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

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#pragma once
#include <DB/Core/ErrorCodes.h>
#include <DB/DataTypes/DataTypeFactory.h>
#include <DB/IO/ReadBufferFromString.h>
#include <DB/IO/WriteBuffer.h>
#include <DB/IO/WriteHelpers.h>
#include <Poco/Util/AbstractConfiguration.h>
#include <vector>
#include <string>
#include <map>
#include <experimental/optional>
namespace DB
{
enum class AttributeUnderlyingType
{
UInt8,
UInt16,
UInt32,
UInt64,
Int8,
Int16,
Int32,
Int64,
Float32,
Float64,
String
};
inline AttributeUnderlyingType getAttributeUnderlyingType(const std::string & type)
{
static const std::unordered_map<std::string, AttributeUnderlyingType> dictionary{
{ "UInt8", AttributeUnderlyingType::UInt8 },
{ "UInt16", AttributeUnderlyingType::UInt16 },
{ "UInt32", AttributeUnderlyingType::UInt32 },
{ "UInt64", AttributeUnderlyingType::UInt64 },
{ "Int8", AttributeUnderlyingType::Int8 },
{ "Int16", AttributeUnderlyingType::Int16 },
{ "Int32", AttributeUnderlyingType::Int32 },
{ "Int64", AttributeUnderlyingType::Int64 },
{ "Float32", AttributeUnderlyingType::Float32 },
{ "Float64", AttributeUnderlyingType::Float64 },
{ "String", AttributeUnderlyingType::String },
{ "Date", AttributeUnderlyingType::UInt16 },
{ "DateTime", AttributeUnderlyingType::UInt32 },
};
const auto it = dictionary.find(type);
if (it != std::end(dictionary))
return it->second;
throw Exception{
"Unknown type " + type,
ErrorCodes::UNKNOWN_TYPE
};
}
inline std::string toString(const AttributeUnderlyingType type)
{
switch (type)
{
case AttributeUnderlyingType::UInt8: return "UInt8";
case AttributeUnderlyingType::UInt16: return "UInt16";
case AttributeUnderlyingType::UInt32: return "UInt32";
case AttributeUnderlyingType::UInt64: return "UInt64";
case AttributeUnderlyingType::Int8: return "Int8";
case AttributeUnderlyingType::Int16: return "Int16";
case AttributeUnderlyingType::Int32: return "Int32";
case AttributeUnderlyingType::Int64: return "Int64";
case AttributeUnderlyingType::Float32: return "Float32";
case AttributeUnderlyingType::Float64: return "Float64";
case AttributeUnderlyingType::String: return "String";
}
throw Exception{
"Unknown attribute_type " + toString(static_cast<int>(type)),
ErrorCodes::ARGUMENT_OUT_OF_BOUND
};
}
/// Min and max lifetimes for a dictionary or it's entry
struct DictionaryLifetime final
{
std::uint64_t min_sec;
std::uint64_t max_sec;
DictionaryLifetime(const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix)
{
const auto & lifetime_min_key = config_prefix + ".min";
const auto has_min = config.has(lifetime_min_key);
this->min_sec = has_min ? config.getInt(lifetime_min_key) : config.getInt(config_prefix);
this->max_sec = has_min ? config.getInt(config_prefix + ".max") : this->min_sec;
}
};
/** Holds the description of a single dictionary attribute:
* - name, used for lookup into dictionary and source;
* - type, used in conjunction with DataTypeFactory and getAttributeUnderlyingTypeByname;
* - null_value, used as a default value for non-existent entries in the dictionary,
* decimal representation for numeric attributes;
* - hierarchical, whether this attribute defines a hierarchy;
* - injective, whether the mapping to parent is injective (can be used for optimization of GROUP BY?)
