// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Author: kenton@google.com (Kenton Varda)
//  Based on original Protocol Buffers design by
//  Sanjay Ghemawat, Jeff Dean, and others.

#include <google/protobuf/wire_format_lite_inl.h>

#ifdef __SSE_4_1__
#include <immintrin.h>
#endif
#include <stack>
#include <string>
#include <vector>
#include <google/protobuf/stubs/logging.h>
#include <google/protobuf/stubs/common.h>
#include <google/protobuf/stubs/stringprintf.h>
#include <google/protobuf/io/coded_stream_inl.h>
#include <google/protobuf/io/zero_copy_stream.h>
#include <google/protobuf/io/zero_copy_stream_impl_lite.h>

namespace google {

namespace protobuf {
namespace internal {


#if !defined(_MSC_VER) || _MSC_VER >= 1900
// Old version of MSVC doesn't like definitions of inline constants, GCC
// requires them.
const int WireFormatLite::kMessageSetItemStartTag;
const int WireFormatLite::kMessageSetItemEndTag;
const int WireFormatLite::kMessageSetTypeIdTag;
const int WireFormatLite::kMessageSetMessageTag;

#endif

// IBM xlC requires prefixing constants with WireFormatLite::
const size_t WireFormatLite::kMessageSetItemTagsSize =
  io::CodedOutputStream::StaticVarintSize32<
      WireFormatLite::kMessageSetItemStartTag>::value +
  io::CodedOutputStream::StaticVarintSize32<
      WireFormatLite::kMessageSetItemEndTag>::value +
  io::CodedOutputStream::StaticVarintSize32<
      WireFormatLite::kMessageSetTypeIdTag>::value +
  io::CodedOutputStream::StaticVarintSize32<
      WireFormatLite::kMessageSetMessageTag>::value;

const WireFormatLite::CppType
WireFormatLite::kFieldTypeToCppTypeMap[MAX_FIELD_TYPE + 1] = {
  static_cast<CppType>(0),  // 0 is reserved for errors

  CPPTYPE_DOUBLE,   // TYPE_DOUBLE
  CPPTYPE_FLOAT,    // TYPE_FLOAT
  CPPTYPE_INT64,    // TYPE_INT64
  CPPTYPE_UINT64,   // TYPE_UINT64
  CPPTYPE_INT32,    // TYPE_INT32
  CPPTYPE_UINT64,   // TYPE_FIXED64
  CPPTYPE_UINT32,   // TYPE_FIXED32
  CPPTYPE_BOOL,     // TYPE_BOOL
  CPPTYPE_STRING,   // TYPE_STRING
  CPPTYPE_MESSAGE,  // TYPE_GROUP
  CPPTYPE_MESSAGE,  // TYPE_MESSAGE
  CPPTYPE_STRING,   // TYPE_BYTES
  CPPTYPE_UINT32,   // TYPE_UINT32
  CPPTYPE_ENUM,     // TYPE_ENUM
  CPPTYPE_INT32,    // TYPE_SFIXED32
  CPPTYPE_INT64,    // TYPE_SFIXED64
  CPPTYPE_INT32,    // TYPE_SINT32
  CPPTYPE_INT64,    // TYPE_SINT64
};

const WireFormatLite::WireType
WireFormatLite::kWireTypeForFieldType[MAX_FIELD_TYPE + 1] = {
  static_cast<WireFormatLite::WireType>(-1),  // invalid
  WireFormatLite::WIRETYPE_FIXED64,           // TYPE_DOUBLE
  WireFormatLite::WIRETYPE_FIXED32,           // TYPE_FLOAT
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_INT64
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_UINT64
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_INT32
  WireFormatLite::WIRETYPE_FIXED64,           // TYPE_FIXED64
  WireFormatLite::WIRETYPE_FIXED32,           // TYPE_FIXED32
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_BOOL
  WireFormatLite::WIRETYPE_LENGTH_DELIMITED,  // TYPE_STRING
  WireFormatLite::WIRETYPE_START_GROUP,       // TYPE_GROUP
  WireFormatLite::WIRETYPE_LENGTH_DELIMITED,  // TYPE_MESSAGE
  WireFormatLite::WIRETYPE_LENGTH_DELIMITED,  // TYPE_BYTES
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_UINT32
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_ENUM
  WireFormatLite::WIRETYPE_FIXED32,           // TYPE_SFIXED32
  WireFormatLite::WIRETYPE_FIXED64,           // TYPE_SFIXED64
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_SINT32
  WireFormatLite::WIRETYPE_VARINT,            // TYPE_SINT64
};

