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Diffstat (limited to 'include/google/protobuf/map_entry_lite.h')
| -rw-r--r-- | include/google/protobuf/map_entry_lite.h | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/include/google/protobuf/map_entry_lite.h b/include/google/protobuf/map_entry_lite.h new file mode 100644 index 0000000000..6b08cd92ba --- /dev/null +++ b/include/google/protobuf/map_entry_lite.h @@ -0,0 +1,563 @@ +// 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_MAP_ENTRY_LITE_H__ +#define GOOGLE_PROTOBUF_MAP_ENTRY_LITE_H__ + +#include <assert.h> + +#include <algorithm> +#include <string> +#include <utility> + +#include <google/protobuf/stubs/casts.h> +#include <google/protobuf/io/coded_stream.h> +#include <google/protobuf/arena.h> +#include <google/protobuf/port.h> +#include <google/protobuf/arenastring.h> +#include <google/protobuf/generated_message_util.h> +#include <google/protobuf/map.h> +#include <google/protobuf/map_type_handler.h> +#include <google/protobuf/parse_context.h> +#include <google/protobuf/wire_format_lite.h> + +// Must be included last. +#include <google/protobuf/port_def.inc> +#ifdef SWIG +#error "You cannot SWIG proto headers" +#endif + +namespace google { +namespace protobuf { +namespace internal { +template <typename Derived, typename Key, typename Value, + WireFormatLite::FieldType kKeyFieldType, + WireFormatLite::FieldType kValueFieldType> +class MapEntry; +template <typename Derived, typename Key, typename Value, + WireFormatLite::FieldType kKeyFieldType, + WireFormatLite::FieldType kValueFieldType> +class MapFieldLite; +} // namespace internal +} // namespace protobuf +} // namespace google + +namespace google { +namespace protobuf { +namespace internal { + +// MoveHelper::Move is used to set *dest. It copies *src, or moves it (in +// the C++11 sense), or swaps it. *src is left in a sane state for +// subsequent destruction, but shouldn't be used for anything. +template <bool is_enum, bool is_message, bool is_stringlike, typename T> +struct MoveHelper { // primitives + static void Move(T* src, T* dest) { *dest = *src; } +}; + +template <bool is_message, bool is_stringlike, typename T> +struct MoveHelper<true, is_message, is_stringlike, T> { // enums + static void Move(T* src, T* dest) { *dest = *src; } + // T is an enum here, so allow conversions to and from int. + static void Move(T* src, int* dest) { *dest = static_cast<int>(*src); } + static void Move(int* src, T* dest) { *dest = static_cast<T>(*src); } +}; + +template <bool is_stringlike, typename T> +struct MoveHelper<false, true, is_stringlike, T> { // messages + static void Move(T* src, T* dest) { dest->Swap(src); } +}; + +template <typename T> +struct MoveHelper<false, false, true, T> { // strings and similar + static void Move(T* src, T* dest) { + *dest = std::move(*src); + } +}; + +// MapEntryImpl is used to implement parsing and serialization of map entries. +// It uses Curious Recursive Template Pattern (CRTP) to provide the type of +// the eventual code to the template code. +template <typename Derived, typename Base, typename Key, typename Value, + WireFormatLite::FieldType kKeyFieldType, + WireFormatLite::FieldType kValueFieldType> +class MapEntryImpl : public Base { + public: + typedef MapEntryFuncs<Key, Value, kKeyFieldType, kValueFieldType> Funcs; + + protected: + // Provide utilities to parse/serialize key/value. Provide utilities to + // manipulate internal stored type. + typedef MapTypeHandler<kKeyFieldType, Key> KeyTypeHandler; + typedef MapTypeHandler<kValueFieldType, Value> ValueTypeHandler; + + // Define internal memory layout. Strings and messages are stored as + // pointers, while other types are stored as values. + typedef typename KeyTypeHandler::TypeOnMemory