src/google/protobuf/message_lite.cc - third_party/protobuf - Git at Google

 // 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.

 #include <climits>
 #include <cstdint>
 #include <string>

 #include <google/protobuf/stubs/logging.h>
 #include <google/protobuf/stubs/common.h>
 #include <google/protobuf/stubs/stringprintf.h>
 #include <google/protobuf/parse_context.h>
 #include <google/protobuf/io/coded_stream.h>
 #include <google/protobuf/io/zero_copy_stream.h>
 #include <google/protobuf/io/zero_copy_stream_impl_lite.h>
 #include <google/protobuf/arena.h>
 #include <google/protobuf/generated_message_table_driven.h>
 #include <google/protobuf/generated_message_util.h>
 #include <google/protobuf/message_lite.h>
 #include <google/protobuf/repeated_field.h>

 #include <google/protobuf/stubs/strutil.h>
 #include <google/protobuf/stubs/stl_util.h>

 #include <google/protobuf/port_def.inc>

 namespace google {
 namespace protobuf {

 std::string MessageLite::InitializationErrorString() const {
   return "(cannot determine missing fields for lite message)";
 }

 std::string MessageLite::DebugString() const {
   std::uintptr_t address = reinterpret_cast<std::uintptr_t>(this);
   return StrCat("MessageLite at 0x", strings::Hex(address));
 }

 namespace {

 // When serializing, we first compute the byte size, then serialize the message.
 // If serialization produces a different number of bytes than expected, we
 // call this function, which crashes.  The problem could be due to a bug in the
 // protobuf implementation but is more likely caused by concurrent modification
 // of the message.  This function attempts to distinguish between the two and
 // provide a useful error message.
 void ByteSizeConsistencyError(size_t byte_size_before_serialization,
                               size_t byte_size_after_serialization,
                               size_t bytes_produced_by_serialization,
                               const MessageLite& message) {
   GOOGLE_CHECK_EQ(byte_size_before_serialization, byte_size_after_serialization)
       << message.GetTypeName()
       << " was modified concurrently during serialization.";
   GOOGLE_CHECK_EQ(bytes_produced_by_serialization, byte_size_before_serialization)
       << "Byte size calculation and serialization were inconsistent.  This "
          "may indicate a bug in protocol buffers or it may be caused by "
          "concurrent modification of "
       << message.GetTypeName() << ".";
   GOOGLE_LOG(FATAL) << "This shouldn't be called if all the sizes are equal.";
 }

 std::string InitializationErrorMessage(const char* action,
                                        const MessageLite& message) {
   // Note:  We want to avoid depending on strutil in the lite library, otherwise
   //   we'd use:
   //
   // return strings::Substitute(
   //   "Can't $0 message of type \"$1\" because it is missing required "
   //   "fields: $2",
   //   action, message.GetTypeName(),
   //   message.InitializationErrorString());

   std::string result;
   result += "Can't ";
   result += action;
   result += " message of type \"";
   result += message.GetTypeName();
   result += "\" because it is missing required fields: ";
   result += message.InitializationErrorString();
   return result;
 }

 inline StringPiece as_string_view(const void* data, int size) {
   return StringPiece(static_cast<const char*>(data), size);
 }

 }  // namespace

 void MessageLite::LogInitializationErrorMessage() const {
   GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *this);
 }

 namespace internal {

 #if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

 template <bool aliasing>
 bool MergePartialFromImpl(StringPiece input, MessageLite* msg) {
   const char* ptr;
   internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
                              aliasing, &ptr, input);
   ptr = msg->_InternalParse(ptr, &ctx);
   // ctx has an explicit limit set (length of string_view).
   return ptr && ctx.EndedAtLimit();
 }

 template <bool aliasing>
 bool MergePartialFromImpl(io::ZeroCopyInputStream* input, MessageLite* msg) {
   const char* ptr;
   internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
                              aliasing, &ptr, input);
   ptr = msg->_InternalParse(ptr, &ctx);
   // ctx has no explicit limit (hence we end on end of stream)
   return ptr && ctx.EndedAtEndOfStream();
 }

 template <bool aliasing>
 bool MergePartialFromImpl(BoundedZCIS input, MessageLite* msg) {
   const char* ptr;
   internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
                              aliasing, &ptr, input.zcis, input.limit);
   ptr = msg->_InternalParse(ptr, &ctx);
   if (PROTOBUF_PREDICT_FALSE(!ptr)) return false;
   ctx.BackUp(ptr);
   return ctx.EndedAtLimit();
 }

