mirror of
https://github.com/octoleo/syncthing.git
synced 2024-12-23 03:18:59 +00:00
fa0101bd60
This changes the BEP protocol to use protocol buffer serialization instead of XDR, and therefore also the database format. The local discovery protocol is also updated to be protocol buffer format. GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3276 LGTM: AudriusButkevicius
603 lines
17 KiB
Go
603 lines
17 KiB
Go
// Copyright (C) 2014 The Syncthing Authors.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at http://mozilla.org/MPL/2.0/.
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package scanner
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import (
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"errors"
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"os"
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"path/filepath"
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"runtime"
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"strings"
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"sync/atomic"
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"time"
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"unicode/utf8"
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"github.com/rcrowley/go-metrics"
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"github.com/syncthing/syncthing/lib/events"
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"github.com/syncthing/syncthing/lib/ignore"
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"github.com/syncthing/syncthing/lib/osutil"
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"github.com/syncthing/syncthing/lib/protocol"
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"github.com/syncthing/syncthing/lib/symlinks"
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"golang.org/x/text/unicode/norm"
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)
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var maskModePerm os.FileMode
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func init() {
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if runtime.GOOS == "windows" {
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// There is no user/group/others in Windows' read-only
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// attribute, and all "w" bits are set in os.FileInfo
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// if the file is not read-only. Do not send these
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// group/others-writable bits to other devices in order to
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// avoid unexpected world-writable files on other platforms.
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maskModePerm = os.ModePerm & 0755
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} else {
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maskModePerm = os.ModePerm
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}
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}
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type Config struct {
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// Folder for which the walker has been created
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Folder string
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// Dir is the base directory for the walk
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Dir string
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// Limit walking to these paths within Dir, or no limit if Sub is empty
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Subs []string
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// BlockSize controls the size of the block used when hashing.
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BlockSize int
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// If Matcher is not nil, it is used to identify files to ignore which were specified by the user.
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Matcher *ignore.Matcher
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// If TempNamer is not nil, it is used to ignore temporary files when walking.
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TempNamer TempNamer
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// Number of hours to keep temporary files for
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TempLifetime time.Duration
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// If CurrentFiler is not nil, it is queried for the current file before rescanning.
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CurrentFiler CurrentFiler
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// If MtimeRepo is not nil, it is used to provide mtimes on systems that
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// don't support setting arbitrary mtimes.
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MtimeRepo MtimeRepo
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// If IgnorePerms is true, changes to permission bits will not be
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// detected. Scanned files will get zero permission bits and the
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// NoPermissionBits flag set.
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IgnorePerms bool
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// When AutoNormalize is set, file names that are in UTF8 but incorrect
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// normalization form will be corrected.
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AutoNormalize bool
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// Number of routines to use for hashing
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Hashers int
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// Our vector clock id
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ShortID protocol.ShortID
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// Optional progress tick interval which defines how often FolderScanProgress
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// events are emitted. Negative number means disabled.
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ProgressTickIntervalS int
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// Signals cancel from the outside - when closed, we should stop walking.
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Cancel chan struct{}
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}
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type TempNamer interface {
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// IsTemporary returns true if path refers to the name of temporary file.
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IsTemporary(path string) bool
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}
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type CurrentFiler interface {
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// CurrentFile returns the file as seen at last scan.
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CurrentFile(name string) (protocol.FileInfo, bool)
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}
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type MtimeRepo interface {
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// GetMtime returns a (possibly modified) actual mtime given a file name
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// and its on disk mtime.
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GetMtime(relPath string, mtime time.Time) time.Time
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}
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func Walk(cfg Config) (chan protocol.FileInfo, error) {
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w := walker{cfg}
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if w.CurrentFiler == nil {
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w.CurrentFiler = noCurrentFiler{}
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}
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if w.TempNamer == nil {
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w.TempNamer = noTempNamer{}
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}
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if w.MtimeRepo == nil {
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w.MtimeRepo = noMtimeRepo{}
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}
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return w.walk()
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}
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type walker struct {
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Config
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}
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// Walk returns the list of files found in the local folder by scanning the
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// file system. Files are blockwise hashed.
