First pass (not yet compiling) at removing all the array handling code from Coded*Stream.

Prod code works, but some tests are broken. Obviously those need fixing, then more tests,
and review benchmarks.

3 files changed, 27 insertions, 102 deletions

diff --git a/src/google/protobuf/compiler/csharp/csharp_repeated_enum_field.cc b/src/google/protobuf/compiler/csharp/csharp_repeated_enum_field.cc
index d223273c..4445c281 100644
--- a/src/google/protobuf/compiler/csharp/csharp_repeated_enum_field.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_repeated_enum_field.cc
@@ -49,7 +49,6 @@ namespace csharp {
 RepeatedEnumFieldGenerator::RepeatedEnumFieldGenerator(
     const FieldDescriptor* descriptor, int fieldOrdinal)
     : FieldGeneratorBase(descriptor, fieldOrdinal) {
-  variables_["packed"] = descriptor->is_packed() ? "Packed" : "";
 }
 
 RepeatedEnumFieldGenerator::~RepeatedEnumFieldGenerator() {
@@ -57,6 +56,10 @@ RepeatedEnumFieldGenerator::~RepeatedEnumFieldGenerator() {
 }
 
 void RepeatedEnumFieldGenerator::GenerateMembers(io::Printer* printer) {
+  printer->Print(
+    variables_,
+    "private static readonly pb::FieldCodec<$type_name$> _repeated_$name$_codec\n"
+    "    = pb::FieldCodec.ForEnum($tag$, x => (int) x, x => ($type_name$) x);");
   printer->Print(variables_,
     "private readonly pbc::RepeatedField<$type_name$> $name$_ = new pbc::RepeatedField<$type_name$>();\n");
   AddDeprecatedFlag(printer);
@@ -76,53 +79,19 @@ void RepeatedEnumFieldGenerator::GenerateMergingCode(io::Printer* printer) {
 void RepeatedEnumFieldGenerator::GenerateParsingCode(io::Printer* printer) {
   printer->Print(
     variables_,
-    "input.ReadEnumArray<$type_name$>($name$_);\n");
+    "$name$_.AddEntriesFrom(input, _repeated_$name$_codec);\n");
 }
 
 void RepeatedEnumFieldGenerator::GenerateSerializationCode(io::Printer* printer) {
   printer->Print(
     variables_,
-    "if ($name$_.Count > 0) {\n");
-  printer->Indent();
-  if (descriptor_->is_packed()) {
-    printer->Print(
-      variables_,
-      "output.WriteRawTag($tag_bytes$);\n"
-      "output.WritePackedEnumArray($name$_);\n");
-  } else {
-    printer->Print(
-      variables_,
-      "output.Write$capitalized_type_name$Array($number$, $name$_);\n");
-  }
-  printer->Outdent();
-  printer->Print("}\n");
+    "$name$_.WriteTo(output, _repeated_$name$_codec);\n");
 }
 
-void RepeatedEnumFieldGenerator::GenerateSerializedSizeCode(io::Printer* printer) {
-  // TODO(jonskeet): Move all this code into CodedOutputStream? It's a lot to repeat everywhere...
-  printer->Print(
-    variables_,
-    "if ($name$_.Count > 0) {\n");
-  printer->Indent();
-  printer->Print("int dataSize = 0;\n");
+void RepeatedEnumFieldGenerator::GenerateSerializedSizeCode(io::Printer* printer) {  
   printer->Print(
     variables_,
-    "foreach ($type_name$ element in $name$_) {\n"
-    "  dataSize += pb::CodedOutputStream.ComputeEnumSize((int) element);\n"
-    "}\n"
-    "size += dataSize;\n");
-  int tagSize = internal::WireFormat::TagSize(descriptor_->number(), descriptor_->type());
-  if (descriptor_->is_packed()) {
-    printer->Print(
-      "size += $tag_size$ + pb::CodedOutputStream.ComputeRawVarint32Size((uint) dataSize);\n",
-      "tag_size", SimpleItoa(tagSize));
-  } else {
-    printer->Print(
-      "size += $tag_size$ * $name$_.Count;\n",
-      "tag_size", SimpleItoa(tagSize), "name", name());
-  }
-  printer->Outdent();
-  printer->Print("}\n");
+    "size += $name$_.CalculateSize(_repeated_$name$_codec);\n");
 }
 
 void RepeatedEnumFieldGenerator::WriteHash(io::Printer* printer) {
diff --git a/src/google/protobuf/compiler/csharp/csharp_repeated_message_field.cc b/src/google/protobuf/compiler/csharp/csharp_repeated_message_field.cc
index 400f0e4f..c74e5d0d 100644
--- a/src/google/protobuf/compiler/csharp/csharp_repeated_message_field.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_repeated_message_field.cc
@@ -57,6 +57,10 @@ RepeatedMessageFieldGenerator::~RepeatedMessageFieldGenerator() {
 void RepeatedMessageFieldGenerator::GenerateMembers(io::Printer* printer) {
   printer->Print(
     variables_,
+    "private static readonly pb::FieldCodec<$type_name$> _repeated_$name$_codec\n"
+    "    = pb::FieldCodec.ForMessage($tag$, $type_name$.Parser);\n");
+  printer->Print(
+    variables_,
     "private readonly pbc::RepeatedField<$type_name$> $name$_ = new pbc::RepeatedField<$type_name$>();\n");
   AddDeprecatedFlag(printer);
   printer->Print(
@@ -75,28 +79,19 @@ void RepeatedMessageFieldGenerator::GenerateMergingCode(io::Printer* printer) {
 void RepeatedMessageFieldGenerator::GenerateParsingCode(io::Printer* printer) {
   printer->Print(
     variables_,
-    "input.ReadMessageArray($name$_, $type_name$.Parser);\n");
+    "$name$_.AddEntriesFrom(input, _repeated_$name$_codec);\n");
 }
 
