src/google/protobuf/compiler/cpp/cpp_map_field.cc

// Protocol Buffers - Google's data interchange format
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#include <google/protobuf/compiler/cpp/cpp_map_field.h>
#include <google/protobuf/compiler/cpp/cpp_helpers.h>
#include <google/protobuf/io/printer.h>
#include <google/protobuf/wire_format.h>
#include <google/protobuf/stubs/strutil.h>

namespace google {
namespace protobuf {
namespace compiler {
namespace cpp {

bool IsProto3Field(const FieldDescriptor* field_descriptor) {
  const FileDescriptor* file_descriptor = field_descriptor->file();
  return file_descriptor->syntax() == FileDescriptor::SYNTAX_PROTO3;
}

void SetMessageVariables(const FieldDescriptor* descriptor,
                         map<string, string>* variables,
                         const Options& options) {
  SetCommonFieldVariables(descriptor, variables, options);
  (*variables)["type"] = FieldMessageTypeName(descriptor);
  (*variables)["stream_writer"] = (*variables)["declared_type"] +
      (HasFastArraySerialization(descriptor->message_type()->file()) ?
       "MaybeToArray" :
       "");
  (*variables)["full_name"] = descriptor->full_name();

  const FieldDescriptor* key =
      descriptor->message_type()->FindFieldByName("key");
  const FieldDescriptor* val =
      descriptor->message_type()->FindFieldByName("value");
  (*variables)["key_cpp"] = PrimitiveTypeName(key->cpp_type());
  switch (val->cpp_type()) {
    case FieldDescriptor::CPPTYPE_MESSAGE:
      (*variables)["val_cpp"] = FieldMessageTypeName(val);
      (*variables)["wrapper"] = "EntryWrapper";
      break;
    case FieldDescriptor::CPPTYPE_ENUM:
      (*variables)["val_cpp"] = ClassName(val->enum_type(), false);
      (*variables)["wrapper"] = "EnumEntryWrapper";
      break;
    default:
      (*variables)["val_cpp"] = PrimitiveTypeName(val->cpp_type());
      (*variables)["wrapper"] = "EntryWrapper";
  }
  (*variables)["key_wire_type"] =
      "::google::protobuf::internal::WireFormatLite::TYPE_" +
      ToUpper(DeclaredTypeMethodName(key->type()));
  (*variables)["val_wire_type"] =
      "::google::protobuf::internal::WireFormatLite::TYPE_" +
      ToUpper(DeclaredTypeMethodName(val->type()));
  (*variables)["map_classname"] = ClassName(descriptor->message_type(), false);
  (*variables)["number"] = SimpleItoa(descriptor->number());
  (*variables)["tag"] = SimpleItoa(internal::WireFormat::MakeTag(descriptor));

  if (HasDescriptorMethods(descriptor->file())) {
    (*variables)["lite"] = "";
  } else {
    (*variables)["lite"] = "Lite";
  }

  if (!IsProto3Field(descriptor) &&
      val->type() == FieldDescriptor::TYPE_ENUM) {
    const EnumValueDescriptor* default_value = val->default_value_enum();
    (*variables)["default_enum_value"] = Int32ToString(default_value->number());
  } else {
    (*variables)["default_enum_value"] = "0";
  }
}

MapFieldGenerator::
MapFieldGenerator(const FieldDescriptor* descriptor,
                              const Options& options)
    : descriptor_(descriptor) {
  SetMessageVariables(descriptor, &variables_, options);
}

MapFieldGenerator::~MapFieldGenerator() {}

void MapFieldGenerator::
GeneratePrivateMembers(io::Printer* printer) const {
  printer->Print(variables_,
      "typedef ::google::protobuf::internal::MapEntryLite<\n"
      "    $key_cpp$, $val_cpp$,\n"
      "    $key_wire_type$,\n"
      "    $val_wire_type$,\n"
      "    $default_enum_value$ >\n"
      "    $map_classname$;\n"
      "::google::protobuf::internal::MapField$lite$<\n"
      "    $key_cpp$, $val_cpp$,\n"
      "    $key_wire_type$,\n"
      "    $val_wire_type$,\n"
      "    $default_enum_value$ > $name$_;\n");
}

