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// Copyright (C) 2010 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#ifndef __ADDRESS_ENTRY_H
#define __ADDRESS_ENTRY_H
/// \brief Address Entry
///
/// Lightweight class that couples an address with a RTT and provides some
/// convenience methods for accessing and updating the information.
#include <stdint.h>
#include <asiolink/io_address.h>
namespace isc {
namespace nsas {
class AddressEntry {
public:
/// Creates an address entry given IOAddress entry and RTT
/// This is the only constructor; the default copy constructor and
/// assignment operator are valid for this object.
///
/// \param address Address object representing this address
/// \param rtt Initial round-trip time
AddressEntry(const asiolink::IOAddress& address, uint32_t rtt = 0) :
address_(address), rtt_(rtt), dead_until_(0)
{}
/// \return Address object
const asiolink::IOAddress& getAddress() const {
return address_;
}
/// \return Current round-trip time
uint32_t getRTT() {
if(dead_until_ != 0 && time(NULL) >= dead_until_){
dead_until_ = 0;
rtt_ = 1; //reset the rtt to a small value so it has an opportunity to be updated
}
return rtt_;
}
/// Set current RTT
///
/// \param rtt New RTT to be associated with this address
void setRTT(uint32_t rtt) {
if(rtt == UNREACHABLE){
dead_until_ = time(NULL) + 5*60;//Cache the unreachable server for 5 minutes (RFC2308 sec7.2)
}
rtt_ = rtt;
}
/// Mark address as unreachable.
void setUnreachable() {
setRTT(UNREACHABLE); // Largest long number is code for unreachable
}
/// Check if address is unreachable
///
/// \return true if the address is unreachable, false if not
bool isUnreachable() {
return (getRTT() == UNREACHABLE); // The getRTT() will check the cache time for unreachable server
}
/// \return true if the object is a V4 address
bool isV4() const {
return (address_.getFamily() == AF_INET);
}
/// \return true if the object is a V6 address
bool isV6() const {
return (address_.getFamily() == AF_INET6);
}
// Next element is defined public for testing
static const uint32_t UNREACHABLE; ///< RTT indicating unreachable address
private:
asiolink::IOAddress address_; ///< Address
uint32_t rtt_; ///< Round-trip time
time_t dead_until_; ///< Dead time for unreachable server
};
} // namespace dns
} // namespace isc
#endif // __ADDRESS_ENTRY_H
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