bool WireFormatLite::SkipField(
    io::CodedInputStream* input, uint32 tag) {
  // Field number 0 is illegal.
  if (WireFormatLite::GetTagFieldNumber(tag) == 0) return false;
  switch (WireFormatLite::GetTagWireType(tag)) {
    case WireFormatLite::WIRETYPE_VARINT: {
      uint64 value;
      if (!input->ReadVarint64(&value)) return false;
      return true;
    }
    case WireFormatLite::WIRETYPE_FIXED64: {
      uint64 value;
      if (!input->ReadLittleEndian64(&value)) return false;
      return true;
    }
    case WireFormatLite::WIRETYPE_LENGTH_DELIMITED: {
      uint32 length;
      if (!input->ReadVarint32(&length)) return false;
      if (!input->Skip(length)) return false;
      return true;
    }
    case WireFormatLite::WIRETYPE_START_GROUP: {
      if (!input->IncrementRecursionDepth()) return false;
      if (!SkipMessage(input)) return false;
      input->DecrementRecursionDepth();
      // Check that the ending tag matched the starting tag.
      if (!input->LastTagWas(WireFormatLite::MakeTag(
          WireFormatLite::GetTagFieldNumber(tag),
          WireFormatLite::WIRETYPE_END_GROUP))) {
        return false;
      }
      return true;
    }
    case WireFormatLite::WIRETYPE_END_GROUP: {
      return false;
    }
    case WireFormatLite::WIRETYPE_FIXED32: {
      uint32 value;
      if (!input->ReadLittleEndian32(&value)) return false;
      return true;
    }
    default: {
      return false;
    }
  }
}

bool WireFormatLite::SkipField(
    io::CodedInputStream* input, uint32 tag, io::CodedOutputStream* output) {
  // Field number 0 is illegal.
  if (WireFormatLite::GetTagFieldNumber(tag) == 0) return false;
  switch (WireFormatLite::GetTagWireType(tag)) {
    case WireFormatLite::WIRETYPE_VARINT: {
      uint64 value;
      if (!input->ReadVarint64(&value)) return false;
      output->WriteVarint32(tag);
      output->WriteVarint64(value);
      return true;
    }
    case WireFormatLite::WIRETYPE_FIXED64: {
      uint64 value;
      if (!input->ReadLittleEndian64(&value)) return false;
      output->WriteVarint32(tag);
      output->WriteLittleEndian64(value);
      return true;
    }
    case WireFormatLite::WIRETYPE_LENGTH_DELIMITED: {
      uint32 length;
      if (!input->ReadVarint32(&length)) return false;
      output->WriteVarint32(tag);
      output->WriteVarint32(length);
      // TODO(mkilavuz): Provide API to prevent extra string copying.
      string temp;
      if (!input->ReadString(&temp, length)) return false;
      output->WriteString(temp);
      return true;
    }
    case WireFormatLite::WIRETYPE_START_GROUP: {
      output->WriteVarint32(tag);
      if (!input->IncrementRecursionDepth()) return false;
      if (!SkipMessage(input, output)) return false;
      input->DecrementRecursionDepth();
      // Check that the ending tag matched the starting tag.
      if (!input->LastTagWas(WireFormatLite::MakeTag(
          WireFormatLite::GetTagFieldNumber(tag),
          WireFormatLite::WIRETYPE_END_GROUP))) {
        return false;
      }
      return true;
    }
    case WireFormatLite::WIRETYPE_END_GROUP: {
      return false;
    }
    case WireFormatLite::WIRETYPE_FIXED32: {
      uint32 value;
      if (!input->ReadLittleEndian32(&value)) return false;
      output->WriteVarint32(tag);
      output->WriteLittleEndian32(value);
      return true;
    }
    default: {
      return false;
    }
  }
}

