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// 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.
// Authors: wink@google.com (Wink Saville),
// kenton@google.com (Kenton Varda)
// Based on original Protocol Buffers design by
// Sanjay Ghemawat, Jeff Dean, and others.
//
// Defines MessageLite, the abstract interface implemented by all (lite
// and non-lite) protocol message objects.
#ifndef GOOGLE_PROTOBUF_MESSAGE_LITE_H__
#define GOOGLE_PROTOBUF_MESSAGE_LITE_H__
#include <climits>
#include <google/protobuf/stubs/common.h>
#include <google/protobuf/stubs/logging.h>
#include <google/protobuf/stubs/once.h>
#include <google/protobuf/arena.h>
#include <google/protobuf/stubs/port.h>
namespace google {
namespace protobuf {
template <typename T>
class RepeatedPtrField;
namespace io {
class CodedInputStream;
class CodedOutputStream;
class ZeroCopyInputStream;
class ZeroCopyOutputStream;
}
namespace internal {
class RepeatedPtrFieldBase;
class WireFormatLite;
class WeakFieldMap;
#ifndef SWIG
// We compute sizes as size_t but cache them as int. This function converts a
// computed size to a cached size. Since we don't proceed with serialization
// if the total size was > INT_MAX, it is not important what this function
// returns for inputs > INT_MAX. However this case should not error or
// GOOGLE_CHECK-fail, because the full size_t resolution is still returned from
// ByteSizeLong() and checked against INT_MAX; we can catch the overflow
// there.
inline int ToCachedSize(size_t size) { return static_cast<int>(size); }
// We mainly calculate sizes in terms of size_t, but some functions that
// compute sizes return "int". These int sizes are expected to always be
// positive. This function is more efficient than casting an int to size_t
// directly on 64-bit platforms because it avoids making the compiler emit a
// sign extending instruction, which we don't want and don't want to pay for.
inline size_t FromIntSize(int size) {
// Convert to unsigned before widening so sign extension is not necessary.
return static_cast<unsigned int>(size);
}
// For cases where a legacy function returns an integer size. We GOOGLE_DCHECK()
// that the conversion will fit within an integer; if this is false then we
// are losing information.
inline int ToIntSize(size_t size) {
GOOGLE_DCHECK_LE(size, static_cast<size_t>(INT_MAX));
return static_cast<int>(size);
}
// This type wraps a variable whose constructor and destructor are explicitly
// called. It is particularly useful for a global variable, without its
// constructor and destructor run on start and end of the program lifetime.
// This circumvents the initial construction order fiasco, while keeping
// the address of the empty string a compile time constant.
//
// Pay special attention to the initialization state of the object.
// 1. The object is "uninitialized" to begin with.
// 2. Call DefaultConstruct() only if the object is uninitialized.
// After the call, the object becomes "initialized".
// 3. Call get() and get_mutable() only if the object is initialized.
// 4. Call Destruct() only if the object is initialized.
// After the call, the object becomes uninitialized.
template <typename T>
class ExplicitlyConstructed {
public:
void DefaultConstruct() {
new (&union_) T();
}
void Destruct() {
get_mutable()->~T();
}
constexpr const T& get() const { return reinterpret_cast<const T&>(union_); }
T* get_mutable() { return reinterpret_cast<T*>(&union_); }
private:
// Prefer c++14 aligned_storage, but for compatibility this will do.
union AlignedUnion {
char space[sizeof(T)];
int64 align_to_int64;
void* align_to_ptr;
} union_;
};
// Default empty string object. Don't use this directly. Instead, call
// GetEmptyString() to get the reference.
LIBPROTOBUF_EXPORT extern ExplicitlyConstructed<::std::string> fixed_address_empty_string;
LIBPROTOBUF_EXPORT inline const ::std::string& GetEmptyStringAlreadyInited() {
return fixed_address_empty_string.get();
}
LIBPROTOBUF_EXPORT size_t StringSpaceUsedExcludingSelfLong(const string& str);
#endif // SWIG
} // namespace internal
// Interface to light weight protocol messages.