void MapFieldGenerator::
GenerateAccessorDeclarations(io::Printer* printer) const {
  printer->Print(variables_,
      "const ::google::protobuf::Map< $key_cpp$, $val_cpp$ >&\n"
      "    $name$() const$deprecation$;\n"
      "::google::protobuf::Map< $key_cpp$, $val_cpp$ >*\n"
      "    mutable_$name$()$deprecation$;\n");
}

void MapFieldGenerator::
GenerateInlineAccessorDefinitions(io::Printer* printer,
                                  bool is_inline) const {
  map<string, string> variables(variables_);
  variables["inline"] = is_inline ? "inline" : "";
  printer->Print(variables,
      "$inline$ const ::google::protobuf::Map< $key_cpp$, $val_cpp$ >&\n"
      "$classname$::$name$() const {\n"
      "  // @@protoc_insertion_point(field_map:$full_name$)\n"
      "  return $name$_.GetMap();\n"
      "}\n"
      "$inline$ ::google::protobuf::Map< $key_cpp$, $val_cpp$ >*\n"
      "$classname$::mutable_$name$() {\n"
      "  // @@protoc_insertion_point(field_mutable_map:$full_name$)\n"
      "  return $name$_.MutableMap();\n"
      "}\n");
}

void MapFieldGenerator::
GenerateClearingCode(io::Printer* printer) const {
  printer->Print(variables_, "$name$_.Clear();\n");
}

void MapFieldGenerator::
GenerateMergingCode(io::Printer* printer) const {
  printer->Print(variables_, "$name$_.MergeFrom(from.$name$_);\n");
}

void MapFieldGenerator::
GenerateSwappingCode(io::Printer* printer) const {
  printer->Print(variables_, "$name$_.Swap(&other->$name$_);\n");
}

void MapFieldGenerator::
GenerateConstructorCode(io::Printer* printer) const {
  if (HasDescriptorMethods(descriptor_->file())) {
    printer->Print(variables_,
        "$name$_.SetAssignDescriptorCallback(\n"
        "    protobuf_AssignDescriptorsOnce);\n"
        "$name$_.SetEntryDescriptor(\n"
        "    &$type$_descriptor_);\n");
  }
}

void MapFieldGenerator::
GenerateMergeFromCodedStream(io::Printer* printer) const {
  const FieldDescriptor* value_field =
      descriptor_->message_type()->FindFieldByName("value");
  printer->Print(variables_,
      "::google::protobuf::scoped_ptr<$map_classname$> entry($name$_.NewEntry());\n");

  if (IsProto3Field(descriptor_) ||
      value_field->type() != FieldDescriptor::TYPE_ENUM) {
    printer->Print(variables_,
        "DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(\n"
        "    input, entry.get()));\n");
    switch (value_field->cpp_type()) {
      case FieldDescriptor::CPPTYPE_MESSAGE:
        printer->Print(variables_,
            "(*mutable_$name$())[entry->key()].Swap("
            "entry->mutable_value());\n");
        break;
      case FieldDescriptor::CPPTYPE_ENUM:
        printer->Print(variables_,
            "(*mutable_$name$())[entry->key()] =\n"
            "    static_cast<$val_cpp$>(*entry->mutable_value());\n");
        break;
      default:
        printer->Print(variables_,
            "(*mutable_$name$())[entry->key()] = *entry->mutable_value();\n");
        break;
    }
  } else {
    printer->Print(variables_,
        "{\n"
        "  ::std::string data;\n"
        "  DO_(::google::protobuf::internal::WireFormatLite::ReadString(input, &data));\n"
        "  DO_(entry->ParseFromString(data));\n"
        "  if ($val_cpp$_IsValid(*entry->mutable_value())) {\n"
        "    (*mutable_$name$())[entry->key()] =\n"
        "        static_cast<$val_cpp$>(*entry->mutable_value());\n"
        "  } else {\n");
    if (HasDescriptorMethods(descriptor_->file())) {
      printer->Print(variables_,
          "    mutable_unknown_fields()"
          "->AddLengthDelimited($number$, data);\n");
    } else {
      printer->Print(variables_,
          "    unknown_fields_stream.WriteVarint32($tag$);\n"
          "    unknown_fields_stream.WriteVarint32(data.size());\n"
          "    unknown_fields_stream.WriteString(data);\n");
    }


