package scanner import ( "bytes" "errors" "io/ioutil" "log" "os" "path/filepath" "strings" "time" "github.com/calmh/syncthing/lamport" "github.com/calmh/syncthing/protocol" ) type Walker struct { // Dir is the base directory for the walk Dir string // BlockSize controls the size of the block used when hashing. BlockSize int // If IgnoreFile is not empty, it is the name used for the file that holds ignore patterns. IgnoreFile string // If TempNamer is not nil, it is used to ignore tempory files when walking. TempNamer TempNamer // If CurrentFiler is not nil, it is queried for the current file before rescanning. CurrentFiler CurrentFiler // If Suppressor is not nil, it is queried for supression of modified files. // Suppressed files will be returned with empty metadata and the Suppressed flag set. // Requires CurrentFiler to be set. Suppressor Suppressor suppressed map[string]bool // file name -> suppression status } type TempNamer interface { // Temporary returns a temporary name for the filed referred to by filepath. TempName(path string) string // IsTemporary returns true if path refers to the name of temporary file. IsTemporary(path string) bool } type Suppressor interface { // Supress returns true if the update to the named file should be ignored. Suppress(name string, fi os.FileInfo) bool } type CurrentFiler interface { // CurrentFile returns the file as seen at last scan. CurrentFile(name string) File } // Walk returns the list of files found in the local repository by scanning the // file system. Files are blockwise hashed. func (w *Walker) Walk() (files []File, ignore map[string][]string, err error) { w.lazyInit() if debug { dlog.Println("Walk", w.Dir, w.BlockSize, w.IgnoreFile) } err = checkDir(w.Dir) if err != nil { return } t0 := time.Now() ignore = make(map[string][]string) hashFiles := w.walkAndHashFiles(&files, ignore) filepath.Walk(w.Dir, w.loadIgnoreFiles(w.Dir, ignore)) filepath.Walk(w.Dir, hashFiles) if debug { t1 := time.Now() d := t1.Sub(t0).Seconds() dlog.Printf("Walk in %.02f ms, %.0f files/s", d*1000, float64(len(files))/d) } err = checkDir(w.Dir) return } // CleanTempFiles removes all files that match the temporary filename pattern. func (w *Walker) CleanTempFiles() { filepath.Walk(w.Dir, w.cleanTempFile) } func (w *Walker) lazyInit() { if w.suppressed == nil { w.suppressed = make(map[string]bool) } } func (w *Walker) loadIgnoreFiles(dir string, ign map[string][]string) filepath.WalkFunc { return func(p string, info os.FileInfo, err error) error { if err != nil { return nil } rn, err := filepath.Rel(dir, p) if err != nil { return nil } if pn, sn := filepath.Split(rn); sn == w.IgnoreFile { pn := strings.Trim(pn, "/") bs, _ := ioutil.ReadFile(p) lines := bytes.Split(bs, []byte("\n")) var patterns []string for _, line := range lines { if len(line) > 0 { patterns = append(patterns, string(line)) } } ign[pn] = patterns } return nil } } func (w *Walker) walkAndHashFiles(res *[]File, ign map[string][]string) filepath.WalkFunc { return func(p string, info os.FileInfo, err error) error { if err != nil { if debug { dlog.Println("error:", p, info, err) } return nil } rn, err := filepath.Rel(w.Dir, p) if err != nil { if debug { dlog.Println("rel error:", p, err) } return nil } if rn == "." { return nil } if w.TempNamer != nil && w.TempNamer.IsTemporary(rn) { // A temporary file if debug { dlog.Println("temporary:", rn) } return nil } if _, sn := filepath.Split(rn); sn == w.IgnoreFile { // An ignore-file; these are ignored themselves if debug { dlog.Println("ignorefile:", rn) } return nil } if w.ignoreFile(ign, rn) { // An ignored file if debug { dlog.Println("ignored:", rn) } if info.IsDir() { return filepath.SkipDir } return nil } if info.Mode().IsDir() { if w.CurrentFiler != nil { cf := w.CurrentFiler.CurrentFile(rn) if cf.Modified == info.ModTime().Unix() && cf.Flags == uint32(info.Mode()&os.ModePerm|protocol.FlagDirectory) { if debug { dlog.Println("unchanged:", cf) } *res = append(*res, cf) } else { f := File{ Name: rn, Version: lamport.Default.Tick(0), Flags: uint32(info.Mode()&os.ModePerm) | protocol.FlagDirectory, Modified: info.ModTime().Unix(), } if debug { dlog.Println("dir:", cf, f) } *res = append(*res, f) } return nil } } if info.Mode().IsRegular() { if w.CurrentFiler != nil { cf := w.CurrentFiler.CurrentFile(rn) if cf.Flags&protocol.FlagDeleted == 0 && cf.Modified == info.ModTime().Unix() { if debug { dlog.Println("unchanged:", cf) } *res = append(*res, cf) return nil } if w.Suppressor != nil && w.Suppressor.Suppress(rn, info) { if !w.suppressed[rn] { w.suppressed[rn] = true log.Printf("INFO: Changes to %q are being temporarily suppressed because it changes too frequently.", p) cf.Suppressed = true cf.Version++ } if debug { dlog.Println("suppressed:", cf) } *res = append(*res, cf) return nil } else if w.suppressed[rn] { log.Printf("INFO: Changes to %q are no longer suppressed.", p) delete(w.suppressed, rn) } } fd, err := os.Open(p) if err != nil { if debug { dlog.Println("open:", p, err) } return nil } defer fd.Close() t0 := time.Now() blocks, err := Blocks(fd, w.BlockSize) if err != nil { if debug { dlog.Println("hash error:", rn, err) } return nil } if debug { t1 := time.Now() dlog.Println("hashed:", rn, ";", len(blocks), "blocks;", info.Size(), "bytes;", int(float64(info.Size())/1024/t1.Sub(t0).Seconds()), "KB/s") } f := File{ Name: rn, Version: lamport.Default.Tick(0), Size: info.Size(), Flags: uint32(info.Mode()), Modified: info.ModTime().Unix(), Blocks: blocks, } *res = append(*res, f) } return nil } } func (w *Walker) cleanTempFile(path string, info os.FileInfo, err error) error { if err != nil { return err } if info.Mode()&os.ModeType == 0 && w.TempNamer.IsTemporary(path) { os.Remove(path) } return nil } func (w *Walker) ignoreFile(patterns map[string][]string, file string) bool { first, last := filepath.Split(file) for prefix, pats := range patterns { if len(prefix) == 0 || prefix == first || strings.HasPrefix(first, prefix+"/") { for _, pattern := range pats { if match, _ := filepath.Match(pattern, last); match { return true } } } } return false } func checkDir(dir string) error { if info, err := os.Stat(dir); err != nil { return err } else if !info.IsDir() { return errors.New(dir + ": not a directory") } return nil }