add option for setting min pack size

cmd/restic/cmd_init.go

@@ -86,7 +86,13 @@ func runInit(opts InitOptions, gopts GlobalOptions, args []string) error {
 		return errors.Fatalf("create repository at %s failed: %v\n", location.StripPassword(gopts.Repo), err)
 	}
 
-	s := repository.New(be, repository.Options{Compression: gopts.Compression})
+	s, err := repository.New(be, repository.Options{
+		Compression: gopts.Compression,
+		PackSize:    gopts.MinPackSize * 1024 * 1024,
+	})
+	if err != nil {
+		return err
+	}
 
 	err = s.Init(gopts.ctx, version, gopts.password, chunkerPolynomial)
 	if err != nil {

cmd/restic/global.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
 	"syscall"
 	"time"
@@ -62,6 +63,7 @@ type GlobalOptions struct {
 	NoCache         bool
 	CleanupCache    bool
 	Compression     repository.CompressionMode
+	MinPackSize     uint
 
 	backend.TransportOptions
 	limiter.Limits
@@ -102,6 +104,9 @@ func init() {
 		return nil
 	})
 
+	// parse min pack size from env, on error the default value will be used
+	minPackSize, _ := strconv.ParseUint(os.Getenv("RESTIC_MIN_PACKSIZE"), 10, 32)
+
 	f := cmdRoot.PersistentFlags()
 	f.StringVarP(&globalOptions.Repo, "repo", "r", os.Getenv("RESTIC_REPOSITORY"), "`repository` to backup to or restore from (default: $RESTIC_REPOSITORY)")
 	f.StringVarP(&globalOptions.RepositoryFile, "repository-file", "", os.Getenv("RESTIC_REPOSITORY_FILE"), "`file` to read the repository location from (default: $RESTIC_REPOSITORY_FILE)")
@@ -121,6 +126,7 @@ func init() {
 	f.Var(&globalOptions.Compression, "compression", "compression mode (only available for repository format version 2), one of (auto|off|max)")
 	f.IntVar(&globalOptions.Limits.UploadKb, "limit-upload", 0, "limits uploads to a maximum rate in KiB/s. (default: unlimited)")
 	f.IntVar(&globalOptions.Limits.DownloadKb, "limit-download", 0, "limits downloads to a maximum rate in KiB/s. (default: unlimited)")
+	f.UintVar(&globalOptions.MinPackSize, "min-packsize", uint(minPackSize), "set min pack size in MiB. (default: $RESTIC_MIN_PACKSIZE)")
 	f.StringSliceVarP(&globalOptions.Options, "option", "o", []string{}, "set extended option (`key=value`, can be specified multiple times)")
 	// Use our "generate" command instead of the cobra provided "completion" command
 	cmdRoot.CompletionOptions.DisableDefaultCmd = true
@@ -440,7 +446,13 @@ func OpenRepository(opts GlobalOptions) (*repository.Repository, error) {
 		}
 	}
 
-	s := repository.New(be, repository.Options{Compression: opts.Compression})
+	s, err := repository.New(be, repository.Options{
+		Compression: opts.Compression,
+		PackSize:    opts.MinPackSize * 1024 * 1024,
+	})
+	if err != nil {
+		return nil, err
+	}
 
 	passwordTriesLeft := 1
 	if stdinIsTerminal() && opts.password == "" {

internal/checker/checker_test.go

@@ -348,7 +348,8 @@ func TestCheckerModifiedData(t *testing.T) {
 	t.Logf("archived as %v", sn.ID().Str())
 
 	beError := &errorBackend{Backend: repo.Backend()}
-	checkRepo := repository.New(beError, repository.Options{})
+	checkRepo, err := repository.New(beError, repository.Options{})
+	test.OK(t, err)
 	test.OK(t, checkRepo.SearchKey(context.TODO(), test.TestPassword, 5, ""))
 
 	chkr := checker.New(checkRepo, false)

internal/repository/packer_manager.go

@@ -36,17 +36,17 @@ type packerManager struct {
 
 	pm       sync.Mutex
 	packer   *Packer
+	packSize uint
 }
 
-const minPackSize = 4 * 1024 * 1024
-
 // newPackerManager returns an new packer manager which writes temporary files
 // to a temporary directory
-func newPackerManager(key *crypto.Key, tpe restic.BlobType, queueFn func(ctx context.Context, t restic.BlobType, p *Packer) error) *packerManager {
+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,
 	}
 }
 
@@ -88,7 +88,7 @@ func (r *packerManager) SaveBlob(ctx context.Context, t restic.BlobType, id rest
 	}
 
 	// if the pack is not full enough, put back to the list
-	if packer.Size() < minPackSize {
+	if packer.Size() < r.packSize {
 		debug.Log("pack is not full enough (%d bytes)", packer.Size())
 		return size, nil
 	}

internal/repository/packer_manager_test.go

@@ -31,7 +31,7 @@ func min(a, b int) int {
 }
 
 func fillPacks(t testing.TB, rnd *rand.Rand, pm *packerManager, buf []byte) (bytes int) {
-	for i := 0; i < 100; i++ {
+	for i := 0; i < 102; i++ {
 		l := rnd.Intn(maxBlobSize)
 		id := randomID(rnd)
 		buf = buf[:l]
@@ -70,7 +70,7 @@ func testPackerManager(t testing.TB) int64 {
 	rnd := rand.New(rand.NewSource(randomSeed))
 
