]>
git.ipfire.org Git - thirdparty/squid.git/blob - src/DiskIO/DiskIOStrategy.h
2 * SQUID Web Proxy Cache http://www.squid-cache.org/
3 * ----------------------------------------------------------
5 * Squid is the result of efforts by numerous individuals from
6 * the Internet community; see the CONTRIBUTORS file for full
7 * details. Many organizations have provided support for Squid's
8 * development; see the SPONSORS file for full details. Squid is
9 * Copyrighted (C) 2001 by the Regents of the University of
10 * California; see the COPYRIGHT file for full details. Squid
11 * incorporates software developed and/or copyrighted by other
12 * sources; see the CREDITS file for full details.
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
28 * Copyright (c) 2003 Robert Collins <robertc@squid-cache.org>
31 #ifndef SQUID_DISKIOSTRATEGY_H
32 #define SQUID_DISKIOSTRATEGY_H
34 #include "base/RefCount.h"
45 virtual ~DiskIOStrategy() {}
47 /** Can the IO Strategy handle more requests ? */
48 virtual bool shedLoad() = 0;
50 /** What is the current load? 999 = 99.9% */
51 virtual int load() = 0;
53 /** Return a handle for performing IO operations */
54 virtual RefCount
<DiskFile
> newFile(char const *path
) = 0;
56 /** flush all IO operations */
57 virtual void sync() {}
59 /** whether the IO Strategy can use unlinkd */
60 virtual bool unlinkdUseful() const = 0;
62 /** unlink a file by path */
63 virtual void unlinkFile(char const *) = 0;
65 /** perform any pending callbacks */
66 virtual int callback() { return 0; }
68 /** Init per-instance logic */
69 virtual void init() {}
71 /** cachemgr output on the IO instance stats */
72 virtual void statfs(StoreEntry
& sentry
)const {}
74 /** module specific options */
75 virtual ConfigOption
*getOptionTree() const { return NULL
;}
78 /* Because we need the DiskFile definition for newFile. */
81 class SingletonIOStrategy
: public DiskIOStrategy
85 SingletonIOStrategy(DiskIOStrategy
*anIO
) : io(anIO
) {}
87 virtual bool shedLoad() { return io
->shedLoad(); }
89 virtual int load() { return io
->load(); }
91 virtual RefCount
<DiskFile
> newFile (char const *path
) {return io
->newFile(path
); }
93 virtual void sync() { io
->sync(); }
95 virtual bool unlinkdUseful() const { return io
->unlinkdUseful(); }
97 virtual void unlinkFile (char const *path
) { io
->unlinkFile(path
); }
99 virtual int callback() { return io
->callback(); }
101 virtual void init() { io
->init(); }
103 virtual void statfs(StoreEntry
& sentry
)const { io
->statfs(sentry
); }
105 virtual ConfigOption
*getOptionTree() const { return io
->getOptionTree(); }
111 #endif /* SQUID_DISKIOSTRATEGY_H */