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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
//
// 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.
//
// Defines Message, the abstract interface implemented by non-lite
// protocol message objects. Although it's possible to implement this
// interface manually, most users will use the protocol compiler to
// generate implementations.
//
// Example usage:
//
// Say you have a message defined as:
//
// message Foo {
// optional string text = 1;
// repeated int32 numbers = 2;
// }
//
// Then, if you used the protocol compiler to generate a class from the above
// definition, you could use it like so:
//
// std::string data; // Will store a serialized version of the message.
//
// {
// // Create a message and serialize it.
// Foo foo;
// foo.set_text("Hello World!");
// foo.add_numbers(1);
// foo.add_numbers(5);
// foo.add_numbers(42);
//
// foo.SerializeToString(&data);
// }
//
// {
// // Parse the serialized message and check that it contains the
// // correct data.
// Foo foo;
// foo.ParseFromString(data);
//
// assert(foo.text() == "Hello World!");
// assert(foo.numbers_size() == 3);
// assert(foo.numbers(0) == 1);
// assert(foo.numbers(1) == 5);
// assert(foo.numbers(2) == 42);
// }
//
// {
// // Same as the last block, but do it dynamically via the Message
// // reflection interface.
// Message* foo = new Foo;
// const Descriptor* descriptor = foo->GetDescriptor();
//
// // Get the descriptors for the fields we're interested in and verify
// // their types.
// const FieldDescriptor* text_field = descriptor->FindFieldByName("text");
// assert(text_field != nullptr);
// assert(text_field->type() == FieldDescriptor::TYPE_STRING);
// assert(text_field->label() == FieldDescriptor::LABEL_OPTIONAL);
// const FieldDescriptor* numbers_field = descriptor->
// FindFieldByName("numbers");
// assert(numbers_field != nullptr);
// assert(numbers_field->type() == FieldDescriptor::TYPE_INT32);
// assert(numbers_field->label() == FieldDescriptor::LABEL_REPEATED);
//
// // Parse the message.
// foo->ParseFromString(data);
//
// // Use the reflection interface to examine the contents.
// const Reflection* reflection = foo->GetReflection();
// assert(reflection->GetString(*foo, text_field) == "Hello World!");
// assert(reflection->FieldSize(*foo, numbers_field) == 3);
// assert(reflection->GetRepeatedInt32(*foo, numbers_field, 0) == 1);
// assert(reflection->GetRepeatedInt32(*foo, numbers_field, 1) == 5);
// assert(reflection->GetRepeatedInt32(*foo, numbers_field, 2) == 42);
//
// delete foo;
// }
#ifndef GOOGLE_PROTOBUF_MESSAGE_H__
#define GOOGLE_PROTOBUF_MESSAGE_H__
#include <iosfwd>
#include <string>
#include <type_traits>
#include <vector>
#include <google/protobuf/stubs/casts.h>
#include <google/protobuf/stubs/common.h>
#include <google/protobuf/arena.h>
#include <google/protobuf/port.h>
#include <google/protobuf/descriptor.h>
#include <google/protobuf/generated_message_reflection.h>
#include <google/protobuf/generated_message_util.h>
#include <google/protobuf/map.h> // TODO(b/211442718): cleanup
#include <google/protobuf/message_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 {
// Defined in this file.
class Message;
class Reflection;
class MessageFactory;
// Defined in other files.
class AssignDescriptorsHelper;
class DynamicMessageFactory;
class GeneratedMessageReflectionTestHelper;
class MapKey;
class MapValueConstRef;
class MapValueRef;
class MapIterator;
class MapReflectionTester;
namespace internal {
struct DescriptorTable;
class MapFieldBase;
class SwapFieldHelper;
class CachedSize;
} // namespace internal
class UnknownFieldSet; // unknown_field_set.h
namespace io {
class ZeroCopyInputStream; // zero_copy_stream.h
class ZeroCopyOutputStream; // zero_copy_stream.h
class CodedInputStream; // coded_stream.h
class CodedOutputStream; // coded_stream.h
} // namespace io
namespace python {
class MapReflectionFriend; // scalar_map_container.h
class MessageReflectionFriend;
} // namespace python
namespace expr {
class CelMapReflectionFriend; // field_backed_map_impl.cc
}
namespace internal {
class MapFieldPrinterHelper; // text_format.cc
}
namespace util {
class MessageDifferencer;
}
namespace internal {
class ReflectionAccessor; // message.cc
class ReflectionOps; // reflection_ops.h
class MapKeySorter; // wire_format.cc
class WireFormat; // wire_format.h
class MapFieldReflectionTest; // map_test.cc
} // namespace internal
template <typename T>
class RepeatedField; // repeated_field.h
template <typename T>
class RepeatedPtrField; // repeated_field.h
// A container to hold message metadata.
struct Metadata {
const Descriptor* descriptor;
const Reflection* reflection;
};
namespace internal {
template <class To>
inline To* GetPointerAtOffset(Message* message, uint32_t offset) {
return reinterpret_cast<To*>(reinterpret_cast<char*>(message) + offset);
}
template <class To>
const To* GetConstPointerAtOffset(const Message* message, uint32_t offset) {
return reinterpret_cast<const To*>(reinterpret_cast<const char*>(message) +
offset);
}
template <class To>
const To& GetConstRefAtOffset(const Message& message, uint32_t offset) {
return *GetConstPointerAtOffset<To>(&message, offset);
}
bool CreateUnknownEnumValues(const FieldDescriptor* field);
// Returns true if "message" is a descendant of "root".
PROTOBUF_EXPORT bool IsDescendant(Message& root, const Message& message);
} // namespace internal
// Abstract interface for protocol messages.
//
// See also MessageLite, which contains most every-day operations. Message
// adds descriptors and reflection on top of that.
//
// The methods of this class that are virtual but not pure-virtual have
// default implementations based on reflection. Message classes which are
// optimized for speed will want to override these with faster implementations,
// but classes optimized for code size may be happy with keeping them. See
// the optimize_for option in descriptor.proto.
//
// Users must not derive from this class. Only the protocol compiler and
// the internal library are allowed to create subclasses.
class PROTOBUF_EXPORT Message : public MessageLite {
public:
constexpr Message() {}
// Basic Operations ------------------------------------------------
// Construct a new instance of the same type. Ownership is passed to the
// caller. (This is also defined in MessageLite, but is defined again here
// for return-type covariance.)
Message* New() const { return New(nullptr); }
// Construct a new instance on the arena. Ownership is passed to the caller
// if arena is a nullptr.
Message* New(Arena* arena) const override = 0;
// Make this message into a copy of the given message. The given message
// must have the same descriptor, but need not necessarily be the same class.
// By default this is just implemented as "Clear(); MergeFrom(from);".
void CopyFrom(const Message& from);
// Merge the fields from the given message into this message. Singular
// fields will be overwritten, if specified in from, except for embedded
// messages which will be merged. Repeated fields will be concatenated.
// The given message must be of the same type as this message (i.e. the
// exact same class).
virtual void MergeFrom(const Message& from);
// Verifies that IsInitialized() returns true. GOOGLE_CHECK-fails otherwise, with
// a nice error message.
void CheckInitialized() const;
// Slowly build a list of all required fields that are not set.
