Merge pull request #213 from restic/refactor

Minor refactor

backend/sftp/sftp.go

@@ -10,6 +10,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"sort"
+	"syscall"
 
 	"github.com/juju/errors"
 	"github.com/pkg/sftp"
@@ -35,6 +36,9 @@ func startClient(program string, args ...string) (*SFTP, error) {
 	// send errors from ssh to stderr
 	cmd.Stderr = os.Stderr
 
+	// ignore signals sent to the parent (e.g. SIGINT)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+
 	// get stdin and stdout
 	wr, err := cmd.StdinPipe()
 	if err != nil {
@@ -452,6 +456,10 @@ func (s *SFTP) Close() error {
 	}
 
 	s.c.Close()
-	// TODO: add timeout after which the process is killed
+
+	if err := s.cmd.Process.Kill(); err != nil {
+		return err
+	}
+
 	return s.cmd.Wait()
 }

cmd/restic/cmd_cat.go

@@ -79,7 +79,7 @@ func (cmd CmdCat) Execute(args []string) error {
 		fmt.Println(string(buf))
 		return nil
 	case "index":
-		buf, err := repo.Load(backend.Index, id)
+		buf, err := repo.LoadAndDecrypt(backend.Index, id)
 		if err != nil {
 			return err
 		}

cmd/restic/lock.go

@@ -49,7 +49,9 @@ func lockRepository(repo *repository.Repository, exclusive bool) (*restic.Lock,
 }
 
 func unlockRepo(lock *restic.Lock) error {
+	debug.Log("unlockRepo", "unlocking repository")
 	if err := lock.Unlock(); err != nil {
+		debug.Log("unlockRepo", "error while unlocking: %v", err)
 		return err
 	}
 
@@ -67,8 +69,10 @@ func unlockAll() error {
 	debug.Log("unlockAll", "unlocking %d locks", len(globalLocks))
 	for _, lock := range globalLocks {
 		if err := lock.Unlock(); err != nil {
+			debug.Log("unlockAll", "error while unlocking: %v", err)
 			return err
 		}
+		debug.Log("unlockAll", "successfully removed lock")
 	}
 
 	return nil

doc/Design.md

@@ -162,7 +162,12 @@ used to reconstruct the index. The files are encrypted and authenticated like
 Data and Tree Blobs, so the outer structure is `IV || Ciphertext || MAC` again.
 The plaintext consists of a JSON document like the following:
 
-    [ {
+    {
+      "obsolete": [
+        "ed54ae36197f4745ebc4b54d10e0f623eaaaedd03013eb7ae90df881b7781452"
+      ],
+      "packs": [
+        {
           "id": "73d04e6125cf3c28a299cc2f3cca3b78ceac396e4fcf9575e34536b26782413c",
           "blobs": [
             {
@@ -183,11 +188,18 @@ The plaintext consists of a JSON document like the following:
               "length": 123
             }
           ]
-    } ]
+        }, [...]
+      ]
+    }
 
-This JSON document lists Blobs with contents. In this example, the Pack
+This JSON document lists Packs and the blobs contained therein. In this
-`73d04e61` contains two data Blobs and one Tree blob, the plaintext hashes are
+example, the Pack `73d04e61` contains two data Blobs and one Tree blob, the
-listed afterwards.
+plaintext hashes are listed afterwards.
+
+The field `obsolete` lists the storage IDs of index files that have been
+replaced with the current index file. This happens when index files are
+repacked, this happens for example when old snapshots are removed and Packs are
+recombined.
 
 There may be an arbitrary number of index files, containing information on
 non-disjoint sets of Packs. The number of packs described in a single file is

repository/config.go

@@ -0,0 +1,87 @@
+package repository
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"io"
+
+	"github.com/restic/restic/backend"
+	"github.com/restic/restic/chunker"
+	"github.com/restic/restic/debug"
+)
+
+// Config contains the configuration for a repository.
+type Config struct {
+	Version           uint        `json:"version"`
+	ID                string      `json:"id"`
+	ChunkerPolynomial chunker.Pol `json:"chunker_polynomial"`
+}
+
+// repositoryIDSize is the length of the ID chosen at random for a new repository.
+const repositoryIDSize = sha256.Size
+
+// RepoVersion is the version that is written to the config when a repository
+// is newly created with Init().
+const RepoVersion = 1
+
+// JSONUnpackedSaver saves unpacked JSON.
+type JSONUnpackedSaver interface {
+	SaveJSONUnpacked(backend.Type, interface{}) (backend.ID, error)
+}
+
+// JSONUnpackedLoader loads unpacked JSON.
+type JSONUnpackedLoader interface {
+	LoadJSONUnpacked(backend.Type, backend.ID, interface{}) error
+}
+
+// CreateConfig creates a config file with a randomly selected polynomial and
+// ID and saves the config in the repository.
+func CreateConfig(r JSONUnpackedSaver) (Config, error) {
+	var (
+		err error
+		cfg Config
+	)
+
+	cfg.ChunkerPolynomial, err = chunker.RandomPolynomial()
+	if err != nil {
+		return Config{}, err
+	}
+
+	newID := make([]byte, repositoryIDSize)
+	_, err = io.ReadFull(rand.Reader, newID)
+	if err != nil {
+		return Config{}, err
+	}
+
+	cfg.ID = hex.EncodeToString(newID)
+	cfg.Version = RepoVersion
+
+	debug.Log("Repo.CreateConfig", "New config: %#v", cfg)
+
+	_, err = r.SaveJSONUnpacked(backend.Config, cfg)
+	return cfg, err
+}
+
+// LoadConfig returns loads, checks and returns the config for a repository.
+func LoadConfig(r JSONUnpackedLoader) (Config, error) {
+	var (
+		cfg Config
+	)
+
+	err := r.LoadJSONUnpacked(backend.Config, nil, &cfg)
+	if err != nil {
+		return Config{}, err
+	}
+
+	if cfg.Version != RepoVersion {
+		return Config{}, errors.New("unsupported repository version")
+	}
+
+	if !cfg.ChunkerPolynomial.Irreducible() {
+		return Config{}, errors.New("invalid chunker polynomial")
+	}
+
+	return cfg, nil
+}

