Database_h.cpp

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#include "joedb/compiler/generator/Database_h.h"
#include "joedb/compiler/nested_namespace.h"
#include "joedb/get_version.h"
 
namespace joedb::generator
{
 ////////////////////////////////////////////////////////////////////////////
 Database_h::Database_h
 ////////////////////////////////////////////////////////////////////////////
 (
  const Compiler_Options &options
 ):
  Generator(".", "Database.h", options)
 {
 }
 
 ////////////////////////////////////////////////////////////////////////////
 void Database_h::write_index_parameters
 ////////////////////////////////////////////////////////////////////////////
 (
  std::ostream &out,
  const Compiler_Options::Index &index
 )
 {
  const Database_Schema &db = options.get_db();
  for (size_t i = 0; i < index.field_ids.size(); i++)
  {
   if (i > 0)
    out << ", ";
   const Field_Id fid = index.field_ids[i];
   write_type(out, db.get_field_type(index.table_id, fid), !index.ordered, true);
   out << " field_value_of_" << db.get_field_name(index.table_id, fid);
  }
 }
 
 ////////////////////////////////////////////////////////////////////////////
 void Database_h::write(std::ostream &out)
 ////////////////////////////////////////////////////////////////////////////
 {
  const Database_Schema &db = options.get_db();
  auto tables = db.get_tables();
 
  namespace_include_guard_open(out, "Database", options.get_name_space());
 
  out << R"RRR(
#include "joedb/Freedom_Keeper.h"
#include "joedb/error/Exception.h"
#include "joedb/error/assert.h"
#include "joedb/get_version.h"
#include "joedb/hash_combine.h"
#include "ids.h"
 
#include <string>
#include <cstring>
#include <vector>
#include <algorithm>
#include <string_view>
 
)RRR";
 
  if (options.has_blob())
   out << "#include \"joedb/Blob.h\"\n";
 
  if (options.has_unique_index())
  {
   out << "#include \"joedb/ui/type_io.h\"\n";
   out << "#include <sstream>\n";
  }
 
  if (options.has_ordered_index())
   out << "#include <map>\n";
 
  if (options.has_unordered_index())
   out << "#include <unordered_map>\n";
 
  out << "\nstatic_assert(std::string_view(joedb::get_version()) == \"";
  out << joedb::get_version() << "\");\n\n";
 
  namespace_open(out, options.get_name_space());
 
  out << "\n /// @namespace " << namespace_string(options.get_name_space());
  out << R"RRR(
 ///
 /// Automatically generated by joedbc
)RRR";
 
  out << R"RRR(
 using joedb::Record_Id;
 using joedb::Table_Id;
 using joedb::Field_Id;
 
)RRR";
 
  for (const auto &[tid, tname]: tables)
   out << " class container_of_" << tname << ";\n";
 
  out << '\n';
 
  for (const auto &index: options.get_indices())
  {
   const bool custom_hash = !index.ordered && index.field_ids.size() > 1;
 
   if (custom_hash)
   {
    const int fields = int(index.field_ids.size());
 
    out << " struct hash_of_index_of_" << index.name;
    out << "\n {\n";
    out << "  size_t operator()(const ";
    write_tuple_type(out, index, false);
    out << "&key) const noexcept\n";
    out << "  {\n";
    out << "   return ";
 
    for (int i = 1; i < fields; i++)
    {
     out << "joedb::hash_combine\n";
     out << std::string(i + 2, ' ') << "(\n";
     out << std::string(i + 3, ' ');
    }
 
    for (int i = fields; --i >= 0;)
    {
     out << "std::hash<";
 
     const Type &type = options.db.get_field_type
     (
      index.table_id,
      index.field_ids[i]
     );
 
     write_type(out, type, false, false);
 
     out << ">()(std::get<" << i << ">(key))\n";
     out << std::string(i + 3, ' ' );
     if (i < fields - 1)
      out << ')';
     if (i > 0)
      out << ",\n" << std::string(i + 3, ' ');
    }
 