// This is much, much slower than IsInitialized() as it is implemented
// purely via reflection. Generally, you should not call this unless you
// have already determined that an error exists by calling IsInitialized().
void FindInitializationErrors(std::vector<std::string>* errors) const;
// Like FindInitializationErrors, but joins all the strings, delimited by
// commas, and returns them.
std::string InitializationErrorString() const override;
// Clears all unknown fields from this message and all embedded messages.
// Normally, if unknown tag numbers are encountered when parsing a message,
// the tag and value are stored in the message's UnknownFieldSet and
// then written back out when the message is serialized. This allows servers
// which simply route messages to other servers to pass through messages
// that have new field definitions which they don't yet know about. However,
// this behavior can have security implications. To avoid it, call this
// method after parsing.
//
// See Reflection::GetUnknownFields() for more on unknown fields.
void DiscardUnknownFields();
// Computes (an estimate of) the total number of bytes currently used for
// storing the message in memory. The default implementation calls the
// Reflection object's SpaceUsed() method.
//
// SpaceUsed() is noticeably slower than ByteSize(), as it is implemented
// using reflection (rather than the generated code implementation for
// ByteSize()). Like ByteSize(), its CPU time is linear in the number of
// fields defined for the proto.
virtual size_t SpaceUsedLong() const;
PROTOBUF_DEPRECATED_MSG("Please use SpaceUsedLong() instead")
int SpaceUsed() const { return internal::ToIntSize(SpaceUsedLong()); }
// Debugging & Testing----------------------------------------------
// Generates a human-readable form of this message for debugging purposes.
// Note that the format and content of a debug string is not guaranteed, may
// change without notice, and should not be depended on. Code that does
// anything except display a string to assist in debugging should use
// TextFormat instead.
std::string DebugString() const;
// Like DebugString(), but with less whitespace.
std::string ShortDebugString() const;
// Like DebugString(), but do not escape UTF-8 byte sequences.
std::string Utf8DebugString() const;
// Convenience function useful in GDB. Prints DebugString() to stdout.
void PrintDebugString() const;
// Reflection-based methods ----------------------------------------
// These methods are pure-virtual in MessageLite, but Message provides
// reflection-based default implementations.
std::string GetTypeName() const override;
void Clear() override;
// Returns whether all required fields have been set. Note that required
// fields no longer exist starting in proto3.
bool IsInitialized() const override;
void CheckTypeAndMergeFrom(const MessageLite& other) override;
// Reflective parser
const char* _InternalParse(const char* ptr,
internal::ParseContext* ctx) override;
size_t ByteSizeLong() const override;
uint8_t* _InternalSerialize(uint8_t* target,
io::EpsCopyOutputStream* stream) const override;
private:
// This is called only by the default implementation of ByteSize(), to
// update the cached size. If you override ByteSize(), you do not need
// to override this. If you do not override ByteSize(), you MUST override
// this; the default implementation will crash.
//
// The method is private because subclasses should never call it; only
// override it. Yes, C++ lets you do that. Crazy, huh?
virtual void SetCachedSize(int size) const;
public:
// Introspection ---------------------------------------------------
// Get a non-owning pointer to a Descriptor for this message's type. This
// describes what fields the message contains, the types of those fields, etc.
// This object remains property of the Message.
const Descriptor* GetDescriptor() const { return GetMetadata().descriptor; }
// Get a non-owning pointer to the Reflection interface for this Message,
// which can be used to read and modify the fields of the Message dynamically
// (in other words, without knowing the message type at compile time). This
// object remains property of the Message.
const Reflection* GetReflection() const { return GetMetadata().reflection; }
protected:
// Get a struct containing the metadata for the Message, which is used in turn
// to implement GetDescriptor() and GetReflection() above.
virtual Metadata GetMetadata() const = 0;
struct ClassData {
// Note: The order of arguments (to, then from) is chosen so that the ABI
// of this function is the same as the CopyFrom method. That is, the
// hidden "this" parameter comes first.
void (*copy_to_from)(Message& to, const Message& from_msg);
void (*merge_to_from)(Message& to, const Message& from_msg);
};
// GetClassData() returns a pointer to a ClassData struct which
// exists in global memory and is unique to each subclass. This uniqueness
// property is used in order to quickly determine whether two messages are
// of the same type.
// TODO(jorg): change to pure virtual
virtual const ClassData* GetClassData() const { return nullptr; }
// CopyWithSourceCheck calls Clear() and then MergeFrom(), and in debug
// builds, checks that calling Clear() on the destination message doesn't
// alter the source. It assumes the messages are known to be of the same
// type, and thus uses GetClassData().
static void CopyWithSourceCheck(Message& to, const Message& from);
// Fail if "from" is a descendant of "to" as such copy is not allowed.
static void FailIfCopyFromDescendant(Message& to, const Message& from);
inline explicit Message(Arena* arena, bool is_message_owned = false)
: MessageLite(arena, is_message_owned) {}
size_t ComputeUnknownFieldsSize(size_t total_size,
internal::CachedSize* cached_size) const;
size_t MaybeComputeUnknownFieldsSize(size_t total_size,
internal::CachedSize* cached_size) const;
protected:
static uint64_t GetInvariantPerBuild(uint64_t salt);
private:
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Message);
};
namespace internal {
// Forward-declare interfaces used to implement RepeatedFieldRef.
// These are protobuf internals that users shouldn't care about.
class RepeatedFieldAccessor;
} // namespace internal
// Forward-declare RepeatedFieldRef templates. The second type parameter is
// used for SFINAE tricks. Users should ignore it.
template <typename T, typename Enable = void>
class RepeatedFieldRef;
template <typename T, typename Enable = void>
class MutableRepeatedFieldRef;
// This interface contains methods that can be used to dynamically access
// and modify the fields of a protocol message. Their semantics are
// similar to the accessors the protocol compiler generates.
//
// To get the Reflection for a given Message, call Message::GetReflection().
//
// This interface is separate from Message only for efficiency reasons;
// the vast majority of implementations of Message will share the same
// implementation of Reflection (GeneratedMessageReflection,
// defined in generated_message.h), and all Messages of a particular class
// should share the same Reflection object (though you should not rely on
// the latter fact).
//
// There are several ways that these methods can be used incorrectly. For
// example, any of the following conditions will lead to undefined
// results (probably assertion failures):
// - The FieldDescriptor is not a field of this message type.
// - The method called is not appropriate for the field's type. For
// each field type in FieldDescriptor::TYPE_*, there is only one
// Get*() method, one Set*() method, and one Add*() method that is
// valid for that type. It should be obvious which (except maybe
// for TYPE_BYTES, which are represented using strings in C++).
// - A Get*() or Set*() method for singular fields is called on a repeated
// field.
// - GetRepeated*(), SetRepeated*(), or Add*() is called on a non-repeated
// field.
// - The Message object passed to any method is not of the right type for
// this Reflection object (i.e. message.GetReflection() != reflection).
