// handleFile queues the copies and pulls as necessary for a single new or
// changed file.
func (p *rwFolder) handleFile(file protocol.FileInfo, copyChan chan<- copyBlocksState, finisherChan chan<- *sharedPullerState) {
curFile, hasCurFile := p.model.CurrentFolderFile(p.folder, file.Name)
if hasCurFile && len(curFile.Blocks) == len(file.Blocks) && scanner.BlocksEqual(curFile.Blocks, file.Blocks) {
// 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(p, "taking shortcut on", file.Name)
events.Default.Log(events.ItemStarted, map[string]string{
"folder": p.folder,
"item": file.Name,
"type": "file",
"action": "metadata",
})
p.queue.Done(file.Name)
var err error
if file.IsSymlink() {
err = p.shortcutSymlink(file)
} else {
err = p.shortcutFile(file)
}
events.Default.Log(events.ItemFinished, map[string]interface{}{
"folder": p.folder,
"item": file.Name,
"error": events.Error(err),
"type": "file",
"action": "metadata",
})
if err != nil {
l.Infoln("Puller: shortcut:", err)
p.newError(file.Name, err)
} else {
p.dbUpdates <- dbUpdateJob{file, dbUpdateShortcutFile}
}
return
}
// Figure out the absolute filenames we need once and for all
tempName := filepath.Join(p.dir, defTempNamer.TempName(file.Name))
realName := filepath.Join(p.dir, file.Name)
if hasCurFile && !curFile.IsDirectory() && !curFile.IsSymlink() {
// 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. If we can't stat the file we'll just pull it.
if info, err := osutil.Lstat(realName); err == nil {
mtime := p.virtualMtimeRepo.GetMtime(file.Name, info.ModTime())
if mtime.Unix() != curFile.Modified || info.Size() != curFile.Size() {
l.Debugln("file modified but not rescanned; not pulling:", realName)
// Scan() is synchronous (i.e. blocks until the scan is
// completed and returns an error), but a scan can't happen
// while we're in the puller routine. Request the scan in the
// background and it'll be handled when the current pulling
// sweep is complete. As we do retries, we'll queue the scan
// for this file up to ten times, but the last nine of those
// scans will be cheap...
go p.Scan([]string{file.Name})
return
}
}
}
scanner.PopulateOffsets(file.Blocks)
reused := 0
var blocks []protocol.BlockInfo
var blocksSize int64
// Check for an old temporary file which might have some blocks we could
// reuse.
tempBlocks, err := scanner.HashFile(tempName, protocol.BlockSize, 0, nil)
if err == nil {
// Check for any reusable blocks in the temp file
tempCopyBlocks, _ := scanner.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 _, block := range file.Blocks {
_, ok := existingBlocks[block.String()]
if !ok {
blocks = append(blocks, block)
blocksSize += int64(block.Size)
}
}
// The sharedpullerstate will know which flags to use when opening the
// temp file depending if we are reusing any blocks or not.
reused = len(file.Blocks) - len(blocks)
if 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(osutil.Remove, tempName)
}
} else {
blocks = file.Blocks
blocksSize = file.Size()
}
if p.checkFreeSpace {
if free, err := osutil.DiskFreeBytes(p.dir); err == nil && free < blocksSize {
l.Warnf(`Folder "%s": insufficient disk space in %s for %s: have %.2f MiB, need %.2f MiB`, p.folder, p.dir, file.Name, float64(free)/1024/1024, float64(blocksSize)/1024/1024)
p.newError(file.Name, errors.New("insufficient space"))
return
}
}
events.Default.Log(events.ItemStarted, map[string]string{
"folder": p.folder,
"item": file.Name,
"type": "file",
"action": "update",
})
s := sharedPullerState{
file: file,
folder: p.folder,
tempName: tempName,
realName: realName,
copyTotal: len(blocks),
copyNeeded: len(blocks),
reused: reused,
ignorePerms: p.ignorePermissions(file),
version: curFile.Version,
mut: sync.NewMutex(),
sparse: p.allowSparse,
}
l.Debugf("%v need file %s; copy %d, reused %v", p, file.Name, len(blocks), reused)
cs := copyBlocksState{
sharedPullerState: &s,
blocks: blocks,
}
copyChan <- cs
}
// 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 (p *rwFolder) pullerIteration(ignores *ignore.Matcher) int {
pullChan := make(chan pullBlockState)
copyChan := make(chan copyBlocksState)
finisherChan := make(chan *sharedPullerState)
updateWg := sync.NewWaitGroup()
copyWg := sync.NewWaitGroup()
pullWg := sync.NewWaitGroup()
doneWg := sync.NewWaitGroup()
l.Debugln(p, "c", p.copiers, "p", p.pullers)
p.dbUpdates = make(chan dbUpdateJob)
updateWg.Add(1)
go func() {
// dbUpdaterRoutine finishes when p.dbUpdates is closed
p.dbUpdaterRoutine()
updateWg.Done()
}()
for i := 0; i < p.copiers; i++ {
copyWg.Add(1)
go func() {
// copierRoutine finishes when copyChan is closed
p.copierRoutine(copyChan, pullChan, finisherChan)
copyWg.Done()
}()
}
for i := 0; i < p.pullers; i++ {
pullWg.Add(1)
go func() {
// pullerRoutine finishes when pullChan is closed
p.pullerRoutine(pullChan, finisherChan)
pullWg.Done()
}()
}
doneWg.Add(1)
// finisherRoutine finishes when finisherChan is closed
go func() {
p.finisherRoutine(finisherChan)
doneWg.Done()
}()
p.model.fmut.RLock()
folderFiles := p.model.folderFiles[p.folder]
p.model.fmut.RUnlock()
// !!!