KeyOnMemory; + typedef typename ValueTypeHandler::TypeOnMemory ValueOnMemory; + + // Enum type cannot be used for MapTypeHandler::Read. Define a type + // which will replace Enum with int. + typedef typename KeyTypeHandler::MapEntryAccessorType KeyMapEntryAccessorType; + typedef + typename ValueTypeHandler::MapEntryAccessorType ValueMapEntryAccessorType; + + // Constants for field number. + static const int kKeyFieldNumber = 1; + static const int kValueFieldNumber = 2; + + // Constants for field tag. + static const uint8_t kKeyTag = + GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kKeyFieldNumber, KeyTypeHandler::kWireType); + static const uint8_t kValueTag = GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG( + kValueFieldNumber, ValueTypeHandler::kWireType); + static const size_t kTagSize = 1; + + public: + // Work-around for a compiler bug (see repeated_field.h). + typedef void MapEntryHasMergeTypeTrait; + typedef Derived EntryType; + typedef Key EntryKeyType; + typedef Value EntryValueType; + static const WireFormatLite::FieldType kEntryKeyFieldType = kKeyFieldType; + static const WireFormatLite::FieldType kEntryValueFieldType = kValueFieldType; + + constexpr MapEntryImpl() + : key_(KeyTypeHandler::Constinit()), + value_(ValueTypeHandler::Constinit()), + _has_bits_{} {} + + explicit MapEntryImpl(Arena* arena) + : Base(arena), + key_(KeyTypeHandler::Constinit()), + value_(ValueTypeHandler::Constinit()), + _has_bits_{} {} + + ~MapEntryImpl() override { + if (Base::GetArenaForAllocation() != nullptr) return; + KeyTypeHandler::DeleteNoArena(key_); + ValueTypeHandler::DeleteNoArena(value_); + } + + // accessors ====================================================== + + virtual inline const KeyMapEntryAccessorType& key() const { + return KeyTypeHandler::GetExternalReference(key_); + } + virtual inline const ValueMapEntryAccessorType& value() const { + return ValueTypeHandler::DefaultIfNotInitialized(value_); + } + inline KeyMapEntryAccessorType* mutable_key() { + set_has_key(); + return KeyTypeHandler::EnsureMutable(&key_, Base::GetArenaForAllocation()); + } + inline ValueMapEntryAccessorType* mutable_value() { + set_has_value(); + return ValueTypeHandler::EnsureMutable(&value_, + Base::GetArenaForAllocation()); + } + + // implements MessageLite ========================================= + + // MapEntryImpl is for implementation only and this function isn't called + // anywhere. Just provide a fake implementation here for MessageLite. + std::string GetTypeName() const override { return ""; } + + void CheckTypeAndMergeFrom(const MessageLite& other) override { + MergeFromInternal(*::google::protobuf::internal::DownCast<const Derived*>(&other)); + } + + const char* _InternalParse(const char* ptr, ParseContext* ctx) final { + while (!ctx->Done(&ptr)) { + uint32_t tag; + ptr = ReadTag(ptr, &tag); + GOOGLE_PROTOBUF_PARSER_ASSERT(ptr); + if (tag == kKeyTag) { + set_has_key(); + KeyMapEntryAccessorType* key = mutable_key(); + ptr = KeyTypeHandler::Read(ptr, ctx, key); + if (!Derived::ValidateKey(key)) return nullptr; + } else if (tag == kValueTag) { + set_has_value(); + ValueMapEntryAccessorType* value = mutable_value(); + ptr = ValueTypeHandler::Read(ptr, ctx, value); + if (!Derived::ValidateValue(value)) return nullptr; + } else { + if (tag == 0 || WireFormatLite::GetTagWireType(tag) == + WireFormatLite::WIRETYPE_END_GROUP) { + ctx->SetLastTag(tag); + return ptr; + } + ptr = UnknownFieldParse(tag, static_cast<std::string*>(nullptr), ptr, + ctx); + } + GOOGLE_PROTOBUF_PARSER_ASSERT(ptr); + } + return ptr; + } + + size_t ByteSizeLong() const override { + size_t size = 0; + size += kTagSize + static_cast<size_t>(KeyTypeHandler::ByteSize(key())); + size += kTagSize + static_cast<size_t>(ValueTypeHandler::ByteSize(value())); + return size; + } + + ::uint8_t* _InternalSerialize( + ::uint8_t* ptr, io::EpsCopyOutputStream* stream) const override { + ptr = KeyTypeHandler::Write(kKeyFieldNumber, key(), ptr, stream); + return ValueTypeHandler::Write(kValueFieldNumber, value(), ptr, stream); + } + + // Don't override SerializeWithCachedSizesToArray. Use MessageLite's. + + int GetCachedSize() const override { + int size = 0; + size += has_key() ? static_cast<int>(kTagSize) + + KeyTypeHandler::GetCachedSize(key()) + : 0; + size += has_value() ? static_cast<int>(kTagSize) + + ValueTypeHandler::GetCachedSize(value()) + : 0; + return size; + } + + bool IsInitialized() const override { + return ValueTypeHandler::IsInitialized(value_); + } + + Base* New(Arena* arena) const override { + Derived* entry = Arena::CreateMessage<Derived>(arena); + return entry; + } + + protected: + // We can't declare this function directly here as it would hide the other + // overload (const Message&). + void MergeFromInternal(const MapEntryImpl& from) { + if (from._has_bits_[0]) { + if (from.has_key()) { + KeyTypeHandler::EnsureMutable(&key_, Base::GetArenaForAllocation()); + KeyTypeHandler::Merge(from.key(), &key_, Base::GetArenaForAllocation()); + set_has_key(); + } + if (from.has_value()) { + ValueTypeHandler::EnsureMutable(&value_, Base::GetArenaForAllocation()); + ValueTypeHandler::Merge(from.value(), &value_, + Base::GetArenaForAllocation()); + set_has_value(); + } + } + } + + public: + void Clear() override { + KeyTypeHandler::Clear(&key_, Base::GetArenaForAllocation()); + ValueTypeHandler::Clear(&value_, Base::GetArenaForAllocation()); + clear_has_key(); + clear_has_value(); + } + + // Parsing using MergePartialFromCodedStream, above, is not as + // efficient as it could be. This helper class provides a speedier way. + template <typename MapField, typename Map> + class Parser { + public: + explicit Parser(MapField* mf) : mf_(mf), map_(mf->MutableMap()) {} + ~Parser() { + if (entry_ != nullptr && entry_->GetArenaForAllocation() == nullptr) + delete entry_; + } + + const char* _InternalParse(const char* ptr, ParseContext* ctx) { + if (PROTOBUF_PREDICT_TRUE(!ctx->Done(&ptr) && *ptr == kKeyTag)) { + ptr = KeyTypeHandler::Read(ptr + 1, ctx, &key_); + if (PROTOBUF_PREDICT_FALSE(!ptr || !Derived::ValidateKey(&key_))) { + return nullptr; + } + if (PROTOBUF_PREDICT_TRUE(!ctx->Done(&ptr) && *ptr == kValueTag)) { + typename Map::size_type map_size = map_->size(); + value_ptr_ = &(*map_)[key_]; + if (PROTOBUF_PREDICT_TRUE(map_size != map_->size())) { + using T = + typename MapIf<ValueTypeHandler::kIsEnum, int*, Value*>::type; + ptr = ValueTypeHandler::Read(ptr + 1, ctx, + reinterpret_cast<T>(value_ptr_)); + if (PROTOBUF_PREDICT_FALSE(!ptr || + !Derived::ValidateValue(value_ptr_))) { + map_->erase(key_); // Failure! Undo insertion. + return nullptr; + } + if (PROTOBUF_PREDICT_TRUE(ctx->Done(&ptr))) return ptr; + if (!ptr) return nullptr; + NewEntry(); + ValueMover::Move(value_ptr_, entry_->mutable_value()); + map_->erase(key_); + goto move_key; + } + } else { + if (!ptr) return nullptr; + } + NewEntry(); + move_key: + KeyMover::Move(&key_, entry_->mutable_key()); + } else { + if (!ptr) return nullptr; + NewEntry(); + } + ptr = entry_->_InternalParse(ptr, ctx); + if (ptr) UseKeyAndValueFromEntry(); + return ptr; + } + + template <typename UnknownType> + const char* ParseWithEnumValidation(const char* ptr, ParseContext* ctx, + bool (*is_valid)(int), + uint32_t field_num, + InternalMetadata* metadata) { + auto entry = NewEntry(); + ptr = entry->_InternalParse(ptr, ctx); + if (!ptr) return nullptr; + if (is_valid(entry->value())) { + UseKeyAndValueFromEntry(); + } else { + WriteLengthDelimited(field_num, entry->SerializeAsString(), + metadata->mutable_unknown_fields<UnknownType>()); + } + return ptr; + } + + MapEntryImpl* NewEntry() { return entry_ = mf_->NewEntry(); } + + const Key& key() const { return key_; } + const Value& value() const { return *value_ptr_; } + + const Key& entry_key() const { return entry_->key(); } + const Value& entry_value() const { return entry_->value(); } + + private: + void UseKeyAndValueFromEntry() { + // Update key_ in case we need it later (because key() is called). + // This is potentially inefficient, especially if the key is + // expensive to copy (e.g., a long string), but this is a cold + // path, so it's not a big deal. + key_ = entry_->key(); + value_ptr_ = &(*map_)[key_]; + ValueMover::Move(entry_->mutable_value(), value_ptr_); + } + + // After reading a key and value successfully, and inserting that data + // into map_, we are not at the end of the input. This is unusual, but + // allowed by the spec. + bool ReadBeyondKeyValuePair(io::CodedInputStream* input) PROTOBUF_COLD { + NewEntry(); + ValueMover::Move(value_ptr_, entry_->mutable_value()); + map_->erase(key_); + KeyMover::Move(&key_, entry_->mutable_key()); + const bool result = entry_->MergePartialFromCodedStream(input); + if (result) UseKeyAndValueFromEntry(); + return result; + } + + typedef MoveHelper<KeyTypeHandler::kIsEnum, KeyTypeHandler::kIsMessage, + KeyTypeHandler::kWireType == + WireFormatLite::WIRETYPE_LENGTH_DELIMITED, + Key> + KeyMover; + typedef MoveHelper<ValueTypeHandler::kIsEnum, ValueTypeHandler::kIsMessage, + ValueTypeHandler::kWireType == + WireFormatLite::WIRETYPE_LENGTH_DELIMITED, + Value> + ValueMover; + + MapField* const mf_; + Map* const map_; + Key key_; + Value* value_ptr_; + MapEntryImpl* entry_ = nullptr; + }; + + protected: + void set_has_key() { _has_bits_[0] |= 0x00000001u; } + bool has_key() const { return (_has_bits_[0] & 0x00000001u) != 0; } + void clear_has_key() { _has_bits_[0] &= ~0x00000001u; } + void set_has_value() { _has_bits_[0] |= 0x00000002u; } + bool has_value() const { return (_has_bits_[0] & 0x00000002u) != 0; } + void clear_has_value() { _has_bits_[0] &= ~0x00000002u; } + + public: + inline Arena* GetArena() const { return Base::GetArena(); } + + protected: // Needed for constructing tables + KeyOnMemory key_; + ValueOnMemory value_; + uint32_t _has_bits_[1]; + + private: + friend class ::PROTOBUF_NAMESPACE_ID::Arena; + typedef void InternalArenaConstructable_; + typedef void DestructorSkippable_; + template <typename C, typename K, typename V, WireFormatLite::FieldType, + WireFormatLite::FieldType> + friend class internal::MapEntry; + template <typename C, typename K, typename V, WireFormatLite::FieldType, + WireFormatLite::FieldType> + friend class internal::MapFieldLite; + + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MapEntryImpl); +}; + +template <typename T, typename Key, typename Value, + WireFormatLite::FieldType kKeyFieldType, + WireFormatLite::FieldType kValueFieldType> +class MapEntryLite : public MapEntryImpl<T, MessageLite, Key, Value, + kKeyFieldType, kValueFieldType> { + public: + typedef MapEntryImpl<T, MessageLite, Key, Value, kKeyFieldType, + kValueFieldType> + SuperType; + constexpr MapEntryLite() {} + explicit MapEntryLite(Arena* arena) : SuperType(arena) {} + ~MapEntryLite() override { + MessageLite::_internal_metadata_.template Delete<std::string>(); + } + void MergeFrom(const MapEntryLite& other) { MergeFromInternal(other); } + + private: + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MapEntryLite); +}; + +// Helpers for deterministic serialization ============================= + +// Iterator base for MapSorterFlat and MapSorterPtr. +template <typename storage_type> +struct MapSorterIt { + storage_type* ptr; + MapSorterIt(storage_type* ptr) : ptr(ptr) {} + bool operator==(const MapSorterIt& other) const { return ptr == other.ptr; } + bool operator!