write the new contents.
 // This means that the file is not overwritten directly but by writing to the
 // backup file first.
-func (b *Buffer) safeWrite(path string, withSudo bool, newFile bool) (int, error) {
+func (b *SharedBuffer) safeWrite(path string, withSudo bool, newFile bool) (int, error) {
 	file, err := openFile(path, withSudo)
 	if err != nil {
 		return 0, err