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

// Protocol Buffers - Google's data interchange format
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// https://developers.google.com/protocol-buffers/
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// This file defines the map container and its helpers to support protobuf maps.
//
// The Map and MapIterator types are provided by this header file.
// Please avoid using other types defined here, unless they are public
// types within Map or MapIterator, such as Map::value_type.

#ifndef GOOGLE_PROTOBUF_MAP_H__
#define GOOGLE_PROTOBUF_MAP_H__


#include <functional>
#include <initializer_list>
#include <iterator>
#include <limits>  // To support Visual Studio 2008
#include <map>
#include <string>
#include <type_traits>
#include <utility>

#if defined(__cpp_lib_string_view)
#include <string_view>
#endif  // defined(__cpp_lib_string_view)

#if !defined(GOOGLE_PROTOBUF_NO_RDTSC) && defined(__APPLE__)
#include <mach/mach_time.h>
#endif

#include <google/protobuf/stubs/common.h>
#include <google/protobuf/arena.h>
#include <google/protobuf/generated_enum_util.h>
#include <google/protobuf/map_type_handler.h>
#include <google/protobuf/port.h>
#include <google/protobuf/stubs/hash.h>

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

// Must be included last.
#include <google/protobuf/port_def.inc>

namespace google {
namespace protobuf {

template <typename Key, typename T>
class Map;

class MapIterator;

template <typename Enum>
struct is_proto_enum;

namespace internal {
template <typename Derived, typename Key, typename T,
          WireFormatLite::FieldType key_wire_type,
          WireFormatLite::FieldType value_wire_type>
class MapFieldLite;

template <typename Derived, typename Key, typename T,
          WireFormatLite::FieldType key_wire_type,
          WireFormatLite::FieldType value_wire_type>
class MapField;

template <typename Key, typename T>
class TypeDefinedMapFieldBase;

class DynamicMapField;

class GeneratedMessageReflection;

// re-implement std::allocator to use arena allocator for memory allocation.
// Used for Map implementation. Users should not use this class
// directly.
template <typename U>
class MapAllocator { … };

KeyForTree;

// Default case: Not transparent.
// We use std::hash<key_type>/std::less<key_type> and all the lookup functions
// only accept `key_type`.
template <typename key_type>
struct TransparentSupport { … };

#if defined(__cpp_lib_string_view)
// If std::string_view is available, we add transparent support for std::string
// keys. We use std::hash<std::string_view> as it supports the input types we
// care about. The lookup functions accept arbitrary `K`. This will include any
// key type that is convertible to std::string_view.
template <>
struct TransparentSupport<std::string> { … };
#endif  // defined(__cpp_lib_string_view)

TreeForMap;

inline bool TableEntryIsEmpty(void* const* table, size_t b) { … }
inline bool TableEntryIsNonEmptyList(void* const* table, size_t b) { … }
inline bool TableEntryIsTree(void* const* table, size_t b) { … }
inline bool TableEntryIsList(void* const* table, size_t b) { … }

// This captures all numeric types.
inline size_t MapValueSpaceUsedExcludingSelfLong(bool) { … }
inline size_t MapValueSpaceUsedExcludingSelfLong(const std::string& str) { … }
template <typename T,
          typename = decltype(std::declval<const T&>().SpaceUsedLong())>
size_t MapValueSpaceUsedExcludingSelfLong(const T& message) { … }

constexpr size_t kGlobalEmptyTableSize = …;
PROTOBUF_EXPORT extern void* const kGlobalEmptyTable[kGlobalEmptyTableSize];

// Space used for the table, trees, and nodes.
// Does not include the indirect space used. Eg the data of a std::string.
template <typename Key>
PROTOBUF_NOINLINE size_t SpaceUsedInTable(void** table, size_t num_buckets,
                                          size_t num_elements,
                                          size_t sizeof_node) { … }

template <typename Map,
          typename = typename std::enable_if<
              !std::is_scalar<typename Map::key_type>::value ||
              !std::is_scalar<typename Map::mapped_type>::value>::type>
size_t SpaceUsedInValues(const Map* map) { … }

inline size_t SpaceUsedInValues(const void*) { … }

}  // namespace internal

// This is the class for Map's internal value_type. Instead of using
// std::pair as value_type, we use this class which provides us more control of
// its process of construction and destruction.
template <typename Key, typename T>
struct PROTOBUF_ATTRIBUTE_STANDALONE_DEBUG MapPair { … };

// Map is an associative container type used to store protobuf map
// fields.  Each Map instance may or may not use a different hash function, a
// different iteration order, and so on.  E.g., please don't examine
// implementation details to decide if the following would work:
//  Map<int, int> m0, m1;
//  m0[0] = m1[0] = m0[1] = m1[1] = 0;
//  assert(m0.begin()->first == m1.begin()->first);  // Bug!
//
// Map's interface is similar to std::unordered_map, except that Map is not
// designed to play well with exceptions.
template <typename Key, typename T>
class Map { … };

}  // namespace protobuf
}  // namespace google

#include <google/protobuf/port_undef.inc>

#endif  // GOOGLE_PROTOBUF_MAP_H__