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func (w *walker) walk() (chan protocol.FileInfo, error) {
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l.Debugln("Walk", w.Dir, w.Subs, w.BlockSize, w.Matcher)
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err := checkDir(w.Dir)
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if err != nil {
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return nil, err
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}
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toHashChan := make(chan protocol.FileInfo)
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finishedChan := make(chan protocol.FileInfo)
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// A routine which walks the filesystem tree, and sends files which have
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// been modified to the counter routine.
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go func() {
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hashFiles := w.walkAndHashFiles(toHashChan, finishedChan)
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if len(w.Subs) == 0 {
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filepath.Walk(w.Dir, hashFiles)
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} else {
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for _, sub := range w.Subs {
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filepath.Walk(filepath.Join(w.Dir, sub), hashFiles)
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}
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}
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close(toHashChan)
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}()
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// We're not required to emit scan progress events, just kick off hashers,
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// and feed inputs directly from the walker.
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if w.ProgressTickIntervalS < 0 {
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newParallelHasher(w.Dir, w.BlockSize, w.Hashers, finishedChan, toHashChan, nil, nil, w.Cancel)
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return finishedChan, nil
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}
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// Defaults to every 2 seconds.
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if w.ProgressTickIntervalS == 0 {
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w.ProgressTickIntervalS = 2
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}
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ticker := time.NewTicker(time.Duration(w.ProgressTickIntervalS) * time.Second)
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// We need to emit progress events, hence we create a routine which buffers
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// the list of files to be hashed, counts the total number of
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// bytes to hash, and once no more files need to be hashed (chan gets closed),
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// start a routine which periodically emits FolderScanProgress events,
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// until a stop signal is sent by the parallel hasher.
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// Parallel hasher is stopped by this routine when we close the channel over
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// which it receives the files we ask it to hash.
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go func() {
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var filesToHash []protocol.FileInfo
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var total int64 = 1
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for file := range toHashChan {
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filesToHash = append(filesToHash, file)
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total += int64(file.Size)
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}
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realToHashChan := make(chan protocol.FileInfo)
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done := make(chan struct{})
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progress := newByteCounter()
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defer progress.Close()
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newParallelHasher(w.Dir, w.BlockSize, w.Hashers, finishedChan, realToHashChan, progress, done, w.Cancel)
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// A routine which actually emits the FolderScanProgress events
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// every w.ProgressTicker ticks, until the hasher routines terminate.
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go func() {
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for {
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select {
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case <-done:
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l.Debugln("Walk progress done", w.Dir, w.Subs, w.BlockSize, w.Matcher)
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ticker.Stop()
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return
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case <-ticker.C:
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current := progress.Total()
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rate := progress.Rate()
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l.Debugf("Walk %s %s current progress %d/%d at %.01f MB/s (%d%%)", w.Dir, w.Subs, current, total, rate/1024/1024, current*100/total)
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events.Default.Log(events.FolderScanProgress, map[string]interface{}{
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"folder": w.Folder,
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"current": current,
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"total": total,
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"rate": rate, // bytes per second
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})
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case <-w.Cancel:
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ticker.Stop()
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return
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}
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}
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}()
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loop:
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for _, file := range filesToHash {
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l.Debugln("real to hash:", file.Name)
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select {
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case realToHashChan <- file:
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case <-w.Cancel:
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break loop
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}
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}
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close(realToHashChan)
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}()
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return finishedChan, nil
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}
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func (w *walker) walkAndHashFiles(fchan, dchan chan protocol.FileInfo) filepath.WalkFunc {
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now := time.Now()
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return func(absPath string, info os.FileInfo, err error) error {
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// Return value used when we are returning early and don't want to
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// process the item. For directories, this means do-not-descend.