    out << ";\n";
 
    out << "  }\n";
    out << " };\n";
   }
 
   out << " using type_of_index_of_" << index.name << " = std::";
 
   if (!index.ordered)
    out << "unordered_";
 
   if (!index.unique)
    out << "multi";
 
   out << "map<";
 
   write_tuple_type(out, index, false);
 
   out << ", id_of_" << options.db.get_table_name(index.table_id);
 
   if (index.ordered)
    out << ", std::less<>";
   else if (custom_hash)
    out << ", hash_of_index_of_" << index.name;
 
   out << ">;\n";
  }
 
  out << "\n namespace detail\n {";
  for (const auto &[tid, tname]: tables)
  {
   out << "\n  struct data_of_" << tname;
 
   out <<"\n  {\n";
   if (db.get_freedom(tid).get_used_count() > Record_Id{0})
    out <<"   Field_Id current_field_id = Field_Id(0);\n";
 
   std::vector<std::string> fields;
 
   for (const auto &[fid, fname]: db.get_fields(tid))
   {
    fields.emplace_back("field_value_of_" + fname);
 
    const joedb::Type &type = db.get_field_type(tid, fid);
 
    out << "   std::vector<";
    write_type(out, type, false, false);
    out << "> " << fields.back() << ";\n";
   }
 
   for (const auto &index: options.get_indices())
   {
    if (index.table_id == tid)
    {
     out << "   std::vector<type_of_index_of_" << index.name;
     out << "::iterator> ";
     fields.emplace_back("iterator_over_" + index.name);
     out << fields.back() << ";\n";
    }
   }
 
  out << R"RRR(
   joedb::Freedom_Keeper freedom_keeper;
 
   size_t size() const {return freedom_keeper.size();}
 
   void resize(size_t new_size)
   {
)RRR";
 
   fields.emplace_back("freedom_keeper");
   for (const std::string &field: fields)
    out << "    " << field << ".resize(new_size);\n";
 
   out << "   }\n  };\n";
  }
  out << " }\n\n";
 
  for (const auto &index: options.get_indices())
   if (!index.unique)
    out << " class range_of_" << index.name << ";\n";
  out << '\n';
 
  out << " /// Store all the tables of the database\n";
  out << " class Database\n {\n";
  out << "  friend class Readable;\n";
 
  for (const auto &[tid, tname]: tables)
   out << "  friend class container_of_"  << tname << ";\n";
 
  for (const auto &index: options.get_indices())
   if (!index.unique)
    out << "  friend class range_of_" << index.name << ";\n";
 
  out << R"RRR(
  public:
   template<typename E = joedb::Exception>
   static void throw_exception(std::string_view message)
   {
    std::string s(")RRR" << namespace_string(options.get_name_space()) << R"RRR(: ");
    s += message;
    throw E(s);
   }
 
)RRR";
 
  //
  // Validity checks
  //
  for (const auto &[tid, tname]: tables)
  {
   out << "   bool is_valid(id_of_" << tname << " id) const {return is_valid_record_id_for_" << tname << "(id.get_record_id());}\n";
  }
 
  out << "\n  protected:\n";
 
  for (const auto &[tid, tname]: tables)
  {
   out << "   detail::data_of_" << tname << " storage_of_" << tname << ";\n";
 
   out << "   bool is_valid_record_id_for_" << tname;
   out << "(Record_Id record_id) const {return storage_of_" << tname;
   out << ".freedom_keeper.is_used(record_id);}\n";
  }
 
