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Diffstat (limited to 'src/google/protobuf/dynamic_message.cc')
| -rw-r--r-- | src/google/protobuf/dynamic_message.cc | 873 |
1 files changed, 873 insertions, 0 deletions
diff --git a/src/google/protobuf/dynamic_message.cc b/src/google/protobuf/dynamic_message.cc new file mode 100644 index 00000000..5d914bf6 --- /dev/null +++ b/src/google/protobuf/dynamic_message.cc @@ -0,0 +1,873 @@ +// 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 GeneratedMessageReflection 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[]". This is because "operator new()" means "Give me some +// space which I can use as I please." while "new uint8[]" 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 <algorithm> +#include <google/protobuf/stubs/hash.h> +#include <memory> +#ifndef _SHARED_PTR_H +#include <google/protobuf/stubs/shared_ptr.h> +#endif + +#include <google/protobuf/stubs/common.h> + +#include <google/protobuf/dynamic_message.h> +#include <google/protobuf/descriptor.h> +#include <google/protobuf/descriptor.pb.h> +#include <google/protobuf/generated_message_util.h> +#include <google/protobuf/generated_message_reflection.h> +#include <google/protobuf/arenastring.h> +#include <google/protobuf/map_field_inl.h> +#include <google/protobuf/reflection_ops.h> +#include <google/protobuf/repeated_field.h> +#include <google/protobuf/map_type_handler.h> +#include <google/protobuf/extension_set.h> +#include <google/protobuf/wire_format.h> +#include <google/protobuf/map_field.h> + +namespace google { +namespace protobuf { + +using internal::WireFormat; +using internal::ExtensionSet; +using internal::GeneratedMessageReflection; +using internal::MapField; +using internal::DynamicMapField; + + +using internal::ArenaStringPtr; + +// =================================================================== +// Some helper tables and functions... + +namespace { + +bool IsMapFieldInApi(const FieldDescriptor* field) { + return field->is_map(); +} + +// 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 >); + case FD::CPPTYPE_INT64 : return sizeof(RepeatedField<int64 >); + case FD::CPPTYPE_UINT32 : return sizeof(RepeatedField<uint32 >); + case FD::CPPTYPE_UINT64 : return sizeof(RepeatedField<uint64 >); + 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<string>); + } + break; + } + } else { + switch (field->cpp_type()) { + case FD::CPPTYPE_INT32 : return sizeof(int32 ); + case FD::CPPTYPE_INT64 : return sizeof(int64 ); + case FD::CPPTYPE_UINT32 : return sizeof(uint32 ); + case FD::CPPTYPE_UINT64 : return sizeof(uint64 ); + 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; +} + +// Compute the byte size of in-memory representation of the oneof fields +// in default oneof instance. +int OneofFieldSpaceUsed(const FieldDescriptor* field) { + typedef FieldDescriptor FD; // avoid line wrapping + switch (field->cpp_type()) { + case FD::CPPTYPE_INT32 : return sizeof(int32 ); + case FD::CPPTYPE_INT64 : return sizeof(int64 ); + case FD::CPPTYPE_UINT32 : return sizeof(uint32 ); + case FD::CPPTYPE_UINT64 : return sizeof(uint64 ); + 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: + 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); +static const int kMaxOneofUnionSize = sizeof(uint64); + +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: + struct TypeInfo { + int size; + int has_bits_offset; + int oneof_case_offset; + int unknown_fields_offset; + int extensions_offset; + int is_default_instance_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). + google::protobuf::scoped_array<int> offsets; + google::protobuf::scoped_ptr<const GeneratedMessageReflection> reflection; + // Don't use a scoped_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 scoped_ptr. + const DynamicMessage* prototype; + void* default_oneof_instance; + + TypeInfo() : prototype(NULL), default_oneof_instance(NULL) {} + + ~TypeInfo() { + delete prototype; + operator delete(default_oneof_instance); + } + }; + + DynamicMessage(const TypeInfo* type_info); + ~DynamicMessage(); + + // Called on the prototype after construction to initialize message fields. + void CrossLinkPrototypes(); + + // implements Message ---------------------------------------------- + + Message* New() const; + Message* New(::google::protobuf::Arena* arena) const; + ::google::protobuf::Arena* GetArena() const { return NULL; }; + + int GetCachedSize() const; + void SetCachedSize(int size) const; + + Metadata GetMetadata() const; + + // 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 + + private: + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DynamicMessage); + DynamicMessage(const