Improve disk performance with buffered io

internal/buffer/line_array.go

@@ -224,7 +224,7 @@ func (la *LineArray) split(pos Loc) {
 
 // removes from start to end
 func (la *LineArray) remove(start, end Loc) []byte {
-	// sub := la.Substr(start, end)
+	sub := la.Substr(start, end)
 	startX := runeToByteIndex(start.X, la.lines[start.Y].data)
 	endX := runeToByteIndex(end.X, la.lines[end.Y].data)
 	if start.Y == end.Y {
@@ -235,7 +235,7 @@ func (la *LineArray) remove(start, end Loc) []byte {
 		la.deleteFromStart(Loc{endX - 1, start.Y + 1})
 		la.joinLines(start.Y, start.Y+1)
 	}
-	return []byte{}
+	return sub
 }
 
 // deleteToEnd deletes from the end of a line to the position

internal/buffer/save.go

@@ -1,6 +1,7 @@
 package buffer
 
 import (
+	"bufio"
 	"bytes"
 	"errors"
 	"io"
@@ -55,7 +56,7 @@ func overwriteFile(name string, enc encoding.Encoding, fn func(io.Writer) error,
 		return
 	}
 
-	w := transform.NewWriter(writeCloser, enc.NewEncoder())
+	w := bufio.NewWriter(transform.NewWriter(writeCloser, enc.NewEncoder()))
 	err = fn(w)
 
 	if e := writeCloser.Close(); e != nil && err == nil {