syncthing/lib/model/rwfolder.go
Jakob Borg 42cc64e2ed
lib/config, lib/model: Auto adjust pullers based on desired amount of pending data (#4748)
This makes the number of pullers vary with the desired amount of outstanding requests instead of being a fixed number.
2018-02-25 10:14:02 +01:00

1966 lines
56 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package model
import (
"bytes"
"errors"
"fmt"
"math/rand"
"path/filepath"
"runtime"
"sort"
"strings"
stdsync "sync"
"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/db"
"github.com/syncthing/syncthing/lib/events"
"github.com/syncthing/syncthing/lib/fs"
"github.com/syncthing/syncthing/lib/ignore"
"github.com/syncthing/syncthing/lib/osutil"
"github.com/syncthing/syncthing/lib/protocol"
"github.com/syncthing/syncthing/lib/scanner"
"github.com/syncthing/syncthing/lib/sha256"
"github.com/syncthing/syncthing/lib/sync"
"github.com/syncthing/syncthing/lib/versioner"
"github.com/syncthing/syncthing/lib/weakhash"
)
var (
blockStats = make(map[string]int)
blockStatsMut = sync.NewMutex()
)
func init() {
folderFactories[config.FolderTypeSendReceive] = newSendReceiveFolder
}
// A pullBlockState is passed to the puller routine for each block that needs
// to be fetched.
type pullBlockState struct {
*sharedPullerState
block protocol.BlockInfo
}
// A copyBlocksState is passed to copy routine if the file has blocks to be
// copied.
type copyBlocksState struct {
*sharedPullerState
blocks []protocol.BlockInfo
have int
}
// Which filemode bits to preserve
const retainBits = fs.ModeSetgid | fs.ModeSetuid | fs.ModeSticky
var (
activity = newDeviceActivity()
errNoDevice = errors.New("peers who had this file went away, or the file has changed while syncing. will retry later")
errSymlinksUnsupported = errors.New("symlinks not supported")
errDirHasToBeScanned = errors.New("directory contains unexpected files, scheduling scan")
errDirHasIgnored = errors.New("directory contains ignored files (see ignore documentation for (?d) prefix)")
errDirNotEmpty = errors.New("directory is not empty")
)
const (
dbUpdateHandleDir = iota
dbUpdateDeleteDir
dbUpdateHandleFile
dbUpdateDeleteFile
dbUpdateShortcutFile
dbUpdateHandleSymlink
dbUpdateInvalidate
)
const (
defaultCopiers = 2
defaultPullerPause = 60 * time.Second
defaultPullerPendingKiB = 8192 // must be larger than block size
maxPullerIterations = 3
)
type dbUpdateJob struct {
file protocol.FileInfo
jobType int
}
type sendReceiveFolder struct {
folder
fs fs.Filesystem
versioner versioner.Versioner
pause time.Duration
queue *jobQueue
errors map[string]string // path -> error string
errorsMut sync.Mutex
}
func newSendReceiveFolder(model *Model, cfg config.FolderConfiguration, ver versioner.Versioner, fs fs.Filesystem) service {
f := &sendReceiveFolder{
folder: newFolder(model, cfg),
fs: fs,
versioner: ver,
queue: newJobQueue(),
errorsMut: sync.NewMutex(),
}
if f.Copiers == 0 {
f.Copiers = defaultCopiers
}
// If the configured max amount of pending data is zero, we use the
// default. If it's configured to something non-zero but less than the
// protocol block size we adjust it upwards accordingly.
if f.PullerMaxPendingKiB == 0 {
f.PullerMaxPendingKiB = defaultPullerPendingKiB
}
if blockSizeKiB := protocol.BlockSize / 1024; f.PullerMaxPendingKiB < blockSizeKiB {
f.PullerMaxPendingKiB = blockSizeKiB
}
f.pause = f.basePause()
return f
}
// Serve will run scans and pulls. It will return when Stop()ed or on a
// critical error.
func (f *sendReceiveFolder) Serve() {
l.Debugln(f, "starting")
defer l.Debugln(f, "exiting")
defer func() {
f.scan.timer.Stop()
// TODO: Should there be an actual FolderStopped state?
f.setState(FolderIdle)
}()
var prevIgnoreHash string
var success bool
pullFailTimer := time.NewTimer(time.Duration(0))
<-pullFailTimer.C
if f.FSWatcherEnabled && f.CheckHealth() == nil {
f.startWatch()
}
initialCompleted := f.initialScanFinished
for {
select {
case <-f.ctx.Done():
return
case <-f.pullScheduled:
pullFailTimer.Stop()
select {
case <-pullFailTimer.C:
default:
}
if prevIgnoreHash, success = f.pull(prevIgnoreHash); !success {
// Pulling failed, try again later.
pullFailTimer.Reset(f.pause)
}
case <-pullFailTimer.C:
if prevIgnoreHash, success = f.pull(prevIgnoreHash); !success {
// Pulling failed, try again later.
pullFailTimer.Reset(f.pause)
// Back off from retrying to pull with an upper limit.
if f.pause < 60*f.basePause() {
f.pause *= 2
}
}
case <-initialCompleted:
// Initial scan has completed, we should do a pull
initialCompleted = nil // never hit this case again
if prevIgnoreHash, success = f.pull(prevIgnoreHash); !success {
// Pulling failed, try again later.
pullFailTimer.Reset(f.pause)
}
// The reason for running the scanner from within the puller is that
// this is the easiest way to make sure we are not doing both at the
// same time.
case <-f.scan.timer.C:
l.Debugln(f, "Scanning subdirectories")
f.scanTimerFired()
case req := <-f.scan.now:
req.err <- f.scanSubdirs(req.subdirs)
case next := <-f.scan.delay:
f.scan.timer.Reset(next)
case fsEvents := <-f.watchChan:
l.Debugln(f, "filesystem notification rescan")
f.scanSubdirs(fsEvents)
case <-f.restartWatchChan:
f.restartWatch()
}
}
}
func (f *sendReceiveFolder) SchedulePull() {
select {
case f.pullScheduled <- struct{}{}:
default:
// We might be busy doing a pull and thus not reading from this
// channel. The channel is 1-buffered, so one notification will be
// queued to ensure we recheck after the pull, but beyond that we must
// make sure to not block index receiving.