TypeInfo* type_info, ::google::protobuf::Arena* arena); + void SharedCtor(); + + inline bool is_prototype() const { + return type_info_->prototype == this || + // If type_info_->prototype is NULL, then we must be constructing + // the prototype now, which means we must be the prototype. + type_info_->prototype == NULL; + } + + inline void* OffsetToPointer(int offset) { + return reinterpret_cast<uint8*>(this) + offset; + } + inline const void* OffsetToPointer(int offset) const { + return reinterpret_cast<const uint8*>(this) + offset; + } + + const TypeInfo* type_info_; + // TODO(kenton): Make this an atomic<int> when C++ supports it. + mutable int cached_byte_size_; +}; + +DynamicMessage::DynamicMessage(const TypeInfo* type_info) + : type_info_(type_info), + cached_byte_size_(0) { + SharedCtor(); +} + +DynamicMessage::DynamicMessage(const TypeInfo* type_info, + ::google::protobuf::Arena* arena) + : type_info_(type_info), + cached_byte_size_(0) { + SharedCtor(); +} + +void DynamicMessage::SharedCtor() { + // 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. + for (int i = 0 ; i < descriptor->oneof_decl_count(); ++i) { + new(OffsetToPointer(type_info_->oneof_case_offset + sizeof(uint32) * i)) + uint32(0); + } + + if (type_info_->is_default_instance_offset != -1) { + *reinterpret_cast<bool*>( + OffsetToPointer(type_info_->is_default_instance_offset)) = false; + } + + new(OffsetToPointer(type_info_->unknown_fields_offset)) UnknownFieldSet; + + if (type_info_->extensions_offset != -1) { + new(OffsetToPointer(type_info_->extensions_offset)) ExtensionSet; + } + + for (int i = 0; i < descriptor->field_count(); i++) { + const FieldDescriptor* field = descriptor->field(i); + void* field_ptr = OffsetToPointer(type_info_->offsets[i]); + if (field->containing_oneof()) { + 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>(); \ + } \ + break; + + HANDLE_TYPE(INT32 , int32 ); + HANDLE_TYPE(INT64 , int64 ); + HANDLE_TYPE(UINT32, uint32); + HANDLE_TYPE(UINT64, uint64); + 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>(); + } + break; + + case FieldDescriptor::CPPTYPE_STRING: + switch (field->options().ctype()) { + default: // TODO(kenton): Support other string reps. + case FieldOptions::STRING: + if (!field->is_repeated()) { + const string* default_value; + if (is_prototype()) { + default_value = &field->default_value_string(); + } else { + default_value = + &(reinterpret_cast<const ArenaStringPtr*>( + type_info_->prototype->OffsetToPointer( + type_info_->offsets[i]))->Get(NULL)); + } + ArenaStringPtr* asp = new(field_ptr) ArenaStringPtr(); + asp->UnsafeSetDefault(default_value); + } else { + new(field_ptr) RepeatedPtrField<string>(); + } + break; + } + break; + + case FieldDescriptor::CPPTYPE_MESSAGE: { + if (!field->is_repeated()) { + new(field_ptr) Message*(NULL); + } else { + if (IsMapFieldInApi(field)) { + new (field_ptr) DynamicMapField( + type_info_->factory->GetPrototypeNoLock(field->message_type())); + } else { + new (field_ptr) RepeatedPtrField<Message>(); + } + } + break; + } + } + } +} + +DynamicMessage::~DynamicMessage() { + const Descriptor* descriptor = type_info_->type; + + reinterpret_cast<UnknownFieldSet*>( + OffsetToPointer(type_info_->unknown_fields_offset))->~UnknownFieldSet(); + + if (type_info_->extensions_offset != -1) { + reinterpret_cast<ExtensionSet*>( + OffsetToPointer(type_info_->extensions_offset))->~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 (field->containing_oneof()) { + void* field_ptr = OffsetToPointer( + type_info_->oneof_case_offset + + sizeof(uint32) * field->containing_oneof()->index()); + if (*(reinterpret_cast<const uint32*>(field_ptr)) == + field->number()) { + field_ptr = OffsetToPointer(type_info_->offsets[ + descriptor->field_count() + field->containing_oneof()->index()]); + if (field->cpp_type() == FieldDescriptor::CPPTYPE_STRING) { + switch (field->options().ctype()) { + default: + case FieldOptions::STRING: { + const ::std::string* default_value = + &(reinterpret_cast<const ArenaStringPtr*>( + reinterpret_cast<uint8*>( + type_info_->default_oneof_instance) + + type_info_->offsets[i]) + ->Get(NULL)); + reinterpret_cast<ArenaStringPtr*>(field_ptr)->Destroy( + default_value, NULL); + break; + } + } + } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) { + delete *reinterpret_cast<Message**>(field_ptr); + } + } + continue; + } + void* field_ptr = OffsetToPointer(type_info_->offsets[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); + HANDLE_TYPE( INT64, int64); + HANDLE_TYPE(UINT32, uint32); + HANDLE_TYPE(UINT64, uint64); + 