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/*
* Copyright 2016-2019 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "AddressInfo.hxx"
#include "Features.hxx"
#include <cassert>
static constexpr int address_family_ranking[] = {
#ifdef HAVE_UN
AF_LOCAL,
#endif
AF_INET6,
};
static bool
IsAddressFamilyBetter(int previous, int next)
{
for (auto i : address_family_ranking) {
if (next == i)
return previous != i;
if (previous == i)
return false;
}
return false;
}
static bool
IsBetter(const AddressInfo &previous, const AddressInfo &next)
{
return IsAddressFamilyBetter(previous.GetFamily(),
next.GetFamily());
}
static bool
IsBetter(const AddressInfo *previous, const AddressInfo &next)
{
return previous == nullptr || IsBetter(*previous, next);
}
const AddressInfo &
AddressInfoList::GetBest() const
{
assert(!empty());
const AddressInfo *best = nullptr;
for (const auto &i : *this)
if (IsBetter(best, i))
best = &i;
assert(best != nullptr);
return *best;
}
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