DiskIOStrategy.h

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/*
 * Copyright (C) 1996-2023 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */
 
#ifndef SQUID_DISKIOSTRATEGY_H
#define SQUID_DISKIOSTRATEGY_H
 
#include "base/RefCount.h"
#include "Store.h"
 
class DiskFile;
 
class ConfigOption;
 
class DiskIOStrategy
{
 
public:
    virtual ~DiskIOStrategy() {}
 
    virtual bool shedLoad() = 0;
 
    virtual int load() = 0;
 
    virtual RefCount<DiskFile> newFile(char const *path) = 0;
 
    virtual void sync() {}
 
    virtual bool unlinkdUseful() const = 0;
 
    virtual void unlinkFile(char const *) = 0;
 
    virtual int callback() { return 0; }
 
    virtual void init() {}
 
    virtual void statfs(StoreEntry &) const {}
 
    virtual ConfigOption *getOptionTree() const {return nullptr;}
};
 
/* Because we need the DiskFile definition for newFile. */
#include "DiskFile.h"
 
class SingletonIOStrategy : public DiskIOStrategy
{
 
public:
    SingletonIOStrategy(DiskIOStrategy *anIO) : io(anIO) {}
 
    bool shedLoad() override { return io->shedLoad(); }
 
    int load() override { return io->load(); }
 
    RefCount<DiskFile> newFile (char const *path) override {return io->newFile(path); }
 
    void sync() override { io->sync(); }
 
    bool unlinkdUseful() const override { return io->unlinkdUseful(); }
 
    void unlinkFile(char const *path) override { io->unlinkFile(path); }
 
    int callback() override { return io->callback(); }
 
    void init() override { io->init(); }
 
    void statfs(StoreEntry & sentry) const override { io->statfs(sentry); }
 
    ConfigOption *getOptionTree() const override { return io->getOptionTree(); }
 
private:
    DiskIOStrategy *io;
};
 
#endif /* SQUID_DISKIOSTRATEGY_H */