}
}
func (f *sendReceiveFolder) String() string {
return fmt.Sprintf("sendReceiveFolder/%s@%p", f.folderID, f)
}
func (f *sendReceiveFolder) pull(prevIgnoreHash string) (curIgnoreHash string, success bool) {
select {
case <-f.initialScanFinished:
default:
// Once the initial scan finished, a pull will be scheduled
return prevIgnoreHash, true
}
if err := f.CheckHealth(); err != nil {
l.Debugln("Skipping pull of", f.Description(), "due to folder error:", err)
return prevIgnoreHash, true
}
f.model.fmut.RLock()
curIgnores := f.model.folderIgnores[f.folderID]
f.model.fmut.RUnlock()
curIgnoreHash = curIgnores.Hash()
ignoresChanged := curIgnoreHash != prevIgnoreHash
l.Debugf("%v pulling (ignoresChanged=%v)", f, ignoresChanged)
f.setState(FolderSyncing)
f.clearErrors()
scanChan := make(chan string)
go f.pullScannerRoutine(scanChan)
var changed int
tries := 0
for {
tries++
changed = f.pullerIteration(curIgnores, ignoresChanged, scanChan)
l.Debugln(f, "changed", changed)
if changed == 0 {
// No files were changed by the puller, so we are in
// sync. Update the local version number.
f.pause = f.basePause()
break
}
if tries == maxPullerIterations {
// We've tried a bunch of times to get in sync, but
// we're not making it. Probably there are write
// errors preventing us. Flag this with a warning and
// wait a bit longer before retrying.
if folderErrors := f.PullErrors(); len(folderErrors) > 0 {
events.Default.Log(events.FolderErrors, map[string]interface{}{
"folder": f.folderID,
"errors": folderErrors,
})
}
l.Infof("Folder %v isn't making progress. Pausing puller for %v.", f.Description(), f.pause)
l.Debugln(f, "next pull in", f.pause)
break
}
}
f.setState(FolderIdle)
close(scanChan)
if changed == 0 {
return curIgnoreHash, true
}
return prevIgnoreHash, false
}
// pullerIteration runs a single puller iteration for the given folder and
// returns the number items that should have been synced (even those that
// might have failed). One puller iteration handles all files currently
// flagged as needed in the folder.
func (f *sendReceiveFolder) pullerIteration(ignores *ignore.Matcher, ignoresChanged bool, scanChan chan<- string) int {
pullChan := make(chan pullBlockState)
copyChan := make(chan copyBlocksState)
finisherChan := make(chan *sharedPullerState)
dbUpdateChan := make(chan dbUpdateJob)
pullWg := sync.NewWaitGroup()
copyWg := sync.NewWaitGroup()
doneWg := sync.NewWaitGroup()
updateWg := sync.NewWaitGroup()
l.Debugln(f, "copiers:", f.Copiers, "pullerPendingKiB:", f.PullerMaxPendingKiB)
updateWg.Add(1)
go func() {
// dbUpdaterRoutine finishes when dbUpdateChan is closed
f.dbUpdaterRoutine(dbUpdateChan)
updateWg.Done()
}()
for i := 0; i < f.Copiers; i++ {
copyWg.Add(1)
go func() {
// copierRoutine finishes when copyChan is closed
f.copierRoutine(copyChan, pullChan, finisherChan)
copyWg.Done()
}()
}
pullWg.Add(1)
go func() {
// pullerRoutine finishes when pullChan is closed
f.pullerRoutine(pullChan, finisherChan)
pullWg.Done()
}()
doneWg.Add(1)
// finisherRoutine finishes when finisherChan is closed
go func() {
f.finisherRoutine(ignores, finisherChan, dbUpdateChan, scanChan)
doneWg.Done()
}()
f.model.fmut.RLock()
folderFiles := f.model.folderFiles[f.folderID]
f.model.fmut.RUnlock()
changed := 0
var processDirectly []protocol.FileInfo
// Iterate the list of items that we need and sort them into piles.
// Regular files to pull goes into the file queue, everything else
// (directories, symlinks and deletes) goes into the "process directly"
// pile.
folderFiles.WithNeed(protocol.LocalDeviceID, func(intf db.FileIntf) bool {
if f.IgnoreDelete && intf.IsDeleted() {
l.Debugln(f, "ignore file deletion (config)", intf.FileName())
return true
}
file := intf.(protocol.FileInfo)
switch {
case ignores.ShouldIgnore(file.Name):
file.Invalidate(f.shortID)
l.Debugln(f, "Handling ignored file", file)
dbUpdateChan <- dbUpdateJob{file, dbUpdateInvalidate}
case runtime.GOOS == "windows" && fs.WindowsInvalidFilename(file.Name):
f.newError("need", file.Name, fs.ErrInvalidFilename)
changed++
return true
case file.IsDeleted():
processDirectly = append(processDirectly, file)
changed++
case file.Type == protocol.FileInfoTypeFile:
// Queue files for processing after directories and symlinks, if
// it has availability.
devices := folderFiles.Availability(file.Name)
for _, dev := range devices {
if _, ok := f.model.Connection(dev); ok {
f.queue.Push(file.Name, file.Size, file.ModTime())
changed++
return true
}
}
l.Debugln(f, "Needed file is unavailable", file)
case runtime.GOOS == "windows" && file.IsSymlink():
file.Invalidate(f.shortID)
l.Debugln(f, "Invalidating symlink (unsupported)", file.Name)
dbUpdateChan <- dbUpdateJob{file, dbUpdateInvalidate}
default:
// Directories, symlinks
processDirectly = append(processDirectly, file)
changed++
}
return true
})
// Sort the "process directly" pile by number of path components. This
// ensures that we handle parents before children.
sort.Sort(byComponentCount(processDirectly))
// Process the list.
fileDeletions := map[string]protocol.FileInfo{}
dirDeletions := []protocol.FileInfo{}
buckets := map[string][]protocol.FileInfo{}
for _, fi := range processDirectly {
// Verify that the thing we are handling lives inside a directory,
// and not a symlink or empty space.
if err := osutil.TraversesSymlink(f.fs, filepath.Dir(fi.Name)); err != nil {
f.newError("traverses d", fi.Name, err)
continue
}
switch {
case fi.IsDeleted():
// A deleted file, directory or symlink
if fi.IsDirectory() {
// Perform directory deletions at the end, as we may have
// files to delete inside them before we get to that point.
dirDeletions = append(dirDeletions, fi)
} else {
fileDeletions[fi.Name] = fi
df, ok := f.model.CurrentFolderFile(f.folderID, fi.Name)
// Local file can be already deleted, but with a lower version
// number, hence the deletion coming in again as part of
// WithNeed, furthermore, the file can simply be of the wrong
// type if we haven't yet managed to pull it.
if ok && !df.IsDeleted() && !df.IsSymlink() && !df.IsDirectory() && !df.IsInvalid() {
// Put files into buckets per first hash
key := string(df.Blocks[0].Hash)
buckets[key] = append(buckets[key], df)
}
}
case fi.IsDirectory() && !fi.IsSymlink():
l.Debugln(f, "Handling directory", fi.Name)
f.handleDir(fi, dbUpdateChan)
case fi.IsSymlink():
l.Debugln("Handling symlink", fi.Name)
l.Debugln(f, "Handling symlink", fi.Name)
f.handleSymlink(fi, dbUpdateChan)
default:
l.Warnln(fi)
panic("unhandleable item type, can't happen")
}
}
// Now do the file queue. Reorder it according to configuration.
switch f.Order {
case config.OrderRandom:
f.queue.Shuffle()
case config.OrderAlphabetic:
// The queue is already in alphabetic order.
case config.OrderSmallestFirst:
f.queue.SortSmallestFirst()
case config.OrderLargestFirst:
f.queue.SortLargestFirst()
case config.OrderOldestFirst:
f.queue.SortOldestFirst()
case config.OrderNewestFirst:
f.queue.SortNewestFirst()
}
// Process the file queue.