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var skip error // nil
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// info nil when error is not nil
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if info != nil && info.IsDir() {
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skip = filepath.SkipDir
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}
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if err != nil {
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l.Debugln("error:", absPath, info, err)
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return skip
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}
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relPath, err := filepath.Rel(w.Dir, absPath)
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if err != nil {
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l.Debugln("rel error:", absPath, err)
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return skip
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}
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if relPath == "." {
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return nil
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}
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mtime := w.MtimeRepo.GetMtime(relPath, info.ModTime())
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if w.TempNamer.IsTemporary(relPath) {
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// A temporary file
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l.Debugln("temporary:", relPath)
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if info.Mode().IsRegular() && mtime.Add(w.TempLifetime).Before(now) {
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os.Remove(absPath)
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l.Debugln("removing temporary:", relPath, mtime)
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}
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return nil
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}
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if sn := filepath.Base(relPath); sn == ".stignore" || sn == ".stfolder" ||
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strings.HasPrefix(relPath, ".stversions") || (w.Matcher != nil && w.Matcher.Match(relPath).IsIgnored()) {
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// An ignored file
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l.Debugln("ignored:", relPath)
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return skip
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}
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if !utf8.ValidString(relPath) {
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l.Warnf("File name %q is not in UTF8 encoding; skipping.", relPath)
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return skip
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}
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relPath, shouldSkip := w.normalizePath(absPath, relPath)
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if shouldSkip {
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return skip
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}
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switch {
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case info.Mode()&os.ModeSymlink == os.ModeSymlink:
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var shouldSkip bool
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shouldSkip, err = w.walkSymlink(absPath, relPath, dchan)
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if err == nil && shouldSkip {
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return skip
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}
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case info.Mode().IsDir():
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err = w.walkDir(relPath, info, mtime, dchan)
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case info.Mode().IsRegular():
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err = w.walkRegular(relPath, info, mtime, fchan)
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}
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return err
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}
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}
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func (w *walker) walkRegular(relPath string, info os.FileInfo, mtime time.Time, fchan chan protocol.FileInfo) error {
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curMode := uint32(info.Mode())
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if runtime.GOOS == "windows" && osutil.IsWindowsExecutable(relPath) {
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curMode |= 0111
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}
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// A file is "unchanged", if it
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// - exists
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// - has the same permissions as previously, unless we are ignoring permissions
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// - was not marked deleted (since it apparently exists now)
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// - had the same modification time as it has now
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// - was not a directory previously (since it's a file now)
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// - was not a symlink (since it's a file now)
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// - was not invalid (since it looks valid now)
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// - has the same size as previously
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cf, ok := w.CurrentFiler.CurrentFile(relPath)
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permUnchanged := w.IgnorePerms || !cf.HasPermissionBits() || PermsEqual(cf.Permissions, curMode)
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if ok && permUnchanged && !cf.IsDeleted() && cf.Modified == mtime.Unix() && !cf.IsDirectory() &&
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!cf.IsSymlink() && !cf.IsInvalid() && cf.Size == info.Size() {
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return nil
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}
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l.Debugln("rescan:", cf, mtime.Unix(), info.Mode()&os.ModePerm)
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f := protocol.FileInfo{
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Name: relPath,
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Type: protocol.FileInfoTypeFile,
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Version: cf.Version.Update(w.ShortID),
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Permissions: curMode & uint32(maskModePerm),
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NoPermissions: w.IgnorePerms,
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Modified: mtime.Unix(),
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Size: info.Size(),
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}
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l.Debugln("to hash:", relPath, f)
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select {
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case fchan <- f:
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case <-w.Cancel:
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return errors.New("cancelled")
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}
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return nil
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}
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func (w *walker) walkDir(relPath string, info os.FileInfo, mtime time.Time, dchan chan protocol.FileInfo) error {
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// A directory is "unchanged", if it
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// - exists
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// - has the same permissions as previously, unless we are ignoring permissions
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// - was not marked deleted (since it apparently exists now)
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// - was a directory previously (not a file or something else)
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// - was not a symlink (since it's a directory now)
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// - was not invalid (since it looks valid now)
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cf, ok := w.CurrentFiler.CurrentFile(relPath)
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permUnchanged := w.IgnorePerms || !cf.HasPermissionBits() || PermsEqual(cf.Permissions, uint32(info.Mode()))
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if ok && permUnchanged && !cf.IsDeleted() && cf.IsDirectory() && !cf.IsSymlink() && !cf.IsInvalid() {
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return nil
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}
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f := protocol.FileInfo{
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Name: relPath,
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Type: protocol.FileInfoTypeDirectory,
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Version: cf.Version.Update(w.ShortID),
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Permissions: uint32(info.Mode() & maskModePerm),
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NoPermissions: w.IgnorePerms,
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Modified: mtime.Unix(),
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}
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l.Debugln("dir:", relPath, f)
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select {
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case dchan <- f:
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case <-w.Cancel:
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return errors.New("cancelled")
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}
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return nil
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}
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// walkSymlinks returns true if the symlink should be skipped, or an error if
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// we should stop walking altogether. filepath.Walk isn't supposed to
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// transcend into symlinks at all, but there are rumours that this may have
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// happened anyway under some circumstances, possibly Windows reparse points
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// or something. Hence the "skip" return from this one.