repository/config_test.go

@@ -0,0 +1,53 @@
+package repository_test
+
+import (
+	"testing"
+
+	"github.com/restic/restic/backend"
+	"github.com/restic/restic/repository"
+	. "github.com/restic/restic/test"
+)
+
+type saver func(backend.Type, interface{}) (backend.ID, error)
+
+func (s saver) SaveJSONUnpacked(t backend.Type, arg interface{}) (backend.ID, error) {
+	return s(t, arg)
+}
+
+type loader func(backend.Type, backend.ID, interface{}) error
+
+func (l loader) LoadJSONUnpacked(t backend.Type, id backend.ID, arg interface{}) error {
+	return l(t, id, arg)
+}
+
+func TestConfig(t *testing.T) {
+	resultConfig := repository.Config{}
+	save := func(tpe backend.Type, arg interface{}) (backend.ID, error) {
+		Assert(t, tpe == backend.Config,
+			"wrong backend type: got %v, wanted %v",
+			tpe, backend.Config)
+
+		cfg := arg.(repository.Config)
+		resultConfig = cfg
+		return backend.ID{}, nil
+	}
+
+	cfg1, err := repository.CreateConfig(saver(save))
+	OK(t, err)
+
+	load := func(tpe backend.Type, id backend.ID, arg interface{}) error {
+		Assert(t, tpe == backend.Config,
+			"wrong backend type: got %v, wanted %v",
+			tpe, backend.Config)
+
+		cfg := arg.(*repository.Config)
+		*cfg = resultConfig
+		return nil
+	}
+
+	cfg2, err := repository.LoadConfig(loader(load))
+	OK(t, err)
+
+	Assert(t, cfg1 == cfg2,
+		"configs aren't equal: %v != %v", cfg1, cfg2)
+}

repository/parallel.go

@@ -0,0 +1,71 @@
+package repository
+
+import (
+	"sync"
+
+	"github.com/restic/restic/backend"
+)
+
+func closeIfOpen(ch chan struct{}) {
+	// only close ch when it is not already closed, in which the case statement runs.
+	select {
+	case <-ch:
+		return
+	default:
+		close(ch)
+	}
+}
+
+// ParallelWorkFunc gets one file ID to work on. If an error is returned,
+// processing stops. If done is closed, the function should return.
+type ParallelWorkFunc func(id string, done <-chan struct{}) error
+
+// FilesInParallel runs n workers of f in parallel, on the IDs that
+// repo.List(t) yield. If f returns an error, the process is aborted and the
+// first error is returned.
+func FilesInParallel(repo backend.Lister, t backend.Type, n uint, f ParallelWorkFunc) error {
+	done := make(chan struct{})
+	defer closeIfOpen(done)
+
+	wg := &sync.WaitGroup{}
+
+	ch := repo.List(t, done)
+
+	errors := make(chan error, n)
+
+	for i := 0; uint(i) < n; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+
+			for {
+				select {
+				case id, ok := <-ch:
+					if !ok {
+						return
+					}
+
+					err := f(id, done)
+					if err != nil {
+						closeIfOpen(done)
+						errors <- err
+						return
+					}
+				case <-done:
+					return
+				}
+			}
+		}()
+	}
+
+	wg.Wait()
+
+	select {
+	case err := <-errors:
+		return err
+	default:
+		break
+	}
+
+	return nil
+}