bool WireFormatLite::SkipMessage(io::CodedInputStream* input) {
  while (true) {
    uint32 tag = input->ReadTag();
    if (tag == 0) {
      // End of input.  This is a valid place to end, so return true.
      return true;
    }

    WireFormatLite::WireType wire_type = WireFormatLite::GetTagWireType(tag);

    if (wire_type == WireFormatLite::WIRETYPE_END_GROUP) {
      // Must be the end of the message.
      return true;
    }

    if (!SkipField(input, tag)) return false;
  }
}

bool WireFormatLite::SkipMessage(io::CodedInputStream* input,
    io::CodedOutputStream* output) {
  while (true) {
    uint32 tag = input->ReadTag();
    if (tag == 0) {
      // End of input.  This is a valid place to end, so return true.
      return true;
    }

    WireFormatLite::WireType wire_type = WireFormatLite::GetTagWireType(tag);

    if (wire_type == WireFormatLite::WIRETYPE_END_GROUP) {
      output->WriteVarint32(tag);
      // Must be the end of the message.
      return true;
    }

    if (!SkipField(input, tag, output)) return false;
  }
}

bool FieldSkipper::SkipField(
    io::CodedInputStream* input, uint32 tag) {
  return WireFormatLite::SkipField(input, tag);
}

bool FieldSkipper::SkipMessage(io::CodedInputStream* input) {
  return WireFormatLite::SkipMessage(input);
}

void FieldSkipper::SkipUnknownEnum(
    int /* field_number */, int /* value */) {
  // Nothing.
}

bool CodedOutputStreamFieldSkipper::SkipField(
    io::CodedInputStream* input, uint32 tag) {
  return WireFormatLite::SkipField(input, tag, unknown_fields_);
}

bool CodedOutputStreamFieldSkipper::SkipMessage(io::CodedInputStream* input) {
  return WireFormatLite::SkipMessage(input, unknown_fields_);
}

void CodedOutputStreamFieldSkipper::SkipUnknownEnum(
    int field_number, int value) {
  unknown_fields_->WriteVarint32(field_number);
  unknown_fields_->WriteVarint64(value);
}

bool WireFormatLite::ReadPackedEnumNoInline(io::CodedInputStream* input,
                                            bool (*is_valid)(int),
                                            RepeatedField<int>* values) {
  uint32 length;
  if (!input->ReadVarint32(&length)) return false;
  io::CodedInputStream::Limit limit = input->PushLimit(length);
  while (input->BytesUntilLimit() > 0) {
    int value;
    if (!google::protobuf::internal::WireFormatLite::ReadPrimitive<
        int, WireFormatLite::TYPE_ENUM>(input, &value)) {
      return false;
    }
    if (is_valid == NULL || is_valid(value)) {
      values->Add(value);
    }
  }
  input->PopLimit(limit);
  return true;
}

bool WireFormatLite::ReadPackedEnumPreserveUnknowns(
    io::CodedInputStream* input,
    int field_number,
    bool (*is_valid)(int),
    io::CodedOutputStream* unknown_fields_stream,
    RepeatedField<int>* values) {
  uint32 length;
  if (!input->ReadVarint32(&length)) return false;
  io::CodedInputStream::Limit limit = input->PushLimit(length);
  while (input->BytesUntilLimit() > 0) {
    int value;
    if (!google::protobuf::internal::WireFormatLite::ReadPrimitive<
        int, WireFormatLite::TYPE_ENUM>(input, &value)) {
      return false;
    }
    if (is_valid == NULL || is_valid(value)) {
      values->Add(value);
    } else {
      uint32 tag = WireFormatLite::MakeTag(field_number,
                                           WireFormatLite::WIRETYPE_VARINT);
      unknown_fields_stream->WriteVarint32(tag);
      unknown_fields_stream->WriteVarint32(value);
    }
  }
  input->PopLimit(limit);
  return true;
}

