package restic import ( "encoding/json" "errors" "fmt" "io" "os" "sync" "github.com/juju/arrar" "github.com/restic/restic/backend" "github.com/restic/restic/chunker" "github.com/restic/restic/debug" ) const ( maxConcurrentFiles = 8 maxConcurrentBlobs = 8 ) type Archiver struct { s Server m *Map fileToken chan struct{} blobToken chan struct{} Error func(dir string, fi os.FileInfo, err error) error Filter func(item string, fi os.FileInfo) bool p *Progress } func NewArchiver(s Server, p *Progress) (*Archiver, error) { var err error arch := &Archiver{ s: s, p: p, fileToken: make(chan struct{}, maxConcurrentFiles), blobToken: make(chan struct{}, maxConcurrentBlobs), } // fill file and blob token for i := 0; i < maxConcurrentFiles; i++ { arch.fileToken <- struct{}{} } for i := 0; i < maxConcurrentBlobs; i++ { arch.blobToken <- struct{}{} } // create new map to store all blobs in arch.m = NewMap() // abort on all errors arch.Error = func(string, os.FileInfo, error) error { return err } // allow all files arch.Filter = func(string, os.FileInfo) bool { return true } return arch, nil } func (arch *Archiver) Save(t backend.Type, data []byte) (Blob, error) { // compute plaintext hash id := backend.Hash(data) debug.Log("Archiver.Save", "Save(%v, %v)\n", t, id.Str()) // test if this blob is already known blob, err := arch.m.FindID(id) if err == nil { debug.Log("Archiver.Save", "Save(%v, %v): reusing %v\n", t, id.Str(), blob.Storage.Str()) id.Free() return blob, nil } // else encrypt and save data blob, err = arch.s.Save(t, data, id) // store blob in storage map smapblob := arch.m.Insert(blob) // if the map has a different storage id for this plaintext blob, use that // one and remove the other. This happens if the same plaintext blob was // stored concurrently and finished earlier than this blob. if blob.Storage.Compare(smapblob.Storage) != 0 { debug.Log("Archiver.Save", "using other block, removing %v\n", blob.Storage.Str()) // remove the blob again // TODO: implement a list of blobs in transport, so this doesn't happen so often err = arch.s.Remove(t, blob.Storage) if err != nil { return Blob{}, err } } debug.Log("Archiver.Save", "Save(%v, %v): new blob %v\n", t, id.Str(), blob) return smapblob, nil } func (arch *Archiver) SaveTreeJSON(item interface{}) (Blob, error) { // convert to json data, err := json.Marshal(item) if err != nil { return Blob{}, err } // check if tree has been saved before buf := backend.Compress(data) id := backend.Hash(buf) blob, err := arch.m.FindID(id) // return the blob if we found it if err == nil { return blob, nil } // otherwise save the data blob, err = arch.s.Save(backend.Tree, buf, id) if err != nil { return Blob{}, err } // store blob in storage map arch.m.Insert(blob) return blob, nil } // SaveFile stores the content of the file on the backend as a Blob by calling // Save for each chunk. func (arch *Archiver) SaveFile(node *Node) (Blobs, error) { file, err := os.Open(node.path) defer file.Close() if err != nil { return nil, err } // check file again fi, err := file.Stat() if err != nil { return nil, err } if fi.ModTime() != node.ModTime { e2 := arch.Error(node.path, fi, errors.New("file was updated, using new version")) if e2 == nil { // create new node n, err := NodeFromFileInfo(node.path, fi) if err != nil { return nil, err } // copy node *node = *n } } var blobs Blobs // if the file is small enough, store it directly if node.Size < chunker.MinSize { // acquire token token := <-arch.blobToken defer func() { arch.blobToken <- token }() buf := GetChunkBuf("blob single file") defer FreeChunkBuf("blob single file", buf) n, err := io.ReadFull(file, buf) if err != nil && err != io.ErrUnexpectedEOF && err != io.EOF { return nil, arrar.Annotate(err, "SaveFile() read small file") } if err == io.EOF { // use empty blob list for empty files blobs = Blobs{} } else { blob, err := arch.Save(backend.Data, buf[:n]) if err != nil { return nil, arrar.Annotate(err, "SaveFile() save chunk") } arch.p.Report(Stat{Bytes: blob.Size}) blobs = Blobs{blob} } } else { // else store all chunks chnker := chunker.New(file) chans := [](<-chan Blob){} defer chnker.Free() chunks := 0 for { buf := GetChunkBuf("blob chunker") chunk, err := chnker.Next(buf) if err == io.EOF { FreeChunkBuf("blob chunker", buf) break } if err != nil { FreeChunkBuf("blob chunker", buf) return nil, arrar.Annotate(err, "SaveFile() chunker.Next()") } chunks++ // acquire token, start goroutine to save chunk token := <-arch.blobToken resCh := make(chan Blob, 1) go func(ch chan<- Blob) { blob, err := arch.Save(backend.Data, chunk.Data) // TODO handle error if err != nil { panic(err) } FreeChunkBuf("blob chunker", buf) arch.p.Report(Stat{Bytes: blob.Size}) arch.blobToken <- token ch <- blob }(resCh) chans = append(chans, resCh) } blobs = []Blob{} for _, ch := range chans { blobs = append(blobs, <-ch) } if len(blobs) != chunks { return nil, fmt.Errorf("chunker returned %v chunks, but only %v blobs saved", chunks, len(blobs)) } } var bytes uint64 node.Content = make([]backend.ID, len(blobs)) for i, blob := range blobs { node.Content[i] = blob.ID bytes += blob.Size } if bytes != node.Size { return nil, fmt.Errorf("errors saving node %q: saved %d bytes, wanted %d bytes", node.path, bytes, node.Size) } debug.Log("Archiver.SaveFile", "SaveFile(%q): %v\n", node.path, blobs) return blobs, nil } func (arch *Archiver) saveTree(t *Tree) (Blob, error) { debug.Log("Archiver.saveTree", "saveTree(%v)\n", t) var wg sync.WaitGroup // add all blobs to global map arch.m.Merge(t.Map) // TODO: do all this in parallel for _, node := range t.Nodes { if node.tree != nil { b, err := arch.saveTree(node.tree) if err != nil { return Blob{}, err } node.Subtree = b.ID t.Map.Insert(b) arch.p.Report(Stat{Dirs: 1}) } else if node.Type == "file" { if len(node.Content) > 0 { removeContent := false // check content for _, id := range node.Content { blob, err := t.Map.FindID(id) if err != nil { debug.Log("Archiver.saveTree", "unable to find storage id for data blob %v", id.Str()) arch.Error(node.path, nil, fmt.Errorf("unable to find storage id for data blob %v", id.Str())) removeContent = true t.Map.DeleteID(id) arch.m.DeleteID(id) continue } if ok, err := arch.s.Test(backend.Data, blob.Storage); !ok || err != nil { debug.Log("Archiver.saveTree", "blob %v not in repository (error is %v)", blob, err) arch.Error(node.path, nil, fmt.Errorf("blob %v not in repository (error is %v)", blob.Storage.Str(), err)) removeContent = true t.Map.DeleteID(id) arch.m.DeleteID(id) } } if removeContent { debug.Log("Archiver.saveTree", "removing content for %s", node.path) node.Content = node.Content[:0] } } if len(node.Content) == 0 { // get token token := <-arch.fileToken // start goroutine wg.Add(1) go func(n *Node) { defer wg.Done() defer func() { arch.fileToken <- token }() var blobs Blobs blobs, n.err = arch.SaveFile(n) for _, b := range blobs { t.Map.Insert(b) } arch.p.Report(Stat{Files: 1}) }(node) } } } wg.Wait() usedIDs := backend.NewIDSet() // check for invalid file nodes for _, node := range t.Nodes { if node.Type == "file" && node.Content == nil && node.err == nil { return Blob{}, fmt.Errorf("node %v has empty content", node.Name) } // remember used hashes if node.Type == "file" && node.Content != nil { for _, id := range node.Content { usedIDs.Insert(id) } } if node.Type == "dir" && node.Subtree != nil { usedIDs.Insert(node.Subtree) } if node.err != nil { err := arch.Error(node.path, nil, node.err) if err != nil { return Blob{}, err } // save error message in node node.Error = node.err.Error() } } before := len(t.Map.IDs()) t.Map.Prune(usedIDs) after := len(t.Map.IDs()) if before != after { debug.Log("Archiver.saveTree", "pruned %d ids from map for tree %v\n", before-after, t) } blob, err := arch.SaveTreeJSON(t) if err != nil { return Blob{}, err } return blob, nil } func (arch *Archiver) Snapshot(dir string, t *Tree, parentSnapshot backend.ID) (*Snapshot, backend.ID, error) { debug.Break("Archiver.Snapshot") arch.p.Start() defer arch.p.Done() sn, err := NewSnapshot(dir) if err != nil { return nil, nil, err } sn.Parent = parentSnapshot blob, err := arch.saveTree(t) if err != nil { return nil, nil, err } sn.Tree = blob // save snapshot blob, err = arch.s.SaveJSON(backend.Snapshot, sn) if err != nil { return nil, nil, err } return sn, blob.Storage, nil }