nextFile:
for {
select {
case <-f.ctx.Done():
// Stop processing files if the puller has been told to stop.
break nextFile
default:
}
fileName, ok := f.queue.Pop()
if !ok {
break
}
fi, ok := f.model.CurrentGlobalFile(f.folderID, fileName)
if !ok {
// File is no longer in the index. Mark it as done and drop it.
f.queue.Done(fileName)
continue
}
if fi.IsDeleted() || fi.Type != protocol.FileInfoTypeFile {
// The item has changed type or status in the index while we
// were processing directories above.
f.queue.Done(fileName)
continue
}
dirName := filepath.Dir(fi.Name)
// Verify that the thing we are handling lives inside a directory,
// and not a symlink or empty space.
if err := osutil.TraversesSymlink(f.fs, dirName); err != nil {
f.newError("traverses q", fi.Name, err)
continue
}
// issues #114 and #4475: This works around a race condition
// between two devices, when one device removes a directory and the
// other creates a file in it. However that happens, we end up with
// a directory for "foo" with the delete bit, but a file "foo/bar"
// that we want to sync. We never create the directory, and hence
// fail to create the file and end up looping forever on it. This
// breaks that by creating the directory and scheduling a scan,
// where it will be found and the delete bit on it removed. The
// user can then clean up as they like...
if _, err := f.fs.Lstat(dirName); fs.IsNotExist(err) {
l.Debugln("%v resurrecting parent directory of %v", f, fi.Name)
if err := f.fs.MkdirAll(dirName, 0755); err != nil {
f.newError("resurrecting parent dir", fi.Name, err)
continue
}
scanChan <- dirName
}
// Check our list of files to be removed for a match, in which case
// we can just do a rename instead.
key := string(fi.Blocks[0].Hash)
for i, candidate := range buckets[key] {
if protocol.BlocksEqual(candidate.Blocks, fi.Blocks) {
// Remove the candidate from the bucket
lidx := len(buckets[key]) - 1
buckets[key][i] = buckets[key][lidx]
buckets[key] = buckets[key][:lidx]
// candidate is our current state of the file, where as the
// desired state with the delete bit set is in the deletion
// map.
desired := fileDeletions[candidate.Name]
// Remove the pending deletion (as we perform it by renaming)
delete(fileDeletions, candidate.Name)
f.renameFile(desired, fi, dbUpdateChan)
f.queue.Done(fileName)
continue nextFile
}
}
// Handle the file normally, by coping and pulling, etc.
f.handleFile(fi, copyChan, finisherChan, dbUpdateChan)
}
// Signal copy and puller routines that we are done with the in data for
// this iteration. Wait for them to finish.
close(copyChan)
copyWg.Wait()
close(pullChan)
pullWg.Wait()
// Signal the finisher chan that there will be no more input.
close(finisherChan)
// Wait for the finisherChan to finish.
doneWg.Wait()
for _, file := range fileDeletions {
l.Debugln(f, "Deleting file", file.Name)
f.deleteFile(file, dbUpdateChan)
}
for i := range dirDeletions {
dir := dirDeletions[len(dirDeletions)-i-1]
l.Debugln(f, "Deleting dir", dir.Name)
f.handleDeleteDir(dir, ignores, dbUpdateChan, scanChan)
}
// Wait for db updates and scan scheduling to complete
close(dbUpdateChan)
updateWg.Wait()
return changed
}
// handleDir creates or updates the given directory
func (f *sendReceiveFolder) handleDir(file protocol.FileInfo, dbUpdateChan chan<- dbUpdateJob) {
// Used in the defer closure below, updated by the function body. Take
// care not declare another err.
var err error
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": file.Name,
"type": "dir",
"action": "update",
})
defer func() {
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": file.Name,
"error": events.Error(err),
"type": "dir",
"action": "update",
})
}()
mode := fs.FileMode(file.Permissions & 0777)
if f.IgnorePerms || file.NoPermissions {
mode = 0777
}
if shouldDebug() {
curFile, _ := f.model.CurrentFolderFile(f.folderID, file.Name)
l.Debugf("need dir\n\t%v\n\t%v", file, curFile)
}
info, err := f.fs.Lstat(file.Name)
switch {
// There is already something under that name, but it's a file/link.
// Most likely a file/link is getting replaced with a directory.
// Remove the file/link and fall through to directory creation.
case err == nil && (!info.IsDir() || info.IsSymlink()):
err = osutil.InWritableDir(f.fs.Remove, f.fs, file.Name)
if err != nil {
f.newError("dir replace", file.Name, err)
return
}
fallthrough
// The directory doesn't exist, so we create it with the right
// mode bits from the start.
case err != nil && fs.IsNotExist(err):
// We declare a function that acts on only the path name, so
// we can pass it to InWritableDir. We use a regular Mkdir and
// not MkdirAll because the parent should already exist.
mkdir := func(path string) error {
err = f.fs.Mkdir(path, mode)
if err != nil || f.IgnorePerms || file.NoPermissions {
return err
}
// Stat the directory so we can check its permissions.
info, err := f.fs.Lstat(path)
if err != nil {
return err
}
// Mask for the bits we want to preserve and add them in to the
// directories permissions.
return f.fs.Chmod(path, mode|(info.Mode()&retainBits))
}
if err = osutil.InWritableDir(mkdir, f.fs, file.Name); err == nil {
dbUpdateChan <- dbUpdateJob{file, dbUpdateHandleDir}
} else {
f.newError("dir mkdir", file.Name, err)
}
return
// Weird error when stat()'ing the dir. Probably won't work to do
// anything else with it if we can't even stat() it.
case err != nil:
f.newError("dir stat", file.Name, err)
return
}
// The directory already exists, so we just correct the mode bits. (We
// don't handle modification times on directories, because that sucks...)
// It's OK to change mode bits on stuff within non-writable directories.
if f.IgnorePerms || file.NoPermissions {
dbUpdateChan <- dbUpdateJob{file, dbUpdateHandleDir}
} else if err := f.fs.Chmod(file.Name, mode|(fs.FileMode(info.Mode())&retainBits)); err == nil {
dbUpdateChan <- dbUpdateJob{file, dbUpdateHandleDir}
} else {
f.newError("dir chmod", file.Name, err)
}
}
// handleSymlink creates or updates the given symlink
func (f *sendReceiveFolder) handleSymlink(file protocol.FileInfo, dbUpdateChan chan<- dbUpdateJob) {
// Used in the defer closure below, updated by the function body. Take
// care not declare another err.
var err error
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": file.Name,
"type": "symlink",
"action": "update",
})
defer func() {
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": file.Name,
"error": events.Error(err),
"type": "symlink",
"action": "update",
})
}()
if shouldDebug() {
curFile, _ := f.model.CurrentFolderFile(f.folderID, file.Name)
l.Debugf("need symlink\n\t%v\n\t%v", file, curFile)
}
if len(file.SymlinkTarget) == 0 {
// Index entry from a Syncthing predating the support for including
// the link target in the index entry. We log this as an error.
err = errors.New("incompatible symlink entry; rescan with newer Syncthing on source")
f.newError("symlink", file.Name, err)
return
}
if _, err = f.fs.Lstat(file.Name); err == nil {
// There is already something under that name. Remove it to replace
// with the symlink. This also handles the "change symlink type"
// path.
