compare low-level windows eof and check temporary flag

internal/agent/sftp/filelister.go

@@ -47,7 +47,7 @@ func (h *SftpHandler) FileLister(dirPath string) (*FileLister, error) {
 			}
 
 			fullPath := filepath.Join(dirPath, entry.Name())
-			if skipFile(fullPath) {
+			if h.skipFile(fullPath) {
 				continue
 			}
 			fileInfos = append(fileInfos, info)

internal/agent/sftp/filter.go

@@ -1,3 +1,5 @@
+//go:build windows
+
 package sftp
 
 import (
@@ -113,15 +115,32 @@ func compileExcludedPaths() []*regexp.Regexp {
 // Precompiled regex patterns for excluded paths
 var excludedPathRegexes = compileExcludedPaths()
 
-func skipFile(path string) bool {
-	normalizedPath := strings.TrimPrefix(path, "C:\\Windows\\TEMP\\pbs-plus-vss\\")
-	normalizedPath = strings.ToUpper(normalizedPath)
+func (h *SftpHandler) skipFile(path string) bool {
+	snapSplit := strings.Split(h.Snapshot.SnapshotPath, "\\")
+	snapRoot := strings.Join(snapSplit[:len(snapSplit)-1], "\\")
+
+	pathWithoutSnap := strings.TrimPrefix(path, snapRoot)
+	normalizedPath := strings.ToUpper(strings.TrimPrefix(pathWithoutSnap, "\\"))
+
+	if strings.TrimSpace(normalizedPath) == "" {
+		return false
+	}
 
 	for _, regex := range excludedPathRegexes {
 		if regex.MatchString(normalizedPath) {
 			return true
 		}
 	}
 
+	isTmp, err := isTemporary(path)
+	if err != nil || isTmp {
+		return true
+	}
+
+	probablyLocked, err := inconsistentSize(path)
+	if err != nil || probablyLocked {
+		return true
+	}
+
 	return false
 }

internal/agent/sftp/windows.go

@@ -0,0 +1,69 @@
+//go:build windows
+
+package sftp
+
+import (
+	"os"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+// FileStandardInfo contains extended information for the file.
+// FILE_STANDARD_INFO in WinBase.h
+// https://docs.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-file_standard_info
+type FileStandardInfo struct {
+	AllocationSize, EndOfFile int64
+	NumberOfLinks             uint32
+	DeletePending, Directory  bool
+}
+
+type FileAttributeTagInfo struct {
+	FileAttributes uint32
+	ReparseTag     uint32
+}
+
+func isTemporary(path string) (bool, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return true, err
+	}
+	defer file.Close()
+
+	at := &FileAttributeTagInfo{}
+	err = windows.GetFileInformationByHandleEx(windows.Handle(file.Fd()), windows.FileAttributeTagInfo, (*byte)(unsafe.Pointer(at)), uint32(unsafe.Sizeof(*at)))
+	if err != nil {
+		return true, err
+	}
+
+	if at.FileAttributes&windows.FILE_ATTRIBUTE_TEMPORARY == windows.FILE_ATTRIBUTE_TEMPORARY {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func inconsistentSize(path string) (bool, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return true, err
+	}
+	defer file.Close()
+
+	si := &FileStandardInfo{}
+	err = windows.GetFileInformationByHandleEx(windows.Handle(file.Fd()), windows.FileStandardInfo, (*byte)(unsafe.Pointer(si)), uint32(unsafe.Sizeof(*si)))
+	if err != nil {
+		return true, err
+	}
+
+	stat, err := os.Lstat(path)
+	if err != nil {
+		return true, err
+	}
+
+	if si.EndOfFile == stat.Size() {
+		return false, nil
+	}
+
+	return true, nil
+}