 #else  // !GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

 inline bool InlineMergePartialEntireStream(io::CodedInputStream* cis,
                                            MessageLite* message,
                                            bool aliasing) {
   return message->MergePartialFromCodedStream(cis) &&
          cis->ConsumedEntireMessage();
 }

 template <bool aliasing>
 bool MergePartialFromImpl(StringPiece input, MessageLite* msg) {
   io::CodedInputStream decoder(reinterpret_cast<const uint8*>(input.data()),
                                input.size());
   return InlineMergePartialEntireStream(&decoder, msg, aliasing);
 }

 template <bool aliasing>
 bool MergePartialFromImpl(BoundedZCIS input, MessageLite* msg) {
   io::CodedInputStream decoder(input.zcis);
   decoder.PushLimit(input.limit);
   return InlineMergePartialEntireStream(&decoder, msg, aliasing) &&
          decoder.BytesUntilLimit() == 0;
 }

 template <bool aliasing>
 bool MergePartialFromImpl(io::ZeroCopyInputStream* input, MessageLite* msg) {
   io::CodedInputStream decoder(input);
   return InlineMergePartialEntireStream(&decoder, msg, aliasing);
 }

 #endif  // !GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

 template bool MergePartialFromImpl<false>(StringPiece input,
                                           MessageLite* msg);
 template bool MergePartialFromImpl<true>(StringPiece input,
                                          MessageLite* msg);
 template bool MergePartialFromImpl<false>(io::ZeroCopyInputStream* input,
                                           MessageLite* msg);
 template bool MergePartialFromImpl<true>(io::ZeroCopyInputStream* input,
                                          MessageLite* msg);
 template bool MergePartialFromImpl<false>(BoundedZCIS input, MessageLite* msg);
 template bool MergePartialFromImpl<true>(BoundedZCIS input, MessageLite* msg);

 }  // namespace internal

 MessageLite* MessageLite::New(Arena* arena) const {
   MessageLite* message = New();
   if (arena != NULL) {
     arena->Own(message);
   }
   return message;
 }

 #if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
 class ZeroCopyCodedInputStream : public io::ZeroCopyInputStream {
  public:
   ZeroCopyCodedInputStream(io::CodedInputStream* cis) : cis_(cis) {}
   bool Next(const void** data, int* size) final {
     if (!cis_->GetDirectBufferPointer(data, size)) return false;
     cis_->Skip(*size);
     return true;
   }
   void BackUp(int count) final { cis_->Advance(-count); }
   bool Skip(int count) final { return cis_->Skip(count); }
   int64 ByteCount() const final { return 0; }

   bool aliasing_enabled() { return cis_->aliasing_enabled_; }

  private:
   io::CodedInputStream* cis_;
 };

 bool MessageLite::MergePartialFromCodedStream(io::CodedInputStream* input) {
   ZeroCopyCodedInputStream zcis(input);
   const char* ptr;
   internal::ParseContext ctx(input->RecursionBudget(), zcis.aliasing_enabled(),
                              &ptr, &zcis);
   // MergePartialFromCodedStream allows terminating the wireformat by 0 or
   // end-group tag. Leaving it up to the caller to verify correct ending by
   // calling LastTagWas on input. We need to maintain this behavior.
   ctx.TrackCorrectEnding();
   ctx.data().pool = input->GetExtensionPool();
   ctx.data().factory = input->GetExtensionFactory();
   ptr = _InternalParse(ptr, &ctx);
   if (PROTOBUF_PREDICT_FALSE(!ptr)) return false;
   ctx.BackUp(ptr);
   if (!ctx.EndedAtEndOfStream()) {
     GOOGLE_DCHECK(ctx.LastTag() != 1);  // We can't end on a pushed limit.
     if (ctx.IsExceedingLimit(ptr)) return false;
     input->SetLastTag(ctx.LastTag());
     return true;
   }
   input->SetConsumed();
   return true;
 }
 #endif  // GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

 bool MessageLite::MergeFromCodedStream(io::CodedInputStream* input) {
   return MergePartialFromCodedStream(input) && IsInitializedWithErrors();
 }

 bool MessageLite::ParseFromCodedStream(io::CodedInputStream* input) {
   Clear();
   return MergeFromCodedStream(input);
 }

