mirror of
https://github.com/matrix-construct/construct
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73 lines
1.7 KiB
C++
73 lines
1.7 KiB
C++
// Matrix Construct
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//
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// Copyright (C) Matrix Construct Developers, Authors & Contributors
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// Copyright (C) 2016-2019 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. The
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// full license for this software is available in the LICENSE file.
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#pragma once
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#define HAVE_IRCD_DB_DATABASE_SNAPSHOT_H
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// Forward declarations for RocksDB because it is not included here.
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namespace rocksdb
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{
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struct Snapshot;
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}
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namespace ircd::db
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{
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uint64_t sequence(const database::snapshot &) noexcept; // Sequence of a snapshot
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uint64_t sequence(const rocksdb::Snapshot *) noexcept;
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}
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/// Database snapshot object. Maintaining this object will maintain a
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/// consistent state of access to the database at the sequence number
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/// from when it's acquired.
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struct ircd::db::database::snapshot
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{
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std::shared_ptr<const rocksdb::Snapshot> s;
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public:
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operator const rocksdb::Snapshot *() const;
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explicit operator bool() const;
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bool operator !() const;
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snapshot() = default;
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explicit snapshot(database &);
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snapshot(const snapshot &) = default;
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snapshot &operator=(const snapshot &) = default;
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~snapshot() noexcept;
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};
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inline bool
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ircd::db::database::snapshot::operator!()
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const
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{
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return !s;
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}
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inline ircd::db::database::snapshot::operator
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bool()
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const
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{
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return bool(s);
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}
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inline ircd::db::database::snapshot::operator
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const rocksdb::Snapshot *()
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const
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{
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return s.get();
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}
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inline uint64_t
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ircd::db::sequence(const database::snapshot &s)
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noexcept
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{
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const rocksdb::Snapshot *const rs(s);
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return sequence(rs);
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}
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