intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 46 insertions, 0 deletions

diff --git a/library/cpp/protobuf/util/merge.cpp b/library/cpp/protobuf/util/merge.cpp
new file mode 100644
index 0000000000..dc2b9cc806
--- /dev/null
+++ b/library/cpp/protobuf/util/merge.cpp
@@ -0,0 +1,46 @@
+#include "merge.h"
+#include "simple_reflection.h"
+
+#include <google/protobuf/message.h>
+
+#include <library/cpp/protobuf/util/proto/merge.pb.h>
+
+namespace NProtoBuf {
+    void RewriteMerge(const Message& src, Message& dst) {
+        const Descriptor* d = src.GetDescriptor();
+        Y_ASSERT(d == dst.GetDescriptor());
+
+        for (int i = 0; i < d->field_count(); ++i) {
+            if (TConstField(src, d->field(i)).Has())
+                TMutableField(dst, d->field(i)).Clear();
+        }
+
+        dst.MergeFrom(src);
+    }
+
+    static void ClearNonMergeable(const Message& src, Message& dst) {
+        const Descriptor* d = src.GetDescriptor();
+        if (d->options().GetExtension(DontMerge)) {
+            dst.Clear();
+            return;
+        }
+
+        for (int i = 0; i < d->field_count(); ++i) {
+            const FieldDescriptor* fd = d->field(i);
+            TConstField srcField(src, fd);
+            if (srcField.Has()) {
+                TMutableField dstField(dst, fd);
+                if (fd->options().GetExtension(DontMergeField))
+                    dstField.Clear();
+                else if (!fd->is_repeated() && dstField.IsMessage() && dstField.Has())
+                    ClearNonMergeable(*srcField.Get<const Message*>(), *dstField.MutableMessage());
+            }
+        }
+    }
+
+    void CustomMerge(const Message& src, Message& dst) {
+        ClearNonMergeable(src, dst);
+        dst.MergeFrom(src);
+    }
+
+}