ClickHouse/dbms/Dictionaries/FlatDictionary.cpp
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

736 lines
26 KiB
C++

#include "FlatDictionary.h"
#include <IO/WriteHelpers.h>
#include "DictionaryBlockInputStream.h"
#include "DictionaryFactory.h"
namespace DB
{
namespace ErrorCodes
{
extern const int TYPE_MISMATCH;
extern const int ARGUMENT_OUT_OF_BOUND;
extern const int BAD_ARGUMENTS;
extern const int DICTIONARY_IS_EMPTY;
extern const int UNSUPPORTED_METHOD;
}
static const auto initial_array_size = 1024;
static const auto max_array_size = 500000;
FlatDictionary::FlatDictionary(
const std::string & database_,
const std::string & name_,
const DictionaryStructure & dict_struct_,
DictionarySourcePtr source_ptr_,
const DictionaryLifetime dict_lifetime_,
bool require_nonempty_,
BlockPtr saved_block_)
: database(database_)
, name(name_)
, full_name{database_.empty() ? name_ : (database_ + "." + name_)}
, dict_struct(dict_struct_)
, source_ptr{std::move(source_ptr_)}
, dict_lifetime(dict_lifetime_)
, require_nonempty(require_nonempty_)
, loaded_ids(initial_array_size, false)
, saved_block{std::move(saved_block_)}
{
createAttributes();
loadData();
calculateBytesAllocated();
}
void FlatDictionary::toParent(const PaddedPODArray<Key> & ids, PaddedPODArray<Key> & out) const
{
const auto null_value = std::get<UInt64>(hierarchical_attribute->null_values);
getItemsImpl<UInt64, UInt64>(
*hierarchical_attribute,
ids,
[&](const size_t row, const UInt64 value) { out[row] = value; },
[&](const size_t) { return null_value; });
}
/// Allow to use single value in same way as array.
static inline FlatDictionary::Key getAt(const PaddedPODArray<FlatDictionary::Key> & arr, const size_t idx)
{
return arr[idx];
}
static inline FlatDictionary::Key getAt(const FlatDictionary::Key & value, const size_t)
{
return value;
}
template <typename ChildType, typename AncestorType>
void FlatDictionary::isInImpl(const ChildType & child_ids, const AncestorType & ancestor_ids, PaddedPODArray<UInt8> & out) const
{
const auto null_value = std::get<UInt64>(hierarchical_attribute->null_values);
const auto & attr = std::get<ContainerType<Key>>(hierarchical_attribute->arrays);
const auto rows = out.size();
size_t loaded_size = attr.size();
for (const auto row : ext::range(0, rows))
{
auto id = getAt(child_ids, row);
const auto ancestor_id = getAt(ancestor_ids, row);
while (id < loaded_size && id != null_value && id != ancestor_id)
id = attr[id];
out[row] = id != null_value && id == ancestor_id;
}
query_count.fetch_add(rows, std::memory_order_relaxed);
}
void FlatDictionary::isInVectorVector(
const PaddedPODArray<Key> & child_ids, const PaddedPODArray<Key> & ancestor_ids, PaddedPODArray<UInt8> & out) const
{
isInImpl(child_ids, ancestor_ids, out);
}
void FlatDictionary::isInVectorConstant(const PaddedPODArray<Key> & child_ids, const Key ancestor_id, PaddedPODArray<UInt8> & out) const
{
isInImpl(child_ids, ancestor_id, out);
}
void FlatDictionary::isInConstantVector(const Key child_id, const PaddedPODArray<Key> & ancestor_ids, PaddedPODArray<UInt8> & out) const
{
isInImpl(child_id, ancestor_ids, out);
}
#define DECLARE(TYPE) \
void FlatDictionary::get##TYPE(const std::string & attribute_name, const PaddedPODArray<Key> & ids, ResultArrayType<TYPE> & out) const \
{ \
const auto & attribute = getAttribute(attribute_name); \
checkAttributeType(full_name, attribute_name, attribute.type, AttributeUnderlyingType::ut##TYPE); \
\
const auto null_value = std::get<TYPE>(attribute.null_values); \
\
getItemsImpl<TYPE, TYPE>( \
attribute, ids, [&](const size_t row, const auto value) { out[row] = value; }, [&](const size_t) { return null_value; }); \
}
DECLARE(UInt8)
DECLARE(UInt16)