//
// You might wonder why there is not any abstract representation for a field
// of arbitrary type. E.g., why isn't there just a "GetField()" method that
// returns "const Field&", where "Field" is some class with accessors like
// "GetInt32Value()". The problem is that someone would have to deal with
// allocating these Field objects. For generated message classes, having to
// allocate space for an additional object to wrap every field would at least
// double the message's memory footprint, probably worse. Allocating the
// objects on-demand, on the other hand, would be expensive and prone to
// memory leaks. So, instead we ended up with this flat interface.
class PROTOBUF_EXPORT Reflection final {
public:
// Get the UnknownFieldSet for the message. This contains fields which
// were seen when the Message was parsed but were not recognized according
// to the Message's definition.
const UnknownFieldSet& GetUnknownFields(const Message& message) const;
// Get a mutable pointer to the UnknownFieldSet for the message. This
// contains fields which were seen when the Message was parsed but were not
// recognized according to the Message's definition.
UnknownFieldSet* MutableUnknownFields(Message* message) const;
// Estimate the amount of memory used by the message object.
size_t SpaceUsedLong(const Message& message) const;
PROTOBUF_DEPRECATED_MSG("Please use SpaceUsedLong() instead")
int SpaceUsed(const Message& message) const {
return internal::ToIntSize(SpaceUsedLong(message));
}
// Check if the given non-repeated field is set.
bool HasField(const Message& message, const FieldDescriptor* field) const;
// Get the number of elements of a repeated field.
int FieldSize(const Message& message, const FieldDescriptor* field) const;
// Clear the value of a field, so that HasField() returns false or
// FieldSize() returns zero.
void ClearField(Message* message, const FieldDescriptor* field) const;
// Check if the oneof is set. Returns true if any field in oneof
// is set, false otherwise.
bool HasOneof(const Message& message,
const OneofDescriptor* oneof_descriptor) const;
void ClearOneof(Message* message,
const OneofDescriptor* oneof_descriptor) const;
// Returns the field descriptor if the oneof is set. nullptr otherwise.
const FieldDescriptor* GetOneofFieldDescriptor(
const Message& message, const OneofDescriptor* oneof_descriptor) const;
// Removes the last element of a repeated field.
// We don't provide a way to remove any element other than the last
// because it invites inefficient use, such as O(n^2) filtering loops
// that should have been O(n). If you want to remove an element other
// than the last, the best way to do it is to re-arrange the elements
// (using Swap()) so that the one you want removed is at the end, then
// call RemoveLast().
void RemoveLast(Message* message, const FieldDescriptor* field) const;
// Removes the last element of a repeated message field, and returns the
// pointer to the caller. Caller takes ownership of the returned pointer.
PROTOBUF_NODISCARD Message* ReleaseLast(Message* message,
const FieldDescriptor* field) const;
// Similar to ReleaseLast() without internal safety and ownershp checks. This
// method should only be used when the objects are on the same arena or paired
// with a call to `UnsafeArenaAddAllocatedMessage`.
Message* UnsafeArenaReleaseLast(Message* message,
const FieldDescriptor* field) const;
// Swap the complete contents of two messages.
void Swap(Message* message1, Message* message2) const;
// Swap fields listed in fields vector of two messages.
void SwapFields(Message* message1, Message* message2,
const std::vector<const FieldDescriptor*>& fields) const;
// Swap two elements of a repeated field.
void SwapElements(Message* message, const FieldDescriptor* field, int index1,
int index2) const;
// Swap without internal safety and ownership checks. This method should only
// be used when the objects are on the same arena.
void UnsafeArenaSwap(Message* lhs, Message* rhs) const;
// SwapFields without internal safety and ownership checks. This method should
// only be used when the objects are on the same arena.
void UnsafeArenaSwapFields(
Message* lhs, Message* rhs,
const std::vector<const FieldDescriptor*>& fields) const;
// List all fields of the message which are currently set, except for unknown
// fields, but including extension known to the parser (i.e. compiled in).
// Singular fields will only be listed if HasField(field) would return true
// and repeated fields will only be listed if FieldSize(field) would return
// non-zero. Fields (both normal fields and extension fields) will be listed
// ordered by field number.
// Use Reflection::GetUnknownFields() or message.unknown_fields() to also get
// access to fields/extensions unknown to the parser.
void ListFields(const Message& message,
std::vector<const FieldDescriptor*>* output) const;
// Singular field getters ------------------------------------------
// These get the value of a non-repeated field. They return the default
// value for fields that aren't set.
int32_t GetInt32(const Message& message, const FieldDescriptor* field) const;
int64_t GetInt64(const Message& message, const FieldDescriptor* field) const;
uint32_t GetUInt32(const Message& message,
const FieldDescriptor* field) const;
uint64_t GetUInt64(const Message& message,
const FieldDescriptor* field) const;
float GetFloat(const Message& message, const FieldDescriptor* field) const;
double GetDouble(const Message& message, const FieldDescriptor* field) const;
bool GetBool(const Message& message, const FieldDescriptor* field) const;
std::string GetString(const Message& message,
const FieldDescriptor* field) const;
const EnumValueDescriptor* GetEnum(const Message& message,
const FieldDescriptor* field) const;
// GetEnumValue() returns an enum field's value as an integer rather than
// an EnumValueDescriptor*. If the integer value does not correspond to a
// known value descriptor, a new value descriptor is created. (Such a value
// will only be present when the new unknown-enum-value semantics are enabled
// for a message.)
int GetEnumValue(const Message& message, const FieldDescriptor* field) const;
// See MutableMessage() for the meaning of the "factory" parameter.
const Message& GetMessage(const Message& message,
const FieldDescriptor* field,
MessageFactory* factory = nullptr) const;
// Get a string value without copying, if possible.
//
// GetString() necessarily returns a copy of the string. This can be
// inefficient when the std::string is already stored in a std::string object
// in the underlying message. GetStringReference() will return a reference to
// the underlying std::string in this case. Otherwise, it will copy the
// string into *scratch and return that.
//
// Note: It is perfectly reasonable and useful to write code like:
// str = reflection->GetStringReference(message, field, &str);
// This line would ensure that only one copy of the string is made
// regardless of the field's underlying representation. When initializing
// a newly-constructed string, though, it's just as fast and more
// readable to use code like:
// std::string str = reflection->GetString(message, field);
const std::string& GetStringReference(const Message& message,
const FieldDescriptor* field,
std::string* scratch) const;
// Singular field mutators -----------------------------------------
// These mutate the value of a non-repeated field.
void SetInt32(Message* message, const FieldDescriptor* field,
int32_t value) const;
void SetInt64(Message* message, const FieldDescriptor* field,
int64_t value) const;
void SetUInt32(Message* message, const FieldDescriptor* field,
uint32_t value) const;
void SetUInt64(Message* message, const FieldDescriptor* field,
uint64_t value) const;
void SetFloat(Message* message, const FieldDescriptor* field,
float value) const;
void SetDouble(Message* message, const FieldDescriptor* field,
double value) const;
void SetBool(Message* message, const FieldDescriptor* field,
bool value) const;
void SetString(Message* message, const FieldDescriptor* field,
std::string value) const;
void SetEnum(Message* message, const FieldDescriptor* field,
const EnumValueDescriptor* value) const;
// Set an enum field's value with an integer rather than EnumValueDescriptor.
