text: // 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/unknown_field_set.h>
  
  #include <google/protobuf/stubs/logging.h>
  #include <google/protobuf/stubs/common.h>
  #include <google/protobuf/io/coded_stream.h>
  #include <google/protobuf/io/zero_copy_stream.h>
  #include <google/protobuf/io/zero_copy_stream_impl.h>
  #include <google/protobuf/wire_format.h>
  #include <google/protobuf/stubs/stl_util.h>
  
  namespace google {
  namespace protobuf {
  
  namespace {
  // This global instance is returned by unknown_fields() on any message class
  // when the object has no unknown fields. This is necessary because we now
  // instantiate the UnknownFieldSet dynamically only when required.
  UnknownFieldSet* default_unknown_field_set_instance_ = NULL;
  
  void DeleteDefaultUnknownFieldSet() {
    delete default_unknown_field_set_instance_;
  }
  
  void InitDefaultUnknownFieldSet() {
    default_unknown_field_set_instance_ = new UnknownFieldSet();
    internal::OnShutdown(&DeleteDefaultUnknownFieldSet);
  }
  
  GOOGLE_PROTOBUF_DECLARE_ONCE(default_unknown_field_set_once_init_);
  }
  
  const UnknownFieldSet* UnknownFieldSet::default_instance() {
    ::google::protobuf::GoogleOnceInit(&default_unknown_field_set_once_init_,
                   &InitDefaultUnknownFieldSet);
    return default_unknown_field_set_instance_;
  }
  
  UnknownFieldSet::UnknownFieldSet()
      : fields_(NULL) {}
  
  UnknownFieldSet::~UnknownFieldSet() {
    Clear();
    delete fields_;
  }
  
  void UnknownFieldSet::ClearFallback() {
    if (fields_ != NULL) {
      for (int i = 0; i < fields_->size(); i++) {
        (*fields_)[i].Delete();
      }
      delete fields_;
      fields_ = NULL;
    }
  }
  
  void UnknownFieldSet::ClearAndFreeMemory() {
    if (fields_ != NULL) {
      Clear();
    }
  }
  
  void UnknownFieldSet::InternalMergeFrom(const UnknownFieldSet& other) {
    int other_field_count = other.field_count();
    if (other_field_count > 0) {
      fields_ = new vector<UnknownField>();
      for (int i = 0; i < other_field_count; i++) {
        fields_->push_back((*other.fields_)[i]);
        fields_->back().DeepCopy((*other.fields_)[i]);
      }
    }
  }
  
  void UnknownFieldSet::MergeFrom(const UnknownFieldSet& other) {
    int other_field_count = other.field_count();
    if (other_field_count > 0) {
      if (fields_ == NULL) fields_ = new vector<UnknownField>();
      for (int i = 0; i < other_field_count; i++) {
        fields_->push_back((*other.fields_)[i]);
        fields_->back().DeepCopy((*other.fields_)[i]);
      }
    }
  }
  
  // A specialized MergeFrom for performance when we are merging from an UFS that
  // is temporary and can be destroyed in the process.
  void UnknownFieldSet::MergeFromAndDestroy(UnknownFieldSet* other) {
    int other_field_count = other->field_count();
    if (other_field_count > 0) {
      if (fields_ == NULL) fields_ = new vector<UnknownField>();
      for (int i = 0; i < other_field_count; i++) {
        fields_->push_back((*other->fields_)[i]);
        (*other->fields_)[i].Reset();
      }
    }
    delete other->fields_;
    other->fields_ = NULL;
  }
  
  int UnknownFieldSet::SpaceUsedExcludingSelf() const {
    if (fields_ == NULL) return 0;
  
    int total_size = sizeof(*fields_) + sizeof(UnknownField) * fields_->size();
  
    for (int i = 0; i < fields_->size(); i++) {
      const UnknownField& field = (*fields_)[i];
      switch (field.type()) {
        case UnknownField::TYPE_LENGTH_DELIMITED:
          total_size += sizeof(*field.length_delimited_.string_value_) +
                        internal::StringSpaceUsedExcludingSelf(
                            *field.length_delimited_.string_value_);
          break;
        case UnknownField::TYPE_GROUP:
          total_size += field.group_->SpaceUsed();
          break;
        default:
          break;
      }
    }
    return total_size;
  }
  
  int UnknownFieldSet::SpaceUsed() const {
    return sizeof(*this) + SpaceUsedExcludingSelf();
  }
  
  void UnknownFieldSet::AddVarint(int number, uint64 value) {
    UnknownField field;
    field.number_ = number;
    field.SetType(UnknownField::TYPE_VARINT);
    field.varint_ = value;
    if (fields_ == NULL) fields_ = new vector<UnknownField>();
    fields_->push_back(field);
  }
  
  void UnknownFieldSet::AddFixed32(int number, uint32 value) {
    UnknownField field;
    field.number_ = number;
    field.SetType(UnknownField::TYPE_FIXED32);
    field.fixed32_ = value;
    if (fields_ == NULL) fields_ = new vector<UnknownField>();
    fields_->push_back(field);
  }
  
  void UnknownFieldSet::AddFixed64(int number, uint64 value) {
    UnknownField field;
    field.number_ = number;
    field.SetType(UnknownField::TYPE_FIXED64);
    field.fixed64_ = value;
    if (fields_ == NULL) fields_ = new vector<UnknownField>();
    fields_->push_back(field);
  }
  
  string* UnknownFieldSet::AddLengthDelimited(int number) {
    UnknownField field;
    field.number_ = number;
    field.SetType(UnknownField::TYPE_LENGTH_DELIMITED);
    field.length_delimited_.string_value_ = new string;
    if (fields_ == NULL) fields_ = new vector<UnknownField>();
    fields_->push_back(field);
    return field.length_delimited_.string_value_;
  }
  
