Refactor a bit.

service/rawdatastore/datastore_impl.go

Index: service/rawdatastore/datastore_impl.go
diff --git a/helper/datastore_impl.go b/service/rawdatastore/datastore_impl.go
similarity index 84%
rename from helper/datastore_impl.go
rename to service/rawdatastore/datastore_impl.go
index 0f7d4de7d6f5cd786d3e6ee6965c7e650293aa32..2c8980442c9733a7dbd6032421c81811e14c9c92 100644
--- a/helper/datastore_impl.go
+++ b/service/rawdatastore/datastore_impl.go
@@ -4,7 +4,7 @@
 
 // HEAVILY adapted from github.com/golang/appengine/datastore
 
-package helper
+package rawdatastore
 
 import (
 	"errors"
@@ -17,26 +17,15 @@ import (
 	"unicode"
 
 	"github.com/luci/gae"
+	"github.com/luci/gae/service/blobstore"
 )
 
 // Entities with more than this many indexed properties will not be saved.
 const maxIndexedProperties = 20000
 
-var (
-	typeOfDSKey               = reflect.TypeOf((*gae.DSKey)(nil)).Elem()
-	typeOfDSPropertyConverter = reflect.TypeOf((*gae.DSPropertyConverter)(nil)).Elem()
-	typeOfGeoPoint            = reflect.TypeOf(gae.DSGeoPoint{})
-	typeOfTime                = reflect.TypeOf(time.Time{})
-	typeOfString              = reflect.TypeOf("")
-	typeOfInt64               = reflect.TypeOf(int64(0))
-	typeOfBool                = reflect.TypeOf(true)
-
-	valueOfnilDSKey = reflect.Zero(typeOfDSKey)
-)
-
 type structTag struct {
 	name           string
-	idxSetting     gae.IndexSetting
+	idxSetting     IndexSetting
 	isSlice        bool
 	substructCodec *structCodec
 	convert        bool
@@ -57,7 +46,7 @@ type structPLS struct {
 	c *structCodec
 }
 
-var _ gae.DSPropertyLoadSaver = (*structPLS)(nil)
+var _ PropertyLoadSaver = (*structPLS)(nil)
 
 // typeMismatchReason returns a string explaining why the property p could not
 // be stored in an entity field of type v.Type().
@@ -66,7 +55,7 @@ func typeMismatchReason(val interface{}, v reflect.Value) string {
 	return fmt.Sprintf("type mismatch: %s versus %v", entityType, v.Type())
 }
 
-func (p *structPLS) Load(propMap gae.DSPropertyMap) error {
+func (p *structPLS) Load(propMap PropertyMap) error {
 	if err := p.Problem(); err != nil {
 		return err
 	}
@@ -81,7 +70,7 @@ func (p *structPLS) Load(propMap gae.DSPropertyMap) error {
 				if t == nil {
 					t = p.o.Type()
 				}
-				convFailures = append(convFailures, &gae.ErrDSFieldMismatch{
+				convFailures = append(convFailures, &ErrFieldMismatch{
 					StructType: t,
 					FieldName:  name,
 					Reason:     reason,
@@ -97,7 +86,7 @@ func (p *structPLS) Load(propMap gae.DSPropertyMap) error {
 	return nil
 }
 
-func loadInner(codec *structCodec, structValue reflect.Value, index int, name string, p gae.DSProperty, requireSlice bool) string {
+func loadInner(codec *structCodec, structValue reflect.Value, index int, name string, p Property, requireSlice bool) string {
 	var v reflect.Value
 	// Traverse a struct's struct-typed fields.
 	for {
@@ -128,8 +117,8 @@ func loadInner(codec *structCodec, structValue reflect.Value, index int, name st
 
