1
0
Fork 0
mirror of https://github.com/restic/restic.git synced 2024-12-23 08:16:36 +00:00
restic/archiver.go
2015-01-04 20:07:30 +01:00

285 lines
5.7 KiB
Go

package restic
import (
"fmt"
"io"
"os"
"sync"
"github.com/juju/arrar"
"github.com/restic/restic/backend"
"github.com/restic/restic/chunker"
)
const (
maxConcurrentFiles = 8
maxConcurrentBlobs = 8
)
type Archiver struct {
s Server
ch *ContentHandler
bl *BlobList // blobs used for the current snapshot
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{}{}
}
// 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 }
arch.bl = NewBlobList()
arch.ch = NewContentHandler(s)
// load all blobs from all snapshots
err = arch.ch.LoadAllMaps()
if err != nil {
return nil, err
}
return arch, nil
}
func (arch *Archiver) Save(t backend.Type, data []byte) (Blob, error) {
blob, err := arch.ch.Save(t, data)
if err != nil {
return Blob{}, err
}
// store blob in storage map for current snapshot
arch.bl.Insert(blob)
return blob, nil
}
func (arch *Archiver) SaveJSON(t backend.Type, item interface{}) (Blob, error) {
blob, err := arch.ch.SaveJSON(t, item)
if err != nil {
return Blob{}, err
}
// store blob in storage map for current snapshot
arch.bl.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) error {
file, err := os.Open(node.path)
defer file.Close()
if err != nil {
return arrar.Annotate(err, "SaveFile()")
}
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 arrar.Annotate(err, "SaveFile() read small file")
}
if err == io.EOF {
// use empty blob list for empty files
blobs = Blobs{}
} else {
blob, err := arch.ch.Save(backend.Data, buf[:n])
if err != nil {
return 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 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.ch.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 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
arch.bl.Insert(blob)
bytes += blob.Size
}
if bytes != node.Size {
return fmt.Errorf("errors saving node %q: saved %d bytes, wanted %d bytes", node.path, bytes, node.Size)
}
return nil
}
func (arch *Archiver) saveTree(t *Tree) (Blob, error) {
var wg sync.WaitGroup
for _, node := range *t {
if node.Tree != nil && node.Subtree == nil {
b, err := arch.saveTree(node.Tree)
if err != nil {
return Blob{}, err
}
node.Subtree = b.ID
arch.p.Report(Stat{Dirs: 1})
} else if node.Type == "file" && 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
}()
// TODO: handle error
err := arch.SaveFile(n)
if err != nil {
panic(err)
}
arch.p.Report(Stat{Files: 1})
}(node)
} else {
arch.p.Report(Stat{Other: 1})
}
}
wg.Wait()
// check for invalid file nodes
for _, node := range *t {
if node.Type == "file" && node.Content == nil {
return Blob{}, fmt.Errorf("node %v has empty content", node.Name)
}
}
blob, err := arch.SaveJSON(backend.Tree, 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) {
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.ID
// save bloblist
blob, err = arch.SaveJSON(backend.Map, arch.bl)
if err != nil {
return nil, nil, err
}
sn.Map = blob.Storage
// save snapshot
blob, err = arch.SaveJSON(backend.Snapshot, sn)
if err != nil {
return nil, nil, err
}
return sn, blob.Storage, nil
}