ClickHouse/dbms/include/DB/Dictionaries/DictionarySourceFactory.h

100 lines
2.8 KiB
C++

#pragma once
#include <DB/Core/Block.h>
#include <DB/Dictionaries/DictionaryStructure.h>
#include <DB/Dictionaries/FileDictionarySource.h>
#include <DB/Dictionaries/MySQLDictionarySource.h>
#include <DB/Dictionaries/ClickHouseDictionarySource.h>
#include <DB/Dictionaries/MongoDBDictionarySource.h>
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <common/singleton.h>
#include <memory>
#include <DB/Core/FieldVisitors.h>
namespace DB
{
namespace
{
Block createSampleBlock(const DictionaryStructure & dict_struct)
{
Block block{
ColumnWithTypeAndName{new ColumnUInt64{1}, new DataTypeUInt64, dict_struct.id.name}
};
if (dict_struct.range_min)
for (const auto & attribute : { dict_struct.range_min, dict_struct.range_max })
block.insert(
ColumnWithTypeAndName{new ColumnUInt16{1}, new DataTypeDate, attribute->name});
for (const auto & attribute : dict_struct.attributes)
{
auto column = attribute.type->createColumn();
column->insert(attribute.null_value);
block.insert(ColumnWithTypeAndName{column, attribute.type, attribute.name});
}
return block;
}
}
/// creates IDictionarySource instance from config and DictionaryStructure
class DictionarySourceFactory : public Singleton<DictionarySourceFactory>
{
public:
DictionarySourcePtr create(
const std::string & name, Poco::Util::AbstractConfiguration & config, const std::string & config_prefix,
const DictionaryStructure & dict_struct, Context & context) const
{
Poco::Util::AbstractConfiguration::Keys keys;
config.keys(config_prefix, keys);
if (keys.size() != 1)
throw Exception{
name +": element dictionary.source should have exactly one child element",
ErrorCodes::EXCESSIVE_ELEMENT_IN_CONFIG
};
auto sample_block = createSampleBlock(dict_struct);
const auto & source_type = keys.front();
if ("file" == source_type)
{
if (dict_struct.has_expressions)
throw Exception{
"Dictionary source of type `file` does not support attribute expressions",
ErrorCodes::LOGICAL_ERROR
};
const auto filename = config.getString(config_prefix + ".file.path");
const auto format = config.getString(config_prefix + ".file.format");
return std::make_unique<FileDictionarySource>(filename, format, sample_block, context);
}
else if ("mysql" == source_type)
{
return std::make_unique<MySQLDictionarySource>(dict_struct, config, config_prefix + ".mysql", sample_block);
}
else if ("clickhouse" == source_type)
{
return std::make_unique<ClickHouseDictionarySource>(dict_struct, config, config_prefix + ".clickhouse",
sample_block, context);
}
else if ("mongodb" == source_type)
{
return std::make_unique<MongoDBDictionarySource>(dict_struct, config, config_prefix + ".mongodb",
sample_block, context);
}
throw Exception{
name + ": unknown dictionary source type: " + source_type,
ErrorCodes::UNKNOWN_ELEMENT_IN_CONFIG
};
}
};
}