1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/libfsserver/include/fsserver/page_queue.h Thu Apr 15 23:15:17 2021 +0200
1.3 @@ -0,0 +1,69 @@
1.4 +/*
1.5 + * A page queue abstraction.
1.6 + *
1.7 + * Copyright (C) 2021 Paul Boddie <paul@boddie.org.uk>
1.8 + *
1.9 + * This program is free software; you can redistribute it and/or
1.10 + * modify it under the terms of the GNU General Public License as
1.11 + * published by the Free Software Foundation; either version 2 of
1.12 + * the License, or (at your option) any later version.
1.13 + *
1.14 + * This program is distributed in the hope that it will be useful,
1.15 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.17 + * GNU General Public License for more details.
1.18 + *
1.19 + * You should have received a copy of the GNU General Public License
1.20 + * along with this program; if not, write to the Free Software
1.21 + * Foundation, Inc., 51 Franklin Street, Fifth Floor,
1.22 + * Boston, MA 02110-1301, USA
1.23 + */
1.24 +
1.25 +#pragma once
1.26 +
1.27 +#include <list>
1.28 +#include <map>
1.29 +
1.30 +#include <mem/flexpage.h>
1.31 +#include <mem/memory.h>
1.32 +#include <fsserver/page_owner.h>
1.33 +
1.34 +
1.35 +
1.36 +/* Collection types. */
1.37 +
1.38 +typedef struct { Flexpage *flexpage; PageOwner *owner; } QueueEntry;
1.39 +typedef std::list<QueueEntry> Queue;
1.40 +
1.41 +typedef std::pair<Flexpage *, Queue::iterator> Position;
1.42 +typedef std::map<Flexpage *, Queue::iterator> Positions;
1.43 +
1.44 +
1.45 +
1.46 +/* A queue of managed pages. */
1.47 +
1.48 +class PageQueue
1.49 +{
1.50 +protected:
1.51 +
1.52 + /* Helper methods. */
1.53 +
1.54 + virtual void discard(Queue &queue, Memory *memory);
1.55 +
1.56 + virtual bool remove(Queue &queue, Positions &positions, PageOwner *owner, Flexpage *flexpage);
1.57 +
1.58 +public:
1.59 + virtual ~PageQueue();
1.60 +
1.61 + virtual void close(Memory *memory) = 0;
1.62 +
1.63 + virtual void pop(PageOwner **owner, Flexpage **flexpage) = 0;
1.64 +
1.65 + virtual void push(PageOwner *owner, Flexpage *flexpage) = 0;
1.66 +
1.67 + virtual void push_front(PageOwner *owner, Flexpage *flexpage) = 0;
1.68 +
1.69 + virtual bool remove(PageOwner *owner, Flexpage *flexpage) = 0;
1.70 +};
1.71 +
1.72 +// vim: tabstop=4 expandtab shiftwidth=4