 bool MessageLite::ParsePartialFromCodedStream(io::CodedInputStream* input) {
   Clear();
   return MergePartialFromCodedStream(input);
 }

 bool MessageLite::ParseFromZeroCopyStream(io::ZeroCopyInputStream* input) {
   return ParseFrom<kParse>(input);
 }

 bool MessageLite::ParsePartialFromZeroCopyStream(
     io::ZeroCopyInputStream* input) {
   return ParseFrom<kParsePartial>(input);
 }

 bool MessageLite::MergePartialFromBoundedZeroCopyStream(
     io::ZeroCopyInputStream* input, int size) {
   return ParseFrom<kMergePartial>(internal::BoundedZCIS{input, size});
 }

 bool MessageLite::MergeFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
                                                  int size) {
   return ParseFrom<kMerge>(internal::BoundedZCIS{input, size});
 }

 bool MessageLite::ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
                                                  int size) {
   return ParseFrom<kParse>(internal::BoundedZCIS{input, size});
 }

 bool MessageLite::ParsePartialFromBoundedZeroCopyStream(
     io::ZeroCopyInputStream* input, int size) {
   return ParseFrom<kParsePartial>(internal::BoundedZCIS{input, size});
 }

 bool MessageLite::ParseFromString(const std::string& data) {
   return ParseFrom<kParse>(data);
 }

 bool MessageLite::ParsePartialFromString(const std::string& data) {
   return ParseFrom<kParsePartial>(data);
 }

 bool MessageLite::ParseFromArray(const void* data, int size) {
   return ParseFrom<kParse>(as_string_view(data, size));
 }

 bool MessageLite::ParsePartialFromArray(const void* data, int size) {
   return ParseFrom<kParsePartial>(as_string_view(data, size));
 }

 bool MessageLite::MergeFromString(const std::string& data) {
   return ParseFrom<kMerge>(data);
 }


 // ===================================================================

 uint8* MessageLite::SerializeWithCachedSizesToArray(uint8* target) const {
   const internal::SerializationTable* table =
       static_cast<const internal::SerializationTable*>(InternalGetTable());
   auto deterministic =
       io::CodedOutputStream::IsDefaultSerializationDeterministic();
   if (table) {
     return internal::TableSerializeToArray(*this, table, deterministic, target);
   } else {
     if (deterministic) {
       // We only optimize this when using optimize_for = SPEED.  In other cases
       // we just use the CodedOutputStream path.
       int size = GetCachedSize();
       io::ArrayOutputStream out(target, size);
       io::CodedOutputStream coded_out(&out);
       coded_out.SetSerializationDeterministic(true);
       SerializeWithCachedSizes(&coded_out);
       GOOGLE_CHECK(!coded_out.HadError());
       return target + size;
     } else {
       return InternalSerializeWithCachedSizesToArray(target);
     }
   }
 }

 bool MessageLite::SerializeToCodedStream(io::CodedOutputStream* output) const {
   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
   return SerializePartialToCodedStream(output);
 }

 bool MessageLite::SerializePartialToCodedStream(
     io::CodedOutputStream* output) const {
   const size_t size = ByteSizeLong();  // Force size to be cached.
   if (size > INT_MAX) {
     GOOGLE_LOG(ERROR) << GetTypeName()
                << " exceeded maximum protobuf size of 2GB: " << size;
     return false;
   }

   if (!output->IsSerializationDeterministic()) {
     uint8* buffer = output->GetDirectBufferForNBytesAndAdvance(size);
     if (buffer != nullptr) {
       uint8* end = InternalSerializeWithCachedSizesToArray(buffer);
       if (end - buffer != size) {
         ByteSizeConsistencyError(size, ByteSizeLong(), end - buffer, *this);
       }
       return true;
     }
   }
   int original_byte_count = output->ByteCount();
   SerializeWithCachedSizes(output);
   if (output->HadError()) {
     return false;
   }
   int final_byte_count = output->ByteCount();

   if (final_byte_count - original_byte_count != size) {
     ByteSizeConsistencyError(size, ByteSizeLong(),
                              final_byte_count - original_byte_count, *this);
   }

   return true;
 }

 bool MessageLite::SerializeToZeroCopyStream(
     io::ZeroCopyOutputStream* output) const {
   io::CodedOutputStream encoder(output);
   return SerializeToCodedStream(&encoder);
 }

