Move ObjectContext out of reflectx where it doesn't belong

Author: kszafran

convert.go

@@ -0,0 +1,8 @@
+package sqlx
+
+import (
+	_ "unsafe"
+)
+
+//go:linkname convertAssign database/sql.convertAssign
+func convertAssign(dest, src interface{}) error

reflectx/reflect.go

@@ -11,7 +11,6 @@ import (
 	"runtime"
 	"strings"
 	"sync"
-	_ "unsafe"
 )
 
 // A FieldInfo is metadata for a struct field.
@@ -202,56 +201,6 @@ func (m *Mapper) TraversalsByNameFunc(t reflect.Type, names []string, fn func(in
 	return nil
 }
 
-// ObjectContext provides a single layer to abstract away
-// nested struct scanning functionality
-type ObjectContext struct {
-	value reflect.Value
-}
-
-func NewObjectContext() *ObjectContext {
-	return &ObjectContext{}
-}
-
-// NewRow updates the object reference.
-// This ensures all columns point to the same object
-func (o *ObjectContext) NewRow(value reflect.Value) {
-	o.value = value
-}
-
-// FieldForIndexes returns the value for address. If the address is a nested struct,
-// a nestedFieldScanner is returned instead of the standard value reference
-func (o *ObjectContext) FieldForIndexes(indexes []int) reflect.Value {
-	if len(indexes) == 1 {
-		return FieldByIndexes(o.value, indexes)
-	}
-
-	obj := &nestedFieldScanner{
-		parent:  o,
-		indexes: indexes,
-	}
-
-	return reflect.ValueOf(obj).Elem()
-}
-
-// nestedFieldScanner will only forward the Scan to the nested value if
-// the database value is not nil.
-type nestedFieldScanner struct {
-	parent  *ObjectContext
-	indexes []int
-}
-
-// Scan implements sql.Scanner.
-func (o *nestedFieldScanner) Scan(src interface{}) error {
-	if src == nil {
-		return nil
-	}
-	dest := FieldByIndexes(o.parent.value, o.indexes)
-	return convertAssign(dest.Addr().Interface(), src)
-}
-
-//go:linkname convertAssign database/sql.convertAssign
-func convertAssign(dest, src interface{}) error
-
 // FieldByIndexes returns a value for the field given by the struct traversal
 // for the given value.
 func FieldByIndexes(v reflect.Value, indexes []int) reflect.Value {

sqlx.go

@@ -621,7 +621,7 @@ func (r *Rows) StructScan(dest interface{}) error {
 		r.started = true
 	}
 
-	octx := reflectx.NewObjectContext()
+	octx := newObjectContext()
 	err := fieldsByTraversal(octx, v, r.fields, r.values, true)
 	if err != nil {
 		return err
@@ -782,7 +782,7 @@ func (r *Row) scanAny(dest interface{}, structOnly bool) error {
 	}
 	values := make([]interface{}, len(columns))
 
-	octx := reflectx.NewObjectContext()
+	octx := newObjectContext()
 
 	err = fieldsByTraversal(octx, v, fields, values, true)
 	if err != nil {
@@ -951,7 +951,7 @@ func scanAll(rows rowsi, dest interface{}, structOnly bool) error {
 			return fmt.Errorf("missing destination name %s in %T", columns[f], dest)
 		}
 		values = make([]interface{}, len(columns))
-		octx := reflectx.NewObjectContext()
+		octx := newObjectContext()
 
 		for rows.Next() {
 			// create a new struct type (which returns PtrTo) and indirect it
@@ -1024,7 +1024,7 @@ func baseType(t reflect.Type, expected reflect.Kind) (reflect.Type, error) {
 // when iterating over many rows.  Empty traversals will get an interface pointer.
 // Because of the necessity of requesting ptrs or values, it's considered a bit too
 // specialized for inclusion in reflectx itself.
-func fieldsByTraversal(octx *reflectx.ObjectContext, v reflect.Value, traversals [][]int, values []interface{}, ptrs bool) error {
+func fieldsByTraversal(octx *objectContext, v reflect.Value, traversals [][]int, values []interface{}, ptrs bool) error {
 	v = reflect.Indirect(v)
 	if v.Kind() != reflect.Struct {
 		return errors.New("argument not a struct")
@@ -1055,3 +1055,50 @@ func missingFields(transversals [][]int) (field int, err error) {
 	}
 	return 0, nil
 }
+
+// objectContext provides a single layer to abstract away
+// nested struct scanning functionality
+type objectContext struct {
+	value reflect.Value
+}
+
+func newObjectContext() *objectContext {
+	return &objectContext{}
+}
+
+// NewRow updates the object reference.
+// This ensures all columns point to the same object
+func (o *objectContext) NewRow(value reflect.Value) {
+	o.value = value
+}
+
+// FieldForIndexes returns the value for address. If the address is a nested struct,
+// a nestedFieldScanner is returned instead of the standard value reference
+func (o *objectContext) FieldForIndexes(indexes []int) reflect.Value {
+	if len(indexes) == 1 {
+		return reflectx.FieldByIndexes(o.value, indexes)
+	}
+
+	obj := &nestedFieldScanner{
+		parent:  o,
+		indexes: indexes,
+	}
+
+	return reflect.ValueOf(obj).Elem()
+}
+
+// nestedFieldScanner will only forward the Scan to the nested value if
+// the database value is not nil.
+type nestedFieldScanner struct {
+	parent  *objectContext
+	indexes []int
+}
+
+// Scan implements sql.Scanner.
+func (o *nestedFieldScanner) Scan(src interface{}) error {
+	if src == nil {
+		return nil
+	}
+	dest := reflectx.FieldByIndexes(o.parent.value, o.indexes)
+	return convertAssign(dest.Addr().Interface(), src)
+}