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

// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#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,
                         std::map<string, string>* variables,
                         const Options& options) {
  SetCommonFieldVariables(descriptor, variables, options);
  (*variables)["type"] = ClassName(descriptor->message_type(), false);
  (*variables)["file_namespace"] =
      FileLevelNamespace(descriptor->file()->name());
  (*variables)["stream_writer"] =
      (*variables)["declared_type"] +
      (HasFastArraySerialization(descriptor->message_type()->file(), options)
           ? "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(), true);
      (*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(), options)) {
    (*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)
    : FieldGenerator(options), descriptor_(descriptor) {
  SetMessageVariables(descriptor, &variables_, options);
}

MapFieldGenerator::~MapFieldGenerator() {}

void MapFieldGenerator::
GeneratePrivateMembers(io::Printer* printer) const {
  printer->Print(variables_,
                 "::google::protobuf::internal::MapField$lite$<\n"
                 "    $map_classname$,\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_,
      "$deprecated_attr$const ::google::protobuf::Map< $key_cpp$, $val_cpp$ >&\n"
      "    $name$() const;\n");
  printer->Annotate("name", descriptor_);
  printer->Print(variables_,
                 "$deprecated_attr$::google::protobuf::Map< $key_cpp$, $val_cpp$ >*\n"
                 "    ${$mutable_$name$$}$();\n");
  printer->Annotate("{", "}", descriptor_);
}

void MapFieldGenerator::
GenerateInlineAccessorDefinitions(io::Printer* printer) const {
  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::
GenerateCopyConstructorCode(io::Printer* printer) const {
  GenerateConstructorCode(printer);
  GenerateMergingCode(printer);
}

void MapFieldGenerator::
GenerateMergeFromCodedStream(io::Printer* printer) const {
    const FieldDescriptor* key_field =
        descriptor_->message_type()->FindFieldByName("key");
  const FieldDescriptor* value_field =
      descriptor_->message_type()->FindFieldByName("value");
  bool using_entry = false;
  string key;
  string value;
  if (IsProto3Field(descriptor_) ||
      value_field->type() != FieldDescriptor::TYPE_ENUM) {
    printer->Print(
        variables_,
        "$map_classname$::Parser< ::google::protobuf::internal::MapField$lite$<\n"
        "    $map_classname$,\n"
        "    $key_cpp$, $val_cpp$,\n"
        "    $key_wire_type$,\n"
        "    $val_wire_type$,\n"
        "    $default_enum_value$ >,\n"
        "  ::google::protobuf::Map< $key_cpp$, $val_cpp$ > >"
        " parser(&$name$_);\n"
        "DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(\n"
        "    input, &parser));\n");
    key = "parser.key()";
    value = "parser.value()";
  } else {
    using_entry = true;
    key = "entry->key()";
    value = "entry->value()";
    printer->Print(variables_,
        "::std::unique_ptr<$map_classname$> entry($name$_.NewEntry());\n");
    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(), options_)) {
      printer->Print(variables_,
          "    mutable_unknown_fields()"
          "->AddLengthDelimited($number$, data);\n");
    } else {
      printer->Print(variables_,
          "    unknown_fields_stream.WriteVarint32($tag$u);\n"
          "    unknown_fields_stream.WriteVarint32(\n"
          "        static_cast< ::google::protobuf::uint32>(data.size()));\n"
          "    unknown_fields_stream.WriteString(data);\n");
    }

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

  if (key_field->type() == FieldDescriptor::TYPE_STRING) {
    GenerateUtf8CheckCodeForString(
        key_field, options_, true, variables_,
        StrCat(key, ".data(), static_cast<int>(", key, ".length()),\n").data(),
        printer);
  }
  if (value_field->type() == FieldDescriptor::TYPE_STRING) {
    GenerateUtf8CheckCodeForString(
        value_field, options_, true, variables_,
        StrCat(value, ".data(), static_cast<int>(", value, ".length()),\n")
            .data(),
        printer);
  }

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

static void GenerateSerializationLoop(io::Printer* printer,
                                      const std::map<string, string>& variables,
                                      bool supports_arenas,
                                      const string& utf8_check,
                                      const string& loop_header,
                                      const string& ptr,
                                      bool loop_via_iterators) {
  printer->Print(variables,
      StrCat("::std::unique_ptr<$map_classname$> entry;\n",
             loop_header, " {\n").c_str());
  printer->Indent();

  printer->Print(variables, StrCat(
      "entry.reset($name$_.New$wrapper$(\n"
      "    ", ptr, "->first, ", ptr, "->second));\n"
      "$write_entry$;\n").c_str());