DECLARE(UInt32)
DECLARE(UInt64)
DECLARE(UInt128)
DECLARE(Int8)
DECLARE(Int16)
DECLARE(Int32)
DECLARE(Int64)
DECLARE(Float32)
DECLARE(Float64)
DECLARE(Decimal32)
DECLARE(Decimal64)
DECLARE(Decimal128)
#undef DECLARE
void FlatDictionary::getString(const std::string & attribute_name, const PaddedPODArray<Key> & ids, ColumnString * out) const
{
const auto & attribute = getAttribute(attribute_name);
checkAttributeType(full_name, attribute_name, attribute.type, AttributeUnderlyingType::utString);
const auto & null_value = std::get<StringRef>(attribute.null_values);
getItemsImpl<StringRef, StringRef>(
attribute,
ids,
[&](const size_t, const StringRef value) { out->insertData(value.data, value.size); },
[&](const size_t) { return null_value; });
}
#define DECLARE(TYPE) \
void FlatDictionary::get##TYPE( \
const std::string & attribute_name, \
const PaddedPODArray<Key> & ids, \
const PaddedPODArray<TYPE> & def, \
ResultArrayType<TYPE> & out) const \
{ \
const auto & attribute = getAttribute(attribute_name); \
checkAttributeType(full_name, attribute_name, attribute.type, AttributeUnderlyingType::ut##TYPE); \
\
getItemsImpl<TYPE, TYPE>( \
attribute, ids, [&](const size_t row, const auto value) { out[row] = value; }, [&](const size_t row) { return def[row]; }); \
}
DECLARE(UInt8)
DECLARE(UInt16)
DECLARE(UInt32)
DECLARE(UInt64)
DECLARE(UInt128)
DECLARE(Int8)
DECLARE(Int16)
DECLARE(Int32)
DECLARE(Int64)
DECLARE(Float32)
DECLARE(Float64)
DECLARE(Decimal32)
DECLARE(Decimal64)
DECLARE(Decimal128)
#undef DECLARE
void FlatDictionary::getString(
const std::string & attribute_name, const PaddedPODArray<Key> & ids, const ColumnString * const def, ColumnString * const out) const
{
const auto & attribute = getAttribute(attribute_name);
checkAttributeType(full_name, attribute_name, attribute.type, AttributeUnderlyingType::utString);
getItemsImpl<StringRef, StringRef>(
attribute,
ids,
[&](const size_t, const StringRef value) { out->insertData(value.data, value.size); },
[&](const size_t row) { return def->getDataAt(row); });
}
#define DECLARE(TYPE) \
void FlatDictionary::get##TYPE( \
const std::string & attribute_name, const PaddedPODArray<Key> & ids, const TYPE def, ResultArrayType<TYPE> & out) const \
{ \
const auto & attribute = getAttribute(attribute_name); \
checkAttributeType(full_name, attribute_name, attribute.type, AttributeUnderlyingType::ut##TYPE); \
\
getItemsImpl<TYPE, TYPE>( \
attribute, ids, [&](const size_t row, const auto value) { out[row] = value; }, [&](const size_t) { return def; }); \
}
DECLARE(UInt8)
DECLARE(UInt16)
DECLARE(UInt32)
DECLARE(UInt64)
DECLARE(UInt128)
DECLARE(Int8)
DECLARE(Int16)
DECLARE(Int32)
DECLARE(Int64)
DECLARE(Float32)
DECLARE(Float64)
DECLARE(Decimal32)
DECLARE(Decimal64)
DECLARE(Decimal128)
#undef DECLARE
void FlatDictionary::getString(
const std::string & attribute_name, const PaddedPODArray<Key> & ids, const String & def, ColumnString * const out) const
{
const auto & attribute = getAttribute(attribute_name);
checkAttributeType(full_name, attribute_name, attribute.type, AttributeUnderlyingType::utString);
FlatDictionary::getItemsImpl<StringRef, StringRef>(
attribute,
ids,
[&](const size_t, const StringRef value) { out->insertData(value.data, value.size); },
[&](const size_t) { return StringRef{def}; });
}
void FlatDictionary::has(const PaddedPODArray<Key> & ids, PaddedPODArray<UInt8> & out) const
{
const auto & attribute = attributes.front();
switch (attribute.type)
{
case AttributeUnderlyingType::utUInt8:
has<UInt8>(attribute, ids, out);
break;
case AttributeUnderlyingType::utUInt16:
has<UInt16>(attribute, ids, out);
break;
case AttributeUnderlyingType::utUInt32:
has<UInt32>(attribute, ids, out);
break;
