Base class for configuration backend pools. More...

#include <base_config_backend_pool.h>

Public Types
typedef boost::shared_ptr< ConfigBackendType >	ConfigBackendTypePtr
	Shared pointer to the Configuration Backend used. More...

Public Member Functions
virtual	~BaseConfigBackendPool ()
	Virtual destructor. More...

void	addBackend (ConfigBackendTypePtr backend)
	Adds a backend to the pool. More...

void	delAllBackends ()
	Deletes all backends from the pool. More...

void	delAllBackends (const std::string &db_type)
	Deletes all backends of the given type from the pool. More...

Protected Member Functions
template<typename ReturnValue , typename... FnPtrArgs, typename... Args>
ReturnValue	createUpdateDeleteProperty (ReturnValue(ConfigBackendType::*MethodPointer)(const db::ServerSelector &, FnPtrArgs...), const db::BackendSelector &backend_selector, const db::ServerSelector &server_selector, Args... input)
	Add, update or delete property from the backend. More...

template<typename PropertyCollectionType >
void	getAllPropertiesConst (PropertyCollectionType(ConfigBackendType::*MethodPointer)(const db::ServerSelector &) const, const db::BackendSelector &backend_selector, const db::ServerSelector &server_selector, PropertyCollectionType &properties) const
	Retrieve all configuration properties from the pool. More...

template<typename PropertyCollectionType , typename... FnPtrArgs, typename... Args>
void	getMultiplePropertiesConst (PropertyCollectionType(ConfigBackendType::*MethodPointer)(const db::ServerSelector &, FnPtrArgs...) const, const db::BackendSelector &backend_selector, const db::ServerSelector &server_selector, PropertyCollectionType &properties, Args... input) const
	Retrieve multiple configuration properties from the pool. More...

template<typename PropertyType , typename... FnPtrArgs, typename... Args>
void	getPropertyPtrConst (PropertyType(ConfigBackendType::*MethodPointer)(const db::ServerSelector &, FnPtrArgs...) const, const db::BackendSelector &backend_selector, const db::ServerSelector &server_selector, PropertyType &property, Args... input) const
	Retrieve a single configuration property from the pool. More...

std::list< ConfigBackendTypePtr >	selectBackends (const db::BackendSelector &backend_selector) const
	Selects existing backends matching the selector. More...

Protected Attributes
std::list< ConfigBackendTypePtr >	backends_
	Holds configuration backends belonging to the pool. More...

Detailed Description

template<typename ConfigBackendType>
class isc::cb::BaseConfigBackendPool< ConfigBackendType >

Base class for configuration backend pools.

Each Kea server supporting databases as a configuration repository can use multiple database instances simultaneously. A pool is a collection of database backends used by a particular server. Different Kea servers use different pools because they store and fetch different configuration information. For example: DHCPv4 server stores and fetches IPv4 subnets, and DHCPv6 server stores and fetches IPv6 subnets. Therefore, each pool type will expose a different API calls.

This template class is a base class for all pools used by various servers. It implements mechanisms for managing multiple backends and for forwarding API calls to one or many database backends depending on the selections made via BackendSelector class.

Template Parameters

ConfigBackendType Type of the configuration backend. This must be a class deriving from BaseConfigBackend class. It is a class dedicated to a particular server type, e.g. DHCPv4 server, and from which database specific backends derive.

Definition at line 43 of file base_config_backend_pool.h.

Member Typedef Documentation

◆ ConfigBackendTypePtr

template<typename ConfigBackendType >

typedef boost::shared_ptr<ConfigBackendType> isc::cb::BaseConfigBackendPool< ConfigBackendType >::ConfigBackendTypePtr

Shared pointer to the Configuration Backend used.

Definition at line 47 of file base_config_backend_pool.h.

Constructor & Destructor Documentation

◆ ~BaseConfigBackendPool()

template<typename ConfigBackendType >

virtual isc::cb::BaseConfigBackendPool< ConfigBackendType >::~BaseConfigBackendPool ( )

inlinevirtual

Virtual destructor.

Definition at line 50 of file base_config_backend_pool.h.

Member Function Documentation

◆ addBackend()

template<typename ConfigBackendType >

void isc::cb::BaseConfigBackendPool< ConfigBackendType >::addBackend ( ConfigBackendTypePtr backend )

inline

Adds a backend to the pool.

Parameters

backend Pointer to a backend to be added.

Definition at line 55 of file base_config_backend_pool.h.