=(const MapSorterIt& other) const { return !(*this == other); } + MapSorterIt& operator++() { ++ptr; return *this; } + MapSorterIt operator++(int) { auto other = *this; ++ptr; return other; } + MapSorterIt operator+(int v) { return MapSorterIt{ptr + v}; } +}; + +// MapSorterFlat stores keys inline with pointers to map entries, so that +// keys can be compared without indirection. This type is used for maps with +// keys that are not strings. +template <typename MapT> +class MapSorterFlat { + public: + using value_type = typename MapT::value_type; + using storage_type = std::pair<typename MapT::key_type, const value_type*>; + + // This const_iterator dereferenes to the map entry stored in the sorting + // array pairs. This is the same interface as the Map::const_iterator type, + // and allows generated code to use the same loop body with either form: + // for (const auto& entry : map) { ... } + // for (const auto& entry : MapSorterFlat(map)) { ... } + struct const_iterator : public MapSorterIt<storage_type> { + using pointer = const typename MapT::value_type*; + using reference = const typename MapT::value_type&; + using MapSorterIt<storage_type>::MapSorterIt; + + pointer operator->() const { return this->ptr->second; } + reference operator*() const { return *this->operator->(); } + }; + + explicit MapSorterFlat(const MapT& m) + : size_(m.size()), items_(size_ ? new storage_type[size_] : nullptr) { + if (!size_) return; + storage_type* it = &items_[0]; + for (const auto& entry : m) { + *it++ = {entry.first, &entry}; + } + std::sort(&items_[0], &items_[size_], + [](const storage_type& a, const storage_type& b) { + return a.first < b.first; + }); + } + size_t size() const { return size_; } + const_iterator begin() const { return {items_.get()}; } + const_iterator end() const { return {items_.get() + size_}; } + + private: + size_t size_; + std::unique_ptr<storage_type[]> items_; +}; + +// MapSorterPtr stores and sorts pointers to map entries. This type is used for +// maps with keys that are strings. +template <typename MapT> +class MapSorterPtr { + public: + using value_type = typename MapT::value_type; + using storage_type = const typename MapT::value_type*; + + // This const_iterator dereferenes the map entry pointer stored in the sorting + // array. This is the same interface as the Map::const_iterator type, and + // allows generated code to use the same loop body with either form: + // for (const auto& entry : map) { ... } + // for (const auto& entry : MapSorterPtr(map)) { ... } + struct const_iterator : public MapSorterIt<storage_type> { + using pointer = const typename MapT::value_type*; + using reference = const typename MapT::value_type&; + using MapSorterIt<storage_type>::MapSorterIt; + + pointer operator->() const { return *this->ptr; } + reference operator*() const { return *this->operator->(); } + }; + + explicit MapSorterPtr(const MapT& m) + : size_(m.size()), items_(size_ ? new storage_type[size_] : nullptr) { + if (!size_) return; + storage_type* it = &items_[0]; + for (const auto& entry : m) { + *it++ = &entry; + } + std::sort(&items_[0], &items_[size_], + [](const storage_type& a, const storage_type& b) { + return a->first < b->first; + }); + } + size_t size() const { return size_; } + const_iterator begin() const { return {items_.get()}; } + const_iterator end() const { return {items_.get() + size_}; } + + private: + size_t size_; + std::unique_ptr<storage_type[]> items_; +}; + +} // namespace internal +} // namespace protobuf +} // namespace google + +#include <google/protobuf/port_undef.inc> + +#endif // GOOGLE_PROTOBUF_MAP_ENTRY_LITE_H__ |