| // 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. |
| |
| // Author: kenton@google.com (Kenton Varda) |
| // Based on original Protocol Buffers design by |
| // Sanjay Ghemawat, Jeff Dean, and others. |
| // |
| // DynamicMessage is implemented by constructing a data structure which |
| // has roughly the same memory layout as a generated message would have. |
| // Then, we use Reflection to implement our reflection interface. All |
| // the other operations we need to implement (e.g. parsing, copying, |
| // etc.) are already implemented in terms of Reflection, so the rest is |
| // easy. |
| // |
| // The up side of this strategy is that it's very efficient. We don't |
| // need to use hash_maps or generic representations of fields. The |
| // down side is that this is a low-level memory management hack which |
| // can be tricky to get right. |
| // |
| // As mentioned in the header, we only expose a DynamicMessageFactory |
| // publicly, not the DynamicMessage class itself. This is because |
| // GenericMessageReflection wants to have a pointer to a "default" |
| // copy of the class, with all fields initialized to their default |
| // values. We only want to construct one of these per message type, |
| // so DynamicMessageFactory stores a cache of default messages for |
| // each type it sees (each unique Descriptor pointer). The code |
| // refers to the "default" copy of the class as the "prototype". |
| // |
| // Note on memory allocation: This module often calls "operator new()" |
| // to allocate untyped memory, rather than calling something like |
| // "new uint8_t[]". This is because "operator new()" means "Give me some |
| // space which I can use as I please." while "new uint8_t[]" means "Give |
| // me an array of 8-bit integers.". In practice, the later may return |
| // a pointer that is not aligned correctly for general use. I believe |
| // Item 8 of "More Effective C++" discusses this in more detail, though |
| // I don't have the book on me right now so I'm not sure. |
| |
| #include <google/protobuf/dynamic_message.h> |
| |
| #include <algorithm> |
| #include <cstddef> |
| #include <memory> |
| #include <new> |
| #include <unordered_map> |
| |
| #include <google/protobuf/descriptor.h> |
| #include <google/protobuf/descriptor.pb.h> |
| #include <google/protobuf/generated_message_reflection.h> |
| #include <google/protobuf/generated_message_util.h> |
| #include <google/protobuf/unknown_field_set.h> |
| #include <google/protobuf/stubs/hash.h> |
| #include <google/protobuf/arenastring.h> |
| #include <google/protobuf/extension_set.h> |
| #include <google/protobuf/map_field.h> |
| #include <google/protobuf/map_field_inl.h> |
| #include <google/protobuf/map_type_handler.h> |
| #include <google/protobuf/reflection_ops.h> |
| #include <google/protobuf/repeated_field.h> |
| #include <google/protobuf/wire_format.h> |
| |
| // Must be included last. |
| #include <google/protobuf/port_def.inc> |
| |
| namespace google { |
| namespace protobuf { |
| |
| using internal::DynamicMapField; |
| using internal::ExtensionSet; |
| using internal::MapField; |
| |
| |
| using internal::ArenaStringPtr; |
| |
| // =================================================================== |
| // Some helper tables and functions... |
| |
| namespace { |
| |
| bool IsMapFieldInApi(const FieldDescriptor* field) { return field->is_map(); } |
| |
| // Sync with helpers.h. |
| inline bool HasHasbit(const FieldDescriptor* field) { |
| // This predicate includes proto3 message fields only if they have "optional". |
| // Foo submsg1 = 1; // HasHasbit() == false |
