Current File : //backups/router/usr/local/include/kea/dhcpsrv/cfg_expiration.h
// Copyright (C) 2015-2022 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#ifndef CFG_EXPIRATION_H
#define CFG_EXPIRATION_H
#include <asiolink/interval_timer.h>
#include <cc/cfg_to_element.h>
#include <dhcpsrv/timer_mgr.h>
#include <boost/shared_ptr.hpp>
#include <functional>
#include <stdint.h>
#include <string>
namespace isc {
namespace dhcp {
/// @brief Holds configuration parameters pertaining to lease expiration
/// and lease affinity.
///
/// This class holds the values of the following configuration parameters:
///
/// - reclaim-timer-wait-time - is the time between two cycles of processing
/// expired leases, expressed in seconds, i.e. the time between the end of
/// one cycle and the beginning of the next cycle. If this value is 0, the
/// expired leases are not processed.
///
/// - flush-reclaimed-timer-wait-time - is the time between two cycles of
/// recycling "expired-reclaimed" leases, expressed in seconds. If this
/// value is 0, the expired leases are removed by the leases reclamation
/// routine rather than recycling function. The recycling function is not
/// executed and the value of the "hold-reclaimed-time" is ignored.
///
/// - hold-reclaimed-time -is the time for which "expired-reclaimed" leases
/// are held in the lease database in the "expired-reclaimed" state after
/// they expire. If this time is set to 0, the recycling function is not
/// executed and the value of the "recycle-timer-wait-time" is ignored.
/// This value is expressed in seconds.
///
/// - max-reclaim-leases - is the maximum number of leases to be processed
/// in a single cycle. If this value is 0, all expired leases are
/// processed in a single cycle, unless the maximum processing time
/// (configured with the "max-time") parameter elapses first.
///
/// - max-reclaim-time - the maximum time that a single processing cycle
/// may last, expressed in milliseconds. If this value is 0, there is no
/// limitation for the maximum processing time. This value is expressed
/// in milliseconds.
///
/// - unwarned-reclaim-cycles - is the number of consecutive processing
/// cycles of expired leases, after which the system issues a warning if
/// there are still expired leases in the database. If this value is 0,
/// the warning is never issued.
///
/// The @c CfgExpiration class provides a collection of accessors and
/// modifiers to manage the data. Each accessor checks if the given value
/// is in range allowed for this value.
class CfgExpiration : public isc::data::CfgToElement {
public:
/// @name Default values.
///@{
///
/// @brief Default value for reclaim-timer-wait-time.
static const uint16_t DEFAULT_RECLAIM_TIMER_WAIT_TIME;
/// @brief Default value for flush-reclaimed-timer-wait-time.
static const uint16_t DEFAULT_FLUSH_RECLAIMED_TIMER_WAIT_TIME;
/// @brief Default value for hold-reclaimed-time.
static const uint32_t DEFAULT_HOLD_RECLAIMED_TIME;
/// @brief Default value for max-reclaim-leases.
static const uint32_t DEFAULT_MAX_RECLAIM_LEASES;
/// @brief Default value for max-reclaim-time.
static const uint16_t DEFAULT_MAX_RECLAIM_TIME;
/// @brief Default value for unwarned-reclaim-cycles.
static const uint16_t DEFAULT_UNWARNED_RECLAIM_CYCLES;
///@}
/// @name Upper limits for the parameters
///@{
///
/// @brief Maximum value for reclaim-timer-wait-time.
static const uint16_t LIMIT_RECLAIM_TIMER_WAIT_TIME;
/// @brief Maximum value for flush-reclaimed-timer-wait-time.
static const uint16_t LIMIT_FLUSH_RECLAIMED_TIMER_WAIT_TIME;
/// @brief Maximum value for hold-reclaimed-time.
static const uint32_t LIMIT_HOLD_RECLAIMED_TIME;
/// @brief Maximum value for max-reclaim-leases.
static const uint32_t LIMIT_MAX_RECLAIM_LEASES;
/// @brief Default value for max-reclaim-time.
static const uint16_t LIMIT_MAX_RECLAIM_TIME;
/// @brief Maximum value for unwarned-reclaim-cycles.
static const uint16_t LIMIT_UNWARNED_RECLAIM_CYCLES;
///@}
/// @name Timers' names
///@{
/// @brief Name of the timer for reclaiming expired leases.
static const std::string RECLAIM_EXPIRED_TIMER_NAME;
/// @brief Name of the timer for flushing reclaimed leases.
static const std::string FLUSH_RECLAIMED_TIMER_NAME;
///@}
/// @brief Constructor.