case AttributeUnderlyingType::utUInt64:
has<UInt64>(attribute, ids, out);
break;
case AttributeUnderlyingType::utUInt128:
has<UInt128>(attribute, ids, out);
break;
case AttributeUnderlyingType::utInt8:
has<Int8>(attribute, ids, out);
break;
case AttributeUnderlyingType::utInt16:
has<Int16>(attribute, ids, out);
break;
case AttributeUnderlyingType::utInt32:
has<Int32>(attribute, ids, out);
break;
case AttributeUnderlyingType::utInt64:
has<Int64>(attribute, ids, out);
break;
case AttributeUnderlyingType::utFloat32:
has<Float32>(attribute, ids, out);
break;
case AttributeUnderlyingType::utFloat64:
has<Float64>(attribute, ids, out);
break;
case AttributeUnderlyingType::utString:
has<String>(attribute, ids, out);
break;
case AttributeUnderlyingType::utDecimal32:
has<Decimal32>(attribute, ids, out);
break;
case AttributeUnderlyingType::utDecimal64:
has<Decimal64>(attribute, ids, out);
break;
case AttributeUnderlyingType::utDecimal128:
has<Decimal128>(attribute, ids, out);
break;
}
}
void FlatDictionary::createAttributes()
{
const auto size = dict_struct.attributes.size();
attributes.reserve(size);
for (const auto & attribute : dict_struct.attributes)
{
attribute_index_by_name.emplace(attribute.name, attributes.size());
attributes.push_back(createAttributeWithType(attribute.underlying_type, attribute.null_value));
if (attribute.hierarchical)
{
hierarchical_attribute = &attributes.back();
if (hierarchical_attribute->type != AttributeUnderlyingType::utUInt64)
throw Exception{full_name + ": hierarchical attribute must be UInt64.", ErrorCodes::TYPE_MISMATCH};
}
}
}
void FlatDictionary::blockToAttributes(const Block & block)
{
const IColumn & id_column = *block.safeGetByPosition(0).column;
element_count += id_column.size();
for (const size_t attribute_idx : ext::range(0, attributes.size()))
{
const IColumn & attribute_column = *block.safeGetByPosition(attribute_idx + 1).column;
Attribute & attribute = attributes[attribute_idx];
for (const auto row_idx : ext::range(0, id_column.size()))
setAttributeValue(attribute, id_column[row_idx].get<UInt64>(), attribute_column[row_idx]);
}
}
void FlatDictionary::updateData()
{
if (!saved_block || saved_block->rows() == 0)
{
auto stream = source_ptr->loadUpdatedAll();
stream->readPrefix();
while (const auto block = stream->read())
{
/// We are using this to keep saved data if input stream consists of multiple blocks
if (!saved_block)
saved_block = std::make_shared<DB::Block>(block.cloneEmpty());
for (const auto attribute_idx : ext::range(0, attributes.size() + 1))
{
const IColumn & update_column = *block.getByPosition(attribute_idx).column.get();
MutableColumnPtr saved_column = saved_block->getByPosition(attribute_idx).column->assumeMutable();
saved_column->insertRangeFrom(update_column, 0, update_column.size());
}
}
stream->readSuffix();
}
else
{
auto stream = source_ptr->loadUpdatedAll();
stream->readPrefix();
while (Block block = stream->read())
{
const auto & saved_id_column = *saved_block->safeGetByPosition(0).column;
const auto & update_id_column = *block.safeGetByPosition(0).column;
std::unordered_map<Key, std::vector<size_t>> update_ids;
for (size_t row = 0; row < update_id_column.size(); ++row)
{
const auto id = update_id_column.get64(row);
update_ids[id].push_back(row);
}
const size_t saved_rows = saved_id_column.size();
IColumn::Filter filter(saved_rows);
std::unordered_map<Key, std::vector<size_t>>::iterator it;
for (size_t row = 0; row < saved_id_column.size(); ++row)
{
auto id = saved_id_column.get64(row);
it = update_ids.find(id);
if (it != update_ids.end())
filter[row] = 0;
else
filter[row] = 1;
}
auto block_columns = block.mutateColumns();
for (const auto attribute_idx : ext::range(0, attributes.size() + 1))
