ClickHouse/src/Interpreters/EmbeddedDictionaries.h
2020-04-03 18:14:31 +03:00

93 lines
2.3 KiB
C++

#pragma once
#include <thread>
#include <functional>
#include <Common/MultiVersion.h>
#include <Common/ThreadPool.h>
#include <Poco/Event.h>
namespace Poco { class Logger; namespace Util { class AbstractConfiguration; } }
class RegionsHierarchies;
class RegionsNames;
class GeoDictionariesLoader;
namespace DB
{
class Context;
/// Metrica's Dictionaries which can be used in functions.
class EmbeddedDictionaries
{
private:
Poco::Logger * log;
Context & context;
MultiVersion<RegionsHierarchies> regions_hierarchies;
MultiVersion<RegionsNames> regions_names;
std::unique_ptr<GeoDictionariesLoader> geo_dictionaries_loader;
/// Directories' updating periodicity (in seconds).
int reload_period;
int cur_reload_period = 1;
bool is_fast_start_stage = true;
mutable std::mutex mutex;
ThreadFromGlobalPool reloading_thread;
Poco::Event destroy;
void handleException(const bool throw_on_error) const;
/** Updates directories (dictionaries) every reload_period seconds.
* If all dictionaries are not loaded at least once, try reload them with exponential delay (1, 2, ... reload_period).
* If all dictionaries are loaded, update them using constant reload_period delay.
*/
void reloadPeriodically();
/// Updates dictionaries.
bool reloadImpl(const bool throw_on_error, const bool force_reload = false);
template <typename Dictionary>
using DictionaryReloader = std::function<std::unique_ptr<Dictionary>(const Poco::Util::AbstractConfiguration & config)>;
template <typename Dictionary>
bool reloadDictionary(
MultiVersion<Dictionary> & dictionary,
DictionaryReloader<Dictionary> reload_dictionary,
const bool throw_on_error,
const bool force_reload);
public:
/// Every reload_period seconds directories are updated inside a separate thread.
EmbeddedDictionaries(
std::unique_ptr<GeoDictionariesLoader> geo_dictionaries_loader,
Context & context,
const bool throw_on_error);
/// Forcibly reloads all dictionaries.
void reload();
~EmbeddedDictionaries();
MultiVersion<RegionsHierarchies>::Version getRegionsHierarchies() const
{
return regions_hierarchies.get();
}
MultiVersion<RegionsNames>::Version getRegionsNames() const
{
return regions_names.get();
}
};
}