  
  UnknownFieldSet* UnknownFieldSet::AddGroup(int number) {
    UnknownField field;
    field.number_ = number;
    field.SetType(UnknownField::TYPE_GROUP);
    field.group_ = new UnknownFieldSet;
    if (fields_ == NULL) fields_ = new vector<UnknownField>();
    fields_->push_back(field);
    return field.group_;
  }
  
  void UnknownFieldSet::AddField(const UnknownField& field) {
    if (fields_ == NULL) fields_ = new vector<UnknownField>();
    fields_->push_back(field);
    fields_->back().DeepCopy(field);
  }
  
  void UnknownFieldSet::DeleteSubrange(int start, int num) {
    // Delete the specified fields.
    for (int i = 0; i < num; ++i) {
      (*fields_)[i + start].Delete();
    }
    // Slide down the remaining fields.
    for (int i = start + num; i < fields_->size(); ++i) {
      (*fields_)[i - num] = (*fields_)[i];
    }
    // Pop off the # of deleted fields.
    for (int i = 0; i < num; ++i) {
      fields_->pop_back();
    }
    if (fields_ && fields_->size() == 0) {
      // maintain invariant: never hold fields_ if empty.
      delete fields_;
      fields_ = NULL;
    }
  }
  
  void UnknownFieldSet::DeleteByNumber(int number) {
    if (fields_ == NULL) return;
    int left = 0;  // The number of fields left after deletion.
    for (int i = 0; i < fields_->size(); ++i) {
      UnknownField* field = &(*fields_)[i];
      if (field->number() == number) {
        field->Delete();
      } else {
        if (i != left) {
          (*fields_)[left] = (*fields_)[i];
        }
        ++left;
      }
    }
    fields_->resize(left);
    if (left == 0) {
      // maintain invariant: never hold fields_ if empty.
      delete fields_;
      fields_ = NULL;
    }
  }
  
  bool UnknownFieldSet::MergeFromCodedStream(io::CodedInputStream* input) {
    UnknownFieldSet other;
    if (internal::WireFormat::SkipMessage(input, &other) &&
        input->ConsumedEntireMessage()) {
      MergeFromAndDestroy(&other);
      return true;
    } else {
      return false;
    }
  }
  
  bool UnknownFieldSet::ParseFromCodedStream(io::CodedInputStream* input) {
    Clear();
    return MergeFromCodedStream(input);
  }
  
  bool UnknownFieldSet::ParseFromZeroCopyStream(io::ZeroCopyInputStream* input) {
    io::CodedInputStream coded_input(input);
    return (ParseFromCodedStream(&coded_input) &&
            coded_input.ConsumedEntireMessage());
  }
  
  bool UnknownFieldSet::ParseFromArray(const void* data, int size) {
    io::ArrayInputStream input(data, size);
    return ParseFromZeroCopyStream(&input);
  }
  
  void UnknownField::Delete() {
    switch (type()) {
      case UnknownField::TYPE_LENGTH_DELIMITED:
        delete length_delimited_.string_value_;
        break;
      case UnknownField::TYPE_GROUP:
        delete group_;
        break;
      default:
        break;
    }
  }
  
  // Reset all owned ptrs, a special function for performance, to avoid double
  // owning the ptrs, when we merge from a temporary UnknownFieldSet objects.
  void UnknownField::Reset() {
    switch (type()) {
      case UnknownField::TYPE_LENGTH_DELIMITED:
        length_delimited_.string_value_ = NULL;
        break;
      case UnknownField::TYPE_GROUP: {
        group_ = NULL;
        break;
      }
      default:
        break;
    }
  }
  
  void UnknownField::DeepCopy(const UnknownField& other) {
    switch (type()) {
      case UnknownField::TYPE_LENGTH_DELIMITED:
        length_delimited_.string_value_ = new string(
            *length_delimited_.string_value_);
        break;
      case UnknownField::TYPE_GROUP: {
        UnknownFieldSet* group = new UnknownFieldSet();
        group->InternalMergeFrom(*group_);
        group_ = group;
        break;
      }
      default:
        break;
    }
  }
  
  
  void UnknownField::SerializeLengthDelimitedNoTag(
      io::CodedOutputStream* output) const {
    GOOGLE_DCHECK_EQ(TYPE_LENGTH_DELIMITED, type());
    const string& data = *length_delimited_.string_value_;
    output->WriteVarint32(data.size());
    output->WriteRawMaybeAliased(data.data(), data.size());
  }
  
  uint8* UnknownField::SerializeLengthDelimitedNoTagToArray(uint8* target) const {
    GOOGLE_DCHECK_EQ(TYPE_LENGTH_DELIMITED, type());
    const string& data = *length_delimited_.string_value_;
    target = io::CodedOutputStream::WriteVarint32ToArray(data.size(), target);
    target = io::CodedOutputStream::WriteStringToArray(data, target);
    return target;
  }
  
  }  // namespace protobuf
  }  // namespace google
  