del code related to last n lines

src/ledger/file.go

@@ -1,17 +1,13 @@
 package ledger
 
 import (
-	"bufio"
-	"bytes"
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
 	"sort"
-	"strings"
 	"unicode"
 )
 
@@ -65,89 +61,6 @@ func (files Files) Amend(old, now Delta) error {
 	return files.Add(transaction.payee, []Delta{old, now}...)
 }
 
-func (files Files) TempGetLastNLines(n int) ([]string, error) {
-	p := files.paths()[0]
-	f, err := os.Open(p)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	return peekLastNLines(io.Discard, bufio.NewReader(f), n)
-}
-
-func (files Files) TempSetLastNLines(n int, lines []string) error {
-	p := files.paths()[0]
-
-	newFile, err := func() (string, error) {
-		w, err := ioutil.TempFile(os.TempDir(), path.Base(p))
-		if err != nil {
-			return "", err
-		}
-		defer w.Close()
-
-		r, err := os.Open(p)
-		if err != nil {
-			return "", err
-		}
-		defer r.Close()
-
-		if _, err := peekLastNLines(w, bufio.NewReader(r), n); err != nil {
-			return "", err
-		}
-		for i := range lines {
-			if len(strings.TrimSpace(lines[i])) == 0 {
-				continue
-			}
-			if _, err := fmt.Fprintln(w, lines[i]); err != nil {
-				return "", err
-			}
-		}
-		if err := w.Close(); err != nil {
-			return "", err
-		}
-		return w.Name(), nil
-	}()
-	if err != nil {
-		return err
-	}
-
-	r, err := os.Open(newFile)
-	if err != nil {
-		return err
-	}
-	defer r.Close()
-
-	w, err := os.Create(p)
-	if err != nil {
-		return err
-	}
-	defer w.Close()
-
-	_, err = io.Copy(w, r)
-	return err
-}
-
-func peekLastNLines(w io.Writer, r *bufio.Reader, n int) ([]string, error) {
-	lastNLines := make([]string, 0, n)
-	for {
-		line, err := r.ReadBytes('\n')
-		if len(bytes.TrimSpace(line)) > 0 {
-			lastNLines = append(lastNLines, string(bytes.TrimRight(line, "\n")))
-			for i := 0; i < len(lastNLines)-n; i++ {
-				fmt.Fprintln(w, lastNLines[i])
-			}
-			lastNLines = lastNLines[max(0, len(lastNLines)-n):]
-		}
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return nil, err
-		}
-	}
-	return lastNLines, nil
-}
-
 func (files Files) paths() []string {
 	result := make([]string, 0, len(files))
 	for i := range files {