◆ createUpdateDeleteProperty()

template<typename ConfigBackendType >

template<typename ReturnValue , typename... FnPtrArgs, typename... Args>

ReturnValue isc::cb::BaseConfigBackendPool< ConfigBackendType >::createUpdateDeleteProperty	(	ReturnValue(ConfigBackendType::*)(const db::ServerSelector &, FnPtrArgs...)	MethodPointer,
		const db::BackendSelector &	backend_selector,
		const db::ServerSelector &	server_selector,
		Args...	input
	)

inlineprotected

Add, update or delete property from the backend.

This is a common method for storing a single configuration property in a database, updating an existing property or deleting the property. The server specific backends call this method. For example, the DHCPv6 configuration backend pool may use this function to implement a createUpdateSubnet6 method:

void createUpdateSubnet6(const Subnet6Ptr& subnet,
                         const BackendSelector& backend_selector,
                         const ServerSelector& server_selector) {
    createUpdateDeleteProperty<void, const Subnet6Ptr&>
        (&ConfigBackendDHCPv6::createUpdateSubnet6, backend_selector,
         server_selector, subnet, selector);
}

where ConfigBackendDHCPv6::createUpdateSubnet6 has the following signature:

void createUpdateSubnet6(const ServerSelector&, const Subnet6Ptr&);

The backend selector must point to exactly one backend. If more than one backend is selected, an exception is thrown. If no backend is selected an exception is thrown either.

Template Parameters

ReturnValue	Returned value, typically void or uint64_t.
FnPtrArgs	Parameter pack holding argument types of the backend method to be invoked.
Args	Parameter pack holding types of the arguments provided in the call to this method.

Parameters

MethodPointer	Pointer to the backend method to be called.
backend_selector	Backend selector.
server_selector	Server selector.
input	Objects used as arguments to the backend method to be called.

Exceptions

db::NoSuchDatabase	if no database matching the given selector was found.
db::AmbiguousDatabase	if multiple databases matching the selector were found.

Returns: Number of affected properties, if the value is non void.

Definition at line 360 of file base_config_backend_pool.h.

◆ delAllBackends() [1/2]

template<typename ConfigBackendType >

void isc::cb::BaseConfigBackendPool< ConfigBackendType >::delAllBackends ( )

inline

Deletes all backends from the pool.

Definition at line 60 of file base_config_backend_pool.h.

◆ delAllBackends() [2/2]

template<typename ConfigBackendType >

void isc::cb::BaseConfigBackendPool< ConfigBackendType >::delAllBackends ( const std::string & db_type )

inline

Deletes all backends of the given type from the pool.

Parameters

db_type backend to remove

Definition at line 67 of file base_config_backend_pool.h.

◆ getAllPropertiesConst()

template<typename ConfigBackendType >

template<typename PropertyCollectionType >

void isc::cb::BaseConfigBackendPool< ConfigBackendType >::getAllPropertiesConst	(	PropertyCollectionType(ConfigBackendType::*)(const db::ServerSelector &) const	MethodPointer,
		const db::BackendSelector &	backend_selector,
		const db::ServerSelector &	server_selector,
		PropertyCollectionType &	properties
	)		const

inlineprotected

Retrieve all configuration properties from the pool.

This is a common method for retrieving all configuration properties from the databases. The server specific backends call this method to retrieve all objects of the same type. For example, the DHCPv4 configuration backend pool may use this function to implement a getAllSubnets4 method:

Subnet4Collection getAllSubnets4(const BackendSelector&, const ServerSelector&) const {
    Subnet4Collection subnets;
    getAllPropertiesConst<Subnet6Collection>
        (&ConfigBackendDHCPv4::getAllSubnets4, subnets, backend_selector,
         server_selector);
    return (subnets);
}

where ConfigBackendDHCPv4::getAllSubnets4 has the following signature:

Subnet4Collection getAllSubnets4(const ServerSelector&) const;

If the backend selector is set to "unspecified", this method will iterate over existing backends and call the MethodPointer method on each backend. It will return the first non-empty list returned by one of the backends.

Template Parameters

PropertyCollectionType Type of the container into which the properties are stored.

Parameters

	MethodPointer	Pointer to the backend method to be called.
	backend_selector	Backend selector.
	server_selector	Server selector.
[out]	properties	Reference to the collection of retrieved properties.

Exceptions

db::NoSuchDatabase if no database matching the given selector was found.

Definition at line 282 of file base_config_backend_pool.h.