 bool MessageLite::SerializePartialToZeroCopyStream(
     io::ZeroCopyOutputStream* output) const {
   io::CodedOutputStream encoder(output);
   return SerializePartialToCodedStream(&encoder);
 }

 bool MessageLite::AppendToString(std::string* output) const {
   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
   return AppendPartialToString(output);
 }

 bool MessageLite::AppendPartialToString(std::string* output) const {
   size_t old_size = output->size();
   size_t byte_size = ByteSizeLong();
   if (byte_size > INT_MAX) {
     GOOGLE_LOG(ERROR) << GetTypeName()
                << " exceeded maximum protobuf size of 2GB: " << byte_size;
     return false;
   }

   STLStringResizeUninitialized(output, old_size + byte_size);
   uint8* start =
       reinterpret_cast<uint8*>(io::mutable_string_data(output) + old_size);
   uint8* end = SerializeWithCachedSizesToArray(start);
   if (end - start != byte_size) {
     ByteSizeConsistencyError(byte_size, ByteSizeLong(), end - start, *this);
   }
   return true;
 }

 bool MessageLite::SerializeToString(std::string* output) const {
   output->clear();
   return AppendToString(output);
 }

 bool MessageLite::SerializePartialToString(std::string* output) const {
   output->clear();
   return AppendPartialToString(output);
 }

 bool MessageLite::SerializeToArray(void* data, int size) const {
   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
   return SerializePartialToArray(data, size);
 }

 bool MessageLite::SerializePartialToArray(void* data, int size) const {
   const size_t byte_size = ByteSizeLong();
   if (byte_size > INT_MAX) {
     GOOGLE_LOG(ERROR) << GetTypeName()
                << " exceeded maximum protobuf size of 2GB: " << byte_size;
     return false;
   }
   if (size < byte_size) return false;
   uint8* start = reinterpret_cast<uint8*>(data);
   uint8* end = SerializeWithCachedSizesToArray(start);
   if (end - start != byte_size) {
     ByteSizeConsistencyError(byte_size, ByteSizeLong(), end - start, *this);
   }
   return true;
 }

 std::string MessageLite::SerializeAsString() const {
   // If the compiler implements the (Named) Return Value Optimization,
   // the local variable 'output' will not actually reside on the stack
   // of this function, but will be overlaid with the object that the
   // caller supplied for the return value to be constructed in.
   std::string output;
   if (!AppendToString(&output)) output.clear();
   return output;
 }

 std::string MessageLite::SerializePartialAsString() const {
   std::string output;
   if (!AppendPartialToString(&output)) output.clear();
   return output;
 }

 void MessageLite::SerializeWithCachedSizes(
     io::CodedOutputStream* output) const {
   GOOGLE_DCHECK(InternalGetTable());
   internal::TableSerialize(
       *this,
       static_cast<const internal::SerializationTable*>(InternalGetTable()),
       output);
 }

 // The table driven code optimizes the case that the CodedOutputStream buffer
 // is large enough to serialize into it directly.
 // If the proto is optimized for speed, this method will be overridden by
 // generated code for maximum speed. If the proto is optimized for size or
 // is lite, then we need to specialize this to avoid infinite recursion.
 uint8* MessageLite::InternalSerializeWithCachedSizesToArray(
     uint8* target) const {
   const internal::SerializationTable* table =
       static_cast<const internal::SerializationTable*>(InternalGetTable());
   if (table == NULL) {
     // We only optimize this when using optimize_for = SPEED.  In other cases
     // we just use the CodedOutputStream path.
     int size = GetCachedSize();
     io::ArrayOutputStream out(target, size);
     io::CodedOutputStream coded_out(&out);
     SerializeWithCachedSizes(&coded_out);
     GOOGLE_CHECK(!coded_out.HadError());
     return target + size;
   } else {
     return internal::TableSerializeToArray(*this, table, false, target);
   }
 }

 namespace internal {

 template <>
 MessageLite* GenericTypeHandler<MessageLite>::NewFromPrototype(
     const MessageLite* prototype, Arena* arena) {
   return prototype->New(arena);
 }
 template <>
 void GenericTypeHandler<MessageLite>::Merge(const MessageLite& from,
                                             MessageLite* to) {
   to->CheckTypeAndMergeFrom(from);
 }
 template <>
 void GenericTypeHandler<std::string>::Merge(const std::string& from,
                                             std::string* to) {
   *to = from;
 }

 }  // namespace internal

 }  // namespace protobuf
 }  // namespace google
	// 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.