// For proto3 this is just setting the enum field to the value specified, for
// proto2 it's more complicated. If value is a known enum value the field is
// set as usual. If the value is unknown then it is added to the unknown field
// set. Note this matches the behavior of parsing unknown enum values.
// If multiple calls with unknown values happen than they are all added to the
// unknown field set in order of the calls.
void SetEnumValue(Message* message, const FieldDescriptor* field,
int value) const;
// Get a mutable pointer to a field with a message type. If a MessageFactory
// is provided, it will be used to construct instances of the sub-message;
// otherwise, the default factory is used. If the field is an extension that
// does not live in the same pool as the containing message's descriptor (e.g.
// it lives in an overlay pool), then a MessageFactory must be provided.
// If you have no idea what that meant, then you probably don't need to worry
// about it (don't provide a MessageFactory). WARNING: If the
// FieldDescriptor is for a compiled-in extension, then
// factory->GetPrototype(field->message_type()) MUST return an instance of
// the compiled-in class for this type, NOT DynamicMessage.
Message* MutableMessage(Message* message, const FieldDescriptor* field,
MessageFactory* factory = nullptr) const;
// Replaces the message specified by 'field' with the already-allocated object
// sub_message, passing ownership to the message. If the field contained a
// message, that message is deleted. If sub_message is nullptr, the field is
// cleared.
void SetAllocatedMessage(Message* message, Message* sub_message,
const FieldDescriptor* field) const;
// Similar to `SetAllocatedMessage`, but omits all internal safety and
// ownership checks. This method should only be used when the objects are on
// the same arena or paired with a call to `UnsafeArenaReleaseMessage`.
void UnsafeArenaSetAllocatedMessage(Message* message, Message* sub_message,
const FieldDescriptor* field) const;
// Releases the message specified by 'field' and returns the pointer,
// ReleaseMessage() will return the message the message object if it exists.
// Otherwise, it may or may not return nullptr. In any case, if the return
// value is non-null, the caller takes ownership of the pointer.
// If the field existed (HasField() is true), then the returned pointer will
// be the same as the pointer returned by MutableMessage().
// This function has the same effect as ClearField().
PROTOBUF_NODISCARD Message* ReleaseMessage(
Message* message, const FieldDescriptor* field,
MessageFactory* factory = nullptr) const;
// Similar to `ReleaseMessage`, but omits all internal safety and ownership
// checks. This method should only be used when the objects are on the same
// arena or paired with a call to `UnsafeArenaSetAllocatedMessage`.
Message* UnsafeArenaReleaseMessage(Message* message,
const FieldDescriptor* field,
MessageFactory* factory = nullptr) const;
// Repeated field getters ------------------------------------------
// These get the value of one element of a repeated field.
int32_t GetRepeatedInt32(const Message& message, const FieldDescriptor* field,
int index) const;
int64_t GetRepeatedInt64(const Message& message, const FieldDescriptor* field,
int index) const;
uint32_t GetRepeatedUInt32(const Message& message,
const FieldDescriptor* field, int index) const;
uint64_t GetRepeatedUInt64(const Message& message,
const FieldDescriptor* field, int index) const;
float GetRepeatedFloat(const Message& message, const FieldDescriptor* field,
int index) const;
double GetRepeatedDouble(const Message& message, const FieldDescriptor* field,
int index) const;
bool GetRepeatedBool(const Message& message, const FieldDescriptor* field,
int index) const;
std::string GetRepeatedString(const Message& message,
const FieldDescriptor* field, int index) const;
const EnumValueDescriptor* GetRepeatedEnum(const Message& message,
const FieldDescriptor* field,
int index) const;
// GetRepeatedEnumValue() returns an enum field's value as an integer rather
// than an EnumValueDescriptor*. If the integer value does not correspond to a
// known value descriptor, a new value descriptor is created. (Such a value
// will only be present when the new unknown-enum-value semantics are enabled
// for a message.)
int GetRepeatedEnumValue(const Message& message, const FieldDescriptor* field,
int index) const;
const Message& GetRepeatedMessage(const Message& message,
const FieldDescriptor* field,
int index) const;
// See GetStringReference(), above.
const std::string& GetRepeatedStringReference(const Message& message,
const FieldDescriptor* field,
int index,
std::string* scratch) const;
// Repeated field mutators -----------------------------------------
// These mutate the value of one element of a repeated field.
void SetRepeatedInt32(Message* message, const FieldDescriptor* field,
int index, int32_t value) const;
void SetRepeatedInt64(Message* message, const FieldDescriptor* field,
int index, int64_t value) const;
void SetRepeatedUInt32(Message* message, const FieldDescriptor* field,
int index, uint32_t value) const;
void SetRepeatedUInt64(Message* message, const FieldDescriptor* field,
int index, uint64_t value) const;
void SetRepeatedFloat(Message* message, const FieldDescriptor* field,
int index, float value) const;
void SetRepeatedDouble(Message* message, const FieldDescriptor* field,
int index, double value) const;
void SetRepeatedBool(Message* message, const FieldDescriptor* field,
int index, bool value) const;
void SetRepeatedString(Message* message, const FieldDescriptor* field,
int index, std::string value) const;
void SetRepeatedEnum(Message* message, const FieldDescriptor* field,
int index, const EnumValueDescriptor* value) const;
// Set an enum field's value with an integer rather than EnumValueDescriptor.
// For proto3 this is just setting the enum field to the value specified, for
// proto2 it's more complicated. If value is a known enum value the field is
// set as usual. If the value is unknown then it is added to the unknown field
// set. Note this matches the behavior of parsing unknown enum values.
// If multiple calls with unknown values happen than they are all added to the
// unknown field set in order of the calls.
void SetRepeatedEnumValue(Message* message, const FieldDescriptor* field,
int index, int value) const;
// Get a mutable pointer to an element of a repeated field with a message
// type.
Message* MutableRepeatedMessage(Message* message,
const FieldDescriptor* field,
int index) const;
// Repeated field adders -------------------------------------------
// These add an element to a repeated field.
void AddInt32(Message* message, const FieldDescriptor* field,
int32_t value) const;
void AddInt64(Message* message, const FieldDescriptor* field,
int64_t value) const;
void AddUInt32(Message* message, const FieldDescriptor* field,
uint32_t value) const;
void AddUInt64(Message* message, const FieldDescriptor* field,
uint64_t value) const;
void AddFloat(Message* message, const FieldDescriptor* field,
float value) const;
void AddDouble(Message* message, const FieldDescriptor* field,
double value) const;
void AddBool(Message* message, const FieldDescriptor* field,
bool value) const;
void AddString(Message* message, const FieldDescriptor* field,
std::string value) const;
void AddEnum(Message* message, const FieldDescriptor* field,
const EnumValueDescriptor* value) const;
// Add an integer value to a repeated enum field rather than
// EnumValueDescriptor. For proto3 this is just setting the enum field to the
// value specified, for proto2 it's more complicated. If value is a known enum
// value the field is set as usual. If the value is unknown then it is added
// to the unknown field set. Note this matches the behavior of parsing unknown
// enum values. If multiple calls with unknown values happen than they are all
// added to the unknown field set in order of the calls.
void AddEnumValue(Message* message, const FieldDescriptor* field,
int value) const;
// See MutableMessage() for comments on the "factory" parameter.