err = osutil.InWritableDir(f.fs.Remove, f.fs, file.Name)
if err != nil {
f.newError("symlink remove", file.Name, err)
return
}
}
// We declare a function that acts on only the path name, so
// we can pass it to InWritableDir.
createLink := func(path string) error {
return f.fs.CreateSymlink(file.SymlinkTarget, path)
}
if err = osutil.InWritableDir(createLink, f.fs, file.Name); err == nil {
dbUpdateChan <- dbUpdateJob{file, dbUpdateHandleSymlink}
} else {
f.newError("symlink create", file.Name, err)
}
}
// handleDeleteDir attempts to remove a directory that was deleted on a remote
func (f *sendReceiveFolder) handleDeleteDir(file protocol.FileInfo, ignores *ignore.Matcher, dbUpdateChan chan<- dbUpdateJob, scanChan chan<- string) {
// Used in the defer closure below, updated by the function body. Take
// care not declare another err.
var err error
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": file.Name,
"type": "dir",
"action": "delete",
})
defer func() {
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": file.Name,
"error": events.Error(err),
"type": "dir",
"action": "delete",
})
}()
err = f.deleteDir(file.Name, ignores, scanChan)
if err != nil {
f.newError("delete dir", file.Name, err)
return
}
dbUpdateChan <- dbUpdateJob{file, dbUpdateDeleteDir}
}
// deleteFile attempts to delete the given file
func (f *sendReceiveFolder) deleteFile(file protocol.FileInfo, dbUpdateChan chan<- dbUpdateJob) {
// Used in the defer closure below, updated by the function body. Take
// care not declare another err.
var err error
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": file.Name,
"type": "file",
"action": "delete",
})
defer func() {
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": file.Name,
"error": events.Error(err),
"type": "file",
"action": "delete",
})
}()
cur, ok := f.model.CurrentFolderFile(f.folderID, file.Name)
if ok && f.inConflict(cur.Version, file.Version) {
// There is a conflict here. Move the file to a conflict copy instead
// of deleting. Also merge with the version vector we had, to indicate
// we have resolved the conflict.
file.Version = file.Version.Merge(cur.Version)
err = osutil.InWritableDir(func(name string) error {
return f.moveForConflict(name, file.ModifiedBy.String())
}, f.fs, file.Name)
} else if f.versioner != nil && !cur.IsSymlink() {
err = osutil.InWritableDir(f.versioner.Archive, f.fs, file.Name)
} else {
err = osutil.InWritableDir(f.fs.Remove, f.fs, file.Name)
}
if err == nil || fs.IsNotExist(err) {
// It was removed or it doesn't exist to start with
dbUpdateChan <- dbUpdateJob{file, dbUpdateDeleteFile}
} else if _, serr := f.fs.Lstat(file.Name); serr != nil && !fs.IsPermission(serr) {
// We get an error just looking at the file, and it's not a permission
// problem. Lets assume the error is in fact some variant of "file
// does not exist" (possibly expressed as some parent being a file and
// not a directory etc) and that the delete is handled.
dbUpdateChan <- dbUpdateJob{file, dbUpdateDeleteFile}
} else {
f.newError("delete file", file.Name, err)
}
}
// renameFile attempts to rename an existing file to a destination
// and set the right attributes on it.
func (f *sendReceiveFolder) renameFile(source, target protocol.FileInfo, dbUpdateChan chan<- dbUpdateJob) {
// Used in the defer closure below, updated by the function body. Take
// care not declare another err.
var err error
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": source.Name,
"type": "file",
"action": "delete",
})
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": target.Name,
"type": "file",
"action": "update",
})
defer func() {
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": source.Name,
"error": events.Error(err),
"type": "file",
"action": "delete",
})
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": target.Name,
"error": events.Error(err),
"type": "file",
"action": "update",
})
}()
l.Debugln(f, "taking rename shortcut", source.Name, "->", target.Name)
if f.versioner != nil {
err = osutil.Copy(f.fs, source.Name, target.Name)
if err == nil {
err = osutil.InWritableDir(f.versioner.Archive, f.fs, source.Name)
}
} else {
err = osutil.TryRename(f.fs, source.Name, target.Name)
}
if err == nil {
blockStatsMut.Lock()
blockStats["total"] += len(target.Blocks)
blockStats["renamed"] += len(target.Blocks)
blockStatsMut.Unlock()
// The file was renamed, so we have handled both the necessary delete
// of the source and the creation of the target. Fix-up the metadata,
// and update the local index of the target file.
dbUpdateChan <- dbUpdateJob{source, dbUpdateDeleteFile}
err = f.shortcutFile(target)
if err != nil {
err = fmt.Errorf("from %s: %s", source.Name, err.Error())
f.newError("rename shortcut", target.Name, err)
return
}
dbUpdateChan <- dbUpdateJob{target, dbUpdateHandleFile}
} else {
// We failed the rename so we have a source file that we still need to
// get rid of. Attempt to delete it instead so that we make *some*
// progress. The target is unhandled.
err = osutil.InWritableDir(f.fs.Remove, f.fs, source.Name)
if err != nil {
err = fmt.Errorf("from %s: %s", source.Name, err.Error())
f.newError("rename delete", target.Name, err)
return
}
dbUpdateChan <- dbUpdateJob{source, dbUpdateDeleteFile}
}
}
// This is the flow of data and events here, I think...
//
// +-----------------------+
// | | - - - - > ItemStarted
// | handleFile | - - - - > ItemFinished (on shortcuts)
// | |
// +-----------------------+
// |
// | copyChan (copyBlocksState; unless shortcut taken)
// |
// | +-----------------------+
// | | +-----------------------+
// +--->| | |
// | | copierRoutine |
// +-| |
// +-----------------------+
// |
// | pullChan (sharedPullerState)
// |
// | +-----------------------+
// | | +-----------------------+
// +-->| | |
// | | pullerRoutine |
// +-| |
// +-----------------------+
// |
// | finisherChan (sharedPullerState)
// |
// | +-----------------------+
// | | |
// +-->| finisherRoutine | - - - - > ItemFinished
// | |
// +-----------------------+
// handleFile queues the copies and pulls as necessary for a single new or
// changed file.
func (f *sendReceiveFolder) handleFile(file protocol.FileInfo, copyChan chan<- copyBlocksState, finisherChan chan<- *sharedPullerState, dbUpdateChan chan<- dbUpdateJob) {
curFile, hasCurFile := f.model.CurrentFolderFile(f.folderID, file.Name)
have, need := blockDiff(curFile.Blocks, file.Blocks)
if hasCurFile && len(need) == 0 {
// We are supposed to copy the entire file, and then fetch nothing. We
// are only updating metadata, so we don't actually *need* to make the
// copy.