 	doConversion := func(v reflect.Value) (string, bool) {
 		a := v.Addr()
-		if conv, ok := a.Interface().(gae.DSPropertyConverter); ok {
-			err := conv.FromDSProperty(p)
+		if conv, ok := a.Interface().(PropertyConverter); ok {
+			err := conv.FromProperty(p)
 			if err != nil {
 				return err.Error(), true
 			}
@@ -158,7 +147,7 @@ func loadInner(codec *structCodec, structValue reflect.Value, index int, name st
 		}
 	} else {
 		knd := v.Kind()
-		if v.Type().Implements(typeOfDSKey) {
+		if v.Type().Implements(typeOfKey) {
 			knd = reflect.Interface
 		}
 		switch knd {
@@ -179,7 +168,7 @@ func loadInner(codec *structCodec, structValue reflect.Value, index int, name st
 			v.SetBool(x)
 		case reflect.String:
 			switch x := pVal.(type) {
-			case gae.BSKey:
+			case blobstore.Key:
 				v.SetString(string(x))
 			case string:
 				v.SetString(x)
@@ -198,7 +187,7 @@ func loadInner(codec *structCodec, structValue reflect.Value, index int, name st
 			}
 			v.SetFloat(x)
 		case reflect.Interface:
-			x, ok := pVal.(gae.DSKey)
+			x, ok := pVal.(Key)
 			if !ok && pVal != nil {
 				return typeMismatchReason(pVal, v)
 			}
@@ -214,7 +203,7 @@ func loadInner(codec *structCodec, structValue reflect.Value, index int, name st
 				}
 				v.Set(reflect.ValueOf(x))
 			case typeOfGeoPoint:
-				x, ok := pVal.(gae.DSGeoPoint)
+				x, ok := pVal.(GeoPoint)
 				if !ok && pVal != nil {
 					return typeMismatchReason(pVal, v)
 				}
@@ -226,7 +215,7 @@ func loadInner(codec *structCodec, structValue reflect.Value, index int, name st
 			switch x := pVal.(type) {
 			case []byte:
 				v.SetBytes(x)
-			case gae.DSByteString:
+			case ByteString:
 				v.SetBytes([]byte(x))
 			default:
 				panic(fmt.Errorf("helper: impossible: %s", typeMismatchReason(pVal, v)))
@@ -241,13 +230,13 @@ func loadInner(codec *structCodec, structValue reflect.Value, index int, name st
 	return ""
 }
 
-func (p *structPLS) Save(withMeta bool) (gae.DSPropertyMap, error) {
+func (p *structPLS) Save(withMeta bool) (PropertyMap, error) {
 	size := len(p.c.byName)
 	if withMeta {
 		size += len(p.c.byMeta)
 	}
-	ret := make(gae.DSPropertyMap, size)
-	if _, err := p.save(ret, "", gae.ShouldIndex); err != nil {
+	ret := make(PropertyMap, size)
+	if _, err := p.save(ret, "", ShouldIndex); err != nil {
 		return nil, err
 	}
 	if withMeta {
@@ -256,22 +245,22 @@ func (p *structPLS) Save(withMeta bool) (gae.DSPropertyMap, error) {
 			if err != nil {
 				return nil, err // TODO(riannucci): should these be ignored?
 			}
-			p := gae.DSProperty{}
-			if err = p.SetValue(val, gae.NoIndex); err != nil {
+			p := Property{}
+			if err = p.SetValue(val, NoIndex); err != nil {
 				return nil, err
 			}
-			ret["$"+k] = []gae.DSProperty{p}
+			ret["$"+k] = []Property{p}
 		}
 	}
 	return ret, nil
 }
 
-func (p *structPLS) save(propMap gae.DSPropertyMap, prefix string, is gae.IndexSetting) (idxCount int, err error) {
+func (p *structPLS) save(propMap PropertyMap, prefix string, is IndexSetting) (idxCount int, err error) {
 	if err = p.Problem(); err != nil {
 		return
 	}
 
-	saveProp := func(name string, si gae.IndexSetting, v reflect.Value, st *structTag) (err error) {
+	saveProp := func(name string, si IndexSetting, v reflect.Value, st *structTag) (err error) {
 		if st.substructCodec != nil {
 			count, err := (&structPLS{v, st.substructCodec}).save(propMap, name, si)
 			if err == nil {
@@ -283,9 +272,9 @@ func (p *structPLS) save(propMap gae.DSPropertyMap, prefix string, is gae.IndexS
 			return err
 		}
 
