1 files changed, 38 insertions, 2 deletions

diff --git a/src/google/protobuf/util/field_mask_util.h b/src/google/protobuf/util/field_mask_util.h
index 92f69893..644161b9 100644
--- a/src/google/protobuf/util/field_mask_util.h
+++ b/src/google/protobuf/util/field_mask_util.h
@@ -45,11 +45,18 @@ class LIBPROTOBUF_EXPORT FieldMaskUtil {
   typedef google::protobuf::FieldMask FieldMask;
 
  public:
-  // Converts FieldMask to/from string, formatted according to proto3 JSON
-  // spec for FieldMask (e.g., "foo,bar,baz.quz").
+  // Converts FieldMask to/from string, formatted by separating each path
+  // with a comma (e.g., "foo_bar,baz.quz").
   static string ToString(const FieldMask& mask);
   static void FromString(StringPiece str, FieldMask* out);
 
+  // Converts FieldMask to/from string, formatted according to proto3 JSON
+  // spec for FieldMask (e.g., "fooBar,baz.quz"). If the field name is not
+  // style conforming (i.e., not snake_case when converted to string, or not
+  // camelCase when converted from string), the conversion will fail.
+  static bool ToJsonString(const FieldMask& mask, string* out);
+  static bool FromJsonString(StringPiece str, FieldMask* out);
+
   // Checks whether the given path is valid for type T.
   template <typename T>
   static bool IsValidPath(StringPiece path) {
@@ -105,6 +112,35 @@ class LIBPROTOBUF_EXPORT FieldMaskUtil {
                              const MergeOptions& options, Message* destination);
 
  private:
+  friend class SnakeCaseCamelCaseTest;
+  // Converts a field name from snake_case to camelCase:
+  //   1. Every character after "_" will be converted to uppercase.
+  //   2. All "_"s are removed.
+  // The conversion will fail if:
+  //   1. The field name contains uppercase letters.
+  //   2. Any character after a "_" is not a lowercase letter.
+  // If the conversion succeeds, it's guaranteed that the resulted
+  // camelCase name will yield the original snake_case name when
+  // converted using CamelCaseToSnakeCase().
+  //
+  // Note that the input can contain characters not allowed in C identifiers.
+  // For example, "foo_bar,baz_quz" will be converted to "fooBar,bazQuz"
+  // successfully.
+  static bool SnakeCaseToCamelCase(StringPiece input, string* output);
+  // Converts a field name from camelCase to snake_case:
+  //   1. Every uppercase letter is converted to lowercase with a additional
+  //      preceding "-".
+  // The conversion will fail if:
+  //   1. The field name contains "_"s.
+  // If the conversion succeeds, it's guaranteed that the resulted
+  // snake_case name will yield the original camelCase name when
+  // converted using SnakeCaseToCamelCase().
+  //
+  // Note that the input can contain characters not allowed in C identifiers.
+  // For example, "fooBar,bazQuz" will be converted to "foo_bar,baz_quz"
+  // successfully.
+  static bool CamelCaseToSnakeCase(StringPiece input, string* output);
+
   static bool InternalIsValidPath(const Descriptor* descriptor,
                                   StringPiece path);