{
auto & column = saved_block->safeGetByPosition(attribute_idx).column;
const auto & filtered_column = column->filter(filter, -1);
block_columns[attribute_idx]->insertRangeFrom(*filtered_column.get(), 0, filtered_column->size());
}
saved_block->setColumns(std::move(block_columns));
}
stream->readSuffix();
}
if (saved_block)
blockToAttributes(*saved_block.get());
}
void FlatDictionary::loadData()
{
if (!source_ptr->hasUpdateField())
{
auto stream = source_ptr->loadAll();
stream->readPrefix();
while (const auto block = stream->read())
blockToAttributes(block);
stream->readSuffix();
}
else
updateData();
if (require_nonempty && 0 == element_count)
throw Exception{full_name + ": dictionary source is empty and 'require_nonempty' property is set.", ErrorCodes::DICTIONARY_IS_EMPTY};
}
template <typename T>
void FlatDictionary::addAttributeSize(const Attribute & attribute)
{
const auto & array_ref = std::get<ContainerType<T>>(attribute.arrays);
bytes_allocated += sizeof(PaddedPODArray<T>) + array_ref.allocated_bytes();
bucket_count = array_ref.capacity();
}
void FlatDictionary::calculateBytesAllocated()
{
bytes_allocated += attributes.size() * sizeof(attributes.front());
for (const auto & attribute : attributes)
{
switch (attribute.type)
{
case AttributeUnderlyingType::utUInt8:
addAttributeSize<UInt8>(attribute);
break;
case AttributeUnderlyingType::utUInt16:
addAttributeSize<UInt16>(attribute);
break;
case AttributeUnderlyingType::utUInt32:
addAttributeSize<UInt32>(attribute);
break;
case AttributeUnderlyingType::utUInt64:
addAttributeSize<UInt64>(attribute);
break;
case AttributeUnderlyingType::utUInt128:
addAttributeSize<UInt128>(attribute);
break;
case AttributeUnderlyingType::utInt8:
addAttributeSize<Int8>(attribute);
break;
case AttributeUnderlyingType::utInt16:
addAttributeSize<Int16>(attribute);
break;
case AttributeUnderlyingType::utInt32:
addAttributeSize<Int32>(attribute);
break;
case AttributeUnderlyingType::utInt64:
addAttributeSize<Int64>(attribute);
break;
case AttributeUnderlyingType::utFloat32:
addAttributeSize<Float32>(attribute);
break;
case AttributeUnderlyingType::utFloat64:
addAttributeSize<Float64>(attribute);
break;
case AttributeUnderlyingType::utDecimal32:
addAttributeSize<Decimal32>(attribute);
break;
case AttributeUnderlyingType::utDecimal64:
addAttributeSize<Decimal64>(attribute);
break;
case AttributeUnderlyingType::utDecimal128:
addAttributeSize<Decimal128>(attribute);
break;
case AttributeUnderlyingType::utString:
{
addAttributeSize<StringRef>(attribute);
bytes_allocated += sizeof(Arena) + attribute.string_arena->size();
break;
}
}
}
}
template <typename T>
void FlatDictionary::createAttributeImpl(Attribute & attribute, const Field & null_value)
{
attribute.null_values = T(null_value.get<NearestFieldType<T>>());
const auto & null_value_ref = std::get<T>(attribute.null_values);
attribute.arrays.emplace<ContainerType<T>>(initial_array_size, null_value_ref);
}
template <>
void FlatDictionary::createAttributeImpl<String>(Attribute & attribute, const Field & null_value)
{
attribute.string_arena = std::make_unique<Arena>();
const String & string = null_value.get<String>();
const char * string_in_arena = attribute.string_arena->insert(string.data(), string.size());
attribute.null_values.emplace<StringRef>(string_in_arena, string.size());
attribute.arrays.emplace<ContainerType<StringRef>>(initial_array_size, StringRef(string_in_arena, string.size()));
}
FlatDictionary::Attribute FlatDictionary::createAttributeWithType(const AttributeUnderlyingType type, const Field & null_value)
{
Attribute attr{type, {}, {}, {}};
switch (type)
{
case AttributeUnderlyingType::utUInt8:
createAttributeImpl<UInt8>(attr, null_value);