-		prop := gae.DSProperty{}
+		prop := Property{}
 		if st.convert {
-			prop, err = v.Addr().Interface().(gae.DSPropertyConverter).ToDSProperty()
+			prop, err = v.Addr().Interface().(PropertyConverter).ToProperty()
 		} else {
 			err = prop.SetValue(v.Interface(), si)
 		}
@@ -293,7 +282,7 @@ func (p *structPLS) save(propMap gae.DSPropertyMap, prefix string, is gae.IndexS
 			return err
 		}
 		propMap[name] = append(propMap[name], prop)
-		if prop.IndexSetting() == gae.ShouldIndex {
+		if prop.IndexSetting() == ShouldIndex {
 			idxCount++
 			if idxCount > maxIndexedProperties {
 				return errors.New("gae: too many indexed properties")
@@ -312,8 +301,8 @@ func (p *structPLS) save(propMap gae.DSPropertyMap, prefix string, is gae.IndexS
 		}
 		v := p.o.Field(i)
 		is1 := is
-		if st.idxSetting == gae.NoIndex {
-			is1 = gae.NoIndex
+		if st.idxSetting == NoIndex {
+			is1 = NoIndex
 		}
 		if st.isSlice {
 			for j := 0; j < v.Len(); j++ {
@@ -336,7 +325,7 @@ func (p *structPLS) GetMeta(key string) (interface{}, error) {
 	}
 	idx, ok := p.c.byMeta[key]
 	if !ok {
-		return nil, gae.ErrDSMetaFieldUnset
+		return nil, ErrMetaFieldUnset
 	}
 	st := p.c.byIndex[idx]
 	val := st.metaVal
@@ -355,7 +344,7 @@ func (p *structPLS) SetMeta(key string, val interface{}) (err error) {
 	}
 	idx, ok := p.c.byMeta[key]
 	if !ok {
-		return gae.ErrDSMetaFieldUnset
+		return ErrMetaFieldUnset
 	}
 	if !p.c.byIndex[idx].canSet {
 		return fmt.Errorf("gae/helper: cannot set meta %q: unexported field", key)
@@ -475,7 +464,7 @@ func getStructCodecLocked(t reflect.Type) (c *structCodec) {
 
 		substructType := reflect.Type(nil)
 		ft := f.Type
-		if reflect.PtrTo(ft).Implements(typeOfDSPropertyConverter) {
+		if reflect.PtrTo(ft).Implements(typeOfPropertyConverter) {
 			st.convert = true
 		} else {
 			switch f.Type.Kind() {
@@ -484,7 +473,7 @@ func getStructCodecLocked(t reflect.Type) (c *structCodec) {
 					substructType = ft
 				}
 			case reflect.Slice:
-				if reflect.PtrTo(ft.Elem()).Implements(typeOfDSPropertyConverter) {
+				if reflect.PtrTo(ft.Elem()).Implements(typeOfPropertyConverter) {
 					st.convert = true
 				} else if ft.Elem().Kind() == reflect.Struct {
 					substructType = ft.Elem()
@@ -492,7 +481,7 @@ func getStructCodecLocked(t reflect.Type) (c *structCodec) {
 				st.isSlice = ft.Elem().Kind() != reflect.Uint8
 				c.hasSlice = c.hasSlice || st.isSlice
 			case reflect.Interface:
-				if ft != typeOfDSKey {
+				if ft != typeOfKey {
 					c.problem = me("field %q has non-concrete interface type %s",
 						f.Name, f.Type)
 					return
@@ -536,8 +525,8 @@ func getStructCodecLocked(t reflect.Type) (c *structCodec) {
 					t = t.Elem()
 				}
 				v := reflect.New(t).Elem().Interface()
-				v, _ = gae.DSUpconvertUnderlyingType(v, t)
-				if _, err := gae.DSPropertyTypeOf(v, false); err != nil {
+				v, _ = UpconvertUnderlyingType(v, t)
+				if _, err := PropertyTypeOf(v, false); err != nil {
 					c.problem = me("field %q has invalid type: %s", name, ft)
 					return
 				}
@@ -551,7 +540,7 @@ func getStructCodecLocked(t reflect.Type) (c *structCodec) {
 		}
 		st.name = name
 		if opts == "noindex" {
-			st.idxSetting = gae.NoIndex
+			st.idxSetting = NoIndex
 		}
 	}
 	if c.problem == errRecursiveStruct {