| // optional Foo submsg2 = 2; // HasHasbit() == true |
| // This is slightly odd, as adding "optional" to a singular proto3 field does |
| // not change the semantics or API. However whenever any field in a message |
| // has a hasbit, it forces reflection to include hasbit offsets for *all* |
| // fields, even if almost all of them are set to -1 (no hasbit). So to avoid |
| // causing a sudden size regression for ~all proto3 messages, we give proto3 |
| // message fields a hasbit only if "optional" is present. If the user is |
| // explicitly writing "optional", it is likely they are writing it on |
| // primitive fields also. |
| return (field->has_optional_keyword() || field->is_required()) && |
| !field->options().weak(); |
| } |
| |
| inline bool InRealOneof(const FieldDescriptor* field) { |
| return field->containing_oneof() && |
| !field->containing_oneof()->is_synthetic(); |
| } |
| |
| // Compute the byte size of the in-memory representation of the field. |
| int FieldSpaceUsed(const FieldDescriptor* field) { |
| typedef FieldDescriptor FD; // avoid line wrapping |
| if (field->label() == FD::LABEL_REPEATED) { |
| switch (field->cpp_type()) { |
| case FD::CPPTYPE_INT32: |
| return sizeof(RepeatedField<int32_t>); |
| case FD::CPPTYPE_INT64: |
| return sizeof(RepeatedField<int64_t>); |
| case FD::CPPTYPE_UINT32: |
| return sizeof(RepeatedField<uint32_t>); |
| case FD::CPPTYPE_UINT64: |
| return sizeof(RepeatedField<uint64_t>); |
| case FD::CPPTYPE_DOUBLE: |
| return sizeof(RepeatedField<double>); |
| case FD::CPPTYPE_FLOAT: |
| return sizeof(RepeatedField<float>); |
| case FD::CPPTYPE_BOOL: |
| return sizeof(RepeatedField<bool>); |
| case FD::CPPTYPE_ENUM: |
| return sizeof(RepeatedField<int>); |
| case FD::CPPTYPE_MESSAGE: |
| if (IsMapFieldInApi(field)) { |
| return sizeof(DynamicMapField); |
| } else { |
| return sizeof(RepeatedPtrField<Message>); |
| } |
| |
| case FD::CPPTYPE_STRING: |
| switch (field->options().ctype()) { |
| default: // TODO(kenton): Support other string reps. |
| case FieldOptions::STRING: |
| return sizeof(RepeatedPtrField<std::string>); |
| } |
| break; |
| } |
| } else { |
| switch (field->cpp_type()) { |
| case FD::CPPTYPE_INT32: |
| return sizeof(int32_t); |
| case FD::CPPTYPE_INT64: |
| return sizeof(int64_t); |
| case FD::CPPTYPE_UINT32: |
| return sizeof(uint32_t); |
| case FD::CPPTYPE_UINT64: |
| return sizeof(uint64_t); |
| case FD::CPPTYPE_DOUBLE: |
| return sizeof(double); |
| case FD::CPPTYPE_FLOAT: |
| return sizeof(float); |
| case FD::CPPTYPE_BOOL: |
| return sizeof(bool); |
| case FD::CPPTYPE_ENUM: |
| return sizeof(int); |
| |
| case FD::CPPTYPE_MESSAGE: |
| return sizeof(Message*); |
| |
| case FD::CPPTYPE_STRING: |
| switch (field->options().ctype()) { |
| default: // TODO(kenton): Support other string reps. |
| case FieldOptions::STRING: |
| return sizeof(ArenaStringPtr); |
| } |
| break; |
| } |
| } |
| |
| GOOGLE_LOG(DFATAL) << "Can't get here."; |
| return 0; |
| } |
| |
| inline int DivideRoundingUp(int i, int j) { return (i + (j - 1)) / j; } |
| |
| static const int kSafeAlignment = sizeof(uint64_t); |
| static const int kMaxOneofUnionSize = sizeof(uint64_t); |
| |
| inline int AlignTo(int offset, int alignment) { |
| return DivideRoundingUp(offset, alignment) * alignment; |
| } |
| |
| // Rounds the given byte offset up to the next offset aligned such that any |
| // type may be stored at it. |
| inline int AlignOffset(int offset) { return AlignTo(offset, kSafeAlignment); } |
| |
| #define bitsizeof(T) (sizeof(T) * 8) |
| |
| } // namespace |
| |
| // =================================================================== |