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func (w *walker) walkSymlink(absPath, relPath string, dchan chan protocol.FileInfo) (skip bool, err error) {
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// If the target is a directory, do NOT descend down there. This will
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// cause files to get tracked, and removing the symlink will as a result
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// remove files in their real location.
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if !symlinks.Supported {
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return true, nil
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}
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// We always rehash symlinks as they have no modtime or
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// permissions. We check if they point to the old target by
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// checking that their existing blocks match with the blocks in
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// the index.
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target, targetType, err := symlinks.Read(absPath)
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if err != nil {
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l.Debugln("readlink error:", absPath, err)
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return true, nil
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}
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blocks, err := Blocks(strings.NewReader(target), w.BlockSize, 0, nil)
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if err != nil {
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l.Debugln("hash link error:", absPath, err)
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return true, nil
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}
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// A symlink is "unchanged", if
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// - it exists
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// - it wasn't deleted (because it isn't now)
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// - it was a symlink
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// - it wasn't invalid
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// - the symlink type (file/dir) was the same
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// - the block list (i.e. hash of target) was the same
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cf, ok := w.CurrentFiler.CurrentFile(relPath)
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if ok && !cf.IsDeleted() && cf.IsSymlink() && !cf.IsInvalid() && SymlinkTypeEqual(targetType, cf) && BlocksEqual(cf.Blocks, blocks) {
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return true, nil
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}
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f := protocol.FileInfo{
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Name: relPath,
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Type: SymlinkType(targetType),
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Version: cf.Version.Update(w.ShortID),
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Modified: 0,
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NoPermissions: true, // Symlinks don't have permissions of their own
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Blocks: blocks,
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}
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l.Debugln("symlink changedb:", absPath, f)
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select {
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case dchan <- f:
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case <-w.Cancel:
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return false, errors.New("cancelled")
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}
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return false, nil
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}
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// normalizePath returns the normalized relative path (possibly after fixing
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// it on disk), or skip is true.
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func (w *walker) normalizePath(absPath, relPath string) (normPath string, skip bool) {
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if runtime.GOOS == "darwin" {
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// Mac OS X file names should always be NFD normalized.
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normPath = norm.NFD.String(relPath)
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} else {
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// Every other OS in the known universe uses NFC or just plain
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// doesn't bother to define an encoding. In our case *we* do care,
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// so we enforce NFC regardless.
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normPath = norm.NFC.String(relPath)
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}
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if relPath != normPath {
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// The file name was not normalized.
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if !w.AutoNormalize {
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// We're not authorized to do anything about it, so complain and skip.
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l.Warnf("File name %q is not in the correct UTF8 normalization form; skipping.", relPath)
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return "", true
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}
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// We will attempt to normalize it.
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normalizedPath := filepath.Join(w.Dir, normPath)
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if _, err := osutil.Lstat(normalizedPath); os.IsNotExist(err) {
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// Nothing exists with the normalized filename. Good.
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if err = os.Rename(absPath, normalizedPath); err != nil {
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l.Infof(`Error normalizing UTF8 encoding of file "%s": %v`, relPath, err)
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return "", true
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}
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l.Infof(`Normalized UTF8 encoding of file name "%s".`, relPath)
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} else {
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// There is something already in the way at the normalized
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// file name.
