database::core::backend_registry Class Reference

Singleton registry for database backend plugins. More...

#include <backend_registry.h>

Collaboration diagram for database::core::backend_registry:

Public Member Functions
	backend_registry (const backend_registry &)=delete
backend_registry &	operator= (const backend_registry &)=delete
	backend_registry (backend_registry &&)=delete
backend_registry &	operator= (backend_registry &&)=delete
kcenon::common::VoidResult	register_backend (const std::string &name, backend_factory_fn factory)
	Register a backend factory function.
kcenon::common::VoidResult	unregister_backend (const std::string &name)
	Unregister a backend (for testing or dynamic unloading)
std::unique_ptr< database_backend >	create (const std::string &name) const
	Create a backend instance by name.
bool	has_backend (const std::string &name) const
	Check if a backend is registered.
std::vector< std::string >	available_backends () const
	Get list of all registered backend names.
size_t	backend_count () const
	Get number of registered backends.
void	clear ()
	Clear all registered backends (for testing)

Static Public Member Functions
static backend_registry &	instance ()
	Get the singleton instance.

Private Member Functions
	backend_registry ()=default
	~backend_registry ()=default

Private Attributes
std::mutex	mutex_
std::map< std::string, backend_factory_fn >	factories_

Detailed Description

Singleton registry for database backend plugins.

Thread Safety:

• All public methods are thread-safe
• Uses internal mutex for synchronization
• Safe for concurrent registration and creation

Singleton Pattern:

• Uses Meyer's singleton (thread-safe in C++11+)
• No manual memory management required
• Automatic cleanup on program exit

Definition at line 72 of file backend_registry.h.

Constructor & Destructor Documentation

backend_registry() [1/3]

database::core::backend_registry::backend_registry ( const backend_registry & )

delete

backend_registry() [2/3]

database::core::backend_registry::backend_registry ( backend_registry && )

delete

backend_registry() [3/3]

database::core::backend_registry::backend_registry ( )

privatedefault

~backend_registry()

database::core::backend_registry::~backend_registry ( )

privatedefault

Member Function Documentation

available_backends()

std::vector< std::string > database::core::backend_registry::available_backends

(

)

const

Get list of all registered backend names.

Returns

Vector of backend names

Thread Safety: This method is thread-safe

Example:

auto backends = backend_registry::instance().available_backends();
for (const auto& name : backends) {
    std::cout << "Available: " << name << std::endl;
}

Definition at line 86 of file backend_registry.cpp.

{
    std::lock_guard<std::mutex> lock(mutex_);
 
    std::vector<std::string> names;
    names.reserve(factories_.size());
 
    for (const auto& pair : factories_)
    {
        names.push_back(pair.first);
    }
 
    // Sort for consistent output
    std::sort(names.begin(), names.end());
 
    return names;
}

References factories_, and mutex_.

Referenced by database::core::available_backends(), TEST_F(), and TEST_F().

Here is the caller graph for this function:

backend_count()

size_t database::core::backend_registry::backend_count

(

)

const

Get number of registered backends.

Returns

Count of registered backends

Thread Safety: This method is thread-safe

Definition at line 104 of file backend_registry.cpp.

{
    std::lock_guard<std::mutex> lock(mutex_);
    return factories_.size();
}

References factories_, and mutex_.

Referenced by TEST_F().

Here is the caller graph for this function:

clear()

void database::core::backend_registry::clear

(

)

Clear all registered backends (for testing)

Thread Safety: This method is thread-safe

Warning: This should only be used in test code. It will remove all registered backends including built-in ones.

Definition at line 110 of file backend_registry.cpp.

{
    std::lock_guard<std::mutex> lock(mutex_);
    factories_.clear();
}

References factories_, and mutex_.

Referenced by BackendRegistryTest::SetUp(), BackendRegistryTest::TearDown(), TEST_F(), and TEST_F().

Here is the caller graph for this function:

create()

std::unique_ptr< database_backend > database::core::backend_registry::create

(

const std::string &

name

)

const

Create a backend instance by name.

Parameters

name	Backend name (e.g., "postgresql", "sqlite")

Returns

Unique pointer to backend, or nullptr if not found

Thread Safety: This method is thread-safe

Example:

auto backend = backend_registry::instance().create("postgresql");
if (!backend) {
    std::cerr << "PostgreSQL backend not available" << std::endl;
}

Definition at line 59 of file backend_registry.cpp.