  //
  // Indices
  //
  if (!options.get_indices().empty())
   out << '\n';
 
  for (const auto &index: options.get_indices())
  {
   const std::string &tname = db.get_table_name(index.table_id);
 
   out << "   type_of_index_of_" << index.name;
   out << " index_of_" << index.name << ";\n";
 
   out << "   void remove_index_of_" << index.name << "(Record_Id record_id)\n";
   out << "   {\n";
   out << "    auto &iterator = storage_of_" << tname;
   out << ".iterator_over_" << index.name << "[to_underlying(record_id)];\n";
   out << "    if (iterator != index_of_" << index.name << ".end())\n";
   out << "    {\n";
   out << "     index_of_" << index.name << ".erase(iterator);\n";
   out << "     iterator = index_of_" << index.name << ".end();\n";
   out << "    }\n";
   out << "   }\n";
 
   out << "   void add_index_of_" << index.name << "(Record_Id record_id)\n";
   out << "   {\n";
   out << "    auto result = index_of_" << index.name;
   out << ".insert\n    (\n     type_of_index_of_" << index.name;
   out << "::value_type\n     (\n      ";
   write_tuple_type(out, index, true);
   out << '(';
   for (size_t i = 0; i < index.field_ids.size(); i++)
   {
    if (i > 0)
     out << ", ";
    out << "storage_of_" << tname << ".field_value_of_";
    out << db.get_field_name(index.table_id, index.field_ids[i]);
    out << "[to_underlying(record_id)]";
   }
   out << ')';
   out << ",\n      id_of_" << tname << "(record_id)\n     )\n    );\n";
   if (index.unique)
   {
    out << "    if (!result.second)\n";
    out << "    {\n";
    out << "     std::ostringstream out;\n";
    out << "     out << \"" << index.name << " unique index failure: (\";\n";
    for (size_t i = 0; i < index.field_ids.size(); i++)
    {
     if (i > 0)
      out << "     out << \", \";\n";
     const auto type = db.get_field_type(index.table_id, index.field_ids[i]);
     out << "     joedb::write_" << get_type_string(type) << "(out, ";
     out << "storage_of_" << tname << ".field_value_of_";
     out << db.get_field_name(index.table_id, index.field_ids[i]);
     out << "[to_underlying(record_id)]";
     if (type.get_type_id() == joedb::Type::Type_Id::reference)
      out << ".get_record_id()";
     out << ");\n";
    }
    out << "     out << \") at id = \" << record_id << ' ';\n";
    out << "     out << \"was already at id = \" << result.first->second.get_id();\n";
    out << "     throw_exception(out.str());\n";
    out << "    }\n";
    out << "    storage_of_" << tname << ".iterator_over_" << index.name << "[to_underlying(record_id)] = result.first;\n";
   }
   else
    out << "    storage_of_" << tname << ".iterator_over_" << index.name << "[to_underlying(record_id)] = result;\n";
   out << "   }\n";
  }
 
  //
  // Internal data-modification functions
  //
  out << '\n';
  for (const auto &[tid, tname]: tables)
  {
   out << "   void internal_delete_" << tname << "(Record_Id record_id)\n";
   out << "   {\n";
   out << "    JOEDB_RELEASE_ASSERT(is_valid_record_id_for_" << tname << "(record_id));\n";
 
   for (const auto &index: options.get_indices())
    if (index.table_id == tid)
     out << "    remove_index_of_" << index.name << "(record_id);\n";
 
   for (const auto &[fid, fname]: db.get_fields(tid))
   {
    const Type &type = db.get_field_type(tid, fid);
 
    out << "    storage_of_" << tname << ".field_value_of_";
    out << fname << "[to_underlying(record_id)]";
 
    if (type.get_type_id() == Type::Type_Id::string)
    {
     out << ".clear()";
    }
    else if (type.get_type_id() == Type::Type_Id::reference)
    {
     out << " = ";
     write_type(out, type, false, false);
     out << "(joedb::Record_Id::null)";
    }
    else if (type.get_type_id() == Type::Type_Id::blob)
    {
     out << " = joedb::Blob()";
    }
    else
    {
     out << " = 0";
    }
 
    out << ";\n";
   }
 
   out << "    storage_of_" << tname << ".freedom_keeper.free(record_id);\n";
   out << "   }\n";
  }
 