l.Debugln(f, "taking shortcut on", file.Name)
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": file.Name,
"type": "file",
"action": "metadata",
})
f.queue.Done(file.Name)
err := f.shortcutFile(file)
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": file.Name,
"error": events.Error(err),
"type": "file",
"action": "metadata",
})
if err != nil {
f.newError("shortcut", file.Name, err)
} else {
dbUpdateChan <- dbUpdateJob{file, dbUpdateShortcutFile}
}
return
}
tempName := fs.TempName(file.Name)
populateOffsets(file.Blocks)
blocks := make([]protocol.BlockInfo, 0, len(file.Blocks))
var blocksSize int64
reused := make([]int32, 0, len(file.Blocks))
// Check for an old temporary file which might have some blocks we could
// reuse.
tempBlocks, err := scanner.HashFile(f.ctx, f.fs, tempName, protocol.BlockSize, nil, false)
if err == nil {
// Check for any reusable blocks in the temp file
tempCopyBlocks, _ := blockDiff(tempBlocks, file.Blocks)
// block.String() returns a string unique to the block
existingBlocks := make(map[string]struct{}, len(tempCopyBlocks))
for _, block := range tempCopyBlocks {
existingBlocks[block.String()] = struct{}{}
}
// Since the blocks are already there, we don't need to get them.
for i, block := range file.Blocks {
_, ok := existingBlocks[block.String()]
if !ok {
blocks = append(blocks, block)
blocksSize += int64(block.Size)
} else {
reused = append(reused, int32(i))
}
}
// The sharedpullerstate will know which flags to use when opening the
// temp file depending if we are reusing any blocks or not.
if len(reused) == 0 {
// Otherwise, discard the file ourselves in order for the
// sharedpuller not to panic when it fails to exclusively create a
// file which already exists
osutil.InWritableDir(f.fs.Remove, f.fs, tempName)
}
} else {
// Copy the blocks, as we don't want to shuffle them on the FileInfo
blocks = append(blocks, file.Blocks...)
blocksSize = file.Size
}
if f.MinDiskFree.BaseValue() > 0 {
if usage, err := f.fs.Usage("."); err == nil && usage.Free < blocksSize {
l.Warnf(`Folder "%s": insufficient disk space in %s for %s: have %.2f MiB, need %.2f MiB`, f.folderID, f.fs.URI(), file.Name, float64(usage.Free)/1024/1024, float64(blocksSize)/1024/1024)
f.newError("disk space", file.Name, errors.New("insufficient space"))
return
}
}
// Shuffle the blocks
for i := range blocks {
j := rand.Intn(i + 1)
blocks[i], blocks[j] = blocks[j], blocks[i]
}
events.Default.Log(events.ItemStarted, map[string]string{
"folder": f.folderID,
"item": file.Name,
"type": "file",
"action": "update",
})
s := sharedPullerState{
file: file,
fs: f.fs,
folder: f.folderID,
tempName: tempName,
realName: file.Name,
copyTotal: len(blocks),
copyNeeded: len(blocks),
reused: len(reused),
updated: time.Now(),
available: reused,
availableUpdated: time.Now(),
ignorePerms: f.IgnorePerms || file.NoPermissions,
hasCurFile: hasCurFile,
curFile: curFile,
mut: sync.NewRWMutex(),
sparse: !f.DisableSparseFiles,
created: time.Now(),
}
l.Debugf("%v need file %s; copy %d, reused %v", f, file.Name, len(blocks), len(reused))
cs := copyBlocksState{
sharedPullerState: &s,
blocks: blocks,
have: len(have),
}
copyChan <- cs
}
// blockDiff returns lists of common and missing (to transform src into tgt)
// blocks. Both block lists must have been created with the same block size.
func blockDiff(src, tgt []protocol.BlockInfo) ([]protocol.BlockInfo, []protocol.BlockInfo) {
if len(tgt) == 0 {
return nil, nil
}
if len(src) == 0 {
// Copy the entire file
return nil, tgt
}
have := make([]protocol.BlockInfo, 0, len(src))
need := make([]protocol.BlockInfo, 0, len(tgt))
for i := range tgt {
if i >= len(src) {
return have, append(need, tgt[i:]...)
}
if !bytes.Equal(tgt[i].Hash, src[i].Hash) {
// Copy differing block
need = append(need, tgt[i])
} else {
have = append(have, tgt[i])
}
}
return have, need
}
// populateOffsets sets the Offset field on each block
func populateOffsets(blocks []protocol.BlockInfo) {
var offset int64
for i := range blocks {
blocks[i].Offset = offset
offset += int64(blocks[i].Size)
}
}
// shortcutFile sets file mode and modification time, when that's the only
// thing that has changed.
func (f *sendReceiveFolder) shortcutFile(file protocol.FileInfo) error {
if !f.IgnorePerms && !file.NoPermissions {
if err := f.fs.Chmod(file.Name, fs.FileMode(file.Permissions&0777)); err != nil {
f.newError("shortcut chmod", file.Name, err)
return err
}
}
f.fs.Chtimes(file.Name, file.ModTime(), file.ModTime()) // never fails
// This may have been a conflict. We should merge the version vectors so
// that our clock doesn't move backwards.
if cur, ok := f.model.CurrentFolderFile(f.folderID, file.Name); ok {
file.Version = file.Version.Merge(cur.Version)
}
return nil
}
// copierRoutine reads copierStates until the in channel closes and performs
// the relevant copies when possible, or passes it to the puller routine.
func (f *sendReceiveFolder) copierRoutine(in <-chan copyBlocksState, pullChan chan<- pullBlockState, out chan<- *sharedPullerState) {
buf := make([]byte, protocol.BlockSize)
for state := range in {
dstFd, err := state.tempFile()
if err != nil {
// Nothing more to do for this failed file, since we couldn't create a temporary for it.
out <- state.sharedPullerState
continue
}
if f.model.progressEmitter != nil {
f.model.progressEmitter.Register(state.sharedPullerState)
}
folderFilesystems := make(map[string]fs.Filesystem)
var folders []string
f.model.fmut.RLock()
for folder, cfg := range f.model.folderCfgs {
folderFilesystems[folder] = cfg.Filesystem()
folders = append(folders, folder)
}
f.model.fmut.RUnlock()
var file fs.File
var weakHashFinder *weakhash.Finder
if weakhash.Enabled {
blocksPercentChanged := 0
if tot := len(state.file.Blocks); tot > 0 {
blocksPercentChanged = (tot - state.have) * 100 / tot
}
if blocksPercentChanged >= f.WeakHashThresholdPct {
hashesToFind := make([]uint32, 0, len(state.blocks))
for _, block := range state.blocks {
if block.WeakHash != 0 {
hashesToFind = append(hashesToFind, block.WeakHash)
}
}
if len(hashesToFind) > 0 {
file, err = f.fs.Open(state.file.Name)
if err == nil {
weakHashFinder, err = weakhash.NewFinder(file, protocol.BlockSize, hashesToFind)
if err != nil {
l.Debugln("weak hasher", err)
}
}
} else {
l.Debugf("not weak hashing %s. file did not contain any weak hashes", state.file.Name)
}
} else {
l.Debugf("not weak hashing %s. not enough changed %.02f < %d", state.file.Name, blocksPercentChanged, f.WeakHashThresholdPct)
}
} else {
l.Debugf("not weak hashing %s. weak hashing disabled", state.file.Name)
}
for _, block := range state.blocks {
if !f.DisableSparseFiles && state.reused == 0 && block.IsEmpty() {
// The block is a block of all zeroes, and we are not reusing
// a temp file, so there is no need to do anything with it.