break;
case AttributeUnderlyingType::utUInt16:
createAttributeImpl<UInt16>(attr, null_value);
break;
case AttributeUnderlyingType::utUInt32:
createAttributeImpl<UInt32>(attr, null_value);
break;
case AttributeUnderlyingType::utUInt64:
createAttributeImpl<UInt64>(attr, null_value);
break;
case AttributeUnderlyingType::utUInt128:
createAttributeImpl<UInt128>(attr, null_value);
break;
case AttributeUnderlyingType::utInt8:
createAttributeImpl<Int8>(attr, null_value);
break;
case AttributeUnderlyingType::utInt16:
createAttributeImpl<Int16>(attr, null_value);
break;
case AttributeUnderlyingType::utInt32:
createAttributeImpl<Int32>(attr, null_value);
break;
case AttributeUnderlyingType::utInt64:
createAttributeImpl<Int64>(attr, null_value);
break;
case AttributeUnderlyingType::utFloat32:
createAttributeImpl<Float32>(attr, null_value);
break;
case AttributeUnderlyingType::utFloat64:
createAttributeImpl<Float64>(attr, null_value);
break;
case AttributeUnderlyingType::utString:
createAttributeImpl<String>(attr, null_value);
break;
case AttributeUnderlyingType::utDecimal32:
createAttributeImpl<Decimal32>(attr, null_value);
break;
case AttributeUnderlyingType::utDecimal64:
createAttributeImpl<Decimal64>(attr, null_value);
break;
case AttributeUnderlyingType::utDecimal128:
createAttributeImpl<Decimal128>(attr, null_value);
break;
}
return attr;
}
template <typename AttributeType, typename OutputType, typename ValueSetter, typename DefaultGetter>
void FlatDictionary::getItemsImpl(
const Attribute & attribute, const PaddedPODArray<Key> & ids, ValueSetter && set_value, DefaultGetter && get_default) const
{
const auto & attr = std::get<ContainerType<AttributeType>>(attribute.arrays);
const auto rows = ext::size(ids);
for (const auto row : ext::range(0, rows))
{
const auto id = ids[row];
set_value(row, id < ext::size(attr) && loaded_ids[id] ? static_cast<OutputType>(attr[id]) : get_default(row));
}
query_count.fetch_add(rows, std::memory_order_relaxed);
}
template <typename T>
void FlatDictionary::resize(Attribute & attribute, const Key id)
{
if (id >= max_array_size)
throw Exception{full_name + ": identifier should be less than " + toString(max_array_size), ErrorCodes::ARGUMENT_OUT_OF_BOUND};
auto & array = std::get<ContainerType<T>>(attribute.arrays);
if (id >= array.size())
{
const size_t elements_count = id + 1; //id=0 -> elements_count=1
loaded_ids.resize(elements_count, false);
array.resize_fill(elements_count, std::get<T>(attribute.null_values));
}
}
template <typename T>
void FlatDictionary::setAttributeValueImpl(Attribute & attribute, const Key id, const T & value)
{
resize<T>(attribute, id);
auto & array = std::get<ContainerType<T>>(attribute.arrays);
array[id] = value;
loaded_ids[id] = true;
}
template <>
void FlatDictionary::setAttributeValueImpl<String>(Attribute & attribute, const Key id, const String & value)
{
resize<StringRef>(attribute, id);
const auto string_in_arena = attribute.string_arena->insert(value.data(), value.size());
auto & array = std::get<ContainerType<StringRef>>(attribute.arrays);
array[id] = StringRef{string_in_arena, value.size()};
loaded_ids[id] = true;
}
void FlatDictionary::setAttributeValue(Attribute & attribute, const Key id, const Field & value)
{
switch (attribute.type)
{
case AttributeUnderlyingType::utUInt8:
setAttributeValueImpl<UInt8>(attribute, id, value.get<UInt64>());
break;
case AttributeUnderlyingType::utUInt16:
setAttributeValueImpl<UInt16>(attribute, id, value.get<UInt64>());
break;
case AttributeUnderlyingType::utUInt32:
setAttributeValueImpl<UInt32>(attribute, id, value.get<UInt64>());
break;
case AttributeUnderlyingType::utUInt64:
setAttributeValueImpl<UInt64>(attribute, id, value.get<UInt64>());
