implicit_weak_message.h

Go to the documentation of this file.

// 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.
 
#ifndef GOOGLE_PROTOBUF_IMPLICIT_WEAK_MESSAGE_H__
#define GOOGLE_PROTOBUF_IMPLICIT_WEAK_MESSAGE_H__
 
#include <string>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/arena.h>
#include <google/protobuf/message_lite.h>
 
#include <google/protobuf/port_def.inc>
 
#ifdef SWIG
#error "You cannot SWIG proto headers"
#endif
 
// This file is logically internal-only and should only be used by protobuf
// generated code.
 
namespace google {
namespace protobuf {
namespace internal {
 
// An implementation of MessageLite that treats all data as unknown. This type
// acts as a placeholder for an implicit weak field in the case where the true
// message type does not get linked into the binary.
class PROTOBUF_EXPORT ImplicitWeakMessage : public MessageLite {
 public:
  ImplicitWeakMessage() : arena_(NULL) {}
  explicit ImplicitWeakMessage(Arena* arena) : arena_(arena) {}
 
  static const ImplicitWeakMessage* default_instance();
 
  std::string GetTypeName() const override { return ""; }
 
  MessageLite* New() const override { return new ImplicitWeakMessage; }
  MessageLite* New(Arena* arena) const override {
    return Arena::CreateMessage<ImplicitWeakMessage>(arena);
  }
 
  Arena* GetArena() const override { return arena_; }
 
  void Clear() override { data_.clear(); }
 
  bool IsInitialized() const override { return true; }
 
  void CheckTypeAndMergeFrom(const MessageLite& other) override {
    data_.append(static_cast<const ImplicitWeakMessage&>(other).data_);
  }
 
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
  const char* _InternalParse(const char* ptr, ParseContext* ctx) final;
#else
  bool MergePartialFromCodedStream(io::CodedInputStream* input) override;
#endif
 
  size_t ByteSizeLong() const override { return data_.size(); }
 
  void SerializeWithCachedSizes(io::CodedOutputStream* output) const override {
    output->WriteString(data_);
  }
 
  int GetCachedSize() const override { return static_cast<int>(data_.size()); }
 
  typedef void InternalArenaConstructable_;
 
 private:
  Arena* const arena_;
  std::string data_;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ImplicitWeakMessage);
};
 
// A type handler for use with implicit weak repeated message fields.
template <typename ImplicitWeakType>
class ImplicitWeakTypeHandler {
 public:
  typedef ImplicitWeakType Type;
  typedef MessageLite WeakType;
  static const bool Moveable = false;
 
  // With implicit weak fields, we need separate NewFromPrototype and
  // NewFromPrototypeWeak functions. The former is used when we want to create a
  // strong dependency on the message type, and it just delegates to the
  // GenericTypeHandler. The latter avoids creating a strong dependency, by
  // simply calling MessageLite::New.
  static inline MessageLite* NewFromPrototype(const MessageLite* prototype,
                                              Arena* arena = NULL) {
    return prototype->New(arena);
  }
 
  static inline void Delete(MessageLite* value, Arena* arena) {
    if (arena == NULL) {
      delete value;
    }
  }
  static inline Arena* GetArena(MessageLite* value) {
    return value->GetArena();
  }
  static inline void* GetMaybeArenaPointer(MessageLite* value) {
    return value->GetArena();
  }
  static inline void Clear(MessageLite* value) { value->Clear(); }
  static void Merge(const MessageLite& from, MessageLite* to) {
    to->CheckTypeAndMergeFrom(from);
  }
  static inline size_t SpaceUsedLong(const Type& value) {
    return value.SpaceUsedLong();
  }
};
 
}  // namespace internal
}  // namespace protobuf
}  // namespace google
 
#include <google/protobuf/port_undef.inc>
 
#endif  // GOOGLE_PROTOBUF_IMPLICIT_WEAK_MESSAGE_H__