  out << '\n';
  for (const auto &[tid, tname]: tables)
  {
   out << "   void internal_insert_" << tname << "(Record_Id record_id)\n";
   out << "   {\n";
 
   for (const auto &index: options.get_indices())
    if (index.table_id == tid)
    {
     out << "    storage_of_" << tname;
     out << ".iterator_over_" << index.name << "[to_underlying(record_id)] = ";
     out << "index_of_" << index.name << ".end();\n";
    }
 
   out << "    storage_of_" << tname << ".freedom_keeper.use(record_id);\n";
 
   out << "   }\n\n";
 
   out << "   void internal_vector_insert_" << tname << "(Record_Id record_id, size_t size)\n";
   out << "   {\n";
   out << "    JOEDB_RELEASE_ASSERT(storage_of_" << tname << ".freedom_keeper.is_free_vector(record_id, size));\n";
   out << "    storage_of_" << tname << ".freedom_keeper.use_vector(record_id, size);\n";
 
   for (const auto &index: options.get_indices())
    if (index.table_id == tid)
    {
     out << "    std::fill_n\n";
     out << "    (\n";
     out << "     &storage_of_" << tname << ".iterator_over_" << index.name << "[to_underlying(record_id)],\n";
     out << "     size,\n";
     out << "     index_of_" << index.name << ".end()\n";
     out << "    );\n";
    }
 
   out << "   }\n";
  }
 
  out << '\n';
  for (const auto &[tid, tname]: tables)
  {
   for (const auto &[fid, fname]: db.get_fields(tid))
   {
    const Type &type = db.get_field_type(tid, fid);
 
    out << "   void internal_update_" << tname << "__" << fname;
    out << "\n   (\n    Record_Id record_id,\n    ";
    write_type(out, type, false, true);
    out << " field_value_of_" << fname << "\n   )\n";
    out << "   {\n";
    out << "    JOEDB_RELEASE_ASSERT(is_valid_record_id_for_" << tname << "(record_id));\n";
    out << "    storage_of_" << tname << ".field_value_of_" << fname;
    out << "[to_underlying(record_id)] = field_value_of_" << fname;
    out << ";\n";
 
    for (const auto &index: options.get_indices())
    {
     if (index.is_trigger(tid, fid))
     {
      out << "    remove_index_of_" << index.name << "(record_id);\n";
      out << "    add_index_of_" << index.name << "(record_id);\n";
     }
    }
 
    out << "   }\n\n";
 
    out << "   void internal_update_vector_" << tname << "__" << fname << '\n';
    out << "   (\n";
    out << "    Record_Id record_id,\n";
    out << "    size_t size,\n";
    out << "    const ";
    write_type(out, type, false, false);
    out << " *value\n";
    out << "   )\n";
    out << "   {\n";
    out << "    JOEDB_RELEASE_ASSERT(storage_of_" << tname << ".freedom_keeper.is_used_vector(record_id, size));\n";
    out << "    ";
    write_type(out, type, false, false);
    out << " *target = &storage_of_" << tname;
    out << ".field_value_of_" << fname << ".data()[to_underlying(record_id)];\n";
    out << "    if (target != value)\n";
    out << "     std::copy_n(value, size, target);\n";
 
    for (const auto &index: options.get_indices())
    {
     if (index.is_trigger(tid, fid))
     {
      out << "    for (size_t i = 0; i < size; i++)\n";
      out << "     remove_index_of_" << index.name << "(record_id + i);\n";
      out << "    for (size_t i = 0; i < size; i++)\n";
      out << "     add_index_of_" << index.name << "(record_id + i);\n";
     }
    }
 
    out << "   }\n\n";
   }
  }
 
  //
  // Public stuff
  //
  out << "  public:";
 
  for (const auto &[tid, tname]: tables)
  {
   const bool single_row = options.get_table_options(tid).single_row;
 
   out << '\n';
 