//
// This interface is implemented by all protocol message objects. Non-lite
// messages additionally implement the Message interface, which is a
// subclass of MessageLite. Use MessageLite instead when you only need
// the subset of features which it supports -- namely, nothing that uses
// descriptors or reflection. You can instruct the protocol compiler
// to generate classes which implement only MessageLite, not the full
// Message interface, by adding the following line to the .proto file:
//
// option optimize_for = LITE_RUNTIME;
//
// This is particularly useful on resource-constrained systems where
// the full protocol buffers runtime library is too big.
//
// Note that on non-constrained systems (e.g. servers) when you need
// to link in lots of protocol definitions, a better way to reduce
// total code footprint is to use optimize_for = CODE_SIZE. This
// will make the generated code smaller while still supporting all the
// same features (at the expense of speed). optimize_for = LITE_RUNTIME
// is best when you only have a small number of message types linked
// into your binary, in which case the size of the protocol buffers
// runtime itself is the biggest problem.
class LIBPROTOBUF_EXPORT MessageLite {
public:
inline MessageLite() {}
virtual ~MessageLite() {}
// Basic Operations ------------------------------------------------
// Get the name of this message type, e.g. "foo.bar.BazProto".
virtual string GetTypeName() const = 0;
// Construct a new instance of the same type. Ownership is passed to the
// caller.
virtual MessageLite* New() const = 0;
// Construct a new instance on the arena. Ownership is passed to the caller
// if arena is a NULL. Default implementation for backwards compatibility.
virtual MessageLite* New(::google::protobuf::Arena* arena) const;
// Get the arena, if any, associated with this message. Virtual method
// required for generic operations but most arena-related operations should
// use the GetArenaNoVirtual() generated-code method. Default implementation
// to reduce code size by avoiding the need for per-type implementations
// when types do not implement arena support.
virtual ::google::protobuf::Arena* GetArena() const { return NULL; }
// Get a pointer that may be equal to this message's arena, or may not be.
// If the value returned by this method is equal to some arena pointer, then
// this message is on that arena; however, if this message is on some arena,
// this method may or may not return that arena's pointer. As a tradeoff,
// this method may be more efficient than GetArena(). The intent is to allow
// underlying representations that use e.g. tagged pointers to sometimes
// store the arena pointer directly, and sometimes in a more indirect way,
// and allow a fastpath comparison against the arena pointer when it's easy
// to obtain.
virtual void* GetMaybeArenaPointer() const { return GetArena(); }
// Clear all fields of the message and set them to their default values.
// Clear() avoids freeing memory, assuming that any memory allocated
// to hold parts of the message will be needed again to hold the next
// message. If you actually want to free the memory used by a Message,
// you must delete it.
virtual void Clear() = 0;
// Quickly check if all required fields have values set.
virtual bool IsInitialized() const = 0;
// This is not implemented for Lite messages -- it just returns "(cannot
// determine missing fields for lite message)". However, it is implemented
// for full messages. See message.h.
virtual string InitializationErrorString() const;
// If |other| is the exact same class as this, calls MergeFrom(). Otherwise,
// results are undefined (probably crash).
virtual void CheckTypeAndMergeFrom(const MessageLite& other) = 0;
// Parsing ---------------------------------------------------------
// Methods for parsing in protocol buffer format. Most of these are
// just simple wrappers around MergeFromCodedStream(). Clear() will be
// called before merging the input.