| |
| class DynamicMessage : public Message { |
| public: |
| explicit DynamicMessage(const DynamicMessageFactory::TypeInfo* type_info); |
| |
| // This should only be used by GetPrototypeNoLock() to avoid dead lock. |
| DynamicMessage(DynamicMessageFactory::TypeInfo* type_info, bool lock_factory); |
| |
| ~DynamicMessage() override; |
| |
| // Called on the prototype after construction to initialize message fields. |
| // Cross linking the default instances allows for fast reflection access of |
| // unset message fields. Without it we would have to go to the MessageFactory |
| // to get the prototype, which is a much more expensive operation. |
| // |
| // Generated messages do not cross-link to avoid dynamic initialization of the |
| // global instances. |
| // Instead, they keep the default instances in the FieldDescriptor objects. |
| void CrossLinkPrototypes(); |
| |
| // implements Message ---------------------------------------------- |
| |
| Message* New(Arena* arena) const override; |
| |
| int GetCachedSize() const override; |
| void SetCachedSize(int size) const override; |
| |
| Metadata GetMetadata() const override; |
| |
| #if defined(__cpp_lib_destroying_delete) && defined(__cpp_sized_deallocation) |
| static void operator delete(DynamicMessage* msg, std::destroying_delete_t); |
| #else |
| // We actually allocate more memory than sizeof(*this) when this |
| // class's memory is allocated via the global operator new. Thus, we need to |
| // manually call the global operator delete. Calling the destructor is taken |
| // care of for us. This makes DynamicMessage compatible with -fsized-delete. |
| // It doesn't work for MSVC though. |
| #ifndef _MSC_VER |
| static void operator delete(void* ptr) { ::operator delete(ptr); } |
| #endif // !_MSC_VER |
| #endif |
| |
| private: |
| DynamicMessage(const DynamicMessageFactory::TypeInfo* type_info, |
| Arena* arena); |
| |
| void SharedCtor(bool lock_factory); |
| |
| // Needed to get the offset of the internal metadata member. |
| friend class DynamicMessageFactory; |
| |
| bool is_prototype() const; |
| |
| inline void* OffsetToPointer(int offset) { |
| return reinterpret_cast<uint8_t*>(this) + offset; |
| } |
| inline const void* OffsetToPointer(int offset) const { |
| return reinterpret_cast<const uint8_t*>(this) + offset; |
| } |
| |
| void* MutableRaw(int i); |
| void* MutableExtensionsRaw(); |
| void* MutableWeakFieldMapRaw(); |
| void* MutableOneofCaseRaw(int i); |
| void* MutableOneofFieldRaw(const FieldDescriptor* f); |
| |
| const DynamicMessageFactory::TypeInfo* type_info_; |
| mutable std::atomic<int> cached_byte_size_; |
| GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DynamicMessage); |
| }; |
| |
| struct DynamicMessageFactory::TypeInfo { |
| int size; |
| int has_bits_offset; |
| int oneof_case_offset; |
| int extensions_offset; |
| |
| // Not owned by the TypeInfo. |
| DynamicMessageFactory* factory; // The factory that created this object. |
| const DescriptorPool* pool; // The factory's DescriptorPool. |
| const Descriptor* type; // Type of this DynamicMessage. |
| |
| // Warning: The order in which the following pointers are defined is |
| // important (the prototype must be deleted *before* the offsets). |
| std::unique_ptr<uint32_t[]> offsets; |
| std::unique_ptr<uint32_t[]> has_bits_indices; |
| std::unique_ptr<const Reflection> reflection; |
| // Don't use a unique_ptr to hold the prototype: the destructor for |
| // DynamicMessage needs to know whether it is the prototype, and does so by |
| // looking back at this field. This would assume details about the |
