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construct/include/ircd/db/opts.h
Jason Volk d9a4f06bf6 ircd: Employ namespace scope extensions from c++1z/gnu++14.
This is not a move to c++17. If the compiler happens to have support
for c++17 namespace scope resolution, they have been kind enough to
backport it to gnu++14. This limits our support for really old c++14
compilers, but that was limited anyway. GCC 6.1 and clang 3.6 tested.
2017-09-08 03:47:46 -07:00

115 lines
3.3 KiB
C++

/*
* Copyright (C) 2016 Charybdis Development Team
* Copyright (C) 2016 Jason Volk <jason@zemos.net>
*
* 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 is present in all copies.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
*/
#pragma once
#define HAVE_IRCD_DB_OPTS_H
namespace ircd::db
{
template<class T> struct optval;
template<class T> using optlist = std::initializer_list<optval<T>>;
template<class T> bool has_opt(const optlist<T> &, const T &);
template<class T> ssize_t opt_val(const optlist<T> &, const T &);
enum class set;
struct sopts;
enum class get;
struct gopts;
}
template<class T>
struct ircd::db::optval
:std::pair<T, ssize_t>
{
optval(const T &key, const ssize_t &val = std::numeric_limits<ssize_t>::min());
};
enum class ircd::db::set
{
FSYNC, // Uses kernel filesystem synchronization after write (slow)
NO_JOURNAL, // Write Ahead Log (WAL) for some crash recovery
MISSING_COLUMNS // No exception thrown when writing to a deleted column family
};
struct ircd::db::sopts
:optlist<set>
{
template<class... list>
sopts(list&&... l)
:optlist<set>{std::forward<list>(l)...}
{}
};
enum class ircd::db::get
{
PIN, // Keep iter data in memory for iter lifetime (good for lots of ++/--)
CACHE, // Update the cache (CACHE is default for non-iterator operations)
NO_CACHE, // Do not update the cache (NO_CACHE is default for iterators)
NO_SNAPSHOT, // This iterator will have the latest data (tailing)
NO_CHECKSUM, // Integrity of data will be checked unless this is specified
READAHEAD, // Pair with a size in bytes for prefetching additional data
NO_EMPTY, // Option for db::row to not include unassigned cells in the row
};
struct ircd::db::gopts
:optlist<get>
{
database::snapshot snapshot;
template<class... list>
gopts(list&&... l)
:optlist<get>{std::forward<list>(l)...}
{}
};
template<class T>
ssize_t
ircd::db::opt_val(const optlist<T> &list,
const T &opt)
{
for(const auto &p : list)
if(p.first == opt)
return p.second;
return std::numeric_limits<ssize_t>::min();
}
template<class T>
bool
ircd::db::has_opt(const optlist<T> &list,
const T &opt)
{
for(const auto &p : list)
if(p.first == opt)
return true;
return false;
}
template<class T>
ircd::db::optval<T>::optval(const T &key,
const ssize_t &val)
:std::pair<T, ssize_t>{key, val}
{
}