repository/parallel_test.go

@@ -0,0 +1,125 @@
+package repository_test
+
+import (
+	"errors"
+	"math/rand"
+	"testing"
+	"time"
+
+	"github.com/restic/restic/backend"
+	"github.com/restic/restic/repository"
+	. "github.com/restic/restic/test"
+)
+
+type testIDs []string
+
+var lister = testIDs{
+	"40bb581cd36de952985c97a3ff6b21df41ee897d4db2040354caa36a17ff5268",
+	"2e15811a4d14ffac66d36a9ff456019d8de4c10c949d45b643f8477d17e92ff3",
+	"70c11b3ed521ad6b76d905c002ca98b361fca06aca060a063432c7311155a4da",
+	"8056a33e75dccdda701b6c989c7ed0cb71bbb6da13c6427fe5986f0896cc91c0",
+	"79d8776200596aa0237b10d470f7b850b86f8a1a80988ef5c8bee2874ce992e2",
+	"f9f1f29791c6b79b90b35efd083f17a3b163bbbafb1a2fdf43d46d56cffda289",
+	"3834178d05d0f6dd07f872ee0262ff1ace0f0f375768227d3c902b0b66591369",
+	"66d5cc68c9186414806f366ae5493ce7f229212993750a4992be4030f6af28c5",
+	"ebca5af4f397944f68cd215e3dfa2b197a7ba0f7c17d65d9f7390d0a15cde296",
+	"d4511ce6ff732d106275a57e40745c599e987c0da44c42cddbef592aac102437",
+	"f366202f0bfeefaedd7b49e2f21a90d3cbddb97d257a74d788dd34e19a684dae",
+	"a5c17728ab2433cd50636dd5c6c7068c7a44f2999d09c46e8f528466da8a059d",
+	"bae0f9492b9b208233029b87692a1a55cbd7fbe1cf3f6d7bc693ac266a6d6f0e",
+	"9d500187913c7510d71d1902703d312c7aaa56f1e98351385b9535fdabae595e",
+	"ffbddd8a4c1e54d258bb3e16d3929b546b61af63cb560b3e3061a8bef5b24552",
+	"201bb3abf655e7ef71e79ed4fb1079b0502b5acb4d9fad5e72a0de690c50a386",
+	"08eb57bbd559758ea96e99f9b7688c30e7b3bcf0c4562ff4535e2d8edeffaeed",
+	"e50b7223b04985ff38d9e11d1cba333896ef4264f82bd5d0653a028bce70e542",
+	"65a9421cd59cc7b7a71dcd9076136621af607fb4701d2e5c2af23b6396cf2f37",
+	"995a655b3521c19b4d0c266222266d89c8fc62889597d61f45f336091e646d57",
+	"51ec6f0bce77ed97df2dd7ae849338c3a8155a057da927eedd66e3d61be769ad",
+	"7b3923a0c0666431efecdbf6cb171295ec1710b6595eebcba3b576b49d13e214",
+	"2cedcc3d14698bea7e4b0546f7d5d48951dd90add59e6f2d44b693fd8913717d",
+	"fd6770cbd54858fdbd3d7b4239b985e5599180064d93ca873f27e86e8407d011",
+	"9edc51d8e6e04d05c9757848c1bfbfdc8e86b6330982294632488922e59fdb1b",
+	"1a6c4fbb24ad724c968b2020417c3d057e6c89e49bdfb11d91006def65eab6a0",
+	"cb3b29808cd0adfa2dca1f3a04f98114fbccf4eb487cdd4022f49bd70eeb049b",
+	"f55edcb40c619e29a20e432f8aaddc83a649be2c2d1941ccdc474cd2af03d490",
+	"e8ccc1763a92de23566b95c3ad1414a098016ece69a885fc8a72782a7517d17c",
+	"0fe2e3db8c5a12ad7101a63a0fffee901be54319cfe146bead7aec851722f82d",
+	"36be45a6ae7c95ad97cee1b33023be324bce7a7b4b7036e24125679dd9ff5b44",
+	"1685ed1a57c37859fbef1f7efb7509f20b84ec17a765605de43104d2fa37884b",
+	"9d83629a6a004c505b100a0b5d0b246833b63aa067aa9b59e3abd6b74bc4d3a8",
+	"be49a66b60175c5e2ee273b42165f86ef11bb6518c1c79950bcd3f4c196c98bd",
+	"0fd89885d821761b4a890782908e75793028747d15ace3c6cbf0ad56582b4fa5",
+	"94a767519a4e352a88796604943841fea21429f3358b4d5d55596dbda7d15dce",
+	"8dd07994afe6e572ddc9698fb0d13a0d4c26a38b7992818a71a99d1e0ac2b034",
+	"f7380a6f795ed31fbeb2945c72c5fd1d45044e5ab152311e75e007fa530f5847",
+	"5ca1ce01458e484393d7e9c8af42b0ff37a73a2fee0f18e14cff0fb180e33014",
+	"8f44178be3fe0a2bd41f922576fb7a9b19d589754504be746f56c759df328fda",
+	"12d33847c2be711c989f37360dd7aa8537fd14972262a4530634a08fdf32a767",
+	"31e077f5080f78846a00093caff2b6b839519cc47516142eeba9c41d4072a605",
+	"14f01db8a0054e70222b76d2555d70114b4bf8a0f02084324af2df226f14a795",
+	"7f5dbbaf31b4551828e8e76cef408375db9fbcdcdb6b5949f2d1b0c4b8632132",
+	"42a5d9b9bb7e4a16f23ba916bcf87f38c1aa1f2de2ab79736f725850a8ff6a1b",
+	"e06f8f901ea708beba8712a11b6e2d0be7c4b018d0254204ef269bcdf5e8c6cc",
+	"d9ba75785bf45b0c4fd3b2365c968099242483f2f0d0c7c20306dac11fae96e9",
+	"428debbb280873907cef2ec099efe1566e42a59775d6ec74ded0c4048d5a6515",
+	"3b51049d4dae701098e55a69536fa31ad2be1adc17b631a695a40e8a294fe9c0",
+	"168f88aa4b105e9811f5f79439cc1a689be4eec77f3361d42f22fe8f7ddc74a9",
+	"0baa0ab2249b33d64449a899cb7bd8eae5231f0d4ff70f09830dc1faa2e4abee",
+	"0c3896d346b580306a49de29f3a78913a41e14b8461b124628c33a64636241f2",
+	"b18313f1651c15e100e7179aa3eb8ffa62c3581159eaf7f83156468d19781e42",
+	"996361f7d988e48267ccc7e930fed4637be35fe7562b8601dceb7a32313a14c8",
+	"dfb4e6268437d53048d22b811048cd045df15693fc6789affd002a0fc80a6e60",
+	"34dd044c228727f2226a0c9c06a3e5ceb5e30e31cb7854f8fa1cde846b395a58",
+}
+
+func (tests testIDs) List(t backend.Type, done <-chan struct{}) <-chan string {
+	ch := make(chan string)
+
+	go func() {
+		defer close(ch)
+
+		for i := 0; i < 500; i++ {
+			for _, id := range tests {
+				select {
+				case ch <- id:
+				case <-done:
+					return
+				}
+			}
+		}
+	}()
+
+	return ch
+}
+
+func TestFilesInParallel(t *testing.T) {
+	f := func(id string, done <-chan struct{}) error {
+		time.Sleep(1 * time.Millisecond)
+		return nil
+	}
+
+	for n := uint(1); n < 5; n++ {
+		err := repository.FilesInParallel(lister, backend.Data, n*100, f)
+		OK(t, err)
+	}
+}
+
+var errTest = errors.New("test error")
+
+func TestFilesInParallelWithError(t *testing.T) {
+
+	f := func(id string, done <-chan struct{}) error {
+		time.Sleep(1 * time.Millisecond)
+
+		if rand.Float32() < 0.01 {
+			return errTest
+		}
+
+		return nil
+	}
+
+	for n := uint(1); n < 5; n++ {
+		err := repository.FilesInParallel(lister, backend.Data, n*100, f)
+		Equals(t, errTest, err)
+	}
+}

repository/repository.go

@@ -2,9 +2,7 @@ package repository
 
 import (
 	"bytes"
-	"crypto/rand"
 	"crypto/sha256"
-	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -19,13 +17,6 @@ import (
 	"github.com/restic/restic/pack"
 )
 