| // implementation of unique_ptr. |
| const DynamicMessage* prototype; |
| int weak_field_map_offset; // The offset for the weak_field_map; |
| |
| TypeInfo() : prototype(nullptr) {} |
| |
| ~TypeInfo() { delete prototype; } |
| }; |
| |
| DynamicMessage::DynamicMessage(const DynamicMessageFactory::TypeInfo* type_info) |
| : type_info_(type_info), cached_byte_size_(0) { |
| SharedCtor(true); |
| } |
| |
| DynamicMessage::DynamicMessage(const DynamicMessageFactory::TypeInfo* type_info, |
| Arena* arena) |
| : Message(arena), type_info_(type_info), cached_byte_size_(0) { |
| SharedCtor(true); |
| } |
| |
| DynamicMessage::DynamicMessage(DynamicMessageFactory::TypeInfo* type_info, |
| bool lock_factory) |
| : type_info_(type_info), cached_byte_size_(0) { |
| // The prototype in type_info has to be set before creating the prototype |
| // instance on memory. e.g., message Foo { map<int32_t, Foo> a = 1; }. When |
| // creating prototype for Foo, prototype of the map entry will also be |
| // created, which needs the address of the prototype of Foo (the value in |
| // map). To break the cyclic dependency, we have to assign the address of |
| // prototype into type_info first. |
| type_info->prototype = this; |
| SharedCtor(lock_factory); |
| } |
| |
| inline void* DynamicMessage::MutableRaw(int i) { |
| return OffsetToPointer(type_info_->offsets[i]); |
| } |
| inline void* DynamicMessage::MutableExtensionsRaw() { |
| return OffsetToPointer(type_info_->extensions_offset); |
| } |
| inline void* DynamicMessage::MutableWeakFieldMapRaw() { |
| return OffsetToPointer(type_info_->weak_field_map_offset); |
| } |
| inline void* DynamicMessage::MutableOneofCaseRaw(int i) { |
| return OffsetToPointer(type_info_->oneof_case_offset + sizeof(uint32_t) * i); |
| } |
| inline void* DynamicMessage::MutableOneofFieldRaw(const FieldDescriptor* f) { |
| return OffsetToPointer(type_info_->offsets[type_info_->type->field_count() + |
| f->containing_oneof()->index()]); |
| } |
| |
| void DynamicMessage::SharedCtor(bool lock_factory) { |
| // We need to call constructors for various fields manually and set |
| // default values where appropriate. We use placement new to call |
| // constructors. If you haven't heard of placement new, I suggest Googling |
| // it now. We use placement new even for primitive types that don't have |
| // constructors for consistency. (In theory, placement new should be used |
| // any time you are trying to convert untyped memory to typed memory, though |
| // in practice that's not strictly necessary for types that don't have a |
| // constructor.) |
| |
| const Descriptor* descriptor = type_info_->type; |
| // Initialize oneof cases. |
| int oneof_count = 0; |
| for (int i = 0; i < descriptor->oneof_decl_count(); ++i) { |
| if (descriptor->oneof_decl(i)->is_synthetic()) continue; |
| new (MutableOneofCaseRaw(oneof_count++)) uint32_t{0}; |
| } |
| |
| if (type_info_->extensions_offset != -1) { |
| new (MutableExtensionsRaw()) ExtensionSet(GetArenaForAllocation()); |
| } |
| for (int i = 0; i < descriptor->field_count(); i++) { |
| const FieldDescriptor* field = descriptor->field(i); |
| void* field_ptr = MutableRaw(i); |
| if (InRealOneof(field)) { |
| continue; |
| } |
| switch (field->cpp_type()) { |
| #define HANDLE_TYPE(CPPTYPE, TYPE) \ |
| case FieldDescriptor::CPPTYPE_##CPPTYPE: \ |
| if (!field->is_repeated()) { \ |
| new (field_ptr) TYPE(field->default_value_##TYPE()); \ |
| } else { \ |
| new (field_ptr) RepeatedField<TYPE>(GetArenaForAllocation()); \ |
| } \ |
| break; |
| |
| HANDLE_TYPE(INT32, int32_t); |
