icinga2/lib/base/registry.hpp

122 lines
2.0 KiB
C++

/* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */
#ifndef REGISTRY_H
#define REGISTRY_H
#include "base/i2-base.hpp"
#include "base/string.hpp"
#include <boost/signals2.hpp>
#include <map>
#include <mutex>
namespace icinga
{
/**
* A registry.
*
* @ingroup base
*/
template<typename U, typename T>
class Registry
{
public:
typedef std::map<String, T> ItemMap;
void RegisterIfNew(const String& name, const T& item)
{
std::unique_lock<std::mutex> lock(m_Mutex);
if (m_Items.find(name) != m_Items.end())
return;
RegisterInternal(name, item, lock);
}
void Register(const String& name, const T& item)
{
std::unique_lock<std::mutex> lock(m_Mutex);
RegisterInternal(name, item, lock);
}
void Unregister(const String& name)
{
size_t erased;
{
std::unique_lock<std::mutex> lock(m_Mutex);
erased = m_Items.erase(name);
}
if (erased > 0)
OnUnregistered(name);
}
void Clear()
{
typename Registry<U, T>::ItemMap items;
{
std::unique_lock<std::mutex> lock(m_Mutex);
items = m_Items;
}
for (const auto& kv : items) {
OnUnregistered(kv.first);
}
{
std::unique_lock<std::mutex> lock(m_Mutex);
m_Items.clear();
}
}
T GetItem(const String& name) const
{
std::unique_lock<std::mutex> lock(m_Mutex);
auto it = m_Items.find(name);
if (it == m_Items.end())
return T();
return it->second;
}
ItemMap GetItems() const
{
std::unique_lock<std::mutex> lock(m_Mutex);
return m_Items; /* Makes a copy of the map. */
}
boost::signals2::signal<void (const String&, const T&)> OnRegistered;
boost::signals2::signal<void (const String&)> OnUnregistered;
private:
mutable std::mutex m_Mutex;
typename Registry<U, T>::ItemMap m_Items;
void RegisterInternal(const String& name, const T& item, std::unique_lock<std::mutex>& lock)
{
bool old_item = false;
if (m_Items.erase(name) > 0)
old_item = true;
m_Items[name] = item;
lock.unlock();
if (old_item)
OnUnregistered(name);
OnRegistered(name, item);
}
};
}
#endif /* REGISTRY_H */