mirror of
https://github.com/matrix-construct/construct
synced 2024-07-03 09:18:19 +02:00
103 lines
2.6 KiB
C++
103 lines
2.6 KiB
C++
/*
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* Copyright (C) 2016 Charybdis Development Team
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* Copyright (C) 2016 Jason Volk <jason@zemos.net>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice is present in all copies.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#pragma once
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#define HAVE_IRCD_DB_COMPARATOR_H
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namespace ircd::db
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{
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struct comparator;
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struct cmp_int64_t;
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struct cmp_string_view;
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struct reverse_cmp_string_view;
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}
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struct ircd::db::comparator
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{
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string_view name;
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std::function<bool (const string_view &, const string_view &)> less;
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std::function<bool (const string_view &, const string_view &)> equal;
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};
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struct ircd::db::reverse_cmp_string_view
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:db::comparator
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{
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static bool less(const string_view &a, const string_view &b)
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{
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return std::memcmp(a.data(), b.data(), std::min(a.size(), b.size())) > 0;
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}
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static bool equal(const string_view &a, const string_view &b)
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{
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return a == b;
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}
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reverse_cmp_string_view()
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:db::comparator{"reverse_string_view", &less, &equal}
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{}
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};
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struct ircd::db::cmp_string_view
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:db::comparator
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{
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static bool less(const string_view &a, const string_view &b)
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{
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return a < b;
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}
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static bool equal(const string_view &a, const string_view &b)
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{
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return a == b;
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}
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cmp_string_view()
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:db::comparator{"string_view", &less, &equal}
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{}
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};
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struct ircd::db::cmp_int64_t
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:db::comparator
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{
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static bool less(const string_view &sa, const string_view &sb)
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{
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assert(sa.size() == sizeof(int64_t));
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assert(sb.size() == sizeof(int64_t));
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const byte_view<int64_t> a{sa};
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const byte_view<int64_t> b{sb};
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return a < b;
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}
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static bool equal(const string_view &sa, const string_view &sb)
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{
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assert(sa.size() == sizeof(int64_t));
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assert(sb.size() == sizeof(int64_t));
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const byte_view<int64_t> a{sa};
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const byte_view<int64_t> b{sb};
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return a == b;
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}
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cmp_int64_t()
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:db::comparator{"int64_t", &less, &equal}
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{}
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};
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