// Fill the message with a protocol buffer parsed from the given input
// stream. Returns false on a read error or if the input is in the wrong
// format. A successful return does not indicate the entire input is
// consumed, ensure you call ConsumedEntireMessage() to check that if
// applicable.
bool ParseFromCodedStream(io::CodedInputStream* input);
// Like ParseFromCodedStream(), but accepts messages that are missing
// required fields.
bool ParsePartialFromCodedStream(io::CodedInputStream* input);
// Read a protocol buffer from the given zero-copy input stream. If
// successful, the entire input will be consumed.
bool ParseFromZeroCopyStream(io::ZeroCopyInputStream* input);
// Like ParseFromZeroCopyStream(), but accepts messages that are missing
// required fields.
bool ParsePartialFromZeroCopyStream(io::ZeroCopyInputStream* input);
// Read a protocol buffer from the given zero-copy input stream, expecting
// the message to be exactly "size" bytes long. If successful, exactly
// this many bytes will have been consumed from the input.
bool ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input, int size);
// Like ParseFromBoundedZeroCopyStream(), but accepts messages that are
// missing required fields.
bool ParsePartialFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
int size);
// Parses a protocol buffer contained in a string. Returns true on success.
// This function takes a string in the (non-human-readable) binary wire
// format, matching the encoding output by MessageLite::SerializeToString().
// If you'd like to convert a human-readable string into a protocol buffer
// object, see google::protobuf::TextFormat::ParseFromString().
bool ParseFromString(const string& data);
// Like ParseFromString(), but accepts messages that are missing
// required fields.
bool ParsePartialFromString(const string& data);
// Parse a protocol buffer contained in an array of bytes.
bool ParseFromArray(const void* data, int size);
// Like ParseFromArray(), but accepts messages that are missing
// required fields.
bool ParsePartialFromArray(const void* data, int size);
// Reads a protocol buffer from the stream and merges it into this
// Message. Singular fields read from the what is
// already in the Message and repeated fields are appended to those
// already present.
//
// It is the responsibility of the caller to call input->LastTagWas()
// (for groups) or input->ConsumedEntireMessage() (for non-groups) after
// this returns to verify that the message's end was delimited correctly.
//
// ParsefromCodedStream() is implemented as Clear() followed by
// MergeFromCodedStream().
bool MergeFromCodedStream(io::CodedInputStream* input);
// Like MergeFromCodedStream(), but succeeds even if required fields are
// missing in the input.
//
// MergeFromCodedStream() is just implemented as MergePartialFromCodedStream()
// followed by IsInitialized().
virtual bool MergePartialFromCodedStream(io::CodedInputStream* input) = 0;
// Serialization ---------------------------------------------------
// Methods for serializing in protocol buffer format. Most of these
// are just simple wrappers around ByteSize() and SerializeWithCachedSizes().
// Write a protocol buffer of this message to the given output. Returns
// false on a write error. If the message is missing required fields,
// this may GOOGLE_CHECK-fail.
bool SerializeToCodedStream(io::CodedOutputStream* output) const;
// Like SerializeToCodedStream(), but allows missing required fields.
bool SerializePartialToCodedStream(io::CodedOutputStream* output) const;
// Write the message to the given zero-copy output stream. All required
// fields must be set.
bool SerializeToZeroCopyStream(io::ZeroCopyOutputStream* output) const;
// Like SerializeToZeroCopyStream(), but allows missing required fields.
bool SerializePartialToZeroCopyStream(io::ZeroCopyOutputStream* output) const;
// Serialize the message and store it in the given string. All required
// fields must be set.
bool SerializeToString(string* output) const;
// Like SerializeToString(), but allows missing required fields.
bool SerializePartialToString(string* output) const;
// Serialize the message and store it in the given byte array. All required
// fields must be set.
bool SerializeToArray(void* data, int size) const;
// Like SerializeToArray(), but allows missing required fields.
bool SerializePartialToArray(void* data, int size) const;
// Make a string encoding the message. Is equivalent to calling
// SerializeToString() on a string and using that. Returns the empty
// string if SerializeToString() would have returned an error.