| HANDLE_TYPE(INT64, int64_t); |
| HANDLE_TYPE(UINT32, uint32_t); |
| HANDLE_TYPE(UINT64, uint64_t); |
| HANDLE_TYPE(DOUBLE, double); |
| HANDLE_TYPE(FLOAT, float); |
| HANDLE_TYPE(BOOL, bool); |
| #undef HANDLE_TYPE |
| |
| case FieldDescriptor::CPPTYPE_ENUM: |
| if (!field->is_repeated()) { |
| new (field_ptr) int{field->default_value_enum()->number()}; |
| } else { |
| new (field_ptr) RepeatedField<int>(GetArenaForAllocation()); |
| } |
| break; |
| |
| case FieldDescriptor::CPPTYPE_STRING: |
| switch (field->options().ctype()) { |
| default: // TODO(kenton): Support other string reps. |
| case FieldOptions::STRING: |
| if (!field->is_repeated()) { |
| ArenaStringPtr* asp = new (field_ptr) ArenaStringPtr(); |
| asp->InitDefault(); |
| } else { |
| new (field_ptr) |
| RepeatedPtrField<std::string>(GetArenaForAllocation()); |
| } |
| break; |
| } |
| break; |
| |
| case FieldDescriptor::CPPTYPE_MESSAGE: { |
| if (!field->is_repeated()) { |
| new (field_ptr) Message*(nullptr); |
| } else { |
| if (IsMapFieldInApi(field)) { |
| // We need to lock in most cases to avoid data racing. Only not lock |
| // when the constructor is called inside GetPrototype(), in which |
| // case we have already locked the factory. |
| if (lock_factory) { |
| if (GetArenaForAllocation() != nullptr) { |
| new (field_ptr) DynamicMapField( |
| type_info_->factory->GetPrototype(field->message_type()), |
| GetArenaForAllocation()); |
| if (GetOwningArena() != nullptr) { |
| // Needs to destroy the mutex member. |
| GetOwningArena()->OwnDestructor( |
| static_cast<DynamicMapField*>(field_ptr)); |
| } |
| } else { |
| new (field_ptr) DynamicMapField( |
| type_info_->factory->GetPrototype(field->message_type())); |
| } |
| } else { |
| if (GetArenaForAllocation() != nullptr) { |
| new (field_ptr) |
| DynamicMapField(type_info_->factory->GetPrototypeNoLock( |
| field->message_type()), |
| GetArenaForAllocation()); |
| if (GetOwningArena() != nullptr) { |
| // Needs to destroy the mutex member. |
| GetOwningArena()->OwnDestructor( |
| static_cast<DynamicMapField*>(field_ptr)); |
| } |
| } else { |
| new (field_ptr) |
| DynamicMapField(type_info_->factory->GetPrototypeNoLock( |
| field->message_type())); |
| } |
| } |
| } else { |
| new (field_ptr) RepeatedPtrField<Message>(GetArenaForAllocation()); |
| } |
| } |
| break; |
| } |
| } |
| } |
| } |
| |
| bool DynamicMessage::is_prototype() const { |
| return type_info_->prototype == this || |
| // If type_info_->prototype is nullptr, then we must be constructing |
| // the prototype now, which means we must be the prototype. |
| type_info_->prototype == nullptr; |
| } |
| |
| #if defined(__cpp_lib_destroying_delete) && defined(__cpp_sized_deallocation) |
| void DynamicMessage::operator delete(DynamicMessage* msg, |
| std::destroying_delete_t) { |
| const size_t size = msg->type_info_->size; |
| msg->~DynamicMessage(); |
| ::operator delete(msg, size); |
| } |
| #endif |
| |
| DynamicMessage::~DynamicMessage() { |
| const Descriptor* descriptor = type_info_->type; |
| |
| _internal_metadata_.Delete<UnknownFieldSet>(); |
| |
| if (type_info_->extensions_offset != -1) { |
| reinterpret_cast<ExtensionSet*>(MutableExtensionsRaw())->~ExtensionSet(); |
| } |
| |
| // We need to manually run the destructors for repeated fields and strings, |
| // just as we ran their constructors in the DynamicMessage constructor. |
| // We also need to manually delete oneof fields if it is set and is string |
| // or message. |
| // Additionally, if any singular embedded messages have been allocated, we |
| // need to delete them, UNLESS we are the prototype message of this type, |