-// Config contains the configuration for a repository.
-type Config struct {
-	Version           uint        `json:"version"`
-	ID                string      `json:"id"`
-	ChunkerPolynomial chunker.Pol `json:"chunker_polynomial"`
-}
-
 // Repository is used to access a repository in a backend.
 type Repository struct {
 	be      backend.Backend
@@ -38,6 +29,7 @@ type Repository struct {
 	packs []*pack.Packer
 }
 
+// New returns a new repository with backend be.
 func New(be backend.Backend) *Repository {
 	return &Repository{
 		be:  be,
@@ -48,23 +40,23 @@ func New(be backend.Backend) *Repository {
 // Find loads the list of all blobs of type t and searches for names which start
 // with prefix. If none is found, nil and ErrNoIDPrefixFound is returned. If
 // more than one is found, nil and ErrMultipleIDMatches is returned.
-func (s *Repository) Find(t backend.Type, prefix string) (string, error) {
+func (r *Repository) Find(t backend.Type, prefix string) (string, error) {
-	return backend.Find(s.be, t, prefix)
+	return backend.Find(r.be, t, prefix)
 }
 
 // PrefixLength returns the number of bytes required so that all prefixes of
 // all IDs of type t are unique.
-func (s *Repository) PrefixLength(t backend.Type) (int, error) {
+func (r *Repository) PrefixLength(t backend.Type) (int, error) {
-	return backend.PrefixLength(s.be, t)
+	return backend.PrefixLength(r.be, t)
 }
 
-// Load tries to load and decrypt content identified by t and id from the
+// LoadAndDecrypt loads and decrypts data identified by t and id from the
 // backend.
-func (s *Repository) Load(t backend.Type, id backend.ID) ([]byte, error) {
+func (r *Repository) LoadAndDecrypt(t backend.Type, id backend.ID) ([]byte, error) {
 	debug.Log("Repo.Load", "load %v with id %v", t, id.Str())
 
 	// load blob from pack
-	rd, err := s.be.Get(t, id.String())
+	rd, err := r.be.Get(t, id.String())
 	if err != nil {
 		debug.Log("Repo.Load", "error loading %v: %v", id.Str(), err)
 		return nil, err
@@ -86,7 +78,7 @@ func (s *Repository) Load(t backend.Type, id backend.ID) ([]byte, error) {
 	}
 
 	// decrypt
-	plain, err := s.Decrypt(buf)
+	plain, err := r.Decrypt(buf)
 	if err != nil {
 		return nil, err
 	}
@@ -96,10 +88,10 @@ func (s *Repository) Load(t backend.Type, id backend.ID) ([]byte, error) {
 
 // LoadBlob tries to load and decrypt content identified by t and id from a
 // pack from the backend.
-func (s *Repository) LoadBlob(t pack.BlobType, id backend.ID) ([]byte, error) {
+func (r *Repository) LoadBlob(t pack.BlobType, id backend.ID) ([]byte, error) {
 	debug.Log("Repo.LoadBlob", "load %v with id %v", t, id.Str())
 	// lookup pack
-	packID, tpe, offset, length, err := s.idx.Lookup(id)
+	packID, tpe, offset, length, err := r.idx.Lookup(id)
 	if err != nil {
 		debug.Log("Repo.LoadBlob", "id %v not found in index: %v", id.Str(), err)
 		return nil, err
@@ -113,7 +105,7 @@ func (s *Repository) LoadBlob(t pack.BlobType, id backend.ID) ([]byte, error) {
 	debug.Log("Repo.LoadBlob", "id %v found in pack %v at offset %v (length %d)", id.Str(), packID.Str(), offset, length)
 
 	// load blob from pack
-	rd, err := s.be.GetReader(backend.Data, packID.String(), offset, length)
+	rd, err := r.be.GetReader(backend.Data, packID.String(), offset, length)
 	if err != nil {
 		debug.Log("Repo.LoadBlob", "error loading pack %v for %v: %v", packID.Str(), id.Str(), err)
 		return nil, err
@@ -130,7 +122,7 @@ func (s *Repository) LoadBlob(t pack.BlobType, id backend.ID) ([]byte, error) {
 	}
 
 	// decrypt
-	plain, err := s.Decrypt(buf)
+	plain, err := r.Decrypt(buf)
 	if err != nil {
 		return nil, err
 	}
@@ -145,16 +137,16 @@ func (s *Repository) LoadBlob(t pack.BlobType, id backend.ID) ([]byte, error) {
 
 // LoadJSONUnpacked decrypts the data and afterwards calls json.Unmarshal on
 // the item.
-func (s *Repository) LoadJSONUnpacked(t backend.Type, id backend.ID, item interface{}) error {
+func (r *Repository) LoadJSONUnpacked(t backend.Type, id backend.ID, item interface{}) error {
 	// load blob from backend
-	rd, err := s.be.Get(t, id.String())
+	rd, err := r.be.Get(t, id.String())
 	if err != nil {
 		return err
 	}
 	defer rd.Close()
 
 	// decrypt
-	decryptRd, err := crypto.DecryptFrom(s.key, rd)
+	decryptRd, err := crypto.DecryptFrom(r.key, rd)
 	defer decryptRd.Close()
 	if err != nil {
 		return err
@@ -172,22 +164,22 @@ func (s *Repository) LoadJSONUnpacked(t backend.Type, id backend.ID, item interf
 
 // LoadJSONPack calls LoadBlob() to load a blob from the backend, decrypt the
 // data and afterwards call json.Unmarshal on the item.
-func (s *Repository) LoadJSONPack(t pack.BlobType, id backend.ID, item interface{}) error {
+func (r *Repository) LoadJSONPack(t pack.BlobType, id backend.ID, item interface{}) error {
 	// lookup pack
-	packID, _, offset, length, err := s.idx.Lookup(id)
+	packID, _, offset, length, err := r.idx.Lookup(id)
 	if err != nil {
 		return err
 	}
 