	#include <climits>
	#include <cstdint>
	#include <string>

	#include <google/protobuf/stubs/logging.h>
	#include <google/protobuf/stubs/common.h>
	#include <google/protobuf/stubs/stringprintf.h>
	#include <google/protobuf/parse_context.h>
	#include <google/protobuf/io/coded_stream.h>
	#include <google/protobuf/io/zero_copy_stream.h>
	#include <google/protobuf/io/zero_copy_stream_impl_lite.h>
	#include <google/protobuf/arena.h>
	#include <google/protobuf/generated_message_table_driven.h>
	#include <google/protobuf/generated_message_util.h>
	#include <google/protobuf/message_lite.h>
	#include <google/protobuf/repeated_field.h>

	#include <google/protobuf/stubs/strutil.h>
	#include <google/protobuf/stubs/stl_util.h>

	#include <google/protobuf/port_def.inc>

	namespace google {
	namespace protobuf {

	std::string MessageLite::InitializationErrorString() const {
	return "(cannot determine missing fields for lite message)";
	}

	std::string MessageLite::DebugString() const {
	std::uintptr_t address = reinterpret_cast<std::uintptr_t>(this);
	return StrCat("MessageLite at 0x", strings::Hex(address));
	}

	namespace {

	// When serializing, we first compute the byte size, then serialize the message.
	// If serialization produces a different number of bytes than expected, we
	// call this function, which crashes. The problem could be due to a bug in the
	// protobuf implementation but is more likely caused by concurrent modification
	// of the message. This function attempts to distinguish between the two and
	// provide a useful error message.
	void ByteSizeConsistencyError(size_t byte_size_before_serialization,
	size_t byte_size_after_serialization,
	size_t bytes_produced_by_serialization,
	const MessageLite& message) {
	GOOGLE_CHECK_EQ(byte_size_before_serialization, byte_size_after_serialization)
	<< message.GetTypeName()
	<< " was modified concurrently during serialization.";
	GOOGLE_CHECK_EQ(bytes_produced_by_serialization, byte_size_before_serialization)
	<< "Byte size calculation and serialization were inconsistent. This "
	"may indicate a bug in protocol buffers or it may be caused by "
	"concurrent modification of "
	<< message.GetTypeName() << ".";
	GOOGLE_LOG(FATAL) << "This shouldn't be called if all the sizes are equal.";
	}

	std::string InitializationErrorMessage(const char* action,
	const MessageLite& message) {
	// Note: We want to avoid depending on strutil in the lite library, otherwise
	// we'd use:
	//
	// return strings::Substitute(
	// "Can't $0 message of type \"$1\" because it is missing required "
	// "fields: $2",
	// action, message.GetTypeName(),
	// message.InitializationErrorString());

	std::string result;
	result += "Can't ";
	result += action;
	result += " message of type \"";
	result += message.GetTypeName();
	result += "\" because it is missing required fields: ";
	result += message.InitializationErrorString();
	return result;
	}

	inline StringPiece as_string_view(const void* data, int size) {
	return StringPiece(static_cast<const char*>(data), size);
	}

	} // namespace

	void MessageLite::LogInitializationErrorMessage() const {
	GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *this);
	}

	namespace internal {

	#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

	template <bool aliasing>
	bool MergePartialFromImpl(StringPiece input, MessageLite* msg) {
	const char* ptr;
	internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
	aliasing, &ptr, input);
	ptr = msg->_InternalParse(ptr, &ctx);
	// ctx has an explicit limit set (length of string_view).
	return ptr && ctx.EndedAtLimit();
	}

	template <bool aliasing>
	bool MergePartialFromImpl(io::ZeroCopyInputStream* input, MessageLite* msg) {
	const char* ptr;
	internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
	aliasing, &ptr, input);
	ptr = msg->_InternalParse(ptr, &ctx);
	// ctx has no explicit limit (hence we end on end of stream)
	return ptr && ctx.EndedAtEndOfStream();
	}

	template <bool aliasing>
	bool MergePartialFromImpl(BoundedZCIS input, MessageLite* msg) {
	const char* ptr;
	internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
	aliasing, &ptr, input.zcis, input.limit);
	ptr = msg->_InternalParse(ptr, &ctx);
	if (PROTOBUF_PREDICT_FALSE(!ptr)) return false;
	ctx.BackUp(ptr);
	return ctx.EndedAtLimit();
	}