// WithNeed takes a database snapshot (by necessity). By the time we've
// handled a bunch of files it might have become out of date and we might
// be attempting to sync with an old version of a file...
// !!!
changed := 0
fileDeletions := map[string]protocol.FileInfo{}
dirDeletions := []protocol.FileInfo{}
buckets := map[string][]protocol.FileInfo{}
handleFile := func(f protocol.FileInfo) bool {
switch {
case f.IsDeleted():
// A deleted file, directory or symlink
if f.IsDirectory() {
dirDeletions = append(dirDeletions, f)
} else {
fileDeletions[f.Name] = f
df, ok := p.model.CurrentFolderFile(p.folder, f.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() {
// Put files into buckets per first hash
key := string(df.Blocks[0].Hash)
buckets[key] = append(buckets[key], df)
}
}
case f.IsDirectory() && !f.IsSymlink():
// A new or changed directory
l.Debugln("Creating directory", f.Name)
p.handleDir(f)
default:
return false
}
return true
}
folderFiles.WithNeed(protocol.LocalDeviceID, func(intf db.FileIntf) bool {
// Needed items are delivered sorted lexicographically. We'll handle
// directories as they come along, so parents before children. Files
// are queued and the order may be changed later.
file := intf.(protocol.FileInfo)
if ignores.Match(file.Name) {
// This is an ignored file. Skip it, continue iteration.
return true
}
l.Debugln(p, "handling", file.Name)
if !handleFile(file) {
// A new or changed file or symlink. This is the only case where we
// do stuff concurrently in the background
p.queue.Push(file.Name, file.Size(), file.Modified)
}
changed++
return true
})
// Reorder the file queue according to configuration
switch p.order {
case config.OrderRandom:
p.queue.Shuffle()
case config.OrderAlphabetic:
// The queue is already in alphabetic order.
case config.OrderSmallestFirst:
p.queue.SortSmallestFirst()
case config.OrderLargestFirst:
p.queue.SortLargestFirst()
case config.OrderOldestFirst:
p.queue.SortOldestFirst()
case config.OrderNewestFirst:
p.queue.SortNewestFirst()
}
// Process the file queue
nextFile:
for {
select {
case <-p.stop:
// Stop processing files if the puller has been told to stop.
break
default:
}
fileName, ok := p.queue.Pop()
if !ok {
break
}
f, ok := p.model.CurrentGlobalFile(p.folder, fileName)
if !ok {
// File is no longer in the index. Mark it as done and drop it.
p.queue.Done(fileName)
continue
}
// Handles races where an index update arrives changing what the file
// is between queueing and retrieving it from the queue, effectively
// changing how the file should be handled.
if handleFile(f) {
continue
}
if !f.IsSymlink() {
key := string(f.Blocks[0].Hash)
for i, candidate := range buckets[key] {
if scanner.BlocksEqual(candidate.Blocks, f.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)
p.renameFile(desired, f)
p.queue.Done(fileName)
continue nextFile
}
}
}
// Not a rename or a symlink, deal with it.
p.handleFile(f, copyChan, finisherChan)
}
// 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("Deleting file", file.Name)
p.deleteFile(file)
}
for i := range dirDeletions {
dir := dirDeletions[len(dirDeletions)-i-1]
l.Debugln("Deleting dir", dir.Name)
p.deleteDir(dir)
}
// Wait for db updates to complete
close(p.dbUpdates)
updateWg.Wait()
return changed
}