 	// load blob from pack
-	rd, err := s.be.GetReader(backend.Data, packID.String(), offset, length)
+	rd, err := r.be.GetReader(backend.Data, packID.String(), offset, length)
 	if err != nil {
 		return err
 	}
 	defer rd.Close()
 
 	// decrypt
-	decryptRd, err := crypto.DecryptFrom(s.key, rd)
+	decryptRd, err := crypto.DecryptFrom(r.key, rd)
 	defer decryptRd.Close()
 	if err != nil {
 		return err
@@ -209,43 +201,43 @@ const maxPackers = 200
 
 // 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 (s *Repository) findPacker(size uint) (*pack.Packer, error) {
+func (r *Repository) findPacker(size uint) (*pack.Packer, error) {
-	s.pm.Lock()
+	r.pm.Lock()
-	defer s.pm.Unlock()
+	defer r.pm.Unlock()
 
 	// search for a suitable packer
-	if len(s.packs) > 0 {
+	if len(r.packs) > 0 {
 		debug.Log("Repo.findPacker", "searching packer for %d bytes\n", size)
-		for i, p := range s.packs {
+		for i, p := range r.packs {
 			if p.Size()+size < maxPackSize {
 				debug.Log("Repo.findPacker", "found packer %v", p)
 				// remove from list
-				s.packs = append(s.packs[:i], s.packs[i+1:]...)
+				r.packs = append(r.packs[:i], r.packs[i+1:]...)
 				return p, nil
 			}
 		}
 	}
 
 	// no suitable packer found, return new
-	blob, err := s.be.Create()
+	blob, err := r.be.Create()
 	if err != nil {
 		return nil, err
 	}
 	debug.Log("Repo.findPacker", "create new pack %p", blob)
-	return pack.NewPacker(s.key, blob), nil
+	return pack.NewPacker(r.key, blob), nil
 }
 
 // insertPacker appends p to s.packs.
-func (s *Repository) insertPacker(p *pack.Packer) {
+func (r *Repository) insertPacker(p *pack.Packer) {
-	s.pm.Lock()
+	r.pm.Lock()
-	defer s.pm.Unlock()
+	defer r.pm.Unlock()
 
-	s.packs = append(s.packs, p)
+	r.packs = append(r.packs, p)
-	debug.Log("Repo.insertPacker", "%d packers\n", len(s.packs))
+	debug.Log("Repo.insertPacker", "%d packers\n", len(r.packs))
 }
 
 // savePacker stores p in the backend.
-func (s *Repository) savePacker(p *pack.Packer) error {
+func (r *Repository) savePacker(p *pack.Packer) error {
 	debug.Log("Repo.savePacker", "save packer with %d blobs\n", p.Count())
 	_, err := p.Finalize()
 	if err != nil {
@@ -265,23 +257,23 @@ func (s *Repository) savePacker(p *pack.Packer) error {
 	// update blobs in the index
 	for _, b := range p.Blobs() {
 		debug.Log("Repo.savePacker", "  updating blob %v to pack %v", b.ID.Str(), sid.Str())
-		s.idx.Store(b.Type, b.ID, sid, b.Offset, uint(b.Length))
+		r.idx.Store(b.Type, b.ID, sid, b.Offset, uint(b.Length))
 	}
 
 	return nil
 }
 
 // countPacker returns the number of open (unfinished) packers.
-func (s *Repository) countPacker() int {
+func (r *Repository) countPacker() int {
-	s.pm.Lock()
+	r.pm.Lock()
-	defer s.pm.Unlock()
+	defer r.pm.Unlock()
 
-	return len(s.packs)
+	return len(r.packs)
 }
 
-// Save encrypts data and stores it to the backend as type t. If data is small
+// SaveAndEncrypt encrypts data and stores it to the backend as type t. If data is small
 // enough, it will be packed together with other small blobs.
-func (s *Repository) Save(t pack.BlobType, data []byte, id backend.ID) (backend.ID, error) {
+func (r *Repository) SaveAndEncrypt(t pack.BlobType, data []byte, id backend.ID) (backend.ID, error) {
 	if id == nil {
 		// compute plaintext hash
 		id = backend.Hash(data)
@@ -294,13 +286,13 @@ func (s *Repository) Save(t pack.BlobType, data []byte, id backend.ID) (backend.
 	defer freeBuf(ciphertext)
 
 	// encrypt blob
-	ciphertext, err := s.Encrypt(ciphertext, data)
+	ciphertext, err := r.Encrypt(ciphertext, data)
 	if err != nil {
 		return nil, err
 	}
 
 	// find suitable packer and add blob
-	packer, err := s.findPacker(uint(len(ciphertext)))
+	packer, err := r.findPacker(uint(len(ciphertext)))
 	if err != nil {
 		return nil, err
 	}
@@ -310,23 +302,23 @@ func (s *Repository) Save(t pack.BlobType, data []byte, id backend.ID) (backend.
 