Message* AddMessage(Message* message, const FieldDescriptor* field,
MessageFactory* factory = nullptr) const;
// Appends an already-allocated object 'new_entry' to the repeated field
// specified by 'field' passing ownership to the message.
void AddAllocatedMessage(Message* message, const FieldDescriptor* field,
Message* new_entry) const;
// Similar to AddAllocatedMessage() without internal safety and ownership
// checks. This method should only be used when the objects are on the same
// arena or paired with a call to `UnsafeArenaReleaseLast`.
void UnsafeArenaAddAllocatedMessage(Message* message,
const FieldDescriptor* field,
Message* new_entry) const;
// Get a RepeatedFieldRef object that can be used to read the underlying
// repeated field. The type parameter T must be set according to the
// field's cpp type. The following table shows the mapping from cpp type
// to acceptable T.
//
// field->cpp_type() T
// CPPTYPE_INT32 int32_t
// CPPTYPE_UINT32 uint32_t
// CPPTYPE_INT64 int64_t
// CPPTYPE_UINT64 uint64_t
// CPPTYPE_DOUBLE double
// CPPTYPE_FLOAT float
// CPPTYPE_BOOL bool
// CPPTYPE_ENUM generated enum type or int32_t
// CPPTYPE_STRING std::string
// CPPTYPE_MESSAGE generated message type or google::protobuf::Message
//
// A RepeatedFieldRef object can be copied and the resulted object will point
// to the same repeated field in the same message. The object can be used as
// long as the message is not destroyed.
//
// Note that to use this method users need to include the header file
// "reflection.h" (which defines the RepeatedFieldRef class templates).
template <typename T>
RepeatedFieldRef<T> GetRepeatedFieldRef(const Message& message,
const FieldDescriptor* field) const;
// Like GetRepeatedFieldRef() but return an object that can also be used
// manipulate the underlying repeated field.
template <typename T>
MutableRepeatedFieldRef<T> GetMutableRepeatedFieldRef(
Message* message, const FieldDescriptor* field) const;
// DEPRECATED. Please use Get(Mutable)RepeatedFieldRef() for repeated field
// access. The following repeated field accessors will be removed in the
// future.
//
// Repeated field accessors -------------------------------------------------
// The methods above, e.g. GetRepeatedInt32(msg, fd, index), provide singular
// access to the data in a RepeatedField. The methods below provide aggregate
// access by exposing the RepeatedField object itself with the Message.
// Applying these templates to inappropriate types will lead to an undefined
// reference at link time (e.g. GetRepeatedField<***double>), or possibly a
// template matching error at compile time (e.g. GetRepeatedPtrField<File>).
//
// Usage example: my_doubs = refl->GetRepeatedField<double>(msg, fd);
// DEPRECATED. Please use GetRepeatedFieldRef().
//
// for T = Cord and all protobuf scalar types except enums.
template <typename T>
PROTOBUF_DEPRECATED_MSG("Please use GetRepeatedFieldRef() instead")
const RepeatedField<T>& GetRepeatedField(const Message& msg,
const FieldDescriptor* d) const {
return GetRepeatedFieldInternal<T>(msg, d);
}
// DEPRECATED. Please use GetMutableRepeatedFieldRef().
//
// for T = Cord and all protobuf scalar types except enums.
template <typename T>
PROTOBUF_DEPRECATED_MSG("Please use GetMutableRepeatedFieldRef() instead")
RepeatedField<T>* MutableRepeatedField(Message* msg,
const FieldDescriptor* d) const {
return MutableRepeatedFieldInternal<T>(msg, d);
}
// DEPRECATED. Please use GetRepeatedFieldRef().
//
// for T = std::string, google::protobuf::internal::StringPieceField
// google::protobuf::Message & descendants.
template <typename T>
PROTOBUF_DEPRECATED_MSG("Please use GetRepeatedFieldRef() instead")
const RepeatedPtrField<T>& GetRepeatedPtrField(
const Message& msg, const FieldDescriptor* d) const {
return GetRepeatedPtrFieldInternal<T>(msg, d);
}
// DEPRECATED. Please use GetMutableRepeatedFieldRef().
//
// for T = std::string, google::protobuf::internal::StringPieceField
// google::protobuf::Message & descendants.
template <typename T>
PROTOBUF_DEPRECATED_MSG("Please use GetMutableRepeatedFieldRef() instead")
RepeatedPtrField<T>* MutableRepeatedPtrField(Message* msg,
const FieldDescriptor* d) const {
return MutableRepeatedPtrFieldInternal<T>(msg, d);
}
// Extensions ----------------------------------------------------------------
// Try to find an extension of this message type by fully-qualified field
// name. Returns nullptr if no extension is known for this name or number.
const FieldDescriptor* FindKnownExtensionByName(
const std::string& name) const;
// Try to find an extension of this message type by field number.
// Returns nullptr if no extension is known for this name or number.
const FieldDescriptor* FindKnownExtensionByNumber(int number) const;
// Feature Flags -------------------------------------------------------------
// Does this message support storing arbitrary integer values in enum fields?
// If |true|, GetEnumValue/SetEnumValue and associated repeated-field versions
// take arbitrary integer values, and the legacy GetEnum() getter will
// dynamically create an EnumValueDescriptor for any integer value without
// one. If |false|, setting an unknown enum value via the integer-based
// setters results in undefined behavior (in practice, GOOGLE_DCHECK-fails).
//
// Generic code that uses reflection to handle messages with enum fields
// should check this flag before using the integer-based setter, and either
// downgrade to a compatible value or use the UnknownFieldSet if not. For
// example:
//
// int new_value = GetValueFromApplicationLogic();
// if (reflection->SupportsUnknownEnumValues()) {
// reflection->SetEnumValue(message, field, new_value);
// } else {
// if (field_descriptor->enum_type()->
// FindValueByNumber(new_value) != nullptr) {
// reflection->SetEnumValue(message, field, new_value);
// } else if (emit_unknown_enum_values) {
// reflection->MutableUnknownFields(message)->AddVarint(
// field->number(), new_value);
// } else {
// // convert value to a compatible/default value.
// new_value = CompatibleDowngrade(new_value);
// reflection->SetEnumValue(message, field, new_value);
// }
// }
bool SupportsUnknownEnumValues() const;
// Returns the MessageFactory associated with this message. This can be
// useful for determining if a message is a generated message or not, for
// example:
// if (message->GetReflection()->GetMessageFactory() ==
// google::protobuf::MessageFactory::generated_factory()) {
// // This is a generated message.
// }
// It can also be used to create more messages of this type, though
// Message::New() is an easier way to accomplish this.
MessageFactory* GetMessageFactory() const;
private:
template <typename T>
const RepeatedField<T>& GetRepeatedFieldInternal(
const Message& message, const FieldDescriptor* field) const;
template <typename T>
RepeatedField<T>* MutableRepeatedFieldInternal(
Message* message, const FieldDescriptor* field) const;
template <typename T>
const RepeatedPtrField<T>& GetRepeatedPtrFieldInternal(
const Message& message, const FieldDescriptor* field) const;
template <typename T>
RepeatedPtrField<T>* MutableRepeatedPtrFieldInternal(
Message* message, const FieldDescriptor* field) const;
// Obtain a pointer to a Repeated Field Structure and do some type checking:
// on field->cpp_type(),
// on field->field_option().ctype() (if ctype >= 0)
// of field->message_type() (if message_type != nullptr).