	#else // !GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

	inline bool InlineMergePartialEntireStream(io::CodedInputStream* cis,
	MessageLite* message,
	bool aliasing) {
	return message->MergePartialFromCodedStream(cis) &&
	cis->ConsumedEntireMessage();
	}

	template <bool aliasing>
	bool MergePartialFromImpl(StringPiece input, MessageLite* msg) {
	io::CodedInputStream decoder(reinterpret_cast<const uint8*>(input.data()),
	input.size());
	return InlineMergePartialEntireStream(&decoder, msg, aliasing);
	}

	template <bool aliasing>
	bool MergePartialFromImpl(BoundedZCIS input, MessageLite* msg) {
	io::CodedInputStream decoder(input.zcis);
	decoder.PushLimit(input.limit);
	return InlineMergePartialEntireStream(&decoder, msg, aliasing) &&
	decoder.BytesUntilLimit() == 0;
	}

	template <bool aliasing>
	bool MergePartialFromImpl(io::ZeroCopyInputStream* input, MessageLite* msg) {
	io::CodedInputStream decoder(input);
	return InlineMergePartialEntireStream(&decoder, msg, aliasing);
	}

	#endif // !GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

	template bool MergePartialFromImpl<false>(StringPiece input,
	MessageLite* msg);
	template bool MergePartialFromImpl<true>(StringPiece input,
	MessageLite* msg);
	template bool MergePartialFromImpl<false>(io::ZeroCopyInputStream* input,
	MessageLite* msg);
	template bool MergePartialFromImpl<true>(io::ZeroCopyInputStream* input,
	MessageLite* msg);
	template bool MergePartialFromImpl<false>(BoundedZCIS input, MessageLite* msg);
	template bool MergePartialFromImpl<true>(BoundedZCIS input, MessageLite* msg);

	} // namespace internal

	MessageLite* MessageLite::New(Arena* arena) const {
	MessageLite* message = New();
	if (arena != NULL) {
	arena->Own(message);
	}
	return message;
	}

	#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
	class ZeroCopyCodedInputStream : public io::ZeroCopyInputStream {
	public:
	ZeroCopyCodedInputStream(io::CodedInputStream* cis) : cis_(cis) {}
	bool Next(const void** data, int* size) final {
	if (!cis_->GetDirectBufferPointer(data, size)) return false;
	cis_->Skip(*size);
	return true;
	}
	void BackUp(int count) final { cis_->Advance(-count); }
	bool Skip(int count) final { return cis_->Skip(count); }
	int64 ByteCount() const final { return 0; }

	bool aliasing_enabled() { return cis_->aliasing_enabled_; }

	private:
	io::CodedInputStream* cis_;
	};

	bool MessageLite::MergePartialFromCodedStream(io::CodedInputStream* input) {
	ZeroCopyCodedInputStream zcis(input);
	const char* ptr;
	internal::ParseContext ctx(input->RecursionBudget(), zcis.aliasing_enabled(),
	&ptr, &zcis);
	// MergePartialFromCodedStream allows terminating the wireformat by 0 or
	// end-group tag. Leaving it up to the caller to verify correct ending by
	// calling LastTagWas on input. We need to maintain this behavior.
	ctx.TrackCorrectEnding();
	ctx.data().pool = input->GetExtensionPool();
	ctx.data().factory = input->GetExtensionFactory();
	ptr = _InternalParse(ptr, &ctx);
	if (PROTOBUF_PREDICT_FALSE(!ptr)) return false;
	ctx.BackUp(ptr);
	if (!ctx.EndedAtEndOfStream()) {
	GOOGLE_DCHECK(ctx.LastTag() != 1); // We can't end on a pushed limit.
	if (ctx.IsExceedingLimit(ptr)) return false;
	input->SetLastTag(ctx.LastTag());
	return true;
	}
	input->SetConsumed();
	return true;
	}
	#endif // GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER

	bool MessageLite::MergeFromCodedStream(io::CodedInputStream* input) {
	return MergePartialFromCodedStream(input) && IsInitializedWithErrors();
	}

	bool MessageLite::ParseFromCodedStream(io::CodedInputStream* input) {
	Clear();
	return MergeFromCodedStream(input);
	}

