1 files changed, 71 insertions, 0 deletions
diff --git a/src/mongo/gotools/common/json/dbpointer.go b/src/mongo/gotools/common/json/dbpointer.go
new file mode 100644
index 00000000000..24582038576
--- /dev/null
+++ b/src/mongo/gotools/common/json/dbpointer.go
@@ -0,0 +1,71 @@
+package json
+
+import (
+	"fmt"
+	"gopkg.in/mgo.v2/bson"
+	"reflect"
+)
+
+// Transition functions for recognizing DBPointer.
+// Adapted from encoding/json/scanner.go.
+
+// stateDB is the state after reading `DB`.
+func stateDBP(s *scanner, c int) int {
+	if c == 'o' {
+		s.step = generateState("DBPointer", []byte("inter"), stateConstructor)
+		return scanContinue
+	}
+	return s.error(c, "in literal DBPointer (expecting 'o')")
+}
+
+// Decodes a DBRef literal stored in the underlying byte data into v.
+func (d *decodeState) storeDBPointer(v reflect.Value) {
+	op := d.scanWhile(scanSkipSpace)
+	if op != scanBeginCtor {
+		d.error(fmt.Errorf("expected beginning of constructor"))
+	}
+
+	args := d.ctorInterface()
+	if len(args) != 2 {
+		d.error(fmt.Errorf("expected 2 arguments to DBPointer constructor, but %v received", len(args)))
+	}
+	switch kind := v.Kind(); kind {
+	case reflect.Interface:
+		arg0, ok := args[0].(string)
+		if !ok {
+			d.error(fmt.Errorf("expected first argument to DBPointer to be of type string"))
+		}
+		arg1, ok := args[1].(ObjectId)
+		if !ok {
+			d.error(fmt.Errorf("expected second argument to DBPointer to be of type ObjectId, but ended up being %t", args[1]))
+		}
+		id := bson.ObjectIdHex(string(arg1))
+		v.Set(reflect.ValueOf(DBPointer{arg0, id}))
+	default:
+		d.error(fmt.Errorf("cannot store %v value into %v type", dbPointerType, kind))
+	}
+}
+
+// Returns a DBRef literal from the underlying byte data.
+func (d *decodeState) getDBPointer() interface{} {
+	op := d.scanWhile(scanSkipSpace)
+	if op != scanBeginCtor {
+		d.error(fmt.Errorf("expected beginning of constructor"))
+	}
+
+	args := d.ctorInterface()
+	if err := ctorNumArgsMismatch("DBPointer", 2, len(args)); err != nil {
+		d.error(err)
+	}
+	arg0, ok := args[0].(string)
+	if !ok {
+		d.error(fmt.Errorf("expected string for first argument of DBPointer constructor"))
+	}
+	arg1, ok := args[1].(ObjectId)
+	if !ok {
+		d.error(fmt.Errorf("expected ObjectId for second argument of DBPointer constructor"))
+	}
+	id := bson.ObjectIdHex(string(arg1))
+
+	return DBPointer{arg0, id}
+}