// If we were reusing a temp file and had this block to copy,
// it would be because the block in the temp file was *not* a
// block of all zeroes, so then we should not skip it.
// Pretend we copied it.
state.copiedFromOrigin()
state.copyDone(block)
continue
}
if s := int(block.Size); s > cap(buf) {
buf = make([]byte, s)
} else {
buf = buf[:s]
}
found, err := weakHashFinder.Iterate(block.WeakHash, buf, func(offset int64) bool {
if _, err := verifyBuffer(buf, block); err != nil {
return true
}
_, err = dstFd.WriteAt(buf, block.Offset)
if err != nil {
state.fail("dst write", err)
}
if offset == block.Offset {
state.copiedFromOrigin()
} else {
state.copiedFromOriginShifted()
}
return false
})
if err != nil {
l.Debugln("weak hasher iter", err)
}
if !found {
found = f.model.finder.Iterate(folders, block.Hash, func(folder, path string, index int32) bool {
fs := folderFilesystems[folder]
fd, err := fs.Open(path)
if err != nil {
return false
}
_, err = fd.ReadAt(buf, protocol.BlockSize*int64(index))
fd.Close()
if err != nil {
return false
}
hash, err := verifyBuffer(buf, block)
if err != nil {
if hash != nil {
l.Debugf("Finder block mismatch in %s:%s:%d expected %q got %q", folder, path, index, block.Hash, hash)
err = f.model.finder.Fix(folder, path, index, block.Hash, hash)
if err != nil {
l.Warnln("finder fix:", err)
}
} else {
l.Debugln("Finder failed to verify buffer", err)
}
return false
}
_, err = dstFd.WriteAt(buf, block.Offset)
if err != nil {
state.fail("dst write", err)
}
if path == state.file.Name {
state.copiedFromOrigin()
}
return true
})
}
if state.failed() != nil {
break
}
if !found {
state.pullStarted()
ps := pullBlockState{
sharedPullerState: state.sharedPullerState,
block: block,
}
pullChan <- ps
} else {
state.copyDone(block)
}
}
if file != nil {
// os.File used to return invalid argument if nil.
// fs.File panics as it's an interface.
file.Close()
}
out <- state.sharedPullerState
}
}
func verifyBuffer(buf []byte, block protocol.BlockInfo) ([]byte, error) {
if len(buf) != int(block.Size) {
return nil, fmt.Errorf("length mismatch %d != %d", len(buf), block.Size)
}
hf := sha256.New()
_, err := hf.Write(buf)
if err != nil {
return nil, err
}
hash := hf.Sum(nil)
if !bytes.Equal(hash, block.Hash) {
return hash, fmt.Errorf("hash mismatch %x != %x", hash, block.Hash)
}
return hash, nil
}
func (f *sendReceiveFolder) pullerRoutine(in <-chan pullBlockState, out chan<- *sharedPullerState) {
requestLimiter := newByteSemaphore(f.PullerMaxPendingKiB * 1024)
wg := sync.NewWaitGroup()
for state := range in {
if state.failed() != nil {
out <- state.sharedPullerState
continue
}
// The requestLimiter limits how many pending block requests we have
// ongoing at any given time, based on the size of the blocks
// themselves.
state := state
bytes := int(state.block.Size)
requestLimiter.take(bytes)
wg.Add(1)
go func() {
defer wg.Done()
defer requestLimiter.give(bytes)
f.pullBlock(state, out)
}()
}
wg.Wait()
}
func (f *sendReceiveFolder) pullBlock(state pullBlockState, out chan<- *sharedPullerState) {
// Get an fd to the temporary file. Technically we don't need it until
// after fetching the block, but if we run into an error here there is
// no point in issuing the request to the network.
fd, err := state.tempFile()
if err != nil {
out <- state.sharedPullerState
return
}
if !f.DisableSparseFiles && state.reused == 0 && state.block.IsEmpty() {
// There is no need to request a block of all zeroes. Pretend we
// requested it and handled it correctly.
state.pullDone(state.block)
out <- state.sharedPullerState
return
}
var lastError error
candidates := f.model.Availability(f.folderID, state.file.Name, state.file.Version, state.block)
for {
// Select the least busy device to pull the block from. If we found no
// feasible device at all, fail the block (and in the long run, the
// file).
selected, found := activity.leastBusy(candidates)
if !found {
if lastError != nil {
state.fail("pull", lastError)
} else {
state.fail("pull", errNoDevice)
}
break
}
candidates = removeAvailability(candidates, selected)
// Fetch the block, while marking the selected device as in use so that
// leastBusy can select another device when someone else asks.
activity.using(selected)
buf, lastError := f.model.requestGlobal(selected.ID, f.folderID, state.file.Name, state.block.Offset, int(state.block.Size), state.block.Hash, selected.FromTemporary)
activity.done(selected)
if lastError != nil {
l.Debugln("request:", f.folderID, state.file.Name, state.block.Offset, state.block.Size, "returned error:", lastError)
continue
}
// Verify that the received block matches the desired hash, if not
// try pulling it from another device.
_, lastError = verifyBuffer(buf, state.block)
if lastError != nil {
l.Debugln("request:", f.folderID, state.file.Name, state.block.Offset, state.block.Size, "hash mismatch")
continue
}
// Save the block data we got from the cluster
_, err = fd.WriteAt(buf, state.block.Offset)
if err != nil {
state.fail("save", err)
} else {
state.pullDone(state.block)
}
break
}
out <- state.sharedPullerState
}
func (f *sendReceiveFolder) performFinish(ignores *ignore.Matcher, state *sharedPullerState, dbUpdateChan chan<- dbUpdateJob, scanChan chan<- string) error {
// Set the correct permission bits on the new file
if !f.IgnorePerms && !state.file.NoPermissions {
if err := f.fs.Chmod(state.tempName, fs.FileMode(state.file.Permissions&0777)); err != nil {
return err
}
}
if stat, err := f.fs.Lstat(state.file.Name); err == nil {
// There is an old file or directory already in place. We need to
// handle that.
curMode := uint32(stat.Mode())
if runtime.GOOS == "windows" && osutil.IsWindowsExecutable(state.file.Name) {
curMode |= 0111
}
// Check that the file on disk is what we expect it to be according
// to the database. If there's a mismatch here, there might be local
// changes that we don't know about yet and we should scan before
// touching the file. There is also a case where we think the file
// should be there, but it was removed, which is a conflict, yet
// creations always wins when competing with a deletion, so no need
// to handle that specially.