 void RepeatedMessageFieldGenerator::GenerateSerializationCode(io::Printer* printer) {
-  // TODO(jonskeet): Bake the foreach loop into the generated code? We lose the
-  // advantage of knowing the tag bytes this way :(
   printer->Print(
     variables_,
-    "if ($name$_.Count > 0) {\n"
-    "  output.WriteMessageArray($number$, $name$_);\n"
-    "}\n");
+    "$name$_.WriteTo(output, _repeated_$name$_codec);\n");
 }
 
 void RepeatedMessageFieldGenerator::GenerateSerializedSizeCode(io::Printer* printer) {
   printer->Print(
     variables_,
-    "if ($name$_.Count > 0) {\n"
-    "  foreach ($type_name$ element in $name$_) {\n"
-    "    size += pb::CodedOutputStream.ComputeMessageSize(element);\n"
-    "  }\n"
-    "  size += $tag_size$ * $name$_.Count;\n"
-    "}\n");
+    "size += $name$_.CalculateSize(_repeated_$name$_codec);\n");
 }
 
 void RepeatedMessageFieldGenerator::WriteHash(io::Printer* printer) {
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 a78a74c0..a3014da8 100644
--- a/src/google/protobuf/compiler/csharp/csharp_repeated_primitive_field.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_repeated_primitive_field.cc
@@ -49,7 +49,6 @@ namespace csharp {
 RepeatedPrimitiveFieldGenerator::RepeatedPrimitiveFieldGenerator(
     const FieldDescriptor* descriptor, int fieldOrdinal)
     : FieldGeneratorBase(descriptor, fieldOrdinal) {
-  variables_["packed"] = descriptor->is_packed() ? "Packed" : "";
 }
 
 RepeatedPrimitiveFieldGenerator::~RepeatedPrimitiveFieldGenerator() {
@@ -57,6 +56,10 @@ RepeatedPrimitiveFieldGenerator::~RepeatedPrimitiveFieldGenerator() {
 }
 
 void RepeatedPrimitiveFieldGenerator::GenerateMembers(io::Printer* printer) {
+  printer->Print(
+    variables_,
+    "private static readonly pb::FieldCodec<$type_name$> _repeated_$name$_codec\n"
+    "    = pb::FieldCodec.For$capitalized_type_name$($tag$);\n");
   printer->Print(variables_,
     "private readonly pbc::RepeatedField<$type_name$> $name$_ = new pbc::RepeatedField<$type_name$>();\n");
   AddDeprecatedFlag(printer);
@@ -74,63 +77,21 @@ void RepeatedPrimitiveFieldGenerator::GenerateMergingCode(io::Printer* printer)
 }
 
 void RepeatedPrimitiveFieldGenerator::GenerateParsingCode(io::Printer* printer) {
-  printer->Print(variables_,
-    "input.Read$capitalized_type_name$Array($name$_);\n");
+  printer->Print(
+    variables_,
+    "$name$_.AddEntriesFrom(input, _repeated_$name$_codec);\n");
 }
 
-void RepeatedPrimitiveFieldGenerator::GenerateSerializationCode(
-    io::Printer* printer) {
+void RepeatedPrimitiveFieldGenerator::GenerateSerializationCode(io::Printer* printer) {
   printer->Print(
     variables_,
-    "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");
+    "$name$_.WriteTo(output, _repeated_$name$_codec);\n");
 }
 
-void RepeatedPrimitiveFieldGenerator::GenerateSerializedSizeCode(
-    io::Printer* printer) {
-  // TODO(jonskeet): Do this in the runtime if possible. It's a pain, but it must be feasible...
+void RepeatedPrimitiveFieldGenerator::GenerateSerializedSizeCode(io::Printer* printer) {
   printer->Print(
-    "if ($name$_.Count > 0) {\n",
-    "name", name());
-  printer->Indent();
-  printer->Print("int dataSize = 0;\n");
-  int fixedSize = GetFixedSize(descriptor_->type());
-  if (fixedSize == -1) {
-    printer->Print(
-      variables_,
-      "foreach ($type_name$ element in $name$_) {\n"
-      "  dataSize += pb::CodedOutputStream.Compute$capitalized_type_name$Size(element);\n"
-      "}\n");
-  } else {
-    printer->Print(
-      "dataSize = $size$ * $name$_.Count;\n",
-      "size", SimpleItoa(fixedSize), "name", name());
-  }
-  printer->Print("size += dataSize;\n");
-  int tagSize = internal::WireFormat::TagSize(descriptor_->number(), descriptor_->type());
-  if (descriptor_->is_packed()) {
-    printer->Print(
-      "size += $tag_size$ + pb::CodedOutputStream.ComputeInt32Size(dataSize);\n",
-      "tag_size", SimpleItoa(tagSize));
-  } else {
-    printer->Print(
-      "size += $tag_size$ * $name$_.Count;\n",
-      "tag_size", SimpleItoa(tagSize), "name", name());
-  }
-  printer->Outdent();
-  printer->Print("}\n");
+    variables_,
+    "size += $name$_.CalculateSize(_repeated_$name$_codec);\n");
 }
 
 void RepeatedPrimitiveFieldGenerator::WriteHash(io::Printer* printer) {