///
/// Sets all parameters to their defaults.
///
/// @param test_mode Indicates if the instance should be created in the
/// test mode. In this mode the intervals for the timers are considered to
/// be specified in milliseconds, rather than seconds. This facilitates
/// testing execution of timers without the delays.
CfgExpiration(const bool test_mode = false);
/// @brief Returns reclaim-timer-wait-time
uint16_t getReclaimTimerWaitTime() const {
return (reclaim_timer_wait_time_);
}
/// @brief Sets reclaim-timer-wait-time
///
/// @param reclaim_timer_wait_time New value.
void setReclaimTimerWaitTime(const int64_t reclaim_timer_wait_time);
/// @brief Returns flush-reclaimed-timer-wait-time.
uint16_t getFlushReclaimedTimerWaitTime() const {
return (flush_reclaimed_timer_wait_time_);
}
/// @brief Sets flush-reclaimed-timer-wait-time.
///
/// @param flush_reclaimed_wait_time New value.
void setFlushReclaimedTimerWaitTime(const int64_t flush_reclaimed_wait_time);
/// @brief Returns hold-reclaimed-time.
uint32_t getHoldReclaimedTime() const {
return (hold_reclaimed_time_);
}
/// @brief Sets hold-reclaimed-time
///
/// @param hold_reclaimed_time New value.
void setHoldReclaimedTime(const int64_t hold_reclaimed_time);
/// @brief Returns max-reclaim-leases.
uint32_t getMaxReclaimLeases() const {
return (max_reclaim_leases_);
}
/// @brief Sets max-reclaim-leases.
///
/// @param max_reclaim_leases New value.
void setMaxReclaimLeases(const int64_t max_reclaim_leases);
/// @brief Returns max-reclaim-time.
uint16_t getMaxReclaimTime() const {
return (max_reclaim_time_);
}
/// @brief Sets max-reclaim-time.
///
/// @param max_reclaim_time New value.
void setMaxReclaimTime(const int64_t max_reclaim_time);
/// @brief Returns unwarned-reclaim-cycles.
uint16_t getUnwarnedReclaimCycles() const {
return (unwarned_reclaim_cycles_);
}
/// @brief Sets unwarned-reclaim-cycles.
///
/// @param unwarned_reclaim_cycles New value.
void setUnwarnedReclaimCycles(const int64_t unwarned_reclaim_cycles);
/// @brief Setup timers for the reclamation of expired leases according
/// to the configuration parameters.
///
/// This method includes the logic for setting the interval timers
/// performing the reclamation of the expired leases and the removal
/// of expired-reclaimed leases.
///
/// The following is the sample code illustrating how to call this function
/// to setup the leases reclamation for the DHCPv4 server.
/// @code
/// CfgExpiration cfg;
///
/// (set some cfg values here)
///
/// AllocEnginePtr alloc_engine(new AllocEngine(...));
/// cfg.setupTimers(&AllocEngine::reclaimExpiredLeases4,
/// &AllocEngine::deleteExpiredReclaimedLeases4,
/// alloc_engine.get());
/// @endcode
///
/// @param reclaim_fun Pointer to the leases reclamation routine.
/// @param delete_fun Pointer to the function which removes the
/// expired-reclaimed leases from the lease database.
/// @param instance_ptr Pointer to the instance of the object which
/// implements the lease reclamation routine. Typically it will be
/// the pointer to the @c AllocEngine. In case of unit tests it
/// will be a pointer to some test class which provides stub
/// implementation of the leases reclamation routines.