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<string>*>(field_ptr) + ->~RepeatedPtrField<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: { + const ::std::string* default_value = + &(reinterpret_cast<const ArenaStringPtr*>( + type_info_->prototype->OffsetToPointer( + type_info_->offsets[i]))->Get(NULL)); + reinterpret_cast<ArenaStringPtr*>(field_ptr)->Destroy( + default_value, NULL); + break; + } + } + } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) { + if (!is_prototype()) { + Message* message = *reinterpret_cast<Message**>(field_ptr); + if (message != NULL) { + 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); + void* field_ptr = OffsetToPointer(type_info_->offsets[i]); + if (field->containing_oneof()) { + field_ptr = reinterpret_cast<uint8*>( + type_info_->default_oneof_instance) + type_info_->offsets[i]; + } + + if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE && + !field->is_repeated()) { + // 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()); + } + } + + // Set as the default instance -- this affects field-presence semantics for + // proto3. + if (type_info_->is_default_instance_offset != -1) { + void* is_default_instance_ptr = + OffsetToPointer(type_info_->is_default_instance_offset); + *reinterpret_cast<bool*>(is_default_instance_ptr) = true; + } +} + +Message* DynamicMessage::New() const { + void* new_base = operator new(type_info_->size); + memset(new_base, 0, type_info_->size); + return new(new_base) DynamicMessage(type_info_); +} + +Message* DynamicMessage::New(::google::protobuf::Arena* arena) const { + if (arena != NULL) { + Message* message = New(); + arena->Own(message); + return message; + } else { + return New(); + } +} + +int DynamicMessage::GetCachedSize() const { + return cached_byte_size_; +} + +void DynamicMessage::SetCachedSize(int size) const { + // This is theoretically not thread-compatible, but in practice it works + // because if multiple threads write this simultaneously, they will be + // writing the exact same value. + GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN(); + cached_byte_size_ = size; + GOOGLE_SAFE_CONCURRENT_WRITES_END(); +} + +Metadata DynamicMessage::GetMetadata() const { + Metadata metadata; + metadata.descriptor = type_info_->type; + metadata.reflection = type_info_->reflection.get(); + return metadata; +} + +// =================================================================== + +struct DynamicMessageFactory::PrototypeMap { + typedef hash_map<const Descriptor*, const DynamicMessage::TypeInfo*> Map; + Map map_; +}; + +DynamicMessageFactory::DynamicMessageFactory() + : pool_(NULL), delegate_to_generated_factory_(false), + prototypes_(new PrototypeMap) { +} + +DynamicMessageFactory::DynamicMessageFactory(const DescriptorPool* pool) + : pool_(pool), delegate_to_generated_factory_(false), + prototypes_(new PrototypeMap) { +} + +DynamicMessageFactory::~DynamicMessageFactory() { + for (PrototypeMap::Map::iterator iter = prototypes_->map_.begin(); + iter != prototypes_->map_.end(); ++iter) { + DeleteDefaultOneofInstance(iter->second->type, + iter->second->offsets.get(), + iter->second->default_oneof_instance); + 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 DynamicMessage::TypeInfo** target = &prototypes_->map_[type]; + if (*target != NULL) { + // Already exists. + return (*target)->prototype; + } + + DynamicMessage::TypeInfo* type_info = new DynamicMessage::TypeInfo; + *target = type_info; + + type_info->type = type; + type_info->pool = (pool_ == NULL) ? type->file()->pool() : pool_; + type_info->factory = this; + + // We need to construct all the structures passed to + // GeneratedMessageReflection'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. + + // Compute size and offsets. + int* offsets = new int[type->field_count() + type->oneof_decl_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. + if (type->file()->syntax() == FileDescriptor::SYNTAX_PROTO3) { + type_info->has_bits_offset = -1; + } else { + type_info->has_bits_offset = size; + int has_bits_array_size = + DivideRoundingUp(type->field_count(), bitsizeof(uint32)); + size += has_bits_array_size * sizeof(uint32); + size = AlignOffset(size); + } + + // The is_default_instance member, if any. + if (type->file()->syntax() == FileDescriptor::SYNTAX_PROTO3) { + type_info->is_default_instance_offset = size; + size += sizeof(bool); + size = AlignOffset(size); + } else { + type_info->is_default_instance_offset = -1; + } + + // The oneof_case, if any. It is an array of uint32s. + if (type->oneof_decl_count() > 0) { + type_info->oneof_case_offset = size; + size += type->oneof_decl_count() * sizeof(uint32); + 