| // in which case any embedded messages are other prototypes and shouldn't |
| // be touched. |
| for (int i = 0; i < descriptor->field_count(); i++) { |
| const FieldDescriptor* field = descriptor->field(i); |
| if (InRealOneof(field)) { |
| void* field_ptr = MutableOneofCaseRaw(field->containing_oneof()->index()); |
| if (*(reinterpret_cast<const int32_t*>(field_ptr)) == field->number()) { |
| field_ptr = MutableOneofFieldRaw(field); |
| if (field->cpp_type() == FieldDescriptor::CPPTYPE_STRING) { |
| switch (field->options().ctype()) { |
| default: |
| case FieldOptions::STRING: { |
| reinterpret_cast<ArenaStringPtr*>(field_ptr)->Destroy(); |
| break; |
| } |
| } |
| } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) { |
| delete *reinterpret_cast<Message**>(field_ptr); |
| } |
| } |
| continue; |
| } |
| void* field_ptr = MutableRaw(i); |
| |
| if (field->is_repeated()) { |
| switch (field->cpp_type()) { |
| #define HANDLE_TYPE(UPPERCASE, LOWERCASE) \ |
| case FieldDescriptor::CPPTYPE_##UPPERCASE: \ |
| reinterpret_cast<RepeatedField<LOWERCASE>*>(field_ptr) \ |
| ->~RepeatedField<LOWERCASE>(); \ |
| break |
| |
| HANDLE_TYPE(INT32, int32_t); |
| HANDLE_TYPE(INT64, int64_t); |
| HANDLE_TYPE(UINT32, uint32_t); |
| HANDLE_TYPE(UINT64, uint64_t); |
| HANDLE_TYPE(DOUBLE, double); |
| HANDLE_TYPE(FLOAT, float); |
| HANDLE_TYPE(BOOL, bool); |
| HANDLE_TYPE(ENUM, int); |
| #undef HANDLE_TYPE |
| |
| case FieldDescriptor::CPPTYPE_STRING: |
| switch (field->options().ctype()) { |
| default: // TODO(kenton): Support other string reps. |
| case FieldOptions::STRING: |
| reinterpret_cast<RepeatedPtrField<std::string>*>(field_ptr) |
| ->~RepeatedPtrField<std::string>(); |
| break; |
| } |
| break; |
| |
| case FieldDescriptor::CPPTYPE_MESSAGE: |
| if (IsMapFieldInApi(field)) { |
| reinterpret_cast<DynamicMapField*>(field_ptr)->~DynamicMapField(); |
| } else { |
| reinterpret_cast<RepeatedPtrField<Message>*>(field_ptr) |
| ->~RepeatedPtrField<Message>(); |
| } |
| break; |
| } |
| |
| } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_STRING) { |
| switch (field->options().ctype()) { |
| default: // TODO(kenton): Support other string reps. |
| case FieldOptions::STRING: { |
| reinterpret_cast<ArenaStringPtr*>(field_ptr)->Destroy(); |
| break; |
| } |
| } |
| } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) { |
| if (!is_prototype()) { |
| Message* message = *reinterpret_cast<Message**>(field_ptr); |
| if (message != nullptr) { |
| delete message; |
| } |
| } |
| } |
| } |
| } |
| |
| void DynamicMessage::CrossLinkPrototypes() { |
| // This should only be called on the prototype message. |
| GOOGLE_CHECK(is_prototype()); |
| |
| DynamicMessageFactory* factory = type_info_->factory; |
| const Descriptor* descriptor = type_info_->type; |
| |
| // Cross-link default messages. |
| for (int i = 0; i < descriptor->field_count(); i++) { |
| const FieldDescriptor* field = descriptor->field(i); |
| if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE && |
| !field->options().weak() && !InRealOneof(field) && |
| !field->is_repeated()) { |
| void* field_ptr = MutableRaw(i); |
| // For fields with message types, we need to cross-link with the |
| // prototype for the field's type. |
| // For singular fields, the field is just a pointer which should |
| // point to the prototype. |
| *reinterpret_cast<const Message**>(field_ptr) = |
| factory->GetPrototypeNoLock(field->message_type()); |
| } |
| } |
| } |
| |
| Message* DynamicMessage::New(Arena* arena) const { |
| if (arena != nullptr) { |
| void* new_base = Arena::CreateArray<char>(arena, type_info_->size); |
