From a45f557c4bde3f1434eaab776ee0d20eeb20c888 Mon Sep 17 00:00:00 2001
From: Jarek Kowalski <jaak@jkowalski.net>
Date: Sat, 14 Oct 2017 15:49:32 -0700
Subject: [PATCH] changed object.ManagerOptions into a struct

---
 cli/command_snapshot_create.go |  4 +++-
 cli/config.go                  |  4 +---
 object/object_manager.go       | 30 ++++++++++++++----------------
 object/object_manager_test.go  |  8 ++++----
 repo/connection.go             |  4 ++--
 5 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/cli/command_snapshot_create.go b/cli/command_snapshot_create.go
index 0bc7f6ced..7d05e49fe 100644
--- a/cli/command_snapshot_create.go
+++ b/cli/command_snapshot_create.go
@@ -41,7 +41,9 @@ var (
 
 func runBackupCommand(c *kingpin.ParseContext) error {
 	rep := mustOpenRepository(&repo.Options{
-		ObjectManagerOptions: []object.ManagerOption{object.WriteBack(*snapshotCreateWriteBack)},
+		ObjectManagerOptions: object.ManagerOptions{
+			WriteBack: *snapshotCreateWriteBack,
+		},
 	})
 	defer rep.Close()
 
diff --git a/cli/config.go b/cli/config.go
index c73eb53d0..5a3e58173 100644
--- a/cli/config.go
+++ b/cli/config.go
@@ -12,8 +12,6 @@ import (
 	"runtime"
 	"strings"
 
-	"github.com/kopia/kopia/object"
-
 	"github.com/bgentry/speakeasy"
 	"github.com/kopia/kopia/auth"
 	"github.com/kopia/kopia/fs"
@@ -81,7 +79,7 @@ func applyOptionsFromFlags(opts *repo.Options) *repo.Options {
 	}
 
 	if *traceObjectManager {
-		opts.ObjectManagerOptions = append(opts.ObjectManagerOptions, object.Trace(log.Printf))
+		opts.ObjectManagerOptions.Trace = log.Printf
 	}
 
 	return opts
diff --git a/object/object_manager.go b/object/object_manager.go
index a8752cfc8..fbd3c0a89 100644
--- a/object/object_manager.go
+++ b/object/object_manager.go
@@ -186,23 +186,14 @@ func validateFormat(f *config.RepositoryObjectFormat) error {
 	return nil
 }
 
-type ManagerOption func(om *Manager)
-
-func WriteBack(parallelism int) ManagerOption {
-	return func(om *Manager) {
-		om.async = true
-		om.writeBackSemaphore = make(semaphore, parallelism)
-	}
-}
-
-func Trace(traceFunc func(message string, args ...interface{})) ManagerOption {
-	return func(om *Manager) {
-		om.trace = traceFunc
-	}
+// ManagerOptions specifies object manager options.
+type ManagerOptions struct {
+	WriteBack int
+	Trace     func(message string, args ...interface{})
 }
 
 // NewObjectManager creates an ObjectManager with the specified block manager and format.
-func NewObjectManager(bm blockManager, f config.RepositoryObjectFormat, opts ...ManagerOption) (*Manager, error) {
+func NewObjectManager(bm blockManager, f config.RepositoryObjectFormat, opts ManagerOptions) (*Manager, error) {
 	if err := validateFormat(&f); err != nil {
 		return nil, err
 	}
@@ -227,8 +218,15 @@ func NewObjectManager(bm blockManager, f config.RepositoryObjectFormat, opts ...
 		return os(&f)
 	}
 
-	for _, o := range opts {
-		o(om)
+	if opts.Trace != nil {
+		om.trace = opts.Trace
+	} else {
+		om.trace = nullTrace
+	}
+
+	if opts.WriteBack > 0 {
+		om.async = true
+		om.writeBackSemaphore = make(semaphore, opts.WriteBack)
 	}
 
 	return om, nil
diff --git a/object/object_manager_test.go b/object/object_manager_test.go
index c5e97811e..34793461b 100644
--- a/object/object_manager_test.go
+++ b/object/object_manager_test.go
@@ -63,16 +63,16 @@ func (f *fakeBlockManager) Flush() error {
 	return nil
 }
 
-func setupTest(t *testing.T, mods ...func(o *ManagerOption)) (map[string][]byte, *Manager) {
-	return setupTestWithData(t, map[string][]byte{}, mods...)
+func setupTest(t *testing.T) (map[string][]byte, *Manager) {
+	return setupTestWithData(t, map[string][]byte{}, ManagerOptions{})
 }
 
-func setupTestWithData(t *testing.T, data map[string][]byte, mods ...func(o *ManagerOption)) (map[string][]byte, *Manager) {
+func setupTestWithData(t *testing.T, data map[string][]byte, opts ManagerOptions) (map[string][]byte, *Manager) {
 	r, err := NewObjectManager(&fakeBlockManager{data: data}, config.RepositoryObjectFormat{
 		Version:      1,
 		MaxBlockSize: 200,
 		Splitter:     "FIXED",
-	})
+	}, opts)
 	if err != nil {
 		t.Fatalf("can't create object manager: %v", err)
 	}
diff --git a/repo/connection.go b/repo/connection.go
index b5c3421f6..f1a327779 100644
--- a/repo/connection.go
+++ b/repo/connection.go
@@ -27,7 +27,7 @@ type Options struct {
 	CredentialsCallback func() (auth.Credentials, error)    // Provides credentials required to open the repository if not persisted.
 	TraceStorage        func(f string, args ...interface{}) // Logs all storage access using provided Printf-style function
 
-	ObjectManagerOptions []object.ManagerOption
+	ObjectManagerOptions object.ManagerOptions
 }
 
 // Open opens a Repository specified in the configuration file.
@@ -139,7 +139,7 @@ func connect(ctx context.Context, st storage.Storage, creds auth.Credentials, op
 
 	bm := block.NewManager(st, mm.repoConfig.Format.MaxPackedContentLength, mm.repoConfig.Format.MaxBlockSize, formatter)
 
-	om, err := object.NewObjectManager(bm, mm.repoConfig.Format, options.ObjectManagerOptions...)
+	om, err := object.NewObjectManager(bm, mm.repoConfig.Format, options.ObjectManagerOptions)
 	if err != nil {
 		return nil, fmt.Errorf("unable to open object manager: %v", err)
 	}