#if !defined(PROTOBUF_LITTLE_ENDIAN)

namespace {
void EncodeFixedSizeValue(float v, uint8* dest) {
  WireFormatLite::WriteFloatNoTagToArray(v, dest);
}

void EncodeFixedSizeValue(double v, uint8* dest) {
  WireFormatLite::WriteDoubleNoTagToArray(v, dest);
}

void EncodeFixedSizeValue(uint32 v, uint8* dest) {
  WireFormatLite::WriteFixed32NoTagToArray(v, dest);
}

void EncodeFixedSizeValue(uint64 v, uint8* dest) {
  WireFormatLite::WriteFixed64NoTagToArray(v, dest);
}

void EncodeFixedSizeValue(int32 v, uint8* dest) {
  WireFormatLite::WriteSFixed32NoTagToArray(v, dest);
}

void EncodeFixedSizeValue(int64 v, uint8* dest) {
  WireFormatLite::WriteSFixed64NoTagToArray(v, dest);
}

void EncodeFixedSizeValue(bool v, uint8* dest) {
  WireFormatLite::WriteBoolNoTagToArray(v, dest);
}
}  // anonymous namespace

#endif  // !defined(PROTOBUF_LITTLE_ENDIAN)

template <typename CType>
static void WriteArray(const CType* a, int n, io::CodedOutputStream* output) {
#if defined(PROTOBUF_LITTLE_ENDIAN)
  output->WriteRaw(reinterpret_cast<const char*>(a), n * sizeof(a[0]));
#else
  const int kAtATime = 128;
  uint8 buf[sizeof(CType) * kAtATime];
  for (int i = 0; i < n; i += kAtATime) {
    int to_do = min(kAtATime, n - i);
    uint8* ptr = buf;
    for (int j = 0; j < to_do; j++) {
      EncodeFixedSizeValue(a[i+j], ptr);
      ptr += sizeof(a[0]);
    }
    output->WriteRaw(buf, to_do * sizeof(a[0]));
  }
#endif
}

void WireFormatLite::WriteFloatArray(const float* a, int n,
                                     io::CodedOutputStream* output) {
  WriteArray<float>(a, n, output);
}

void WireFormatLite::WriteDoubleArray(const double* a, int n,
                                     io::CodedOutputStream* output) {
  WriteArray<double>(a, n, output);
}

void WireFormatLite::WriteFixed32Array(const uint32* a, int n,
                                     io::CodedOutputStream* output) {
  WriteArray<uint32>(a, n, output);
}

void WireFormatLite::WriteFixed64Array(const uint64* a, int n,
                                       io::CodedOutputStream* output) {
  WriteArray<uint64>(a, n, output);
}

void WireFormatLite::WriteSFixed32Array(const int32* a, int n,
                                       io::CodedOutputStream* output) {
  WriteArray<int32>(a, n, output);
}

void WireFormatLite::WriteSFixed64Array(const int64* a, int n,
                                       io::CodedOutputStream* output) {
  WriteArray<int64>(a, n, output);
}

void WireFormatLite::WriteBoolArray(const bool* a, int n,
                                    io::CodedOutputStream* output) {
  WriteArray<bool>(a, n, output);
}