 	// add this id to the index, although we don't know yet in which pack it
 	// will be saved, the entry will be updated when the pack is written.
-	s.idx.Store(t, id, nil, 0, 0)
+	r.idx.Store(t, id, nil, 0, 0)
 	debug.Log("Repo.Save", "saving stub for %v (%v) in index", id.Str, t)
 
 	// if the pack is not full enough and there are less than maxPackers
 	// packers, put back to the list
-	if packer.Size() < minPackSize && s.countPacker() < maxPackers {
+	if packer.Size() < minPackSize && r.countPacker() < maxPackers {
 		debug.Log("Repo.Save", "pack is not full enough (%d bytes)", packer.Size())
-		s.insertPacker(packer)
+		r.insertPacker(packer)
 		return id, nil
 	}
 
 	// else write the pack to the backend
-	return id, s.savePacker(packer)
+	return id, r.savePacker(packer)
 }
 
 // SaveFrom encrypts data read from rd and stores it in a pack in the backend as type t.
-func (s *Repository) SaveFrom(t pack.BlobType, id backend.ID, length uint, rd io.Reader) error {
+func (r *Repository) SaveFrom(t pack.BlobType, id backend.ID, length uint, rd io.Reader) error {
 	debug.Log("Repo.SaveFrom", "save id %v (%v, %d bytes)", id.Str(), t, length)
 	if id == nil {
 		return errors.New("id is nil")
@@ -337,7 +329,7 @@ func (s *Repository) SaveFrom(t pack.BlobType, id backend.ID, length uint, rd io
 		return err
 	}
 
-	_, err = s.Save(t, buf, id)
+	_, err = r.SaveAndEncrypt(t, buf, id)
 	if err != nil {
 		return err
 	}
@@ -347,7 +339,7 @@ func (s *Repository) SaveFrom(t pack.BlobType, id backend.ID, length uint, rd io
 
 // SaveJSON serialises item as JSON and encrypts and saves it in a pack in the
 // backend as type t.
-func (s *Repository) SaveJSON(t pack.BlobType, item interface{}) (backend.ID, error) {
+func (r *Repository) SaveJSON(t pack.BlobType, item interface{}) (backend.ID, error) {
 	debug.Log("Repo.SaveJSON", "save %v blob", t)
 	buf := getBuf()[:0]
 	defer freeBuf(buf)
@@ -361,14 +353,14 @@ func (s *Repository) SaveJSON(t pack.BlobType, item interface{}) (backend.ID, er
 	}
 
 	buf = wr.Bytes()
-	return s.Save(t, buf, nil)
+	return r.SaveAndEncrypt(t, buf, nil)
 }
 
 // SaveJSONUnpacked serialises item as JSON and encrypts and saves it in the
 // backend as type t, without a pack. It returns the storage hash.
-func (s *Repository) SaveJSONUnpacked(t backend.Type, item interface{}) (backend.ID, error) {
+func (r *Repository) SaveJSONUnpacked(t backend.Type, item interface{}) (backend.ID, error) {
 	// create file
-	blob, err := s.be.Create()
+	blob, err := r.be.Create()
 	if err != nil {
 		return nil, err
 	}
@@ -378,7 +370,7 @@ func (s *Repository) SaveJSONUnpacked(t backend.Type, item interface{}) (backend
 	hw := backend.NewHashingWriter(blob, sha256.New())
 
 	// encrypt blob
-	ewr := crypto.EncryptTo(s.key, hw)
+	ewr := crypto.EncryptTo(r.key, hw)
 
 	enc := json.NewEncoder(ewr)
 	err = enc.Encode(item)
@@ -406,43 +398,45 @@ func (s *Repository) SaveJSONUnpacked(t backend.Type, item interface{}) (backend
 }
 
 // Flush saves all remaining packs.
-func (s *Repository) Flush() error {
+func (r *Repository) Flush() error {
-	s.pm.Lock()
+	r.pm.Lock()
-	defer s.pm.Unlock()
+	defer r.pm.Unlock()
 
-	debug.Log("Repo.Flush", "manually flushing %d packs", len(s.packs))
+	debug.Log("Repo.Flush", "manually flushing %d packs", len(r.packs))
 
-	for _, p := range s.packs {
+	for _, p := range r.packs {
-		err := s.savePacker(p)
+		err := r.savePacker(p)
 		if err != nil {
 			return err
 		}
 	}
-	s.packs = s.packs[:0]
+	r.packs = r.packs[:0]
 
 	return nil
 }
 
-func (s *Repository) Backend() backend.Backend {
+// Backend returns the backend for the repository.
-	return s.be
+func (r *Repository) Backend() backend.Backend {
+	return r.be
 }
 
-func (s *Repository) Index() *Index {
+// Index returns the currently loaded Index.
-	return s.idx
+func (r *Repository) Index() *Index {
+	return r.idx
 }
 
 // SetIndex instructs the repository to use the given index.
-func (s *Repository) SetIndex(i *Index) {
+func (r *Repository) SetIndex(i *Index) {
-	s.idx = i
+	r.idx = i
 }
 
 // SaveIndex saves all new packs in the index in the backend, returned is the
 // storage ID.
-func (s *Repository) SaveIndex() (backend.ID, error) {
+func (r *Repository) SaveIndex() (backend.ID, error) {
 	debug.Log("Repo.SaveIndex", "Saving index")
 
 	// create blob
-	blob, err := s.be.Create()
+	blob, err := r.be.Create()
 	if err != nil {
 		return nil, err
 	}
@@ -453,9 +447,9 @@ func (s *Repository) SaveIndex() (backend.ID, error) {
 	hw := backend.NewHashingWriter(blob, sha256.New())
 
 	// encrypt blob
-	ewr := crypto.EncryptTo(s.key, hw)
+	ewr := crypto.EncryptTo(r.key, hw)
 
-	err = s.idx.Encode(ewr)
+	err = r.idx.Encode(ewr)
 	if err != nil {
 		return nil, err
 	}
@@ -478,112 +472,90 @@ func (s *Repository) SaveIndex() (backend.ID, error) {
 	return sid, nil
 }
 
-// LoadIndex loads all index files from the backend and merges them with the
+const loadIndexParallelism = 20
-// current index.
-func (s *Repository) LoadIndex() error {
-	debug.Log("Repo.LoadIndex", "Loading index")
-	done := make(chan struct{})
-	defer close(done)
 