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l.Infof(`File "%s" has UTF8 encoding conflict with another file; ignoring.`, relPath)
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return "", true
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}
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relPath = normPath
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}
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return normPath, false
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}
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func checkDir(dir string) error {
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if info, err := osutil.Lstat(dir); err != nil {
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return err
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} else if !info.IsDir() {
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return errors.New(dir + ": not a directory")
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} else {
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l.Debugln("checkDir", dir, info)
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}
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return nil
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}
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func PermsEqual(a, b uint32) bool {
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switch runtime.GOOS {
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case "windows":
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// There is only writeable and read only, represented for user, group
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// and other equally. We only compare against user.
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return a&0600 == b&0600
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default:
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// All bits count
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return a&0777 == b&0777
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}
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}
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func SymlinkTypeEqual(disk symlinks.TargetType, f protocol.FileInfo) bool {
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// If the target is missing, Unix never knows what type of symlink it is
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// and Windows always knows even if there is no target. Which means that
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|
// without this special check a Unix node would be fighting with a Windows
|
|
// node about whether or not the target is known. Basically, if you don't
|
|
// know and someone else knows, just accept it. The fact that you don't
|
|
// know means you are on Unix, and on Unix you don't really care what the
|
|
// target type is. The moment you do know, and if something doesn't match,
|
|
// that will propagate through the cluster.
|
|
switch disk {
|
|
case symlinks.TargetUnknown:
|
|
return true
|
|
case symlinks.TargetDirectory:
|
|
return f.Type == protocol.FileInfoTypeSymlinkDirectory
|
|
case symlinks.TargetFile:
|
|
return f.Type == protocol.FileInfoTypeSymlinkFile
|
|
}
|
|
panic("unknown symlink TargetType")
|
|
}
|
|
|
|
func SymlinkType(t symlinks.TargetType) protocol.FileInfoType {
|
|
switch t {
|
|
case symlinks.TargetFile:
|
|
return protocol.FileInfoTypeSymlinkFile
|
|
case symlinks.TargetDirectory:
|
|
return protocol.FileInfoTypeSymlinkDirectory
|
|
case symlinks.TargetUnknown:
|
|
return protocol.FileInfoTypeSymlinkUnknown
|
|
}
|
|
panic("unknown symlink TargetType")
|
|
}
|
|
|
|
// A byteCounter gets bytes added to it via Update() and then provides the
|
|
// Total() and one minute moving average Rate() in bytes per second.
|
|
type byteCounter struct {
|
|
total int64
|
|
metrics.EWMA
|
|
stop chan struct{}
|
|
}
|
|
|
|
func newByteCounter() *byteCounter {
|
|
c := &byteCounter{
|
|
EWMA: metrics.NewEWMA1(), // a one minute exponentially weighted moving average
|
|
stop: make(chan struct{}),
|
|
}
|
|
go c.ticker()
|
|
return c
|
|
}
|
|
|
|
func (c *byteCounter) ticker() {
|
|
// The metrics.EWMA expects clock ticks every five seconds in order to
|
|
// decay the average properly.
|
|
t := time.NewTicker(5 * time.Second)
|
|
for {
|
|
select {
|
|
case <-t.C:
|
|
c.Tick()
|
|
case <-c.stop:
|
|
t.Stop()
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *byteCounter) Update(bytes int64) {
|
|
atomic.AddInt64(&c.total, bytes)
|
|
c.EWMA.Update(bytes)
|
|
}
|
|
|
|
func (c *byteCounter) Total() int64 {
|
|
return atomic.LoadInt64(&c.total)
|
|
}
|
|
|
|
func (c *byteCounter) Close() {
|
|
close(c.stop)
|
|
}
|
|
|
|
// A no-op CurrentFiler
|
|
|
|
type noCurrentFiler struct{}
|
|
|
|
func (noCurrentFiler) CurrentFile(name string) (protocol.FileInfo, bool) {
|
|
return protocol.FileInfo{}, false
|
|
}
|
|
|
|
// A no-op TempNamer
|
|
|
|
type noTempNamer struct{}
|
|
|
|
func (noTempNamer) IsTemporary(path string) bool {
|
|
return false
|
|
}
|
|
|
|
// A no-op MtimeRepo
|
|
|
|
type noMtimeRepo struct{}
|
|
|
|
func (noMtimeRepo) GetMtime(relPath string, mtime time.Time) time.Time {
|
|
return mtime
|
|
}
|