package repository import ( "bufio" "context" "io" "os" "runtime" "sync" "github.com/restic/restic/internal/backend" "github.com/restic/restic/internal/errors" "github.com/restic/restic/internal/hashing" "github.com/restic/restic/internal/restic" "github.com/restic/restic/internal/crypto" "github.com/restic/restic/internal/debug" "github.com/restic/restic/internal/fs" "github.com/restic/restic/internal/pack" "github.com/minio/sha256-simd" ) // packer holds a pack.packer together with a hash writer. type packer struct { *pack.Packer tmpfile *os.File bufWr *bufio.Writer } // packerManager keeps a list of open packs and creates new on demand. type packerManager struct { tpe restic.BlobType key *crypto.Key queueFn func(ctx context.Context, t restic.BlobType, p *packer) error pm sync.Mutex packer *packer packSize uint } // newPackerManager returns a new packer manager which writes temporary files // to a temporary directory func newPackerManager(key *crypto.Key, tpe restic.BlobType, packSize uint, queueFn func(ctx context.Context, t restic.BlobType, p *packer) error) *packerManager { return &packerManager{ tpe: tpe, key: key, queueFn: queueFn, packSize: packSize, } } func (r *packerManager) Flush(ctx context.Context) error { r.pm.Lock() defer r.pm.Unlock() if r.packer != nil { debug.Log("manually flushing pending pack") err := r.queueFn(ctx, r.tpe, r.packer) if err != nil { return err } r.packer = nil } return nil } func (r *packerManager) SaveBlob(ctx context.Context, t restic.BlobType, id restic.ID, ciphertext []byte, uncompressedLength int) (int, error) { r.pm.Lock() defer r.pm.Unlock() var err error packer := r.packer // use separate packer if compressed length is larger than the packsize // this speeds up the garbage collection of oversized blobs and reduces the cache size // as the oversize blobs are only downloaded if necessary if len(ciphertext) >= int(r.packSize) || r.packer == nil { packer, err = r.newPacker() if err != nil { return 0, err } // don't store packer for oversized blob if r.packer == nil { r.packer = packer } } // save ciphertext // Add only appends bytes in memory to avoid being a scaling bottleneck size, err := packer.Add(t, id, ciphertext, uncompressedLength) if err != nil { return 0, err } // if the pack and header is not full enough, put back to the list if packer.Size() < r.packSize && !packer.HeaderFull() { debug.Log("pack is not full enough (%d bytes)", packer.Size()) return size, nil } if packer == r.packer { // forget full packer r.packer = nil } // call while holding lock to prevent findPacker from creating new packers if the uploaders are busy // else write the pack to the backend err = r.queueFn(ctx, t, packer) if err != nil { return 0, err } return size + packer.HeaderOverhead(), nil } // findPacker returns a packer for a new blob of size bytes. Either a new one is // created or one is returned that already has some blobs. func (r *packerManager) newPacker() (pck *packer, err error) { debug.Log("create new pack") tmpfile, err := fs.TempFile("", "restic-temp-pack-") if err != nil { return nil, errors.WithStack(err) } bufWr := bufio.NewWriter(tmpfile) p := pack.NewPacker(r.key, bufWr) pck = &packer{ Packer: p, tmpfile: tmpfile, bufWr: bufWr, } return pck, nil } // savePacker stores p in the backend. func (r *Repository) savePacker(ctx context.Context, t restic.BlobType, p *packer) error { debug.Log("save packer for %v with %d blobs (%d bytes)\n", t, p.Packer.Count(), p.Packer.Size()) err := p.Packer.Finalize() if err != nil { return err } err = p.bufWr.Flush() if err != nil { return err } // calculate sha256 hash in a second pass var rd io.Reader rd, err = backend.NewFileReader(p.tmpfile, nil) if err != nil { return err } beHasher := r.be.Hasher() var beHr *hashing.Reader if beHasher != nil { beHr = hashing.NewReader(rd, beHasher) rd = beHr } hr := hashing.NewReader(rd, sha256.New()) _, err = io.Copy(io.Discard, hr) if err != nil { return err } id := restic.IDFromHash(hr.Sum(nil)) h := backend.Handle{Type: backend.PackFile, Name: id.String(), IsMetadata: t.IsMetadata()} var beHash []byte if beHr != nil { beHash = beHr.Sum(nil) } rrd, err := backend.NewFileReader(p.tmpfile, beHash) if err != nil { return err } err = r.be.Save(ctx, h, rrd) if err != nil { debug.Log("Save(%v) error: %v", h, err) return err } debug.Log("saved as %v", h) err = p.tmpfile.Close() if err != nil { return errors.Wrap(err, "close tempfile") } // on windows the tempfile is automatically deleted on close if runtime.GOOS != "windows" { err = fs.RemoveIfExists(p.tmpfile.Name()) if err != nil { return errors.WithStack(err) } } // update blobs in the index debug.Log(" updating blobs %v to pack %v", p.Packer.Blobs(), id) r.idx.StorePack(id, p.Packer.Blobs()) // Save index if full return r.idx.SaveFullIndex(ctx, r) }