	bool MessageLite::ParsePartialFromCodedStream(io::CodedInputStream* input) {
	Clear();
	return MergePartialFromCodedStream(input);
	}

	bool MessageLite::ParseFromZeroCopyStream(io::ZeroCopyInputStream* input) {
	return ParseFrom<kParse>(input);
	}

	bool MessageLite::ParsePartialFromZeroCopyStream(
	io::ZeroCopyInputStream* input) {
	return ParseFrom<kParsePartial>(input);
	}

	bool MessageLite::MergePartialFromBoundedZeroCopyStream(
	io::ZeroCopyInputStream* input, int size) {
	return ParseFrom<kMergePartial>(internal::BoundedZCIS{input, size});
	}

	bool MessageLite::MergeFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
	int size) {
	return ParseFrom<kMerge>(internal::BoundedZCIS{input, size});
	}

	bool MessageLite::ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
	int size) {
	return ParseFrom<kParse>(internal::BoundedZCIS{input, size});
	}

	bool MessageLite::ParsePartialFromBoundedZeroCopyStream(
	io::ZeroCopyInputStream* input, int size) {
	return ParseFrom<kParsePartial>(internal::BoundedZCIS{input, size});
	}

	bool MessageLite::ParseFromString(const std::string& data) {
	return ParseFrom<kParse>(data);
	}

	bool MessageLite::ParsePartialFromString(const std::string& data) {
	return ParseFrom<kParsePartial>(data);
	}

	bool MessageLite::ParseFromArray(const void* data, int size) {
	return ParseFrom<kParse>(as_string_view(data, size));
	}

	bool MessageLite::ParsePartialFromArray(const void* data, int size) {
	return ParseFrom<kParsePartial>(as_string_view(data, size));
	}

	bool MessageLite::MergeFromString(const std::string& data) {
	return ParseFrom<kMerge>(data);
	}


	// ===================================================================

	uint8* MessageLite::SerializeWithCachedSizesToArray(uint8* target) const {
	const internal::SerializationTable* table =
	static_cast<const internal::SerializationTable*>(InternalGetTable());
	auto deterministic =
	io::CodedOutputStream::IsDefaultSerializationDeterministic();
	if (table) {
	return internal::TableSerializeToArray(*this, table, deterministic, target);
	} else {
	if (deterministic) {
	// We only optimize this when using optimize_for = SPEED. In other cases
	// we just use the CodedOutputStream path.
	int size = GetCachedSize();
	io::ArrayOutputStream out(target, size);
	io::CodedOutputStream coded_out(&out);
	coded_out.SetSerializationDeterministic(true);
	SerializeWithCachedSizes(&coded_out);
	GOOGLE_CHECK(!coded_out.HadError());
	return target + size;
	} else {
	return InternalSerializeWithCachedSizesToArray(target);
	}
	}
	}

	bool MessageLite::SerializeToCodedStream(io::CodedOutputStream* output) const {
	GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
	return SerializePartialToCodedStream(output);
	}

	bool MessageLite::SerializePartialToCodedStream(
	io::CodedOutputStream* output) const {
	const size_t size = ByteSizeLong(); // Force size to be cached.
	if (size > INT_MAX) {
	GOOGLE_LOG(ERROR) << GetTypeName()
	<< " exceeded maximum protobuf size of 2GB: " << size;
	return false;
	}

	if (!output->IsSerializationDeterministic()) {
	uint8* buffer = output->GetDirectBufferForNBytesAndAdvance(size);
	if (buffer != nullptr) {
	uint8* end = InternalSerializeWithCachedSizesToArray(buffer);
	if (end - buffer != size) {
	ByteSizeConsistencyError(size, ByteSizeLong(), end - buffer, *this);
	}
	return true;
	}
	}
	int original_byte_count = output->ByteCount();
	SerializeWithCachedSizes(output);
	if (output->HadError()) {
	return false;
	}
	int final_byte_count = output->ByteCount();

	if (final_byte_count - original_byte_count != size) {
	ByteSizeConsistencyError(size, ByteSizeLong(),
	final_byte_count - original_byte_count, *this);
	}

	return true;
	}

	bool MessageLite::SerializeToZeroCopyStream(
	io::ZeroCopyOutputStream* output) const {
	io::CodedOutputStream encoder(output);
	return SerializeToCodedStream(&encoder);
	}

	bool MessageLite::SerializePartialToZeroCopyStream(
	io::ZeroCopyOutputStream* output) const {
	io::CodedOutputStream encoder(output);
	return SerializePartialToCodedStream(&encoder);
	}

	bool MessageLite::AppendToString(std::string* output) const {
	GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
	return AppendPartialToString(output);
	}

	bool MessageLite::AppendPartialToString(std::string* output) const {
	size_t old_size = output->size();
	size_t byte_size = ByteSizeLong();
	if (byte_size > INT_MAX) {
	GOOGLE_LOG(ERROR) << GetTypeName()
	<< " exceeded maximum protobuf size of 2GB: " << byte_size;
	return false;
	}

