Use the fact that we know the tag size and bytes at codegen time to optimize.

1 files changed, 16 insertions, 5 deletions

diff --git a/src/google/protobuf/compiler/csharp/csharp_repeated_primitive_field.cc b/src/google/protobuf/compiler/csharp/csharp_repeated_primitive_field.cc
index a5457785..fe8a4364 100644
--- a/src/google/protobuf/compiler/csharp/csharp_repeated_primitive_field.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_repeated_primitive_field.cc
@@ -82,9 +82,20 @@ void RepeatedPrimitiveFieldGenerator::GenerateSerializationCode(
     io::Printer* printer) {
   printer->Print(
     variables_,
-    "if ($name$_.Count > 0) {\n"
-    "  output.Write$packed$$capitalized_type_name$Array($number$, $name$_);\n"
-    "}\n");
+    "if ($name$_.Count > 0) {\n");
+  printer->Indent();
+  if (descriptor_->is_packed()) {
+    printer->Print(
+      variables_,
+      "output.WriteRawTag($tag_bytes$);\n"
+      "output.WritePacked$capitalized_type_name$Array($name$_);\n");
+  } else {
+    printer->Print(
+      variables_,
+      "output.Write$capitalized_type_name$Array($number$, $name$_);\n");
+  }
+  printer->Outdent();
+  printer->Print("}\n");
 }
 
 void RepeatedPrimitiveFieldGenerator::GenerateSerializedSizeCode(
@@ -100,7 +111,7 @@ void RepeatedPrimitiveFieldGenerator::GenerateSerializedSizeCode(
     printer->Print(
       variables_,
       "foreach ($type_name$ element in $name$_) {\n"
-      "  dataSize += pb::CodedOutputStream.Compute$capitalized_type_name$SizeNoTag(element);\n"
+      "  dataSize += pb::CodedOutputStream.Compute$capitalized_type_name$Size(element);\n"
       "}\n");
   } else {
     printer->Print(
@@ -111,7 +122,7 @@ void RepeatedPrimitiveFieldGenerator::GenerateSerializedSizeCode(
   int tagSize = internal::WireFormat::TagSize(descriptor_->number(), descriptor_->type());
   if (descriptor_->is_packed()) {
     printer->Print(
-      "size += $tag_size$ + pb::CodedOutputStream.ComputeInt32SizeNoTag(dataSize);\n",
+      "size += $tag_size$ + pb::CodedOutputStream.ComputeInt32Size(dataSize);\n",
       "tag_size", SimpleItoa(tagSize));
   } else {
     printer->Print(