void WireFormatLite::WriteInt32(int field_number, int32 value,
                                io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteInt32NoTag(value, output);
}
void WireFormatLite::WriteInt64(int field_number, int64 value,
                                io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteInt64NoTag(value, output);
}
void WireFormatLite::WriteUInt32(int field_number, uint32 value,
                                 io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteUInt32NoTag(value, output);
}
void WireFormatLite::WriteUInt64(int field_number, uint64 value,
                                 io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteUInt64NoTag(value, output);
}
void WireFormatLite::WriteSInt32(int field_number, int32 value,
                                 io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteSInt32NoTag(value, output);
}
void WireFormatLite::WriteSInt64(int field_number, int64 value,
                                 io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteSInt64NoTag(value, output);
}
void WireFormatLite::WriteFixed32(int field_number, uint32 value,
                                  io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_FIXED32, output);
  WriteFixed32NoTag(value, output);
}
void WireFormatLite::WriteFixed64(int field_number, uint64 value,
                                  io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_FIXED64, output);
  WriteFixed64NoTag(value, output);
}
void WireFormatLite::WriteSFixed32(int field_number, int32 value,
                                   io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_FIXED32, output);
  WriteSFixed32NoTag(value, output);
}
void WireFormatLite::WriteSFixed64(int field_number, int64 value,
                                   io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_FIXED64, output);
  WriteSFixed64NoTag(value, output);
}
void WireFormatLite::WriteFloat(int field_number, float value,
                                io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_FIXED32, output);
  WriteFloatNoTag(value, output);
}
void WireFormatLite::WriteDouble(int field_number, double value,
                                 io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_FIXED64, output);
  WriteDoubleNoTag(value, output);
}
void WireFormatLite::WriteBool(int field_number, bool value,
                               io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteBoolNoTag(value, output);
}
void WireFormatLite::WriteEnum(int field_number, int value,
                               io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_VARINT, output);
  WriteEnumNoTag(value, output);
}

void WireFormatLite::WriteString(int field_number, const string& value,
                                 io::CodedOutputStream* output) {
  // String is for UTF-8 text only
  WriteTag(field_number, WIRETYPE_LENGTH_DELIMITED, output);
  GOOGLE_CHECK_LE(value.size(), kint32max);
  output->WriteVarint32(value.size());
  output->WriteString(value);
}
void WireFormatLite::WriteStringMaybeAliased(
    int field_number, const string& value,
    io::CodedOutputStream* output) {
  // String is for UTF-8 text only
  WriteTag(field_number, WIRETYPE_LENGTH_DELIMITED, output);
  GOOGLE_CHECK_LE(value.size(), kint32max);
  output->WriteVarint32(value.size());
  output->WriteRawMaybeAliased(value.data(), value.size());
}
void WireFormatLite::WriteBytes(int field_number, const string& value,
                                io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_LENGTH_DELIMITED, output);
  GOOGLE_CHECK_LE(value.size(), kint32max);
  output->WriteVarint32(value.size());
  output->WriteString(value);
}
void WireFormatLite::WriteBytesMaybeAliased(
    int field_number, const string& value,
    io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_LENGTH_DELIMITED, output);
  GOOGLE_CHECK_LE(value.size(), kint32max);
  output->WriteVarint32(value.size());
  output->WriteRawMaybeAliased(value.data(), value.size());
}


void WireFormatLite::WriteGroup(int field_number,
                                const MessageLite& value,
                                io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_START_GROUP, output);
  value.SerializeWithCachedSizes(output);
  WriteTag(field_number, WIRETYPE_END_GROUP, output);
}

void WireFormatLite::WriteMessage(int field_number,
                                  const MessageLite& value,
                                  io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_LENGTH_DELIMITED, output);
  const int size = value.GetCachedSize();
  output->WriteVarint32(size);
  value.SerializeWithCachedSizes(output);
}

void WireFormatLite::WriteGroupMaybeToArray(int field_number,
                                            const MessageLite& value,
                                            io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_START_GROUP, output);
  const int size = value.GetCachedSize();
  uint8* target = output->GetDirectBufferForNBytesAndAdvance(size);
  if (target != NULL) {
    uint8* end = value.InternalSerializeWithCachedSizesToArray(
        output->IsSerializationDeterministic(), target);
    GOOGLE_DCHECK_EQ(end - target, size);
  } else {
    value.SerializeWithCachedSizes(output);
  }
  WriteTag(field_number, WIRETYPE_END_GROUP, output);
}