*/
struct DictionaryAttribute final
{
const std::string name;
const AttributeUnderlyingType underlying_type;
const DataTypePtr type;
const std::string expression;
const Field null_value;
const bool hierarchical;
const bool injective;
};
struct DictionarySpecialAttribute final
{
const std::string name;
const std::string expression;
DictionarySpecialAttribute(const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix)
: name{config.getString(config_prefix + ".name", "")},
expression{config.getString(config_prefix + ".expression", "")}
{
if (name.empty() && !expression.empty())
throw Exception{
"Element " + config_prefix + ".name is empty",
ErrorCodes::BAD_ARGUMENTS
};
}
};
/// Name of identifier plus list of attributes
struct DictionaryStructure final
{
std::experimental::optional<DictionarySpecialAttribute> id;
std::experimental::optional<std::vector<DictionaryAttribute>> key;
std::vector<DictionaryAttribute> attributes;
std::experimental::optional<DictionarySpecialAttribute> range_min;
std::experimental::optional<DictionarySpecialAttribute> range_max;
bool has_expressions = false;
DictionaryStructure(const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix)
{
const auto has_id = config.has(config_prefix + ".id");
const auto has_key = config.has(config_prefix + ".key");
if (has_key && has_id)
throw Exception{"Only one of 'id' and 'key' should be specified", ErrorCodes::BAD_ARGUMENTS};
if (has_id)
id.emplace(config, config_prefix + ".id");
else if (has_key)
{
key.emplace(getAttributes(config, config_prefix + ".key", false, false));
if (key->empty())
throw Exception{"Empty 'key' supplied", ErrorCodes::BAD_ARGUMENTS};
}
else
throw Exception{"Dictionary structure should specify either 'id' or 'key'", ErrorCodes::BAD_ARGUMENTS};
if (id)
{
if (id->name.empty())
throw Exception{"'id' cannot be empty", ErrorCodes::BAD_ARGUMENTS};
if (config.has(config_prefix + ".range_min"))
range_min.emplace(config, config_prefix + ".range_min");
if (config.has(config_prefix + ".range_max"))
range_max.emplace(config, config_prefix + ".range_max");
if (!id->expression.empty() ||
(range_min && !range_min->expression.empty()) ||
(range_max && !range_max->expression.empty()))
has_expressions = true;
}
attributes = getAttributes(config, config_prefix);
if (attributes.empty())
throw Exception{"Dictionary has no attributes defined", ErrorCodes::BAD_ARGUMENTS};
}
bool isKeySizeFixed() const
{
if (!key)
return true;
for (const auto key_i : * key)
if (key_i.underlying_type == AttributeUnderlyingType::String)
return false;
return true;
}
std::size_t getKeySize() const
{
return std::accumulate(std::begin(*key), std::end(*key), std::size_t{},
[] (const auto running_size, const auto & key_i) {return running_size + key_i.type->getSizeOfField(); });
}
private:
std::vector<DictionaryAttribute> getAttributes(
const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix,
const bool hierarchy_allowed = true, const bool allow_null_values = true)
{
Poco::Util::AbstractConfiguration::Keys keys;
config.keys(config_prefix, keys);
auto has_hierarchy = false;
std::vector<DictionaryAttribute> attributes;
for (const auto & key : keys)
{
if (0 != strncmp(key.data(), "attribute", strlen("attribute")))
continue;
const auto prefix = config_prefix + '.' + key + '.';
const auto name = config.getString(prefix + "name");
const auto type_string = config.getString(prefix + "type");
const auto type = DataTypeFactory::instance().get(type_string);
const auto underlying_type = getAttributeUnderlyingType(type_string);
const auto expression = config.getString(prefix + "expression", "");
if (!expression.empty())
has_expressions = true;
Field null_value;
if (allow_null_values)
{
const auto null_value_string = config.getString(prefix + "null_value");
try
{
ReadBufferFromString null_value_buffer{null_value_string};
type->deserializeText(null_value, null_value_buffer);
}
catch (const std::exception & e)
{
throw Exception{
std::string{"Error parsing null_value: "} + e.what(),
ErrorCodes::BAD_ARGUMENTS
};
}
}
const auto hierarchical = config.getBool(prefix + "hierarchical", false);
const auto injective = config.getBool(prefix + "injective", false);
if (name.empty())
throw Exception{
"Properties 'name' and 'type' of an attribute cannot be empty",
ErrorCodes::BAD_ARGUMENTS
};
if (has_hierarchy && !hierarchy_allowed)
throw Exception{
"Hierarchy not allowed in '" + prefix,
ErrorCodes::BAD_ARGUMENTS
};
if (has_hierarchy && hierarchical)
throw Exception{
"Only one hierarchical attribute supported",
ErrorCodes::BAD_ARGUMENTS
};
has_hierarchy = has_hierarchy || hierarchical;
attributes.emplace_back(DictionaryAttribute{
name, underlying_type, type, expression, null_value, hierarchical, injective
});
}
return attributes;
}
};
}