From 4660c2e859d6c64a834f3114b3e40e2a85da195c Mon Sep 17 00:00:00 2001
From: Nicola Murino <nicola.murino@gmail.com>
Date: Thu, 25 Jul 2024 18:39:02 +0200
Subject: [PATCH] replace hand-written slice utilities with methods from slices
 package

SFTPGo depends on Go 1.22 so we can use slices package

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>
---
 internal/common/connection.go | 11 +++++------
 internal/util/util.go         |  9 ---------
 2 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/internal/common/connection.go b/internal/common/connection.go
index e7f9c9a8..713e386a 100644
--- a/internal/common/connection.go
+++ b/internal/common/connection.go
@@ -21,6 +21,7 @@ import (
 	"io/fs"
 	"os"
 	"path"
+	"slices"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -1827,7 +1828,7 @@ func (l *DirListerAt) Add(fi os.FileInfo) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
 
-	l.info = append(l.info, fi)
+	l.info = slices.Insert(l.info, 0, fi)
 }
 
 // ListAt implements sftp.ListerAt
@@ -1840,10 +1841,10 @@ func (l *DirListerAt) ListAt(f []os.FileInfo, _ int64) (int, error) {
 	}
 	if len(f) <= len(l.info) {
 		files := make([]os.FileInfo, 0, len(f))
-		for idx := len(l.info) - 1; idx >= 0; idx-- {
+		for idx := range l.info {
 			files = append(files, l.info[idx])
 			if len(files) == len(f) {
-				l.info = l.info[:idx]
+				l.info = l.info[idx+1:]
 				n := copy(f, files)
 				return n, nil
 			}
@@ -1865,9 +1866,7 @@ func (l *DirListerAt) Next(limit int) ([]os.FileInfo, error) {
 		}
 		files = l.user.FilterListDir(files, l.virtualPath)
 		if len(l.info) > 0 {
-			for _, fi := range l.info {
-				files = util.PrependFileInfo(files, fi)
-			}
+			files = slices.Concat(l.info, files)
 			l.info = nil
 		}
 		if err != nil || len(files) > 0 {
diff --git a/internal/util/util.go b/internal/util/util.go
index 54dd0bcd..0274d97d 100644
--- a/internal/util/util.go
+++ b/internal/util/util.go
@@ -809,15 +809,6 @@ func GetRedactedURL(rawurl string) string {
 	return u.Redacted()
 }
 
-// PrependFileInfo prepends a file info to a slice in an efficient way.
-// We, optimistically, assume that the slice has enough capacity
-func PrependFileInfo(files []os.FileInfo, info os.FileInfo) []os.FileInfo {
-	files = append(files, nil)
-	copy(files[1:], files)
-	files[0] = info
-	return files
-}
-
 // GetTLSVersion returns the TLS version for integer:
 // - 12 means TLS 1.2
 // - 13 means TLS 1.3