   //
   // Declaration of container access
   //
   out << "   container_of_" << tname << " get_" << tname << "_table() const;\n\n";
 
   out << "   id_of_" << tname << " next(id_of_" << tname << " id) const\n";
   out << "   {\n";
   out << "    return id_of_" << tname << "\n    (\n     Record_Id(storage_of_" << tname << ".freedom_keeper.get_next(id.get_record_id()))\n    );\n";
   out << "   }\n\n";
 
   out << "   id_of_" << tname << " previous(id_of_" << tname << " id) const\n";
   out << "   {\n";
   out << "    return id_of_" << tname << "\n    (\n     Record_Id(storage_of_" << tname << ".freedom_keeper.get_previous(id.get_record_id()))\n    );\n";
   out << "   }\n\n";
 
   if (!single_row)
   {
    out << "   template<class Comparator>\n";
    out << "   std::vector<id_of_" << tname << "> sorted_" << tname;
    out << "(Comparator comparator) const;\n\n";
   }
 
   //
   // Easy access to null
   //
   out << "   static id_of_" << tname << " null_" << tname << "()\n";
   out << "   {\n";
   out << "    return id_of_" << tname << "();\n";
   out << "   }\n";
 
   //
   // the_<table>
   //
   if (single_row)
   {
    out << "   static constexpr id_of_" << tname << " the_" << tname << "()\n";
    out << "   {\n";
    out << "    return id_of_" << tname << "{0};\n";
    out << "   }\n";
   }
 
   //
   // Loop over fields
   //
   for (const auto &[fid, fname]: db.get_fields(tid))
   {
    const Type &type = db.get_field_type(tid, fid);
 
    out << '\n';
 
    //
    // Getter
    //
    out << "   ";
    write_type(out, type, true, false);
    out << " get_" << fname << "(id_of_" << tname << " record";
    if (single_row)
     out << " = id_of_" << tname << "{0}";
    out << ") const\n";
    out << "   {\n";
    out << "    JOEDB_RELEASE_ASSERT(is_valid_record_id_for_" << tname << "(record.get_record_id()));\n";
    out << "    return (";
    write_type(out, type, true, false);
    out << ")(storage_of_" << tname;
    out << ".field_value_of_" << fname << "[record.get_id()]);\n";
    out << "   }\n";
   }
  }
 
  //
  // get_index_of_X
  //
  for (const auto &index: options.get_indices())
  {
   out << '\n';
   out << "   const type_of_index_of_" << index.name;
   out << " &get_index_of_" << index.name << "()\n";
   out << "   {\n";
   out << "    return index_of_" << index.name << ";\n";
   out << "   }\n";
  }
 
  //
  // find_index
  //
  for (const auto &index: options.get_indices())
  {
   if (index.unique)
   {
    const std::string &tname = db.get_table_name(index.table_id);
    out << '\n';
 
    out << "   id_of_" << tname << " next_" << index.name << '(';
    out << "id_of_" << tname << " id) const\n";
    out << "   {\n";
    out << "    JOEDB_RELEASE_ASSERT(is_valid_record_id_for_" << tname << "(id.get_record_id()));\n";
    out << "    auto iterator = storage_of_" << tname << ".iterator_over_" << index.name << "[id.get_id()];\n";
    out << "    ++iterator;\n";
    out << "    if (iterator != index_of_" << index.name << ".end())\n";
    out << "     return iterator->second;\n";
    out << "    else\n";
    out << "     return id_of_" << tname << "();\n";
    out << "   }\n";
 
    if (index.ordered)
    {
     out << "   id_of_" << tname << " previous_" << index.name << '(';
     out << "id_of_" << tname << " id) const\n";
     out << "   {\n";
     out << "    JOEDB_RELEASE_ASSERT(is_valid_record_id_for_" << tname << "(id.get_record_id()));\n";
     out << "    auto iterator = storage_of_" << tname << ".iterator_over_" << index.name << "[id.get_id()];\n";
     out << "    if (iterator != index_of_" << index.name << ".begin())\n";
     out << "     return (--iterator)->second;\n";
     out << "    else\n";
     out << "     return id_of_" << tname << "();\n";
     out << "   }\n";
    }
 