    printer->Print(variables_,
        "  }\n"
        "}\n");
  }

  // If entry is allocated by arena, its desctructor should be avoided.
  if (SupportsArenas(descriptor_)) {
    printer->Print(variables_,
        "if (entry->GetArena() != NULL) entry.release();\n");
  }
}

void MapFieldGenerator::
GenerateSerializeWithCachedSizes(io::Printer* printer) const {
  printer->Print(variables_,
      "{\n"
      "  ::google::protobuf::scoped_ptr<$map_classname$> entry;\n"
      "  for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
      "      it = $name$().begin(); it != $name$().end(); ++it) {\n");

  // If entry is allocated by arena, its desctructor should be avoided.
  if (SupportsArenas(descriptor_)) {
    printer->Print(variables_,
        "    if (entry.get() != NULL && entry->GetArena() != NULL) {\n"
        "      entry.release();\n"
        "    }\n");
  }

  printer->Print(variables_,
      "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
      "    ::google::protobuf::internal::WireFormatLite::Write$stream_writer$(\n"
      "        $number$, *entry, output);\n"
      "  }\n");

  // If entry is allocated by arena, its desctructor should be avoided.
  if (SupportsArenas(descriptor_)) {
    printer->Print(variables_,
        "  if (entry.get() != NULL && entry->GetArena() != NULL) {\n"
        "    entry.release();\n"
        "  }\n");
  }

  printer->Print("}\n");
}

void MapFieldGenerator::
GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
  printer->Print(variables_,
      "{\n"
      "  ::google::protobuf::scoped_ptr<$map_classname$> entry;\n"
      "  for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
      "      it = $name$().begin(); it != $name$().end(); ++it) {\n");

  // If entry is allocated by arena, its desctructor should be avoided.
  if (SupportsArenas(descriptor_)) {
    printer->Print(variables_,
        "    if (entry.get() != NULL && entry->GetArena() != NULL) {\n"
        "      entry.release();\n"
        "    }\n");
  }

  printer->Print(variables_,
      "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
      "    target = ::google::protobuf::internal::WireFormatLite::\n"
      "        Write$declared_type$NoVirtualToArray(\n"
      "            $number$, *entry, target);\n"
      "  }\n");

  // If entry is allocated by arena, its desctructor should be avoided.
  if (SupportsArenas(descriptor_)) {
    printer->Print(variables_,
        "  if (entry.get() != NULL && entry->GetArena() != NULL) {\n"
        "    entry.release();\n"
        "  }\n");
  }

  printer->Print("}\n");
}

void MapFieldGenerator::
GenerateByteSize(io::Printer* printer) const {
  printer->Print(variables_,
      "total_size += $tag_size$ * this->$name$_size();\n"
      "{\n"
      "  ::google::protobuf::scoped_ptr<$map_classname$> entry;\n"
      "  for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
      "      it = $name$().begin(); it != $name$().end(); ++it) {\n");

  // If entry is allocated by arena, its desctructor should be avoided.
  if (SupportsArenas(descriptor_)) {
    printer->Print(variables_,
        "    if (entry.get() != NULL && entry->GetArena() != NULL) {\n"
        "      entry.release();\n"
        "    }\n");
  }

  printer->Print(variables_,
      "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
      "    total_size += ::google::protobuf::internal::WireFormatLite::\n"
      "        $declared_type$SizeNoVirtual(*entry);\n"
      "  }\n");

  // If entry is allocated by arena, its desctructor should be avoided.
  if (SupportsArenas(descriptor_)) {
    printer->Print(variables_,
        "  if (entry.get() != NULL && entry->GetArena() != NULL) {\n"
        "    entry.release();\n"
        "  }\n");
  }

  printer->Print("}\n");
}

}  // namespace cpp
}  // namespace compiler
}  // namespace protobuf
}  // namespace google