Method _encode_header

src/proxy/http3/QPACK.cc:366–512

}

int
QPACK::_encode_header(const MIMEField &field, uint16_t base_index, IOBufferBlock *compressed_header, uint16_t &referred_index)
{
  auto  name{field.name_get()};
  char *lowered_name = this->_arena.str_store(name.data(), name.length());
  for (size_t i = 0; i < name.length(); i++) {
    lowered_name[i] = ParseRules::ink_tolower(lowered_name[i]);
  }
  auto value{field.value_get()};

  // TODO Set never_index flag on/off according to encoding headers
  bool never_index = false;

  // Find from tables, and insert / duplicate a entry prior to encode it
  XpackLookupResult lookup_result_static;
  XpackLookupResult lookup_result_dynamic;
  lookup_result_static = StaticTable::lookup(lowered_name, name.length(), value.data(), value.length());
  if (lookup_result_static.match_type != XpackLookupResult::MatchType::EXACT) {
    lookup_result_dynamic = this->_dynamic_table.lookup(lowered_name, name.length(), value.data(), value.length());
    if (lookup_result_dynamic.match_type == XpackLookupResult::MatchType::EXACT) {
      if (this->_dynamic_table.should_duplicate(lookup_result_dynamic.index)) {
        // Duplicate an entry and use the new entry
        uint16_t current_index = lookup_result_dynamic.index;
        lookup_result_dynamic  = this->_dynamic_table.duplicate_entry(current_index);
        if (lookup_result_dynamic.match_type != XpackLookupResult::MatchType::NONE) {
          this->_write_duplicate(current_index);
          QPACKDebug("Wrote Duplicate: current_index=%d", current_index);
          this->_dynamic_table.ref_entry(current_index);
        }
      }
    } else if (lookup_result_static.match_type == XpackLookupResult::MatchType::NAME) {
      if (never_index) {
        // Name in static table is always available. Do nothing.
      } else {
        // Insert both the name and the value
        lookup_result_dynamic = this->_dynamic_table.insert_entry(lowered_name, name.length(), value.data(), value.length());
        if (lookup_result_dynamic.match_type != XpackLookupResult::MatchType::NONE) {
          this->_write_insert_with_name_ref(lookup_result_static.index, false, value.data(), value.length());
          QPACKDebug("Wrote Insert With Name Ref: index=%u, dynamic_table=%d value=%.*s", lookup_result_static.index, false,
                     static_cast<int>(value.length()), value.data());
        }
      }
    } else if (lookup_result_dynamic.match_type == XpackLookupResult::MatchType::NAME) {
      if (never_index) {
        if (this->_dynamic_table.should_duplicate(lookup_result_dynamic.index)) {
          // Duplicate an entry and use the new entry
          uint16_t current_index = lookup_result_dynamic.index;
          lookup_result_dynamic  = this->_dynamic_table.duplicate_entry(current_index);
          if (lookup_result_dynamic.match_type != XpackLookupResult::MatchType::NONE) {
            this->_write_duplicate(current_index);
            QPACKDebug("Wrote Duplicate: current_index=%d", current_index);
            this->_dynamic_table.ref_entry(current_index);
          }
        }
      } else {
        if (this->_dynamic_table.should_duplicate(lookup_result_dynamic.index)) {
          // Duplicate an entry and use the new entry
          uint16_t current_index = lookup_result_dynamic.index;