    out << "   id_of_" << tname << " find_" << index.name << '(';
    write_index_parameters(out, index);
    out << ") const\n";
    out << "   {\n";
    out << "    const auto i = index_of_" << index.name << ".find(";
    write_tuple_type(out, index, true);
    out << '(';
    for (size_t i = 0; i < index.field_ids.size(); i++)
    {
     if (i > 0)
      out << ", ";
     out << "field_value_of_";
     out << db.get_field_name(index.table_id, index.field_ids[i]);
    }
    out << "));\n";
    out << "    if (i == index_of_" << index.name << ".end())\n";
    out << "     return id_of_" << tname << "();\n";
    out << "    else\n";
    out << "     return i->second;\n";
    out << "   }\n";
   }
   else
   {
    out << "   range_of_" << index.name << " find_" << index.name << '(';
    write_index_parameters(out, index);
    out << ") const;\n";
   }
  }
 
  out << " };\n";
 
  //
  // Plain iteration over tables
  //
  for (const auto &[tid, tname]: tables)
  {
   const bool single_row = options.get_table_options(tid).single_row;
 
   out << " /// returned by @ref Database::get_" << tname << "_table\n";
   out << " class container_of_" << tname << "\n";
   out << " {\n";
   out << "  friend class Database;\n";
   out << '\n';
   out << "  private:\n";
   out << "   const Database &db;\n";
   out << "   container_of_" << tname << "(const Database &db): db(db) {}\n";
   out << '\n';
   out << "  public:\n";
   out << "   class iterator\n";
   out << "   {\n";
   out << "    friend class container_of_" << tname << ";\n";
   out << "    private:\n";
 
 
   out << "     const joedb::Freedom_Keeper *fk;\n"; // must use pointer for copy constructor
   out << "     Record_Id index;\n";
   out << "     iterator(const detail::data_of_" << tname << " &data): fk(&data.freedom_keeper), index(joedb::Freedom_Keeper_Constants::used_list) {}\n";
   out << "    public:\n";
   out << "     using iterator_category = std::forward_iterator_tag;\n";
   out << "     using value_type = id_of_" << tname << ";\n";
   out << "     using difference_type = std::ptrdiff_t;\n";
   out << "     using pointer = value_type*;\n";
   out << "     using reference = value_type&;\n";
   out << '\n';
   out << "     bool operator==(const iterator &i) const {return index == i.index;}\n";
   out << "     bool operator!=(const iterator &i) const {return index != i.index;}\n";
   out << "     iterator &operator++() {index = fk->get_next(index); return *this;}\n";
   out << "     iterator operator++(int) {auto copy = *this; index = fk->get_next(index); return copy;}\n";
   out << "     iterator &operator--() {index = fk->get_previous(index); return *this;}\n";
   out << "     iterator operator--(int) {auto copy = *this; index = fk->get_previous(index); return copy;}\n";
   out << "     id_of_" << tname << " operator*() const {return id_of_";
   out << tname << "(Record_Id(index));}\n";
   out << "   };\n";
   out << '\n';
   out << "   iterator begin() const {return ++iterator(db.storage_of_" << tname << ");}\n";
   out << "   iterator end() const {return iterator(db.storage_of_" << tname << ");}\n";
   out << "   bool is_empty() const {return db.storage_of_" << tname
       << ".freedom_keeper.get_used_count() == Record_Id{0};}\n";
   out << "   joedb::index_t get_size() const {return to_underlying(db.storage_of_" << tname << ".freedom_keeper.get_used_count());}\n";
   out << "   static id_of_" << tname << " get_at(size_t i) {return id_of_"
       << tname << "(Record_Id(i));}\n";
   out << "   bool is_valid_at(size_t i) {return db.storage_of_" << tname << ".freedom_keeper.is_used(Record_Id(i));}\n";
 