 	savedBytes := int(0)
-	pm := newPackerManager(crypto.NewRandomKey(), restic.DataBlob, func(ctx context.Context, tp restic.BlobType, p *Packer) error {
+	pm := newPackerManager(crypto.NewRandomKey(), restic.DataBlob, DefaultPackSize, func(ctx context.Context, tp restic.BlobType, p *Packer) error {
 		err := p.Finalize()
 		if err != nil {
 			return err
@@ -104,7 +104,7 @@ func BenchmarkPackerManager(t *testing.B) {
 
 	for i := 0; i < t.N; i++ {
 		rnd.Seed(randomSeed)
-		pm := newPackerManager(crypto.NewRandomKey(), restic.DataBlob, func(ctx context.Context, t restic.BlobType, p *Packer) error {
+		pm := newPackerManager(crypto.NewRandomKey(), restic.DataBlob, DefaultPackSize, func(ctx context.Context, t restic.BlobType, p *Packer) error {
 			return nil
 		})
 		fillPacks(t, rnd, pm, blobBuf)

internal/repository/repository.go

@@ -28,6 +28,10 @@ import (
 
 const MaxStreamBufferSize = 4 * 1024 * 1024
 
+const MinPackSize = 4 * 1024 * 1024
+const DefaultPackSize = 16 * 1024 * 1024
+const MaxPackSize = 128 * 1024 * 1024
+
 // Repository is used to access a repository in a backend.
 type Repository struct {
 	be      restic.Backend
@@ -54,6 +58,7 @@ type Repository struct {
 
 type Options struct {
 	Compression CompressionMode
+	PackSize    uint
 }
 
 // CompressionMode configures if data should be compressed.
@@ -100,14 +105,23 @@ func (c *CompressionMode) Type() string {
 }
 
 // New returns a new repository with backend be.
-func New(be restic.Backend, opts Options) *Repository {
+func New(be restic.Backend, opts Options) (*Repository, error) {
+	if opts.PackSize == 0 {
+		opts.PackSize = DefaultPackSize
+	}
+	if opts.PackSize > MaxPackSize {
+		return nil, errors.Fatalf("pack size larger than limit of %v MiB", MaxPackSize/1024/1024)
+	} else if opts.PackSize < MinPackSize {
+		return nil, errors.Fatalf("pack size smaller than minimum of %v MiB", MinPackSize/1024/1024)
+	}
+
 	repo := &Repository{
 		be:   be,
 		opts: opts,
 		idx:  NewMasterIndex(),
 	}
 
-	return repo
+	return repo, nil
 }
 
 // DisableAutoIndexUpdate deactives the automatic finalization and upload of new
@@ -129,6 +143,11 @@ func (r *Repository) Config() restic.Config {
 	return r.cfg
 }
 
+// MinPackSize return the minimum size of a pack file before uploading
+func (r *Repository) MinPackSize() uint {
+	return r.opts.PackSize
+}
+
 // UseCache replaces the backend with the wrapped cache.
 func (r *Repository) UseCache(c *cache.Cache) {
 	if c == nil {
@@ -497,8 +516,8 @@ func (r *Repository) StartPackUploader(ctx context.Context, wg *errgroup.Group)
 	innerWg, ctx := errgroup.WithContext(ctx)
 	r.packerWg = innerWg
 	r.uploader = newPackerUploader(ctx, innerWg, r, r.be.Connections())
-	r.treePM = newPackerManager(r.key, restic.TreeBlob, r.uploader.QueuePacker)
+	r.treePM = newPackerManager(r.key, restic.TreeBlob, r.MinPackSize(), r.uploader.QueuePacker)
-	r.dataPM = newPackerManager(r.key, restic.DataBlob, r.uploader.QueuePacker)
+	r.dataPM = newPackerManager(r.key, restic.DataBlob, r.MinPackSize(), r.uploader.QueuePacker)
 
 	wg.Go(func() error {
 		return innerWg.Wait()

internal/repository/testing.go

@@ -52,10 +52,13 @@ func TestRepositoryWithBackend(t testing.TB, be restic.Backend, version uint) (r
 		be, beCleanup = TestBackend(t)
 	}
 
-	repo := New(be, Options{})
+	repo, err := New(be, Options{})
+	if err != nil {
+		t.Fatalf("TestRepository(): new repo failed: %v", err)
+	}
 
 	cfg := restic.TestCreateConfig(t, TestChunkerPol, version)
-	err := repo.init(context.TODO(), test.TestPassword, cfg)
+	err = repo.init(context.TODO(), test.TestPassword, cfg)
 	if err != nil {
 		t.Fatalf("TestRepository(): initialize repo failed: %v", err)
 	}
@@ -104,7 +107,10 @@ func TestOpenLocal(t testing.TB, dir string) (r restic.Repository) {
 		t.Fatal(err)
 	}
 
-	repo := New(be, Options{})
+	repo, err := New(be, Options{})
+	if err != nil {
+		t.Fatal(err)
+	}
 	err = repo.SearchKey(context.TODO(), test.TestPassword, 10, "")
 	if err != nil {
 		t.Fatal(err)

internal/restic/repository.go

@@ -25,6 +25,7 @@ type Repository interface {
 	LookupBlobSize(ID, BlobType) (uint, bool)
 
 	Config() Config
+	MinPackSize() uint
 
 	// List calls the function fn for each file of type t in the repository.
 	// When an error is returned by fn, processing stops and List() returns the