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. + 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 (!type->field(i)->containing_oneof()) { + 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++) { + size = AlignTo(size, kSafeAlignment); + offsets[type->field_count() + i] = size; + size += kMaxOneofUnionSize; + } + + // Add the UnknownFieldSet to the end. + size = AlignOffset(size); + type_info->unknown_fields_offset = size; + size += sizeof(UnknownFieldSet); + + // Align the final size to make sure no clever allocators think that + // alignment is not necessary. + size = AlignOffset(size); + type_info->size = size; + + // Allocate the prototype. + void* base = operator new(size); + memset(base, 0, size); + // The prototype in type_info has to be set before creating the prototype + // instance on memory. e.g., message Foo { map<int32, 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 assgin the address of + // prototype into type_info first. + type_info->prototype = static_cast<DynamicMessage*>(base); + DynamicMessage* prototype = new(base) DynamicMessage(type_info); + + // Construct the reflection object. + if (type->oneof_decl_count() > 0) { + // Compute the size of default oneof instance and offsets of default + // oneof fields. + int oneof_size = 0; + for (int i = 0; i < type->oneof_decl_count(); i++) { + for (int j = 0; j < type->oneof_decl(i)->field_count(); j++) { + const FieldDescriptor* field = type->oneof_decl(i)->field(j); + int field_size = OneofFieldSpaceUsed(field); + oneof_size = AlignTo(oneof_size, std::min(kSafeAlignment, field_size)); + offsets[field->index()] = oneof_size; + oneof_size += field_size; + } + } + // Construct default oneof instance. + type_info->default_oneof_instance = ::operator new(oneof_size); + ConstructDefaultOneofInstance(type_info->type, + type_info->offsets.get(), + type_info->default_oneof_instance); + type_info->reflection.reset( + new GeneratedMessageReflection( + type_info->type, + type_info->prototype, + type_info->offsets.get(), + type_info->has_bits_offset, + type_info->unknown_fields_offset, + type_info->extensions_offset, + type_info->default_oneof_instance, + type_info->oneof_case_offset, + type_info->pool, + this, + type_info->size, + -1 /* arena_offset */, + type_info->is_default_instance_offset)); + } else { + type_info->reflection.reset( + new GeneratedMessageReflection( + type_info->type, + type_info->prototype, + type_info->offsets.get(), + type_info->has_bits_offset, + type_info->unknown_fields_offset, + type_info->extensions_offset, + type_info->pool, + this, + type_info->size, + -1 /* arena_offset */, + type_info->is_default_instance_offset)); + } + // Cross link prototypes. + prototype->CrossLinkPrototypes(); + + return prototype; +} + +void DynamicMessageFactory::ConstructDefaultOneofInstance( + const Descriptor* type, + const int offsets[], + void* default_oneof_instance) { + for (int i = 0; i < type->oneof_decl_count(); i++) { + for (int j = 0; j < type->oneof_decl(i)->field_count(); j++) { + const FieldDescriptor* field = type->oneof_decl(i)->field(j); + void* field_ptr = reinterpret_cast<uint8*>( + default_oneof_instance) + offsets[field->index()]; + switch (field->cpp_type()) { +#define HANDLE_TYPE(CPPTYPE, TYPE) \ + case FieldDescriptor::CPPTYPE_##CPPTYPE: \ + new(field_ptr) TYPE(field->default_value_##TYPE()); \ + break; + + HANDLE_TYPE(INT32 , int32 ); + HANDLE_TYPE(INT64 , int64 ); + HANDLE_TYPE(UINT32, uint32); + HANDLE_TYPE(UINT64, uint64); + HANDLE_TYPE(DOUBLE, double); + HANDLE_TYPE(FLOAT , float ); + HANDLE_TYPE(BOOL , bool ); +#undef HANDLE_TYPE + + case FieldDescriptor::CPPTYPE_ENUM: + new(field_ptr) int(field->default_value_enum()->number()); + break; + case FieldDescriptor::CPPTYPE_STRING: + switch (field->options().ctype()) { + default: + case FieldOptions::STRING: + ArenaStringPtr* asp = new (field_ptr) ArenaStringPtr(); + asp->UnsafeSetDefault(&field->default_value_string()); + break; + } + break; + + case FieldDescriptor::CPPTYPE_MESSAGE: { + new(field_ptr) Message*(NULL); + break; + } + } + } + } +} + +void DynamicMessageFactory::DeleteDefaultOneofInstance( + const Descriptor* type, + const int offsets[], + void* default_oneof_instance) { + for (int i = 0; i < type->oneof_decl_count(); i++) { + for (int j = 0; j < type->oneof_decl(i)->field_count(); j++) { + const FieldDescriptor* field = type->oneof_decl(i)->field(j); + if (field->cpp_type() == FieldDescriptor::CPPTYPE_STRING) { + switch (field->options().ctype()) { + default: + case FieldOptions::STRING: + break; + } + } + } + } +} + +} // namespace protobuf +} // namespace google |