◆ getMultiplePropertiesConst()

template<typename ConfigBackendType >

template<typename PropertyCollectionType , typename... FnPtrArgs, typename... Args>

void isc::cb::BaseConfigBackendPool< ConfigBackendType >::getMultiplePropertiesConst	(	PropertyCollectionType(ConfigBackendType::*)(const db::ServerSelector &, FnPtrArgs...) const	MethodPointer,
		const db::BackendSelector &	backend_selector,
		const db::ServerSelector &	server_selector,
		PropertyCollectionType &	properties,
		Args...	input
	)		const

inlineprotected

Retrieve multiple configuration properties from the pool.

This is a common method for retrieving multiple configuration properties from the databases. The server specific backends call this method to retrieve multiple objects of the same type. For example, the DHCPv6 configuration backend pool may use this function to implement a getSubnets6 method:

Subnet6Collection getModifiedSubnets6(const BackendSelector& backend_selector,
                                      const ServerSelector& server_selector,
                                      const ptime& modification_time) const {
    Subnet6Collection subnets;
    getMultiplePropertiesConst<Subnet6Collection, const ptime&>
        (&ConfigBackendDHCPv6::getSubnets6, backend_selector, server_selector,
         subnets, modification_time);
    return (subnets);
}

where ConfigBackendDHCPv6::getSubnets6 has the following signature:

Subnet6Collection getSubnets6(const ServerSelector&, const ptime&) const;

If the backend selector is set to "unspecified", this method will iterate over existing backends and call the MethodPointer method on each backend. It will return the first non-empty list returned by one of the backends.

Template Parameters

PropertyCollectionType	Type of the container into which the properties are stored.
FnPtrArgs	Parameter pack holding argument types of the backend method to be invoked.
Args	Parameter pack holding types of the arguments provided in the call to this method.

Parameters

	MethodPointer	Pointer to the backend method to be called.
	backend_selector	Backend selector.
	server_selector	Server selector.
[out]	properties	Reference to the collection of retrieved properties.
	input	Values to be used as input to the backend call.

Exceptions

db::NoSuchDatabase if no database matching the given selector was found.

Definition at line 211 of file base_config_backend_pool.h.

◆ getPropertyPtrConst()

template<typename ConfigBackendType >

template<typename PropertyType , typename... FnPtrArgs, typename... Args>

void isc::cb::BaseConfigBackendPool< ConfigBackendType >::getPropertyPtrConst	(	PropertyType(ConfigBackendType::*)(const db::ServerSelector &, FnPtrArgs...) const	MethodPointer,
		const db::BackendSelector &	backend_selector,
		const db::ServerSelector &	server_selector,
		PropertyType &	property,
		Args...	input
	)		const

inlineprotected

Retrieve a single configuration property from the pool.

This is common method for retrieving a single configuration property from the databases. The server specific backends call this method to retrieve a single object. For example, the DHCPv4 configuration backend pool may use this function to implement a getSubnet4 method:

Subnet4Ptr getSubnet4(const SubnetID& subnet_id,
                      const BackendSelector& backend_selector,
                      const ServerSelector& server_selector) const {
    Subnet4Ptr subnet;
    getPropertyPtrConst<Subnet4Ptr, const SubnetID&>
        (&ConfigBackendDHCPv4::getSubnet4, backend_selector,
         server_selector, subnet, subnet_id);
    return (subnet);
}

where ConfigBackendDHCPv4::getSubnet4 has the following signature:

Subnet4Ptr getSubnet4(const ServerSelector&, const SubnetID&) const;

If the backend selector is set to "unspecified", this method will iterate over the existing backends and call the MethodPointer method on each backend. It will return the first non-null (or non-zero) value returned by this call. For example: if the first backend returns non-null value, this value is returned via property argument and the calls for the rest of the backends are skipped.

Template Parameters

PropertyType	Type of the object returned by the backend call.
FnPtrArgs	Parameter pack holding argument types of the backend method to be invoked.
Args	Parameter pack holding types of the arguments provided in the call to this method.

Parameters

	MethodPointer	Pointer to the backend method to be called.
	backend_selector	Backend selector.
	server_selector	Server selector.
[out]	property	Reference to the shared pointer where retrieved property should be assigned.
	input	Values to be used as input to the backend call.

Exceptions

db::NoSuchDatabase if no database matching the given selector was found.

Definition at line 129 of file base_config_backend_pool.h.

◆ selectBackends()

template<typename ConfigBackendType >

std::list<ConfigBackendTypePtr> isc::cb::BaseConfigBackendPool< ConfigBackendType >::selectBackends ( const db::BackendSelector & backend_selector ) const