// We use 2 routine rather than 4 (const vs mutable) x (scalar vs pointer).
void* MutableRawRepeatedField(Message* message, const FieldDescriptor* field,
FieldDescriptor::CppType, int ctype,
const Descriptor* message_type) const;
const void* GetRawRepeatedField(const Message& message,
const FieldDescriptor* field,
FieldDescriptor::CppType cpptype, int ctype,
const Descriptor* message_type) const;
// The following methods are used to implement (Mutable)RepeatedFieldRef.
// A Ref object will store a raw pointer to the repeated field data (obtained
// from RepeatedFieldData()) and a pointer to a Accessor (obtained from
// RepeatedFieldAccessor) which will be used to access the raw data.
// Returns a raw pointer to the repeated field
//
// "cpp_type" and "message_type" are deduced from the type parameter T passed
// to Get(Mutable)RepeatedFieldRef. If T is a generated message type,
// "message_type" should be set to its descriptor. Otherwise "message_type"
// should be set to nullptr. Implementations of this method should check
// whether "cpp_type"/"message_type" is consistent with the actual type of the
// field. We use 1 routine rather than 2 (const vs mutable) because it is
// protected and it doesn't change the message.
void* RepeatedFieldData(Message* message, const FieldDescriptor* field,
FieldDescriptor::CppType cpp_type,
const Descriptor* message_type) const;
// The returned pointer should point to a singleton instance which implements
// the RepeatedFieldAccessor interface.
const internal::RepeatedFieldAccessor* RepeatedFieldAccessor(
const FieldDescriptor* field) const;
// Lists all fields of the message which are currently set, except for unknown
// fields and stripped fields. See ListFields for details.
void ListFieldsOmitStripped(
const Message& message,
std::vector<const FieldDescriptor*>* output) const;
bool IsMessageStripped(const Descriptor* descriptor) const {
return schema_.IsMessageStripped(descriptor);
}
friend class TextFormat;
void ListFieldsMayFailOnStripped(
const Message& message, bool should_fail,
std::vector<const FieldDescriptor*>* output) const;
// Returns true if the message field is backed by a LazyField.
//
// A message field may be backed by a LazyField without the user annotation
// ([lazy = true]). While the user-annotated LazyField is lazily verified on
// first touch (i.e. failure on access rather than parsing if the LazyField is
// not initialized), the inferred LazyField is eagerly verified to avoid lazy
// parsing error at the cost of lower efficiency. When reflecting a message
// field, use this API instead of checking field->options().lazy().
bool IsLazyField(const FieldDescriptor* field) const {
return IsLazilyVerifiedLazyField(field) ||
IsEagerlyVerifiedLazyField(field);
}
// Returns true if the field is lazy extension. It is meant to allow python
// reparse lazy field until b/157559327 is fixed.
bool IsLazyExtension(const Message& message,
const FieldDescriptor* field) const;
bool IsLazilyVerifiedLazyField(const FieldDescriptor* field) const;
bool IsEagerlyVerifiedLazyField(const FieldDescriptor* field) const;
friend class FastReflectionMessageMutator;
friend bool internal::IsDescendant(Message& root, const Message& message);
const Descriptor* const descriptor_;
const internal::ReflectionSchema schema_;
const DescriptorPool* const descriptor_pool_;
MessageFactory* const message_factory_;
// Last non weak field index. This is an optimization when most weak fields
// are at the end of the containing message. If a message proto doesn't
// contain weak fields, then this field equals descriptor_->field_count().
int last_non_weak_field_index_;
template <typename T, typename Enable>
friend class RepeatedFieldRef;
template <typename T, typename Enable>
friend class MutableRepeatedFieldRef;
friend class ::PROTOBUF_NAMESPACE_ID::MessageLayoutInspector;
friend class ::PROTOBUF_NAMESPACE_ID::AssignDescriptorsHelper;
friend class DynamicMessageFactory;
friend class GeneratedMessageReflectionTestHelper;
friend class python::MapReflectionFriend;
friend class python::MessageReflectionFriend;
friend class util::MessageDifferencer;
#define GOOGLE_PROTOBUF_HAS_CEL_MAP_REFLECTION_FRIEND
friend class expr::CelMapReflectionFriend;
friend class internal::MapFieldReflectionTest;
friend class internal::MapKeySorter;
friend class internal::WireFormat;
friend class internal::ReflectionOps;
friend class internal::SwapFieldHelper;
// Needed for implementing text format for map.
friend class internal::MapFieldPrinterHelper;
Reflection(const Descriptor* descriptor,
const internal::ReflectionSchema& schema,
const DescriptorPool* pool, MessageFactory* factory);
// Special version for specialized implementations of string. We can't
// call MutableRawRepeatedField directly here because we don't have access to
// FieldOptions::* which are defined in descriptor.pb.h. Including that
// file here is not possible because it would cause a circular include cycle.
// We use 1 routine rather than 2 (const vs mutable) because it is private
// and mutable a repeated string field doesn't change the message.
void* MutableRawRepeatedString(Message* message, const FieldDescriptor* field,
bool is_string) const;
friend class MapReflectionTester;
// Returns true if key is in map. Returns false if key is not in map field.
bool ContainsMapKey(const Message& message, const FieldDescriptor* field,
const MapKey& key) const;
// If key is in map field: Saves the value pointer to val and returns
// false. If key in not in map field: Insert the key into map, saves
// value pointer to val and returns true. Users are able to modify the
// map value by MapValueRef.
bool InsertOrLookupMapValue(Message* message, const FieldDescriptor* field,
const MapKey& key, MapValueRef* val) const;
// If key is in map field: Saves the value pointer to val and returns true.
// Returns false if key is not in map field. Users are NOT able to modify
// the value by MapValueConstRef.
bool LookupMapValue(const Message& message, const FieldDescriptor* field,
const MapKey& key, MapValueConstRef* val) const;
bool LookupMapValue(const Message&, const FieldDescriptor*, const MapKey&,
MapValueRef*) const = delete;
// Delete and returns true if key is in the map field. Returns false
// otherwise.
bool DeleteMapValue(Message* message, const FieldDescriptor* field,
const MapKey& key) const;
// Returns a MapIterator referring to the first element in the map field.
// If the map field is empty, this function returns the same as
// reflection::MapEnd. Mutation to the field may invalidate the iterator.
MapIterator MapBegin(Message* message, const FieldDescriptor* field) const;
// Returns a MapIterator referring to the theoretical element that would
// follow the last element in the map field. It does not point to any
// real element. Mutation to the field may invalidate the iterator.