void WireFormatLite::WriteMessageMaybeToArray(int field_number,
                                              const MessageLite& value,
                                              io::CodedOutputStream* output) {
  WriteTag(field_number, WIRETYPE_LENGTH_DELIMITED, output);
  const int size = value.GetCachedSize();
  output->WriteVarint32(size);
  uint8* target = output->GetDirectBufferForNBytesAndAdvance(size);
  if (target != NULL) {
    uint8* end = value.InternalSerializeWithCachedSizesToArray(
        output->IsSerializationDeterministic(), target);
    GOOGLE_DCHECK_EQ(end - target, size);
  } else {
    value.SerializeWithCachedSizes(output);
  }
}

GOOGLE_ATTRIBUTE_ALWAYS_INLINE static bool ReadBytesToString(
    io::CodedInputStream* input, string* value);
inline static bool ReadBytesToString(io::CodedInputStream* input,
                                     string* value) {
  uint32 length;
  return input->ReadVarint32(&length) &&
      input->InternalReadStringInline(value, length);
}

bool WireFormatLite::ReadBytes(io::CodedInputStream* input, string* value) {
  return ReadBytesToString(input, value);
}

bool WireFormatLite::ReadBytes(io::CodedInputStream* input, string** p) {
  if (*p == &::google::protobuf::internal::GetEmptyStringAlreadyInited()) {
    *p = new ::std::string();
  }
  return ReadBytesToString(input, *p);
}

bool WireFormatLite::VerifyUtf8String(const char* data,
                                      int size,
                                      Operation op,
                                      const char* field_name) {
  if (!IsStructurallyValidUTF8(data, size)) {
    const char* operation_str = NULL;
    switch (op) {
      case PARSE:
        operation_str = "parsing";
        break;
      case SERIALIZE:
        operation_str = "serializing";
        break;
      // no default case: have the compiler warn if a case is not covered.
    }
    string quoted_field_name = "";
    if (field_name != NULL) {
      quoted_field_name = StringPrintf(" '%s'", field_name);
    }
    // no space below to avoid double space when the field name is missing.
    GOOGLE_LOG(ERROR) << "String field" << quoted_field_name << " contains invalid "
               << "UTF-8 data when " << operation_str << " a protocol "
               << "buffer. Use the 'bytes' type if you intend to send raw "
               << "bytes. ";
    return false;
  }
  return true;
}

#ifdef __SSE_4_1__
template<typename T, bool ZigZag, bool SignExtended>
static size_t VarintSize(
    const T* data, const int n,
    const internal::enable_if<sizeof(T) == 4>::type* = NULL) {
#if __cplusplus >= 201103L
  // is_unsigned<T> => !ZigZag
  static_assert((std::is_unsigned<T>::value ^ ZigZag) ||
                std::is_signed<T>::value,
                "Cannot ZigZag encode unsigned types");
  // is_unsigned<T> => !SignExtended
  static_assert((std::is_unsigned<T>::value ^ SignExtended) ||
                std::is_signed<T>::value,
                "Cannot SignExtended unsigned types");
#endif

  union vus32 {
    uint32  u[4];
    int32   s[4];
    __m128i v;
  };

  static const vus32 ones = {{1, 1, 1, 1}};

  // CodedOutputStream::VarintSize32SignExtended returns 10 for negative
  // numbers.  We can apply the UInt32Size algorithm, and simultaneously logical
  // shift the MSB into the LSB to determine if it is negative.
  static const vus32 fives = {{5, 5, 5, 5}};