   out << "   id_of_" << tname << " first() const {return *begin();}\n";
   out << "   id_of_" << tname << " last() const {return *--end();}\n";
   out << "   id_of_" << tname << " get_end() const {return *end();}\n";
 
   out << " };\n";
   out << '\n';
 
   out << " inline container_of_" << tname << " Database::get_" << tname << "_table() const\n";
   out << " {\n";
   out << "  return container_of_" << tname << "(*this);\n";
   out << " }\n";
   out << '\n';
 
   if (!single_row)
   {
    out << " template<class Comparator>\n";
    out << " std::vector<id_of_" << tname << "> Database::sorted_" << tname;
    out << "(Comparator comparator) const\n";
    out << " {\n";
    out << "  std::vector<id_of_" << tname << "> result;\n";
    out << "  for (auto x: get_" << tname << "_table())\n";
    out << "   result.emplace_back(x);\n";
    out << "  std::sort(result.begin(), result.end(), comparator);\n";
    out << "  return result;\n";
    out << " }\n";
   }
  }
 
  //
  // Index ranges for indexes that are not unique
  //
  for (const auto &index: options.get_indices())
  {
   if (!index.unique)
   {
    out << " /// returned by @ref Database::find_" << index.name << '\n';
    out << " class range_of_" << index.name << "\n";
    out << " {\n";
    out << "  friend class Database;\n";
    out << "  private:\n";
    out << "   std::pair<type_of_index_of_" << index.name;
    out << "::const_iterator, type_of_index_of_" << index.name;
    out << "::const_iterator> range;\n";
    out << "   range_of_" << index.name << "(const Database &db";
    for (size_t i = 0; i < index.field_ids.size(); i++)
    {
     out << ", ";
     const Type &type = db.get_field_type(index.table_id, index.field_ids[i]);
     write_type(out, type, !index.ordered, true);
     out << ' ' << db.get_field_name(index.table_id, index.field_ids[i]);
    }
    out << ")\n";
    out << "   {\n";
    out << "    range = db.index_of_" << index.name << ".equal_range(";
    write_tuple_type(out, index, true);
    out << '(';
    for (size_t i = 0; i < index.field_ids.size(); i++)
    {
     if (i > 0)
      out << ", ";
     out << db.get_field_name(index.table_id, index.field_ids[i]);
    }
    out << "));\n";
    out << "   }\n";
    out << "  public:\n";
    out << "   class iterator\n";
    out << "   {\n";
    out << "    friend class range_of_" << index.name << ";\n";
    out << "    private:\n";
    out << "     type_of_index_of_" << index.name;
    out << "::const_iterator map_iterator;\n";
    out << "     iterator(type_of_index_of_" << index.name;
    out << "::const_iterator map_iterator): map_iterator(map_iterator) {}\n"
        << "    public:\n"
        << "     bool operator !=(const iterator &i) const\n"
        << "     {\n"
        << "      return map_iterator != i.map_iterator;\n"
        << "     }\n"
        << "     iterator &operator++() {map_iterator++; return *this;}\n"
        << "     id_of_" << db.get_table_name(index.table_id)
        << " operator*() const {return map_iterator->second;}\n"
        << "   };\n"
        << "   iterator begin() const {return range.first;}\n"
        << "   iterator end() const {return range.second;}\n"
        << "   bool empty() const {return range.first == range.second;}\n"
        << "   size_t size() const {return size_t(std::distance(range.first, range.second));}\n"
        << " };\n\n";
 
    out << " inline range_of_" << index.name << " Database::find_" << index.name << '(';
    write_index_parameters(out, index);
    out << ") const\n";
    out << " {\n";
    out << "  return range_of_" << index.name << "(*this";
    for (size_t i = 0; i < index.field_ids.size(); i++)
    {
     out << ", ";
     out << "field_value_of_";
     out << db.get_field_name(index.table_id, index.field_ids[i]);
    }
    out << ");\n";
    out << " }\n";
   }
  }
 
  namespace_close(out, options.get_name_space());
  namespace_include_guard_close(out);
 }
}