/// @tparam Instance Instance of the object in which both functions
/// are implemented.
template<typename Instance>
void setupTimers(void (Instance::*reclaim_fun)(const size_t, const uint16_t,
const bool, const uint16_t),
void (Instance::*delete_fun)(const uint32_t),
Instance* instance_ptr) const;
/// @brief Unparse a configuration object
///
/// @return a pointer to unparsed configuration
virtual isc::data::ElementPtr toElement() const;
private:
/// @brief Checks if the value being set by one of the modifiers is
/// within an allowed range.
///
/// @param value Value to be checked.
/// @param max_value Maximum allowed value.
/// @param config_parameter_name A name of the configuration parameter
/// (used for logging purposes if value is out of range).
///
/// @throw isc::OutOfRange if the value is negative or greater than
/// the maximum value.
void rangeCheck(const int64_t value, const uint64_t max_value,
const std::string& config_parameter_name) const;
/// @brief reclaim-timer-wait-time
uint16_t reclaim_timer_wait_time_;
/// @brief flush-reclaimed-timer-wait-time
uint16_t flush_reclaimed_timer_wait_time_;
/// @brief hold-reclaimed-time
uint32_t hold_reclaimed_time_;
/// @brief max-reclaim-leases
uint32_t max_reclaim_leases_;
/// @brief max-reclaim-time
uint16_t max_reclaim_time_;
/// @brief unwarned-reclaim-cycles.
uint16_t unwarned_reclaim_cycles_;
/// @brief Pointer to the instance of the Timer Manager.
TimerMgrPtr timer_mgr_;
/// @brief Indicates if the instance is in the test mode.
bool test_mode_;
};
/// @name Pointers to the @c CfgExpiration objects.
///@{
/// @brief Pointer to the Non-const object.
typedef boost::shared_ptr<CfgExpiration> CfgExpirationPtr;
/// @brief Pointer to the const object.
typedef boost::shared_ptr<const CfgExpiration> ConstCfgExpirationPtr;
///@}
template<typename Instance>
void
CfgExpiration::setupTimers(void (Instance::*reclaim_fun)(const size_t,
const uint16_t,
const bool,
const uint16_t),
void (Instance::*delete_fun)(const uint32_t),
Instance* instance_ptr) const {
// One of the parameters passed to the leases' reclamation routine
// is a boolean value which indicates if reclaimed leases should
// be removed by the leases' reclamation routine. This is the case
// when the timer for flushing reclaimed leases is set to 0
// (disabled).
const bool flush_timer_disabled = (getFlushReclaimedTimerWaitTime() == 0);
// If the timer interval for the leases reclamation is non-zero
// the timer will be scheduled.
if (getReclaimTimerWaitTime() > 0) {
// In the test mode the interval is expressed in milliseconds.
// If this is not the test mode, the interval is in seconds.
const long reclaim_interval = test_mode_ ? getReclaimTimerWaitTime() :
1000 * getReclaimTimerWaitTime();
// Register timer for leases' reclamation routine.
timer_mgr_->registerTimer(RECLAIM_EXPIRED_TIMER_NAME,
std::bind(reclaim_fun, instance_ptr,
getMaxReclaimLeases(),
getMaxReclaimTime(),
flush_timer_disabled,
getUnwarnedReclaimCycles()),
reclaim_interval,
asiolink::IntervalTimer::ONE_SHOT);
timer_mgr_->setup(RECLAIM_EXPIRED_TIMER_NAME);
}
// If the interval for the timer flushing expired-reclaimed leases
// is set we will schedule the timer.
if (!flush_timer_disabled) {
// The interval is specified in milliseconds if we're in the test mode.
// It is specified in seconds otherwise.
const long flush_interval = test_mode_ ?
getFlushReclaimedTimerWaitTime() :
1000 * getFlushReclaimedTimerWaitTime();
// Register and setup the timer.
timer_mgr_->registerTimer(FLUSH_RECLAIMED_TIMER_NAME,
std::bind(delete_fun, instance_ptr,
getHoldReclaimedTime()),
flush_interval,
asiolink::IntervalTimer::ONE_SHOT);
timer_mgr_->setup(FLUSH_RECLAIMED_TIMER_NAME);
}
}
} // end of isc::dhcp namespace
} // end of isc namespace
#endif // CFG_EXPIRATION_H
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