chromium/third_party/protobuf/src/google/protobuf/arenastring.h

// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
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#ifndef GOOGLE_PROTOBUF_ARENASTRING_H__
#define GOOGLE_PROTOBUF_ARENASTRING_H__

#include <algorithm>
#include <string>
#include <type_traits>
#include <utility>

#include <google/protobuf/stubs/logging.h>
#include <google/protobuf/stubs/common.h>
#include <google/protobuf/arena.h>
#include <google/protobuf/port.h>
#include <google/protobuf/explicitly_constructed.h>

// must be last:
#include <google/protobuf/port_def.inc>

#ifdef SWIG
#error "You cannot SWIG proto headers"
#endif


namespace google {
namespace protobuf {
namespace internal {
class EpsCopyInputStream;

class SwapFieldHelper;

// Declared in message_lite.h
PROTOBUF_EXPORT extern ExplicitlyConstructedArenaString
    fixed_address_empty_string;

// Lazy string instance to support string fields with non-empty default.
// These are initialized on the first call to .get().
class PROTOBUF_EXPORT LazyString { … };

class TaggedStringPtr { … };

static_assert …;

// This class encapsulates a pointer to a std::string with or without arena
// owned contents, tagged by the bottom bits of the string pointer. It is a
// high-level wrapper that almost directly corresponds to the interface required
// by string fields in generated code. It replaces the old std::string* pointer
// in such cases.
//
// The string pointer is tagged to be either a default, externally owned value,
// a mutable heap allocated value, or an arena allocated value. The object uses
// a single global instance of an empty string that is used as the initial
// default value. Fields that have empty default values directly use this global
// default. Fields that have non empty default values are supported through
// lazily initialized default values managed by the LazyString class.
//
// Generated code and reflection code both ensure that ptr_ is never null.
// Because ArenaStringPtr is used in oneof unions, its constructor is a NOP and
// the field is always manually initialized via method calls.
//
// See TaggedStringPtr for more information about the types of string values
// being held, and the mutable and ownership invariants for each type.
struct PROTOBUF_EXPORT ArenaStringPtr { … };

inline void ArenaStringPtr::InitDefault() { … }

inline void ArenaStringPtr::InitExternal(const std::string* str) { … }

inline void ArenaStringPtr::InitAllocated(std::string* str, Arena* arena) { … }

inline void ArenaStringPtr::Set(const char* s, Arena* arena) { … }

inline void ArenaStringPtr::Set(const char* s, size_t n, Arena* arena) { … }

inline void ArenaStringPtr::SetBytes(ConstStringParam value, Arena* arena) { … }

inline void ArenaStringPtr::SetBytes(std::string&& value, Arena* arena) { … }

inline void ArenaStringPtr::SetBytes(const char* s, Arena* arena) { … }

inline void ArenaStringPtr::SetBytes(const void* p, size_t n, Arena* arena) { … }

// Make sure rhs_arena allocated rhs, and lhs_arena allocated lhs.
inline PROTOBUF_NDEBUG_INLINE void ArenaStringPtr::InternalSwap(  //
    ArenaStringPtr* rhs, Arena* rhs_arena,                        //
    ArenaStringPtr* lhs, Arena* lhs_arena) { … }

inline void ArenaStringPtr::ClearNonDefaultToEmpty() { … }

inline std::string* ArenaStringPtr::UnsafeMutablePointer() { … }


}  // namespace internal
}  // namespace protobuf
}  // namespace google

#include <google/protobuf/port_undef.inc>

#endif  // GOOGLE_PROTOBUF_ARENASTRING_H__