changed := false
switch {
case !state.hasCurFile:
// The file appeared from nowhere
l.Debugln("file exists but not scanned; not finishing:", state.file.Name)
changed = true
case stat.IsDir() != state.curFile.IsDirectory() || stat.IsSymlink() != state.curFile.IsSymlink():
// The file changed type. IsRegular is implicitly tested in the condition above
l.Debugln("file type changed but not rescanned; not finishing:", state.curFile.Name)
changed = true
case stat.IsRegular():
if !stat.ModTime().Equal(state.curFile.ModTime()) || stat.Size() != state.curFile.Size {
l.Debugln("file modified but not rescanned; not finishing:", state.curFile.Name)
changed = true
break
}
// check permissions
fallthrough
case stat.IsDir():
// Dirs only have perm, no modetime/size
if !f.IgnorePerms && !state.curFile.NoPermissions && state.curFile.HasPermissionBits() && !protocol.PermsEqual(state.curFile.Permissions, curMode) {
l.Debugln("file permission modified but not rescanned; not finishing:", state.curFile.Name)
changed = true
}
}
if changed {
scanChan <- state.curFile.Name
return fmt.Errorf("file modified but not rescanned; will try again later")
}
switch {
case stat.IsDir() || stat.IsSymlink():
// It's a directory or a symlink. These are not versioned or
// archived for conflicts, only removed (which of course fails for
// non-empty directories).
if err = f.deleteDir(state.file.Name, ignores, scanChan); err != nil {
return err
}
case f.inConflict(state.curFile.Version, state.file.Version):
// The new file has been changed in conflict with the existing one. We
// should file it away as a conflict instead of just removing or
// archiving. Also merge with the version vector we had, to indicate
// we have resolved the conflict.
state.file.Version = state.file.Version.Merge(state.curFile.Version)
err = osutil.InWritableDir(func(name string) error {
return f.moveForConflict(name, state.file.ModifiedBy.String())
}, f.fs, state.file.Name)
if err != nil {
return err
}
case f.versioner != nil && !state.file.IsSymlink():
// If we should use versioning, let the versioner archive the old
// file before we replace it. Archiving a non-existent file is not
// an error.
if err = osutil.InWritableDir(f.versioner.Archive, f.fs, state.file.Name); err != nil {
return err
}
}
}
// Replace the original content with the new one. If it didn't work,
// leave the temp file in place for reuse.
if err := osutil.TryRename(f.fs, state.tempName, state.file.Name); err != nil {
return err
}
// Set the correct timestamp on the new file
f.fs.Chtimes(state.file.Name, state.file.ModTime(), state.file.ModTime()) // never fails
// Record the updated file in the index
dbUpdateChan <- dbUpdateJob{state.file, dbUpdateHandleFile}
return nil
}
func (f *sendReceiveFolder) finisherRoutine(ignores *ignore.Matcher, in <-chan *sharedPullerState, dbUpdateChan chan<- dbUpdateJob, scanChan chan<- string) {
for state := range in {
if closed, err := state.finalClose(); closed {
l.Debugln(f, "closing", state.file.Name)
f.queue.Done(state.file.Name)
if err == nil {
err = f.performFinish(ignores, state, dbUpdateChan, scanChan)
}
if err != nil {
f.newError("finisher", state.file.Name, err)
} else {
blockStatsMut.Lock()
blockStats["total"] += state.reused + state.copyTotal + state.pullTotal
blockStats["reused"] += state.reused
blockStats["pulled"] += state.pullTotal
// copyOriginShifted is counted towards copyOrigin due to progress bar reasons
// for reporting reasons we want to separate these.
blockStats["copyOrigin"] += state.copyOrigin - state.copyOriginShifted
blockStats["copyOriginShifted"] += state.copyOriginShifted
blockStats["copyElsewhere"] += state.copyTotal - state.copyOrigin
blockStatsMut.Unlock()
}
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": f.folderID,
"item": state.file.Name,
"error": events.Error(err),
"type": "file",
"action": "update",
})
if f.model.progressEmitter != nil {
f.model.progressEmitter.Deregister(state)
}
}
}
}
// Moves the given filename to the front of the job queue
func (f *sendReceiveFolder) BringToFront(filename string) {
f.queue.BringToFront(filename)
}
func (f *sendReceiveFolder) Jobs() ([]string, []string) {
return f.queue.Jobs()
}
// dbUpdaterRoutine aggregates db updates and commits them in batches no
// larger than 1000 items, and no more delayed than 2 seconds.
func (f *sendReceiveFolder) dbUpdaterRoutine(dbUpdateChan <-chan dbUpdateJob) {
const maxBatchTime = 2 * time.Second
batch := make([]dbUpdateJob, 0, maxBatchSizeFiles)
files := make([]protocol.FileInfo, 0, maxBatchSizeFiles)
tick := time.NewTicker(maxBatchTime)
defer tick.Stop()
changedDirs := make(map[string]struct{})
handleBatch := func() {
found := false
var lastFile protocol.FileInfo
for _, job := range batch {
files = append(files, job.file)
switch job.jobType {
case dbUpdateHandleFile, dbUpdateShortcutFile:
changedDirs[filepath.Dir(job.file.Name)] = struct{}{}
case dbUpdateHandleDir:
changedDirs[job.file.Name] = struct{}{}
case dbUpdateHandleSymlink, dbUpdateInvalidate:
// fsyncing symlinks is only supported by MacOS
// and invalidated files are db only changes -> no sync
}
if job.file.IsInvalid() || (job.file.IsDirectory() && !job.file.IsSymlink()) {
continue
}
if job.jobType&(dbUpdateHandleFile|dbUpdateDeleteFile) == 0 {
continue
}
found = true
lastFile = job.file
}
// sync directories
for dir := range changedDirs {
delete(changedDirs, dir)
fd, err := f.fs.Open(dir)
if err != nil {
l.Debugf("fsync %q failed: %v", dir, err)
continue
}
if err := fd.Sync(); err != nil {
l.Debugf("fsync %q failed: %v", dir, err)
}
fd.Close()
}
// All updates to file/folder objects that originated remotely
// (across the network) use this call to updateLocals
f.model.updateLocalsFromPulling(f.folderID, files)
if found {
f.model.receivedFile(f.folderID, lastFile)
}
batch = batch[:0]
files = files[:0]
}
batchSizeBytes := 0
loop:
for {
select {
case job, ok := <-dbUpdateChan:
if !ok {
break loop
}
job.file.Sequence = 0
batch = append(batch, job)
batchSizeBytes += job.file.ProtoSize()
if len(batch) == maxBatchSizeFiles || batchSizeBytes > maxBatchSizeBytes {
handleBatch()
batchSizeBytes = 0
}
case <-tick.C:
if len(batch) > 0 {
handleBatch()
batchSizeBytes = 0
}
}
}
if len(batch) > 0 {
handleBatch()
}
}
// pullScannerRoutine aggregates paths to be scanned after pulling. The scan is
// scheduled once when scanChan is closed (scanning can not happen during pulling).
func (f *sendReceiveFolder) pullScannerRoutine(scanChan <-chan string) {
toBeScanned := make(map[string]struct{})
for path := range scanChan {
toBeScanned[path] = struct{}{}
}
if len(toBeScanned) != 0 {
scanList := make([]string, 0, len(toBeScanned))
for path := range toBeScanned {
l.Debugln(f, "scheduling scan after pulling for", path)
scanList = append(scanList, path)
}
f.Scan(scanList)
}
}
func (f *sendReceiveFolder) inConflict(current, replacement protocol.Vector) bool {
if current.Concurrent(replacement) {
// Obvious case
return true
}
if replacement.Counter(f.shortID) > current.Counter(f.shortID) {
// The replacement file contains a higher version for ourselves than
// what we have. This isn't supposed to be possible, since it's only
// we who can increment that counter. We take it as a sign that
// something is wrong (our index may have been corrupted or removed)
// and flag it as a conflict.