MapIterator MapEnd(Message* message, const FieldDescriptor* field) const;
// Get the number of <key, value> pair of a map field. The result may be
// different from FieldSize which can have duplicate keys.
int MapSize(const Message& message, const FieldDescriptor* field) const;
// Help method for MapIterator.
friend class MapIterator;
friend class WireFormatForMapFieldTest;
internal::MapFieldBase* MutableMapData(Message* message,
const FieldDescriptor* field) const;
const internal::MapFieldBase* GetMapData(const Message& message,
const FieldDescriptor* field) const;
template <class T>
const T& GetRawNonOneof(const Message& message,
const FieldDescriptor* field) const;
template <class T>
T* MutableRawNonOneof(Message* message, const FieldDescriptor* field) const;
template <typename Type>
const Type& GetRaw(const Message& message,
const FieldDescriptor* field) const;
template <typename Type>
inline Type* MutableRaw(Message* message, const FieldDescriptor* field) const;
template <typename Type>
const Type& DefaultRaw(const FieldDescriptor* field) const;
const Message* GetDefaultMessageInstance(const FieldDescriptor* field) const;
inline const uint32_t* GetHasBits(const Message& message) const;
inline uint32_t* MutableHasBits(Message* message) const;
inline uint32_t GetOneofCase(const Message& message,
const OneofDescriptor* oneof_descriptor) const;
inline uint32_t* MutableOneofCase(
Message* message, const OneofDescriptor* oneof_descriptor) const;
inline bool HasExtensionSet(const Message& /* message */) const {
return schema_.HasExtensionSet();
}
const internal::ExtensionSet& GetExtensionSet(const Message& message) const;
internal::ExtensionSet* MutableExtensionSet(Message* message) const;
const internal::InternalMetadata& GetInternalMetadata(
const Message& message) const;
internal::InternalMetadata* MutableInternalMetadata(Message* message) const;
inline bool IsInlined(const FieldDescriptor* field) const;
inline bool HasBit(const Message& message,
const FieldDescriptor* field) const;
inline void SetBit(Message* message, const FieldDescriptor* field) const;
inline void ClearBit(Message* message, const FieldDescriptor* field) const;
inline void SwapBit(Message* message1, Message* message2,
const FieldDescriptor* field) const;
inline const uint32_t* GetInlinedStringDonatedArray(
const Message& message) const;
inline uint32_t* MutableInlinedStringDonatedArray(Message* message) const;
inline bool IsInlinedStringDonated(const Message& message,
const FieldDescriptor* field) const;
inline void SwapInlinedStringDonated(Message* lhs, Message* rhs,
const FieldDescriptor* field) const;
// Shallow-swap fields listed in fields vector of two messages. It is the
// caller's responsibility to make sure shallow swap is safe.
void UnsafeShallowSwapFields(
Message* message1, Message* message2,
const std::vector<const FieldDescriptor*>& fields) const;
// This function only swaps the field. Should swap corresponding has_bit
// before or after using this function.
void SwapField(Message* message1, Message* message2,
const FieldDescriptor* field) const;
// Unsafe but shallow version of SwapField.
void UnsafeShallowSwapField(Message* message1, Message* message2,
const FieldDescriptor* field) const;
template <bool unsafe_shallow_swap>
void SwapFieldsImpl(Message* message1, Message* message2,
const std::vector<const FieldDescriptor*>& fields) const;
template <bool unsafe_shallow_swap>
void SwapOneofField(Message* lhs, Message* rhs,
const OneofDescriptor* oneof_descriptor) const;
inline bool HasOneofField(const Message& message,
const FieldDescriptor* field) const;
inline void SetOneofCase(Message* message,
const FieldDescriptor* field) const;
inline void ClearOneofField(Message* message,
const FieldDescriptor* field) const;
template <typename Type>
inline const Type& GetField(const Message& message,
const FieldDescriptor* field) const;
template <typename Type>
inline void SetField(Message* message, const FieldDescriptor* field,
const Type& value) const;
template <typename Type>
inline Type* MutableField(Message* message,
const FieldDescriptor* field) const;
template <typename Type>
inline const Type& GetRepeatedField(const Message& message,
const FieldDescriptor* field,
int index) const;
template <typename Type>
inline const Type& GetRepeatedPtrField(const Message& message,
const FieldDescriptor* field,
int index) const;
template <typename Type>
inline void SetRepeatedField(Message* message, const FieldDescriptor* field,
int index, Type value) const;
template <typename Type>
inline Type* MutableRepeatedField(Message* message,
const FieldDescriptor* field,
int index) const;
template <typename Type>
inline void AddField(Message* message, const FieldDescriptor* field,
const Type& value) const;
template <typename Type>
inline Type* AddField(Message* message, const FieldDescriptor* field) const;
int GetExtensionNumberOrDie(const Descriptor* type) const;
// Internal versions of EnumValue API perform no checking. Called after checks
// by public methods.
void SetEnumValueInternal(Message* message, const FieldDescriptor* field,
int value) const;
void SetRepeatedEnumValueInternal(Message* message,
const FieldDescriptor* field, int index,
int value) const;
void AddEnumValueInternal(Message* message, const FieldDescriptor* field,
int value) const;
friend inline // inline so nobody can call this function.
void
RegisterAllTypesInternal(const Metadata* file_level_metadata, int size);
friend inline const char* ParseLenDelim(int field_number,
const FieldDescriptor* field,
Message* msg,
const Reflection* reflection,
const char* ptr,
internal::ParseContext* ctx);
friend inline const char* ParsePackedField(const FieldDescriptor* field,
Message* msg,
const Reflection* reflection,
const char* ptr,
internal::ParseContext* ctx);
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Reflection);
};
// Abstract interface for a factory for message objects.
class PROTOBUF_EXPORT MessageFactory {
public:
inline MessageFactory() {}
virtual ~MessageFactory();
// Given a Descriptor, gets or constructs the default (prototype) Message
// of that type. You can then call that message's New() method to construct
// a mutable message of that type.
//
// Calling this method twice with the same Descriptor returns the same
// object. The returned object remains property of the factory. Also, any
// objects created by calling the prototype's New() method share some data
// with the prototype, so these must be destroyed before the MessageFactory
// is destroyed.
//
// The given descriptor must outlive the returned message, and hence must
// outlive the MessageFactory.
//
// Some implementations do not support all types. GetPrototype() will
// return nullptr if the descriptor passed in is not supported.
//
// This method may or may not be thread-safe depending on the implementation.
// Each implementation should document its own degree thread-safety.
virtual const Message* GetPrototype(const Descriptor* type) = 0;
// Gets a MessageFactory which supports all generated, compiled-in messages.
// In other words, for any compiled-in type FooMessage, the following is true:
// MessageFactory::generated_factory()->GetPrototype(
// FooMessage::descriptor()) == FooMessage::default_instance()
// This factory supports all types which are found in
// DescriptorPool::generated_pool(). If given a descriptor from any other
// pool, GetPrototype() will return nullptr. (You can also check if a
// descriptor is for a generated message by checking if
// descriptor->file()->pool() == DescriptorPool::generated_pool().)
//
// This factory is 100% thread-safe; calling GetPrototype() does not modify
// any shared data.
