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git.ipfire.org Git - thirdparty/squid.git/blob - src/DiskIO/DiskIOStrategy.h
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16 * This program is free software; you can redistribute it and/or modify
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23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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26 * You should have received a copy of the GNU General Public License
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30 * Copyright (c) 2003 Robert Collins <robertc@squid-cache.org>
33 #ifndef SQUID_DISKIOSTRATEGY_H
34 #define SQUID_DISKIOSTRATEGY_H
36 #include "squid-old.h"
48 virtual ~DiskIOStrategy() {}
50 /** Can the IO Strategy handle more requests ? */
51 virtual bool shedLoad() = 0;
53 /** What is the current load? 999 = 99.9% */
54 virtual int load() = 0;
56 /** Return a handle for performing IO operations */
57 virtual RefCount
<DiskFile
> newFile(char const *path
) = 0;
59 /** flush all IO operations */
60 virtual void sync() {}
62 /** whether the IO Strategy can use unlinkd */
63 virtual bool unlinkdUseful() const = 0;
65 /** unlink a file by path */
66 virtual void unlinkFile(char const *) = 0;
68 /** perform any pending callbacks */
69 virtual int callback() { return 0; }
71 /** Init per-instance logic */
72 virtual void init() {}
74 /** cachemgr output on the IO instance stats */
75 virtual void statfs(StoreEntry
& sentry
)const {}
77 /** module specific options */
78 virtual ConfigOption
*getOptionTree() const { return NULL
;}
81 /* Because we need the DiskFile definition for newFile. */
84 class SingletonIOStrategy
: public DiskIOStrategy
88 SingletonIOStrategy(DiskIOStrategy
*anIO
) : io(anIO
) {}
90 virtual bool shedLoad() { return io
->shedLoad(); }
92 virtual int load() { return io
->load(); }
94 virtual RefCount
<DiskFile
> newFile (char const *path
) {return io
->newFile(path
); }
96 virtual void sync() { io
->sync(); }
98 virtual bool unlinkdUseful() const { return io
->unlinkdUseful(); }
100 virtual void unlinkFile (char const *path
) { io
->unlinkFile(path
); }
102 virtual int callback() { return io
->callback(); }
104 virtual void init() { io
->init(); }
106 virtual void statfs(StoreEntry
& sentry
)const { io
->statfs(sentry
); }
108 virtual ConfigOption
*getOptionTree() const { return io
->getOptionTree(); }
114 #endif /* SQUID_DISKIOSTRATEGY_H */