fix some function method

diskv_wrapper.go

@@ -1,24 +1,43 @@
 package diskv_wrapper
 
 import (
-	"strings"
+	"errors"
 
 	"github.com/peterbourgon/diskv/v3"
 )
 
-func Init(basePath string) *diskv.Diskv {
+type DiskvWrapper struct {
+	Disk *diskv.Diskv
+}
+
+// New will initialize diskv, if basepath is empty it will return nil, error
+func New(basePath string) (*DiskvWrapper, error) {
+	if basePath == "" {
+		return nil, errors.New("please provide basepath for main store")
+	}
+
 	disk := diskv.New(diskv.Options{
 		BasePath:          basePath,
 		AdvancedTransform: AdvanceTransform,
 		InverseTransform:  InverseTransform,
 		CacheSizeMax:      1024 * 1024,
 	})
 
-	return disk
+	wrapper := &DiskvWrapper{
+		Disk: disk,
+	}
+
+	return wrapper, nil
 }
 
-func GetKeyVersion(d *diskv.Diskv, version string, key string) string {
-	path := strings.Join([]string{version, key}, "/")
+// Init can be used as single method that will return *diskv.Diskv
+func Init(basePath string) *diskv.Diskv {
+	disk := diskv.New(diskv.Options{
+		BasePath:          basePath,
+		AdvancedTransform: AdvanceTransform,
+		InverseTransform:  InverseTransform,
+		CacheSizeMax:      1024 * 1024,
+	})
 
-	return path
+	return disk
 }

example/main.go

@@ -56,7 +56,7 @@ func main() {
 		return
 	}
 
-	path := diskv_wrapper.GetKeyVersion(currentDisk, version, key)
+	path := diskv_wrapper.WritePath(currentDisk, version, key)
 
 	currentDisk.WriteString(path, value)
 

tests/diskv_wrapper_test.go

@@ -9,23 +9,45 @@ import (
 
 var (
 	disk    *diskv.Diskv = diskv_wrapper.Init("disk_test")
-	version string       = "v1"
+	version string       = "v1-test"
 	key     string       = "versionkeytest"
 	data    string       = "this is string of data"
-	path    string       = diskv_wrapper.GetKeyVersion(disk, version, key)
+	path    string       = diskv_wrapper.WritePath(disk, version, key)
 )
 
 func write_disk_version(t *testing.T) {
 	err := diskv_wrapper.WriteVersion(disk, version)
 	if err != nil {
-		t.Errorf("Write version error")
+		t.Errorf("Expected can write version")
 	}
 }
 
 func write_data_string_version(t *testing.T) {
 	err := diskv_wrapper.Write(disk, path, data)
 	if err != nil {
-		t.Errorf("Write data error")
+		t.Errorf("Expected can write data")
+	}
+}
+
+func TestUsingNew(t *testing.T) {
+	vKeyForNew := "version"
+
+	diskv, err := diskv_wrapper.New("disk_test_new")
+	if err != nil {
+		t.Errorf("Expected can create new diskv: %v", err)
+	}
+
+	diskv_wrapper.WriteVersion(diskv.Disk, "v1")
+
+	versionUseOnNew := diskv_wrapper.VersionUse(diskv.Disk)
+
+	if versionUseOnNew != "v1" {
+		t.Errorf("Expected key is %v", vKeyForNew)
+	}
+
+	errorErase := diskv.Disk.EraseAll()
+	if errorErase != nil {
+		t.Errorf("Expected erasing %v data: %v", vKeyForNew, errorErase)
 	}
 }
 

transformer.go

@@ -6,6 +6,7 @@ import (
 	"github.com/peterbourgon/diskv/v3"
 )
 
+// AdvanceTransform to transform key it provided for *diskv and used as Option in *diskv
 func AdvanceTransform(key string) *diskv.PathKey {
 	path := strings.Split(key, "/")
 	last := len(path) - 1
@@ -15,6 +16,7 @@ func AdvanceTransform(key string) *diskv.PathKey {
 	}
 }
 
+// InverseTransform will inverse all written keys on disk. Used by *diskv to determine all keys on disk.
 func InverseTransform(pathKey *diskv.PathKey) (key string) {
 	var path, file []string
 	file = []string{pathKey.FileName[:len(pathKey.FileName)]}

writer.go

@@ -1,9 +1,12 @@
 package diskv_wrapper
 
 import (
+	"strings"
+
 	"github.com/peterbourgon/diskv/v3"
 )
 
+// WriteVersion used to write version file under disk. It contain version info that used in current.
 func WriteVersion(d *diskv.Diskv, version string) error {
 	err := d.WriteString("version", version)
 	if err != nil {
@@ -12,6 +15,14 @@ func WriteVersion(d *diskv.Diskv, version string) error {
 	return err
 }
 
+// WritePath will return a key to be written under `vx` folder
+func WritePath(d *diskv.Diskv, version string, key string) string {
+	path := strings.Join([]string{version, key}, "/")
+
+	return path
+}
+
+// Write is function to fill the data under keys
 func Write(d *diskv.Diskv, key string, value string) error {
 	err := d.WriteString(key, value)
 	if err != nil {