| memset(new_base, 0, type_info_->size); |
| return new (new_base) DynamicMessage(type_info_, arena); |
| } else { |
| void* new_base = operator new(type_info_->size); |
| memset(new_base, 0, type_info_->size); |
| return new (new_base) DynamicMessage(type_info_); |
| } |
| } |
| |
| int DynamicMessage::GetCachedSize() const { |
| return cached_byte_size_.load(std::memory_order_relaxed); |
| } |
| |
| void DynamicMessage::SetCachedSize(int size) const { |
| cached_byte_size_.store(size, std::memory_order_relaxed); |
| } |
| |
| Metadata DynamicMessage::GetMetadata() const { |
| Metadata metadata; |
| metadata.descriptor = type_info_->type; |
| metadata.reflection = type_info_->reflection.get(); |
| return metadata; |
| } |
| |
| // =================================================================== |
| |
| DynamicMessageFactory::DynamicMessageFactory() |
| : pool_(nullptr), delegate_to_generated_factory_(false) {} |
| |
| DynamicMessageFactory::DynamicMessageFactory(const DescriptorPool* pool) |
| : pool_(pool), delegate_to_generated_factory_(false) {} |
| |
| DynamicMessageFactory::~DynamicMessageFactory() { |
| for (auto iter = prototypes_.begin(); iter != prototypes_.end(); ++iter) { |
| delete iter->second; |
| } |
| } |
| |
| const Message* DynamicMessageFactory::GetPrototype(const Descriptor* type) { |
| MutexLock lock(&prototypes_mutex_); |
| return GetPrototypeNoLock(type); |
| } |
| |
| const Message* DynamicMessageFactory::GetPrototypeNoLock( |
| const Descriptor* type) { |
| if (delegate_to_generated_factory_ && |
| type->file()->pool() == DescriptorPool::generated_pool()) { |
| return MessageFactory::generated_factory()->GetPrototype(type); |
| } |
| |
| const TypeInfo** target = &prototypes_[type]; |
| if (*target != nullptr) { |
| // Already exists. |
| return (*target)->prototype; |
| } |
| |
| TypeInfo* type_info = new TypeInfo; |
| *target = type_info; |
| |
| type_info->type = type; |
| type_info->pool = (pool_ == nullptr) ? type->file()->pool() : pool_; |
| type_info->factory = this; |
| |
| // We need to construct all the structures passed to Reflection's constructor. |
| // This includes: |
| // - A block of memory that contains space for all the message's fields. |
| // - An array of integers indicating the byte offset of each field within |
| // this block. |
| // - A big bitfield containing a bit for each field indicating whether |
| // or not that field is set. |
| int real_oneof_count = 0; |
| for (int i = 0; i < type->oneof_decl_count(); i++) { |
| if (!type->oneof_decl(i)->is_synthetic()) { |
| real_oneof_count++; |
| } |
| } |
| |
| // Compute size and offsets. |
| uint32_t* offsets = new uint32_t[type->field_count() + real_oneof_count]; |
| type_info->offsets.reset(offsets); |
| |
| // Decide all field offsets by packing in order. |
| // We place the DynamicMessage object itself at the beginning of the allocated |
| // space. |
| int size = sizeof(DynamicMessage); |
| size = AlignOffset(size); |
| |
| // Next the has_bits, which is an array of uint32s. |
| type_info->has_bits_offset = -1; |
| int max_hasbit = 0; |
| for (int i = 0; i < type->field_count(); i++) { |
| if (HasHasbit(type->field(i))) { |
| if (type_info->has_bits_offset == -1) { |
| // At least one field in the message requires a hasbit, so allocate |
| // hasbits. |
| type_info->has_bits_offset = size; |
| uint32_t* has_bits_indices = new uint32_t[type->field_count()]; |
| for (int j = 0; j < type->field_count(); j++) { |
| // Initialize to -1, fields that need a hasbit will overwrite. |
| has_bits_indices[j] = static_cast<uint32_t>(-1); |