break;
case AttributeUnderlyingType::utUInt128:
setAttributeValueImpl<UInt128>(attribute, id, value.get<UInt128>());
break;
case AttributeUnderlyingType::utInt8:
setAttributeValueImpl<Int8>(attribute, id, value.get<Int64>());
break;
case AttributeUnderlyingType::utInt16:
setAttributeValueImpl<Int16>(attribute, id, value.get<Int64>());
break;
case AttributeUnderlyingType::utInt32:
setAttributeValueImpl<Int32>(attribute, id, value.get<Int64>());
break;
case AttributeUnderlyingType::utInt64:
setAttributeValueImpl<Int64>(attribute, id, value.get<Int64>());
break;
case AttributeUnderlyingType::utFloat32:
setAttributeValueImpl<Float32>(attribute, id, value.get<Float64>());
break;
case AttributeUnderlyingType::utFloat64:
setAttributeValueImpl<Float64>(attribute, id, value.get<Float64>());
break;
case AttributeUnderlyingType::utString:
setAttributeValueImpl<String>(attribute, id, value.get<String>());
break;
case AttributeUnderlyingType::utDecimal32:
setAttributeValueImpl<Decimal32>(attribute, id, value.get<Decimal32>());
break;
case AttributeUnderlyingType::utDecimal64:
setAttributeValueImpl<Decimal64>(attribute, id, value.get<Decimal64>());
break;
case AttributeUnderlyingType::utDecimal128:
setAttributeValueImpl<Decimal128>(attribute, id, value.get<Decimal128>());
break;
}
}
const FlatDictionary::Attribute & FlatDictionary::getAttribute(const std::string & attribute_name) const
{
const auto it = attribute_index_by_name.find(attribute_name);
if (it == std::end(attribute_index_by_name))
throw Exception{full_name + ": no such attribute '" + attribute_name + "'", ErrorCodes::BAD_ARGUMENTS};
return attributes[it->second];
}
template <typename T>
void FlatDictionary::has(const Attribute &, const PaddedPODArray<Key> & ids, PaddedPODArray<UInt8> & out) const
{
const auto ids_count = ext::size(ids);
for (const auto i : ext::range(0, ids_count))
{
const auto id = ids[i];
out[i] = id < loaded_ids.size() && loaded_ids[id];
}
query_count.fetch_add(ids_count, std::memory_order_relaxed);
}
PaddedPODArray<FlatDictionary::Key> FlatDictionary::getIds() const
{
const auto ids_count = ext::size(loaded_ids);
PaddedPODArray<Key> ids;
for (auto idx : ext::range(0, ids_count))
if (loaded_ids[idx])
ids.push_back(idx);
return ids;
}
BlockInputStreamPtr FlatDictionary::getBlockInputStream(const Names & column_names, size_t max_block_size) const
{
using BlockInputStreamType = DictionaryBlockInputStream<FlatDictionary, Key>;
return std::make_shared<BlockInputStreamType>(shared_from_this(), max_block_size, getIds(), column_names);
}
void registerDictionaryFlat(DictionaryFactory & factory)
{
auto create_layout = [=](const std::string & full_name,
const DictionaryStructure & dict_struct,
const Poco::Util::AbstractConfiguration & config,
const std::string & config_prefix,
DictionarySourcePtr source_ptr) -> DictionaryPtr
{
if (dict_struct.key)
throw Exception{"'key' is not supported for dictionary of layout 'flat'", ErrorCodes::UNSUPPORTED_METHOD};
if (dict_struct.range_min || dict_struct.range_max)
throw Exception{full_name
+ ": elements .structure.range_min and .structure.range_max should be defined only "
"for a dictionary of layout 'range_hashed'",
ErrorCodes::BAD_ARGUMENTS};
const String database = config.getString(config_prefix + ".database", "");
const String name = config.getString(config_prefix + ".name");
const DictionaryLifetime dict_lifetime{config, config_prefix + ".lifetime"};
const bool require_nonempty = config.getBool(config_prefix + ".require_nonempty", false);
return std::make_unique<FlatDictionary>(database, name, dict_struct, std::move(source_ptr), dict_lifetime, require_nonempty);
};
factory.registerLayout("flat", create_layout, false);
}
}