// 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
}
func TestCopierFinder(t *testing.T) {
// After diff between required and existing we should:
// Copy: 1, 2, 3, 4, 6, 7, 8
// Since there is no existing file, nor a temp file
// After dropping out blocks found locally:
// Pull: 1, 5, 6, 8
tempFile := filepath.Join("testdata", defTempNamer.TempName("file2"))
err := os.Remove(tempFile)
if err != nil && !os.IsNotExist(err) {
t.Error(err)
}
existingBlocks := []int{0, 2, 3, 4, 0, 0, 7, 0}
existingFile := setUpFile(defTempNamer.TempName("file"), existingBlocks)
requiredFile := existingFile
requiredFile.Blocks = blocks[1:]
requiredFile.Name = "file2"
m := setUpModel(existingFile)
p := setUpRwFolder(m)
copyChan := make(chan copyBlocksState)
pullChan := make(chan pullBlockState, 4)
finisherChan := make(chan *sharedPullerState, 1)
// Run a single fetcher routine
go p.copierRoutine(copyChan, pullChan, finisherChan)
p.handleFile(requiredFile, copyChan, finisherChan)
pulls := []pullBlockState{<-pullChan, <-pullChan, <-pullChan, <-pullChan}
finish := <-finisherChan
select {
case <-pullChan:
t.Fatal("Finisher channel has data to be read")
case <-finisherChan:
t.Fatal("Finisher channel has data to be read")
default:
}
// Verify that the right blocks went into the pull list
for i, eq := range []int{1, 5, 6, 8} {
if string(pulls[i].block.Hash) != string(blocks[eq].Hash) {
t.Errorf("Block %d mismatch: %s != %s", eq, pulls[i].block.String(), blocks[eq].String())
}
if string(finish.file.Blocks[eq-1].Hash) != string(blocks[eq].Hash) {
t.Errorf("Block %d mismatch: %s != %s", eq, finish.file.Blocks[eq-1].String(), blocks[eq].String())
}
}
// Verify that the fetched blocks have actually been written to the temp file
blks, err := scanner.HashFile(tempFile, protocol.BlockSize, 0, nil)
if err != nil {
t.Log(err)
}
for _, eq := range []int{2, 3, 4, 7} {
if string(blks[eq-1].Hash) != string(blocks[eq].Hash) {
t.Errorf("Block %d mismatch: %s != %s", eq, blks[eq-1].String(), blocks[eq].String())
}
}
finish.fd.Close()
os.Remove(tempFile)
}