-	for id := range s.be.List(backend.Index, done) {
+// LoadIndex loads all index files from the backend in parallel and merges them
-		err := s.loadIndex(id)
+// with the current index. The first error that occurred is returned.
+func (r *Repository) LoadIndex() error {
+	debug.Log("Repo.LoadIndex", "Loading index")
+
+	errCh := make(chan error, 1)
+	indexes := make(chan *Index)
+
+	worker := func(id string, done <-chan struct{}) error {
+		idx, err := LoadIndex(r, id)
 		if err != nil {
 			return err
 		}
+
+		select {
+		case indexes <- idx:
+		case <-done:
 		}
+
+		return nil
+	}
+
+	go func() {
+		defer close(indexes)
+		errCh <- FilesInParallel(r.be, backend.Index, loadIndexParallelism, worker)
+	}()
+
+	for idx := range indexes {
+		r.idx.Merge(idx)
+	}
+
+	if err := <-errCh; err != nil {
+		return err
+	}
+
 	return nil
 }
 
-// loadIndex loads the index id and merges it with the currently used index.
+// LoadIndex loads the index id from backend and returns it.
-func (s *Repository) loadIndex(id string) error {
+func LoadIndex(repo *Repository, id string) (*Index, error) {
-	debug.Log("Repo.loadIndex", "Loading index %v", id[:8])
+	debug.Log("LoadIndex", "Loading index %v", id[:8])
-	before := len(s.idx.pack)
 
-	rd, err := s.be.Get(backend.Index, id)
+	rd, err := repo.be.Get(backend.Index, id)
 	defer rd.Close()
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	// decrypt
-	decryptRd, err := crypto.DecryptFrom(s.key, rd)
+	decryptRd, err := crypto.DecryptFrom(repo.key, rd)
 	defer decryptRd.Close()
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	idx, err := DecodeIndex(decryptRd)
 	if err != nil {
-		debug.Log("Repo.loadIndex", "error while decoding index %v: %v", id, err)
+		debug.Log("LoadIndex", "error while decoding index %v: %v", id, err)
-		return err
+		return nil, err
 	}
 
-	s.idx.Merge(idx)
+	return idx, nil
-
-	after := len(s.idx.pack)
-	debug.Log("Repo.loadIndex", "Loaded index %v, added %v blobs", id[:8], after-before)
-
-	return nil
-}
-
-const repositoryIDSize = sha256.Size
-const RepoVersion = 1
-
-func createConfig(s *Repository) (err error) {
-	s.Config.ChunkerPolynomial, err = chunker.RandomPolynomial()
-	if err != nil {
-		return err
-	}
-
-	newID := make([]byte, repositoryIDSize)
-	_, err = io.ReadFull(rand.Reader, newID)
-	if err != nil {
-		return err
-	}
-
-	s.Config.ID = hex.EncodeToString(newID)
-	s.Config.Version = RepoVersion
-
-	debug.Log("Repo.createConfig", "New config: %#v", s.Config)
-
-	_, err = s.SaveJSONUnpacked(backend.Config, s.Config)
-	return err
-}
-
-func (s *Repository) loadConfig(cfg *Config) error {
-	err := s.LoadJSONUnpacked(backend.Config, nil, cfg)
-	if err != nil {
-		return err
-	}
-
-	if cfg.Version != RepoVersion {
-		return errors.New("unsupported repository version")
-	}
-
-	if !cfg.ChunkerPolynomial.Irreducible() {
-		return errors.New("invalid chunker polynomial")
-	}
-
-	return nil
 }
 
 // SearchKey finds a key with the supplied password, afterwards the config is
 // read and parsed.
-func (s *Repository) SearchKey(password string) error {
+func (r *Repository) SearchKey(password string) error {
-	key, err := SearchKey(s, password)
+	key, err := SearchKey(r, password)
 	if err != nil {
 		return err
 	}
 
-	s.key = key.master
+	r.key = key.master
-	s.keyName = key.Name()
+	r.keyName = key.Name()
-	return s.loadConfig(&s.Config)
+	r.Config, err = LoadConfig(r)
+	return err
 }
 
-// Init creates a new master key with the supplied password and initializes the
+// Init creates a new master key with the supplied password, initializes and
-// repository config.
+// saves the repository config.
-func (s *Repository) Init(password string) error {
+func (r *Repository) Init(password string) error {
-	has, err := s.be.Test(backend.Config, "")
+	has, err := r.be.Test(backend.Config, "")
 	if err != nil {
 		return err
 	}
@@ -591,52 +563,58 @@ func (s *Repository) Init(password string) error {
 		return errors.New("repository master key and config already initialized")
 	}
 
-	key, err := createMasterKey(s, password)
+	key, err := createMasterKey(r, password)
 	if err != nil {
 		return err
 	}
 
-	s.key = key.master
+	r.key = key.master
-	s.keyName = key.Name()
+	r.keyName = key.Name()
-	return createConfig(s)
+	r.Config, err = CreateConfig(r)
+	return err
 }
 
-func (s *Repository) Decrypt(ciphertext []byte) ([]byte, error) {
+// Decrypt authenticates and decrypts ciphertext and returns the plaintext.
-	if s.key == nil {
+func (r *Repository) Decrypt(ciphertext []byte) ([]byte, error) {
+	if r.key == nil {
 		return nil, errors.New("key for repository not set")
 	}
 
-	return crypto.Decrypt(s.key, nil, ciphertext)
+	return crypto.Decrypt(r.key, nil, ciphertext)
 }
 
-func (s *Repository) Encrypt(ciphertext, plaintext []byte) ([]byte, error) {
+// Encrypt encrypts and authenticates the plaintext and saves the result in
-	if s.key == nil {
+// ciphertext.
+func (r *Repository) Encrypt(ciphertext, plaintext []byte) ([]byte, error) {
+	if r.key == nil {
 		return nil, errors.New("key for repository not set")
 	}
 
-	return crypto.Encrypt(s.key, ciphertext, plaintext)
+	return crypto.Encrypt(r.key, ciphertext, plaintext)
 }
 
-func (s *Repository) Key() *crypto.Key {
+// Key returns the current master key.
-	return s.key
+func (r *Repository) Key() *crypto.Key {
+	return r.key
 }
 