{
    std::lock_guard<std::mutex> lock(mutex_);
 
    auto it = factories_.find(name);
    if (it == factories_.end())
    {
        return nullptr;
    }
 
    try
    {
        return it->second();
    }
    catch (...)
    {
        // Factory function threw an exception
        return nullptr;
    }
}

References factories_, and mutex_.

Referenced by database::core::create_backend(), database::integrated::create_backend(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), and TEST_F().

Here is the caller graph for this function:

has_backend()

bool database::core::backend_registry::has_backend

(

const std::string &

name

)

const

Check if a backend is registered.

Parameters

name	Backend name to check

Returns

true if backend is registered

Thread Safety: This method is thread-safe

Definition at line 80 of file backend_registry.cpp.

{
    std::lock_guard<std::mutex> lock(mutex_);
    return factories_.find(name) != factories_.end();
}

References factories_, and mutex_.

Referenced by database::core::has_backend().

Here is the caller graph for this function:

instance()

backend_registry & database::core::backend_registry::instance ( )

static

Get the singleton instance.

Returns

Reference to the backend_registry instance

Definition at line 14 of file backend_registry.cpp.

{
    static backend_registry instance;
    return instance;
}

References instance().

Referenced by database::core::available_backends(), database::core::backend_registrar< BackendType >::backend_registrar(), database::core::create_backend(), database::integrated::create_backend(), database::core::has_backend(), instance(), BackendRegistryTest::SetUp(), BackendRegistryTest::TearDown(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), and TEST_F().

Here is the call graph for this function:

Here is the caller graph for this function:

operator=() [1/2]

backend_registry & database::core::backend_registry::operator= ( backend_registry && )

delete

operator=() [2/2]

backend_registry & database::core::backend_registry::operator= ( const backend_registry & )

delete

register_backend()

kcenon::common::VoidResult database::core::backend_registry::register_backend	(	const std::string &	name,
		backend_factory_fn	factory )

Register a backend factory function.

Parameters

name	Backend name (e.g., "postgresql", "sqlite")
factory	Factory function that creates backend instances

Returns

VoidResult::ok() on success, error if name already registered

Thread Safety: This method is thread-safe

Example:

backend_registry::instance().register_backend(
    "postgresql",
    &postgresql_backend::create
);

Definition at line 20 of file backend_registry.cpp.

{
    if (name.empty())
    {
        return kcenon::common::error_info{1, "Backend name cannot be empty", "backend_registry"};
    }
 
    if (!factory)
    {
        return kcenon::common::error_info{2, "Factory function cannot be null", "backend_registry"};
    }
 
    std::lock_guard<std::mutex> lock(mutex_);
 
    // Check if backend already registered
    if (factories_.find(name) != factories_.end())
    {
        return kcenon::common::error_info{3, "Backend '" + name + "' is already registered", "backend_registry"};
    }
 
    factories_[name] = factory;
    return kcenon::common::VoidResult::ok(std::monostate{});
}

References factories_, and mutex_.

Referenced by database::core::backend_registrar< BackendType >::backend_registrar(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), and TEST_F().

Here is the caller graph for this function:

unregister_backend()

kcenon::common::VoidResult database::core::backend_registry::unregister_backend

(

const std::string &

name

)

Unregister a backend (for testing or dynamic unloading)

Parameters

name	Backend name to unregister

Returns

VoidResult::ok() on success, error if not found

Thread Safety: This method is thread-safe

Definition at line 45 of file backend_registry.cpp.

{
    std::lock_guard<std::mutex> lock(mutex_);
 
    auto it = factories_.find(name);
    if (it == factories_.end())
    {
        return kcenon::common::error_info{4, "Backend '" + name + "' not found", "backend_registry"};
    }
 
    factories_.erase(it);
    return kcenon::common::VoidResult::ok(std::monostate{});
}

References factories_, and mutex_.

Referenced by TEST_F(), TEST_F(), and TEST_F().

Here is the caller graph for this function:

Member Data Documentation

factories_

std::map<std::string, backend_factory_fn> database::core::backend_registry::factories_

private

Definition at line 179 of file backend_registry.h.

Referenced by available_backends(), backend_count(), clear(), create(), has_backend(), register_backend(), and unregister_backend().

mutex_

std::mutex database::core::backend_registry::mutex_

mutableprivate

Definition at line 178 of file backend_registry.h.

Referenced by available_backends(), backend_count(), clear(), create(), has_backend(), register_backend(), and unregister_backend().

---

The documentation for this class was generated from the following files:

• database/core/backend_registry.h
• database/core/backend_registry.cpp