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// +build windows
package godirwalk
import (
"fmt"
"os"
)
// Scanner is an iterator to enumerate the contents of a directory.
type Scanner struct {
osDirname string
childName string
dh *os.File // dh is handle to open directory
de *Dirent
err error // err is the error associated with scanning directory
childMode os.FileMode
}
// NewScanner returns a new directory Scanner that lazily enumerates the
// contents of a single directory.
//
// scanner, err := godirwalk.NewScanner(dirname)
// if err != nil {
// fatal("cannot scan directory: %s", err)
// }
//
// for scanner.Scan() {
// dirent, err := scanner.Dirent()
// if err != nil {
// warning("cannot get dirent: %s", err)
// continue
// }
// name := dirent.Name()
// if name == "break" {
// break
// }
// if name == "continue" {
// continue
// }
// fmt.Printf("%v %v\n", dirent.ModeType(), dirent.Name())
// }
// if err := scanner.Err(); err != nil {
// fatal("cannot scan directory: %s", err)
// }
func NewScanner(osDirname string) (*Scanner, error) {
dh, err := os.Open(osDirname)
if err != nil {
return nil, err
}
scanner := &Scanner{
osDirname: osDirname,
dh: dh,
}
return scanner, nil
}
// NewScannerWithScratchBuffer returns a new directory Scanner that lazily
// enumerates the contents of a single directory. On platforms other than
// Windows it uses the provided scratch buffer to read from the file system. On
// Windows the scratch buffer parameter is ignored.
func NewScannerWithScratchBuffer(osDirname string, scratchBuffer []byte) (*Scanner, error) {
return NewScanner(osDirname)
}
// Dirent returns the current directory entry while scanning a directory.
func (s *Scanner) Dirent() (*Dirent, error) {
if s.de == nil {
s.de = &Dirent{
name: s.childName,
path: s.osDirname,
modeType: s.childMode,
}
}
return s.de, nil
}
// done is called when directory scanner unable to continue, with either the
// triggering error, or nil when there are simply no more entries to read from
// the directory.
func (s *Scanner) done(err error) {
if s.dh == nil {
return
}
if cerr := s.dh.Close(); err == nil {
s.err = cerr
}
s.childName, s.osDirname = "", ""
s.de, s.dh = nil, nil
}
// Err returns any error associated with scanning a directory. It is normal to
// call Err after Scan returns false, even though they both ensure Scanner
// resources are released. Do not call until done scanning a directory.
func (s *Scanner) Err() error {
s.done(nil)
return s.err
}
// Name returns the base name of the current directory entry while scanning a
// directory.
func (s *Scanner) Name() string { return s.childName }
// Scan potentially reads and then decodes the next directory entry from the
// file system.
//
// When it returns false, this releases resources used by the Scanner then
// returns any error associated with closing the file system directory resource.
func (s *Scanner) Scan() bool {
if s.dh == nil {
return false
}
s.de = nil
fileinfos, err := s.dh.Readdir(1)
if err != nil {
s.done(err)
return false
}
if l := len(fileinfos); l != 1 {
s.done(fmt.Errorf("expected a single entry rather than %d", l))
return false
}
fi := fileinfos[0]
s.childMode = fi.Mode() & os.ModeType
s.childName = fi.Name()
return true
}
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