-func (s *Repository) KeyName() string {
+// KeyName returns the name of the current key in the backend.
-	return s.keyName
+func (r *Repository) KeyName() string {
+	return r.keyName
 }
 
 // Count returns the number of blobs of a given type in the backend.
-func (s *Repository) Count(t backend.Type) (n uint) {
+func (r *Repository) Count(t backend.Type) (n uint) {
-	for _ = range s.be.List(t, nil) {
+	for _ = range r.be.List(t, nil) {
 		n++
 	}
 
 	return
 }
 
-func (s *Repository) list(t backend.Type, done <-chan struct{}, out chan<- backend.ID) {
+func (r *Repository) list(t backend.Type, done <-chan struct{}, out chan<- backend.ID) {
 	defer close(out)
-	in := s.be.List(t, done)
+	in := r.be.List(t, done)
 
 	var (
 		// disable sending on the outCh until we received a job
@@ -671,22 +649,26 @@ func (s *Repository) list(t backend.Type, done <-chan struct{}, out chan<- backe
 	}
 }
 
-func (s *Repository) List(t backend.Type, done <-chan struct{}) <-chan backend.ID {
+// List returns a channel that yields all IDs of type t in the backend.
+func (r *Repository) List(t backend.Type, done <-chan struct{}) <-chan backend.ID {
 	outCh := make(chan backend.ID)
 
-	go s.list(t, done, outCh)
+	go r.list(t, done, outCh)
 
 	return outCh
 }
 
-func (s *Repository) Delete() error {
+// Delete calls backend.Delete() if implemented, and returns an error
-	if b, ok := s.be.(backend.Deleter); ok {
+// otherwise.
+func (r *Repository) Delete() error {
+	if b, ok := r.be.(backend.Deleter); ok {
 		return b.Delete()
 	}
 
 	return errors.New("Delete() called for backend that does not implement this method")
 }
 
-func (s *Repository) Close() error {
+// Close closes the repository by closing the backend.
-	return s.be.Close()
+func (r *Repository) Close() error {
+	return r.be.Close()
 }

repository/repository_test.go

@@ -6,11 +6,13 @@ import (
 	"crypto/sha256"
 	"encoding/json"
 	"io"
+	"path/filepath"
 	"testing"
 
 	"github.com/restic/restic"
 	"github.com/restic/restic/backend"
 	"github.com/restic/restic/pack"
+	"github.com/restic/restic/repository"
 	. "github.com/restic/restic/test"
 )
 
@@ -80,7 +82,7 @@ func TestSave(t *testing.T) {
 		id := backend.Hash(data)
 
 		// save
-		sid, err := repo.Save(pack.Data, data, nil)
+		sid, err := repo.SaveAndEncrypt(pack.Data, data, nil)
 		OK(t, err)
 
 		Equals(t, id, sid)
@@ -194,3 +196,24 @@ func TestLoadJSONUnpacked(t *testing.T) {
 	Equals(t, sn.Hostname, sn2.Hostname)
 	Equals(t, sn.Username, sn2.Username)
 }
+
+var repoFixture = filepath.Join("testdata", "test-repo.tar.gz")
+
+func TestLoadIndex(t *testing.T) {
+	WithTestEnvironment(t, repoFixture, func(repodir string) {
+		repo := OpenLocalRepo(t, repodir)
+		OK(t, repo.LoadIndex())
+	})
+}
+
+func BenchmarkLoadIndex(b *testing.B) {
+	WithTestEnvironment(b, repoFixture, func(repodir string) {
+		repo := OpenLocalRepo(b, repodir)
+		b.ResetTimer()
+
+		for i := 0; i < b.N; i++ {
+			repo.SetIndex(repository.NewIndex())
+			OK(b, repo.LoadIndex())
+		}
+	})
+}

test/helpers.go

@@ -3,13 +3,18 @@ package test_helper
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"math/rand"
+	"os"
+	"os/exec"
 	"path/filepath"
 	"reflect"
 	"runtime"
 	"testing"
 
 	"github.com/restic/restic/backend"
+	"github.com/restic/restic/backend/local"
+	"github.com/restic/restic/repository"
 )
 
 // Assert fails the test if the condition is false.
@@ -65,3 +70,56 @@ func Random(seed, count int) []byte {
 func RandomReader(seed, size int) *bytes.Reader {
 	return bytes.NewReader(Random(seed, size))
 }
+
+// SetupTarTestFixture extracts the tarFile to outputDir.
+func SetupTarTestFixture(t testing.TB, outputDir, tarFile string) {
+	err := System("sh", "-c", `(cd "$1" && tar xz) < "$2"`,
+		"sh", outputDir, tarFile)
+	OK(t, err)
+}
+
+// System runs the command and returns the exit code. Output is passed on to
+// stdout/stderr.
+func System(command string, args ...string) error {
+	cmd := exec.Command(command, args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}
+
+// WithTestEnvironment creates a test environment, extracts the repository
+// fixture and and calls f with the repository dir.
+func WithTestEnvironment(t testing.TB, repoFixture string, f func(repodir string)) {
+	tempdir, err := ioutil.TempDir(TestTempDir, "restic-test-")
+	OK(t, err)
+
+	fd, err := os.Open(repoFixture)
+	if err != nil {
+		panic(err)
+	}
+	OK(t, fd.Close())
+
+	SetupTarTestFixture(t, tempdir, repoFixture)
+
+	f(filepath.Join(tempdir, "repo"))
+
+	if !TestCleanup {
+		t.Logf("leaving temporary directory %v used for test", tempdir)
+		return
+	}
+
+	OK(t, os.RemoveAll(tempdir))
+}
+
+// OpenLocalRepo opens the local repository located at dir.
+func OpenLocalRepo(t testing.TB, dir string) *repository.Repository {
+	be, err := local.Open(dir)
+	OK(t, err)
+
+	repo := repository.New(be)
+	err = repo.SearchKey(TestPassword)
+	OK(t, err)
+
+	return repo
+}