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

  if (!utf8_check.empty()) {
    // If loop_via_iterators is true then ptr is actually an iterator, and we
    // create a pointer by prefixing it with "&*".
    printer->Print(
        StrCat(utf8_check, "(", (loop_via_iterators ? "&*" : ""), ptr, ");\n")
            .c_str());
  }

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

void MapFieldGenerator::
GenerateSerializeWithCachedSizes(io::Printer* printer) const {
  std::map<string, string> variables(variables_);
  variables["write_entry"] = "::google::protobuf::internal::WireFormatLite::Write" +
                             variables["stream_writer"] + "(\n            " +
                             variables["number"] + ", *entry, output)";
  variables["deterministic"] = "output->IsSerializationDeterministic()";
  GenerateSerializeWithCachedSizes(printer, variables);
}

void MapFieldGenerator::
GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
  std::map<string, string> variables(variables_);
  variables["write_entry"] =
      "target = ::google::protobuf::internal::WireFormatLite::\n"
      "                   InternalWrite" + variables["declared_type"] +
      "NoVirtualToArray(\n                       " + variables["number"] +
      ", *entry, deterministic, target);\n";
  variables["deterministic"] = "deterministic";
  GenerateSerializeWithCachedSizes(printer, variables);
}

void MapFieldGenerator::GenerateSerializeWithCachedSizes(
    io::Printer* printer, const std::map<string, string>& variables) const {
  printer->Print(variables,
      "if (!this->$name$().empty()) {\n");
  printer->Indent();
  const FieldDescriptor* key_field =
      descriptor_->message_type()->FindFieldByName("key");
  const FieldDescriptor* value_field =
      descriptor_->message_type()->FindFieldByName("value");
  const bool string_key = key_field->type() == FieldDescriptor::TYPE_STRING;
  const bool string_value = value_field->type() == FieldDescriptor::TYPE_STRING;

  printer->Print(variables,
      "typedef ::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_pointer\n"
      "    ConstPtr;\n");
  if (string_key) {
    printer->Print(variables,
        "typedef ConstPtr SortItem;\n"
        "typedef ::google::protobuf::internal::"
        "CompareByDerefFirst<SortItem> Less;\n");
  } else {
    printer->Print(variables,
        "typedef ::google::protobuf::internal::SortItem< $key_cpp$, ConstPtr > "
        "SortItem;\n"
        "typedef ::google::protobuf::internal::CompareByFirstField<SortItem> Less;\n");
  }
  string utf8_check;
  if (string_key || string_value) {
    printer->Print(
        "struct Utf8Check {\n"
        "  static void Check(ConstPtr p) {\n");
    printer->Indent();
    printer->Indent();
    if (string_key) {
      GenerateUtf8CheckCodeForString(
          key_field, options_, false, variables,
          "p->first.data(), static_cast<int>(p->first.length()),\n", printer);
    }
    if (string_value) {
      GenerateUtf8CheckCodeForString(
          value_field, options_, false, variables,
          "p->second.data(), static_cast<int>(p->second.length()),\n", printer);
    }
    printer->Outdent();
    printer->Outdent();
    printer->Print(
        "  }\n"
        "};\n");
    utf8_check = "Utf8Check::Check";
  }

  printer->Print(variables,
      "\n"
      "if ($deterministic$ &&\n"
      "    this->$name$().size() > 1) {\n"
      "  ::std::unique_ptr<SortItem[]> items(\n"
      "      new SortItem[this->$name$().size()]);\n"
      "  typedef ::google::protobuf::Map< $key_cpp$, $val_cpp$ >::size_type size_type;\n"
      "  size_type n = 0;\n"
      "  for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
      "      it = this->$name$().begin();\n"
      "      it != this->$name$().end(); ++it, ++n) {\n"
      "    items[static_cast<ptrdiff_t>(n)] = SortItem(&*it);\n"
      "  }\n"
      "  ::std::sort(&items[0], &items[static_cast<ptrdiff_t>(n)], Less());\n");
  printer->Indent();
  GenerateSerializationLoop(printer, variables, SupportsArenas(descriptor_),
      utf8_check, "for (size_type i = 0; i < n; i++)",
      string_key ? "items[static_cast<ptrdiff_t>(i)]" :
                   "items[static_cast<ptrdiff_t>(i)].second", false);
  printer->Outdent();
  printer->Print(
      "} else {\n");
  printer->Indent();
  GenerateSerializationLoop(
      printer, variables, SupportsArenas(descriptor_), utf8_check,
      "for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
      "    it = this->$name$().begin();\n"
      "    it != this->$name$().end(); ++it)",
      "it", true);
  printer->Outdent();
  printer->Print("}\n");
  printer->Outdent();
  printer->Print("}\n");
}

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