//
// This factory is a singleton. The caller must not delete the object.
static MessageFactory* generated_factory();
// For internal use only: Registers a .proto file at static initialization
// time, to be placed in generated_factory. The first time GetPrototype()
// is called with a descriptor from this file, |register_messages| will be
// called, with the file name as the parameter. It must call
// InternalRegisterGeneratedMessage() (below) to register each message type
// in the file. This strange mechanism is necessary because descriptors are
// built lazily, so we can't register types by their descriptor until we
// know that the descriptor exists. |filename| must be a permanent string.
static void InternalRegisterGeneratedFile(
const google::protobuf::internal::DescriptorTable* table);
// For internal use only: Registers a message type. Called only by the
// functions which are registered with InternalRegisterGeneratedFile(),
// above.
static void InternalRegisterGeneratedMessage(const Descriptor* descriptor,
const Message* prototype);
private:
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MessageFactory);
};
#define DECLARE_GET_REPEATED_FIELD(TYPE) \
template <> \
PROTOBUF_EXPORT const RepeatedField<TYPE>& \
Reflection::GetRepeatedFieldInternal<TYPE>( \
const Message& message, const FieldDescriptor* field) const; \
\
template <> \
PROTOBUF_EXPORT RepeatedField<TYPE>* \
Reflection::MutableRepeatedFieldInternal<TYPE>( \
Message * message, const FieldDescriptor* field) const;
DECLARE_GET_REPEATED_FIELD(int32_t)
DECLARE_GET_REPEATED_FIELD(int64_t)
DECLARE_GET_REPEATED_FIELD(uint32_t)
DECLARE_GET_REPEATED_FIELD(uint64_t)
DECLARE_GET_REPEATED_FIELD(float)
DECLARE_GET_REPEATED_FIELD(double)
DECLARE_GET_REPEATED_FIELD(bool)
#undef DECLARE_GET_REPEATED_FIELD
// Tries to downcast this message to a generated message type. Returns nullptr
// if this class is not an instance of T. This works even if RTTI is disabled.
//
// This also has the effect of creating a strong reference to T that will
// prevent the linker from stripping it out at link time. This can be important
// if you are using a DynamicMessageFactory that delegates to the generated
// factory.
template <typename T>
const T* DynamicCastToGenerated(const Message* from) {
// Compile-time assert that T is a generated type that has a
// default_instance() accessor, but avoid actually calling it.
const T& (*get_default_instance)() = &T::default_instance;
(void)get_default_instance;
// Compile-time assert that T is a subclass of google::protobuf::Message.
const Message* unused = static_cast<T*>(nullptr);
(void)unused;
#if PROTOBUF_RTTI
return dynamic_cast<const T*>(from);
#else
bool ok = from != nullptr &&
T::default_instance().GetReflection() == from->GetReflection();
return ok ? down_cast<const T*>(from) : nullptr;
#endif
}
template <typename T>
T* DynamicCastToGenerated(Message* from) {
const Message* message_const = from;
return const_cast<T*>(DynamicCastToGenerated<T>(message_const));
}
// Call this function to ensure that this message's reflection is linked into
// the binary:
//
// google::protobuf::LinkMessageReflection<pkg::FooMessage>();
//
// This will ensure that the following lookup will succeed:
//
// DescriptorPool::generated_pool()->FindMessageTypeByName("pkg.FooMessage");
//
// As a side-effect, it will also guarantee that anything else from the same
// .proto file will also be available for lookup in the generated pool.
//
// This function does not actually register the message, so it does not need
// to be called before the lookup. However it does need to occur in a function
// that cannot be stripped from the binary (ie. it must be reachable from main).
//
// Best practice is to call this function as close as possible to where the
// reflection is actually needed. This function is very cheap to call, so you
// should not need to worry about its runtime overhead except in the tightest
// of loops (on x86-64 it compiles into two "mov" instructions).
template <typename T>
void LinkMessageReflection() {
internal::StrongReference(T::default_instance);
}
// =============================================================================
// Implementation details for {Get,Mutable}RawRepeatedPtrField. We provide
// specializations for <std::string>, <StringPieceField> and <Message> and
// handle everything else with the default template which will match any type
// having a method with signature "static const google::protobuf::Descriptor*
// descriptor()". Such a type presumably is a descendant of google::protobuf::Message.
template <>
inline const RepeatedPtrField<std::string>&
Reflection::GetRepeatedPtrFieldInternal<std::string>(
const Message& message, const FieldDescriptor* field) const {
return *static_cast<RepeatedPtrField<std::string>*>(
MutableRawRepeatedString(const_cast<Message*>(&message), field, true));
}
template <>
inline RepeatedPtrField<std::string>*
Reflection::MutableRepeatedPtrFieldInternal<std::string>(
Message* message, const FieldDescriptor* field) const {
return static_cast<RepeatedPtrField<std::string>*>(
MutableRawRepeatedString(message, field, true));
}
// -----
template <>
inline const RepeatedPtrField<Message>& Reflection::GetRepeatedPtrFieldInternal(
const Message& message, const FieldDescriptor* field) const {
return *static_cast<const RepeatedPtrField<Message>*>(GetRawRepeatedField(
message, field, FieldDescriptor::CPPTYPE_MESSAGE, -1, nullptr));
}
template <>
inline RepeatedPtrField<Message>* Reflection::MutableRepeatedPtrFieldInternal(
Message* message, const FieldDescriptor* field) const {
return static_cast<RepeatedPtrField<Message>*>(MutableRawRepeatedField(
message, field, FieldDescriptor::CPPTYPE_MESSAGE, -1, nullptr));
}
template <typename PB>
inline const RepeatedPtrField<PB>& Reflection::GetRepeatedPtrFieldInternal(
const Message& message, const FieldDescriptor* field) const {
return *static_cast<const RepeatedPtrField<PB>*>(
GetRawRepeatedField(message, field, FieldDescriptor::CPPTYPE_MESSAGE, -1,
PB::default_instance().GetDescriptor()));
}
template <typename PB>
inline RepeatedPtrField<PB>* Reflection::MutableRepeatedPtrFieldInternal(
Message* message, const FieldDescriptor* field) const {
return static_cast<RepeatedPtrField<PB>*>(
MutableRawRepeatedField(message, field, FieldDescriptor::CPPTYPE_MESSAGE,
-1, PB::default_instance().GetDescriptor()));
}
template <typename Type>
const Type& Reflection::DefaultRaw(const FieldDescriptor* field) const {
return *reinterpret_cast<const Type*>(schema_.GetFieldDefault(field));
}
uint32_t Reflection::GetOneofCase(
const Message& message, const OneofDescriptor* oneof_descriptor) const {
GOOGLE_DCHECK(!oneof_descriptor->is_synthetic());
return internal::GetConstRefAtOffset<uint32_t>(
message, schema_.GetOneofCaseOffset(oneof_descriptor));
}
bool Reflection::HasOneofField(const Message& message,
const FieldDescriptor* field) const {
return (GetOneofCase(message, field->containing_oneof()) ==
static_cast<uint32_t>(field->number()));
}
template <typename Type>
const Type& Reflection::GetRaw(const Message& message,
const FieldDescriptor* field) const {
GOOGLE_DCHECK(!schema_.InRealOneof(field) || HasOneofField(message, field))
<< "Field = " << field->full_name();
return internal::GetConstRefAtOffset<Type>(message,
schema_.GetFieldOffset(field));
}
} // namespace protobuf
} // namespace google
#include <google/protobuf/port_undef.inc>
#endif // GOOGLE_PROTOBUF_MESSAGE_H__