return true
}
return false
}
func removeAvailability(availabilities []Availability, availability Availability) []Availability {
for i := range availabilities {
if availabilities[i] == availability {
availabilities[i] = availabilities[len(availabilities)-1]
return availabilities[:len(availabilities)-1]
}
}
return availabilities
}
func (f *sendReceiveFolder) moveForConflict(name string, lastModBy string) error {
if strings.Contains(filepath.Base(name), ".sync-conflict-") {
l.Infoln("Conflict for", name, "which is already a conflict copy; not copying again.")
if err := f.fs.Remove(name); err != nil && !fs.IsNotExist(err) {
return err
}
return nil
}
if f.MaxConflicts == 0 {
if err := f.fs.Remove(name); err != nil && !fs.IsNotExist(err) {
return err
}
return nil
}
ext := filepath.Ext(name)
withoutExt := name[:len(name)-len(ext)]
newName := withoutExt + time.Now().Format(".sync-conflict-20060102-150405-") + lastModBy + ext
err := f.fs.Rename(name, newName)
if fs.IsNotExist(err) {
// We were supposed to move a file away but it does not exist. Either
// the user has already moved it away, or the conflict was between a
// remote modification and a local delete. In either way it does not
// matter, go ahead as if the move succeeded.
err = nil
}
if f.MaxConflicts > -1 {
matches, gerr := f.fs.Glob(withoutExt + ".sync-conflict-????????-??????*" + ext)
if gerr == nil && len(matches) > f.MaxConflicts {
sort.Sort(sort.Reverse(sort.StringSlice(matches)))
for _, match := range matches[f.MaxConflicts:] {
gerr = f.fs.Remove(match)
if gerr != nil {
l.Debugln(f, "removing extra conflict", gerr)
}
}
} else if gerr != nil {
l.Debugln(f, "globbing for conflicts", gerr)
}
}
return err
}
func (f *sendReceiveFolder) newError(context, path string, err error) {
f.errorsMut.Lock()
defer f.errorsMut.Unlock()
// We might get more than one error report for a file (i.e. error on
// Write() followed by Close()); we keep the first error as that is
// probably closer to the root cause.
if _, ok := f.errors[path]; ok {
return
}
l.Infof("Puller (folder %s, file %q): %s: %v", f.Description(), path, context, err)
f.errors[path] = fmt.Sprintf("%s: %s", context, err.Error())
}
func (f *sendReceiveFolder) clearErrors() {
f.errorsMut.Lock()
f.errors = make(map[string]string)
f.errorsMut.Unlock()
}
func (f *sendReceiveFolder) PullErrors() []FileError {
f.errorsMut.Lock()
errors := make([]FileError, 0, len(f.errors))
for path, err := range f.errors {
errors = append(errors, FileError{path, err})
}
sort.Sort(fileErrorList(errors))
f.errorsMut.Unlock()
return errors
}
func (f *sendReceiveFolder) basePause() time.Duration {
if f.PullerPauseS == 0 {
return defaultPullerPause
}
return time.Duration(f.PullerPauseS) * time.Second
}
// deleteDir attempts to delete a directory. It checks for files/dirs inside
// the directory and removes them if possible or returns an error if it fails
func (f *sendReceiveFolder) deleteDir(dir string, ignores *ignore.Matcher, scanChan chan<- string) error {
files, _ := f.fs.DirNames(dir)
toBeDeleted := make([]string, 0, len(files))
hasIgnored := false
hasKnown := false
hasToBeScanned := false
for _, dirFile := range files {
fullDirFile := filepath.Join(dir, dirFile)
if fs.IsTemporary(dirFile) || ignores.Match(fullDirFile).IsDeletable() {
toBeDeleted = append(toBeDeleted, fullDirFile)
} else if ignores != nil && ignores.Match(fullDirFile).IsIgnored() {
hasIgnored = true
} else if cf, ok := f.model.CurrentFolderFile(f.ID, fullDirFile); !ok || cf.IsDeleted() || cf.IsInvalid() {
// Something appeared in the dir that we either are not
// aware of at all, that we think should be deleted or that
// is invalid, but not currently ignored -> schedule scan
scanChan <- fullDirFile
hasToBeScanned = true
} else {
// Dir contains file that is valid according to db and
// not ignored -> something weird is going on
hasKnown = true
}
}
if hasToBeScanned {
return errDirHasToBeScanned
}
if hasIgnored {
return errDirHasIgnored
}
if hasKnown {
return errDirNotEmpty
}
for _, del := range toBeDeleted {
f.fs.RemoveAll(del)
}
err := osutil.InWritableDir(f.fs.Remove, f.fs, dir)
if err == nil || fs.IsNotExist(err) {
// It was removed or it doesn't exist to start with
return nil
}
if _, serr := f.fs.Lstat(dir); serr != nil && !fs.IsPermission(serr) {
// We get an error just looking at the directory, and it's not a
// permission problem. Lets assume the error is in fact some variant
// of "file does not exist" (possibly expressed as some parent being a
// file and not a directory etc) and that the delete is handled.
return nil
}
return err
}
// A []FileError is sent as part of an event and will be JSON serialized.
type FileError struct {
Path string `json:"path"`
Err string `json:"error"`
}
type fileErrorList []FileError
func (l fileErrorList) Len() int {
return len(l)
}
func (l fileErrorList) Less(a, b int) bool {
return l[a].Path < l[b].Path
}
func (l fileErrorList) Swap(a, b int) {
l[a], l[b] = l[b], l[a]
}
// byComponentCount sorts by the number of path components in Name, that is
// "x/y" sorts before "foo/bar/baz".
type byComponentCount []protocol.FileInfo
func (l byComponentCount) Len() int {
return len(l)
}
func (l byComponentCount) Less(a, b int) bool {
return componentCount(l[a].Name) < componentCount(l[b].Name)
}
func (l byComponentCount) Swap(a, b int) {
l[a], l[b] = l[b], l[a]
}
func componentCount(name string) int {
count := 0
for _, codepoint := range name {
if codepoint == fs.PathSeparator {
count++
}
}
return count
}
type byteSemaphore struct {
max int
available int
mut stdsync.Mutex
cond *stdsync.Cond
}
func newByteSemaphore(max int) *byteSemaphore {
s := byteSemaphore{
max: max,
available: max,
}
s.cond = stdsync.NewCond(&s.mut)
return &s
}
func (s *byteSemaphore) take(bytes int) {
if bytes > s.max {
panic("bug: more than max bytes will never be available")
}
s.mut.Lock()
for bytes > s.available {
s.cond.Wait()
}
s.available -= bytes
s.mut.Unlock()
}
func (s *byteSemaphore) give(bytes int) {
s.mut.Lock()
if s.available+bytes > s.max {
panic("bug: can never give more than max")
}
s.available += bytes
s.cond.Broadcast()
s.mut.Unlock()
}