	STLStringResizeUninitialized(output, old_size + byte_size);
	uint8* start =
	reinterpret_cast<uint8*>(io::mutable_string_data(output) + old_size);
	uint8* end = SerializeWithCachedSizesToArray(start);
	if (end - start != byte_size) {
	ByteSizeConsistencyError(byte_size, ByteSizeLong(), end - start, *this);
	}
	return true;
	}

	bool MessageLite::SerializeToString(std::string* output) const {
	output->clear();
	return AppendToString(output);
	}

	bool MessageLite::SerializePartialToString(std::string* output) const {
	output->clear();
	return AppendPartialToString(output);
	}

	bool MessageLite::SerializeToArray(void* data, int size) const {
	GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
	return SerializePartialToArray(data, size);
	}

	bool MessageLite::SerializePartialToArray(void* data, int size) const {
	const size_t byte_size = ByteSizeLong();
	if (byte_size > INT_MAX) {
	GOOGLE_LOG(ERROR) << GetTypeName()
	<< " exceeded maximum protobuf size of 2GB: " << byte_size;
	return false;
	}
	if (size < byte_size) return false;
	uint8* start = reinterpret_cast<uint8*>(data);
	uint8* end = SerializeWithCachedSizesToArray(start);
	if (end - start != byte_size) {
	ByteSizeConsistencyError(byte_size, ByteSizeLong(), end - start, *this);
	}
	return true;
	}

	std::string MessageLite::SerializeAsString() const {
	// If the compiler implements the (Named) Return Value Optimization,
	// the local variable 'output' will not actually reside on the stack
	// of this function, but will be overlaid with the object that the
	// caller supplied for the return value to be constructed in.
	std::string output;
	if (!AppendToString(&output)) output.clear();
	return output;
	}

	std::string MessageLite::SerializePartialAsString() const {
	std::string output;
	if (!AppendPartialToString(&output)) output.clear();
	return output;
	}

	void MessageLite::SerializeWithCachedSizes(
	io::CodedOutputStream* output) const {
	GOOGLE_DCHECK(InternalGetTable());
	internal::TableSerialize(
	*this,
	static_cast<const internal::SerializationTable*>(InternalGetTable()),
	output);
	}

	// The table driven code optimizes the case that the CodedOutputStream buffer
	// is large enough to serialize into it directly.
	// If the proto is optimized for speed, this method will be overridden by
	// generated code for maximum speed. If the proto is optimized for size or
	// is lite, then we need to specialize this to avoid infinite recursion.
	uint8* MessageLite::InternalSerializeWithCachedSizesToArray(
	uint8* target) const {
	const internal::SerializationTable* table =
	static_cast<const internal::SerializationTable*>(InternalGetTable());
	if (table == NULL) {
	// We only optimize this when using optimize_for = SPEED. In other cases
	// we just use the CodedOutputStream path.
	int size = GetCachedSize();
	io::ArrayOutputStream out(target, size);
	io::CodedOutputStream coded_out(&out);
	SerializeWithCachedSizes(&coded_out);
	GOOGLE_CHECK(!coded_out.HadError());
	return target + size;
	} else {
	return internal::TableSerializeToArray(*this, table, false, target);
	}
	}

	namespace internal {

	template <>
	MessageLite* GenericTypeHandler<MessageLite>::NewFromPrototype(
	const MessageLite* prototype, Arena* arena) {
	return prototype->New(arena);
	}
	template <>
	void GenericTypeHandler<MessageLite>::Merge(const MessageLite& from,
	MessageLite* to) {
	to->CheckTypeAndMergeFrom(from);
	}
	template <>
	void GenericTypeHandler<std::string>::Merge(const std::string& from,
	std::string* to) {
	*to = from;
	}

	} // namespace internal

	} // namespace protobuf
	} // namespace google