// Note: If you intend to generate many such strings, you may
// reduce heap fragmentation by instead re-using the same string
// object with calls to SerializeToString().
string SerializeAsString() const;
// Like SerializeAsString(), but allows missing required fields.
string SerializePartialAsString() const;
// Like SerializeToString(), but appends to the data to the string's existing
// contents. All required fields must be set.
bool AppendToString(string* output) const;
// Like AppendToString(), but allows missing required fields.
bool AppendPartialToString(string* output) const;
// Computes the serialized size of the message. This recursively calls
// ByteSizeLong() on all embedded messages.
//
// ByteSizeLong() is generally linear in the number of fields defined for the
// proto.
virtual size_t ByteSizeLong() const = 0;
// Legacy ByteSize() API.
PROTOBUF_RUNTIME_DEPRECATED("Please use ByteSizeLong() instead")
int ByteSize() const {
return internal::ToIntSize(ByteSizeLong());
}
// Serializes the message without recomputing the size. The message must not
// have changed since the last call to ByteSize(), and the value returned by
// ByteSize must be non-negative. Otherwise the results are undefined.
virtual void SerializeWithCachedSizes(
io::CodedOutputStream* output) const;
// Functions below here are not part of the public interface. It isn't
// enforced, but they should be treated as private, and will be private
// at some future time. Unfortunately the implementation of the "friend"
// keyword in GCC is broken at the moment, but we expect it will be fixed.
// Like SerializeWithCachedSizes, but writes directly to *target, returning
// a pointer to the byte immediately after the last byte written. "target"
// must point at a byte array of at least ByteSize() bytes. Whether to use
// deterministic serialization, e.g., maps in sorted order, is determined by
// CodedOutputStream::IsDefaultSerializationDeterministic().
virtual uint8* SerializeWithCachedSizesToArray(uint8* target) const;
// Returns the result of the last call to ByteSize(). An embedded message's
// size is needed both to serialize it (because embedded messages are
// length-delimited) and to compute the outer message's size. Caching
// the size avoids computing it multiple times.
//
// ByteSize() does not automatically use the cached size when available
// because this would require invalidating it every time the message was
// modified, which would be too hard and expensive. (E.g. if a deeply-nested
// sub-message is changed, all of its parents' cached sizes would need to be
// invalidated, which is too much work for an otherwise inlined setter
// method.)
virtual int GetCachedSize() const = 0;
virtual uint8* InternalSerializeWithCachedSizesToArray(bool deterministic,
uint8* target) const;
protected:
// CastToBase allows generated code to cast a RepeatedPtrField<T> to
// RepeatedPtrFieldBase. We try to restrict access to RepeatedPtrFieldBase
// because it is an implementation detail that user code should not access
// directly.
template <typename T>
static ::google::protobuf::internal::RepeatedPtrFieldBase* CastToBase(
::google::protobuf::RepeatedPtrField<T>* repeated) {
return repeated;
}
template <typename T>
static const ::google::protobuf::internal::RepeatedPtrFieldBase& CastToBase(
const ::google::protobuf::RepeatedPtrField<T>& repeated) {
return repeated;
}
template <typename T>
static T* CreateMaybeMessage(Arena* arena) {
return Arena::CreateMaybeMessage<T>(arena);
}
private:
// TODO(gerbens) make this a pure abstract function
virtual const void* InternalGetTable() const { return NULL; }
friend class internal::WireFormatLite;
friend class Message;
friend class internal::WeakFieldMap;
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MessageLite);
};
namespace internal {
extern bool LIBPROTOBUF_EXPORT proto3_preserve_unknown_;
// DO NOT USE: For migration only. Will be removed when Proto3 defaults to
// preserve unknowns.
inline bool GetProto3PreserveUnknownsDefault() {
return proto3_preserve_unknown_;
}
// DO NOT USE: For migration only. Will be removed when Proto3 defaults to
// preserve unknowns.
void LIBPROTOBUF_EXPORT SetProto3PreserveUnknownsDefault(bool preserve);
} // namespace internal
} // namespace protobuf
} // namespace google
#endif // GOOGLE_PROTOBUF_MESSAGE_LITE_H__