  // sum is the vectorized-output of calling CodedOutputStream::VarintSize32 on
  // the processed elements.
  //
  // msb_sum is the count of set most-significant bits.  When computing the
  // vectorized CodedOutputStream::VarintSize32SignExtended, negative values
  // have the most significant bit set.  VarintSize32SignExtended returns 10 and
  // VarintSize32 returns 5.  msb_sum allows us to compute:
  //   VarintSize32SignExtended = msb_sum * 5 + VarintSize32
  vus32 sum, v, msb_sum;
  sum.v = _mm_setzero_si128();
  msb_sum.v = _mm_setzero_si128();

  int rounded = n & ~(3);
  int i;
  for (i = 0; i < rounded; i += 4) {
    v.v = _mm_loadu_si128(reinterpret_cast<const __m128i*>(&data[i]));

    if (ZigZag) {
      // Note:  the right-shift must be arithmetic
      v.v = _mm_xor_si128(_mm_slli_epi32(v.v, 1), _mm_srai_epi32(v.v, 31));
    }

    sum.v = _mm_add_epi32(sum.v, ones.v);
    if (SignExtended) {
      msb_sum.v = _mm_add_epi32(msb_sum.v, _mm_srli_epi32(v.v, 31));
    }

    v.v = _mm_srli_epi32(v.v, 7);

    for (int j = 0; j < 4; j++) {
      __m128i min = _mm_min_epi32(v.v, ones.v);

      sum.v = _mm_add_epi32(sum.v, min);
      v.v   = _mm_srli_epi32(v.v, 7);
    }
  }

  if (SignExtended) {
    vus32 extensions;
    extensions.v = _mm_mullo_epi32(msb_sum.v, fives.v);

    sum.v = _mm_add_epi32(sum.v, extensions.v);
  }

  // TODO(ckennelly): Can we avoid the sign conversion?
  size_t out = _mm_cvtsi128_si32(
      _mm_hadd_epi32(_mm_hadd_epi32(sum.v, ones.v), ones.v));

  // Finish tail.
  for (; i < n; i++) {
    if (ZigZag) {
      out += WireFormatLite::SInt32Size(data[i]);
    } else if (SignExtended) {
      out += WireFormatLite::Int32Size(data[i]);
    } else {
      out += WireFormatLite::UInt32Size(data[i]);
    }
  }

  return out;
}

size_t WireFormatLite::Int32Size(const RepeatedField<int32>& value) {
  return VarintSize<int32, false, true>(value.data(), value.size());
}

size_t WireFormatLite::UInt32Size(const RepeatedField<uint32>& value) {
  return VarintSize<uint32, false, false>(value.data(), value.size());
}

size_t WireFormatLite::SInt32Size(const RepeatedField<int32>& value) {
  return VarintSize<int32, true, true>(value.data(), value.size());
}

size_t WireFormatLite::EnumSize(const RepeatedField<int>& value) {
  // On ILP64, sizeof(int) == 8, which would require a different template.
  return VarintSize<int, false, true>(value.data(), value.size());
}

#else  // !__SSE_4_1__
size_t WireFormatLite::Int32Size(const RepeatedField<int32>& value) {
  size_t out = 0;
  const int n = value.size();
  for (int i = 0; i < n; i++) {
    out += Int32Size(value.Get(i));
  }
  return out;
}

size_t WireFormatLite::UInt32Size(const RepeatedField<uint32>& value) {
  size_t out = 0;
  const int n = value.size();
  for (int i = 0; i < n; i++) {
    out += UInt32Size(value.Get(i));
  }
  return out;
}

size_t WireFormatLite::SInt32Size(const RepeatedField<int32>& value) {
  size_t out = 0;
  const int n = value.size();
  for (int i = 0; i < n; i++) {
    out += SInt32Size(value.Get(i));
  }
  return out;
}

size_t WireFormatLite::EnumSize(const RepeatedField<int>& value) {
  size_t out = 0;
  const int n = value.size();
  for (int i = 0; i < n; i++) {
    out += EnumSize(value.Get(i));
  }
  return out;
}
#endif

}  // namespace internal
}  // namespace protobuf
}  // namespace google