| } |
| type_info->has_bits_indices.reset(has_bits_indices); |
| } |
| type_info->has_bits_indices[i] = max_hasbit++; |
| } |
| } |
| |
| if (max_hasbit > 0) { |
| int has_bits_array_size = DivideRoundingUp(max_hasbit, bitsizeof(uint32_t)); |
| size += has_bits_array_size * sizeof(uint32_t); |
| size = AlignOffset(size); |
| } |
| |
| // The oneof_case, if any. It is an array of uint32s. |
| if (real_oneof_count > 0) { |
| type_info->oneof_case_offset = size; |
| size += real_oneof_count * sizeof(uint32_t); |
| size = AlignOffset(size); |
| } |
| |
| // The ExtensionSet, if any. |
| if (type->extension_range_count() > 0) { |
| type_info->extensions_offset = size; |
| size += sizeof(ExtensionSet); |
| size = AlignOffset(size); |
| } else { |
| // No extensions. |
| type_info->extensions_offset = -1; |
| } |
| |
| // All the fields. |
| // |
| // TODO(b/31226269): Optimize the order of fields to minimize padding. |
| for (int i = 0; i < type->field_count(); i++) { |
| // Make sure field is aligned to avoid bus errors. |
| // Oneof fields do not use any space. |
| if (!InRealOneof(type->field(i))) { |
| int field_size = FieldSpaceUsed(type->field(i)); |
| size = AlignTo(size, std::min(kSafeAlignment, field_size)); |
| offsets[i] = size; |
| size += field_size; |
| } |
| } |
| |
| // The oneofs. |
| for (int i = 0; i < type->oneof_decl_count(); i++) { |
| if (!type->oneof_decl(i)->is_synthetic()) { |
| size = AlignTo(size, kSafeAlignment); |
| offsets[type->field_count() + i] = size; |
| size += kMaxOneofUnionSize; |
| } |
| } |
| |
| type_info->weak_field_map_offset = -1; |
| |
| // Align the final size to make sure no clever allocators think that |
| // alignment is not necessary. |
| type_info->size = size; |
| |
| // Construct the reflection object. |
| |
| // Compute the size of default oneof instance and offsets of default |
| // oneof fields. |
| for (int i = 0; i < type->oneof_decl_count(); i++) { |
| if (type->oneof_decl(i)->is_synthetic()) continue; |
| for (int j = 0; j < type->oneof_decl(i)->field_count(); j++) { |
| const FieldDescriptor* field = type->oneof_decl(i)->field(j); |
| // oneof fields are not accessed through offsets, but we still have the |
| // entry from a legacy implementation. This should be removed at some |
| // point. |
| // Mark the field to prevent unintentional access through reflection. |
| // Don't use the top bit because that is for unused fields. |
| offsets[field->index()] = internal::kInvalidFieldOffsetTag; |
| } |
| } |
| |
| // Allocate the prototype fields. |
| void* base = operator new(size); |
| memset(base, 0, size); |
| |
| // We have already locked the factory so we should not lock in the constructor |
| // of dynamic message to avoid dead lock. |
| DynamicMessage* prototype = new (base) DynamicMessage(type_info, false); |
| |
| internal::ReflectionSchema schema = { |
| type_info->prototype, |
| type_info->offsets.get(), |
| type_info->has_bits_indices.get(), |
| type_info->has_bits_offset, |
| PROTOBUF_FIELD_OFFSET(DynamicMessage, _internal_metadata_), |
| type_info->extensions_offset, |
| type_info->oneof_case_offset, |
| type_info->size, |
| type_info->weak_field_map_offset, |
| nullptr /* inlined_string_indices_ */, |
| 0 /* inlined_string_donated_offset_ */}; |
| |
| type_info->reflection.reset( |
| new Reflection(type_info->type, schema, type_info->pool, this)); |
| |
| // Cross link prototypes. |
| prototype->CrossLinkPrototypes(); |
| |
| return prototype; |
| } |
| |
| } // namespace protobuf |
| } // namespace google |
| |
| #include <google/protobuf/port_undef.inc> // NOLINT |
