src/fs/rock/RockSwapDir.h

   1 /*
   2  * Copyright (C) 1996-2020 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_FS_ROCK_SWAP_DIR_H
  10 #define SQUID_FS_ROCK_SWAP_DIR_H
  11
  12 #include "DiskIO/DiskFile.h"
  13 #include "DiskIO/IORequestor.h"
  14 #include "fs/rock/forward.h"
  15 #include "fs/rock/RockDbCell.h"
  16 #include "ipc/mem/Page.h"
  17 #include "ipc/mem/PageStack.h"
  18 #include "ipc/StoreMap.h"
  19 #include "store/Disk.h"
  20 #include <vector>
  21
  22 class DiskIOStrategy;
  23 class ReadRequest;
  24 class WriteRequest;
  25
  26 namespace Rock
  27 {
  28
  29 /// \ingroup Rock
  30 class SwapDir: public ::SwapDir, public IORequestor, public Ipc::StoreMapCleaner
  31 {
  32 public:
  33     typedef RefCount<SwapDir> Pointer;
  34     typedef Ipc::StoreMap DirMap;
  35
  36     SwapDir();
  37     virtual ~SwapDir();
  38
  39     /* public ::SwapDir API */
  40     virtual void reconfigure();
  41     virtual StoreEntry *get(const cache_key *key);
  42     virtual void evictCached(StoreEntry &);
  43     virtual void evictIfFound(const cache_key *);
  44     virtual void disconnect(StoreEntry &e);
  45     virtual uint64_t currentSize() const;
  46     virtual uint64_t currentCount() const;
  47     virtual bool doReportStat() const;
  48     virtual void finalizeSwapoutSuccess(const StoreEntry &);
  49     virtual void finalizeSwapoutFailure(StoreEntry &);
  50     virtual void create();
  51     virtual void parse(int index, char *path);
  52     virtual bool smpAware() const { return true; }
  53     virtual bool hasReadableEntry(const StoreEntry &) const;
  54
  55     // temporary path to the shared memory map of first slots of cached entries
  56     SBuf inodeMapPath() const;
  57     // temporary path to the shared memory stack of free slots
  58     const char *freeSlotsPath() const;
  59
  60     int64_t entryLimitAbsolute() const { return SwapFilenMax+1; } ///< Core limit
  61     int64_t entryLimitActual() const; ///< max number of possible entries in db
  62     int64_t slotLimitAbsolute() const; ///< Rock store implementation limit
  63     int64_t slotLimitActual() const; ///< total number of slots in this db
  64
  65     /// whether the given slot ID may point to a slot in this db
  66     bool validSlotId(const SlotId slotId) const;
  67
  68     /// finds and returns a free db slot to fill or throws
  69     SlotId reserveSlotForWriting();
  70
  71     /// purges one or more entries to make full() false and free some slots
  72     void purgeSome();
  73
  74     int64_t diskOffset(Ipc::Mem::PageId &pageId) const;
  75     int64_t diskOffset(int filen) const;
  76     void writeError(StoreIOState &sio);
  77
  78     /* StoreMapCleaner API */
  79     virtual void noteFreeMapSlice(const Ipc::StoreMapSliceId fileno);
  80
  81     uint64_t slotSize; ///< all db slots are of this size
  82
  83 protected:
  84     /* Store API */
  85     virtual bool anchorToCache(StoreEntry &entry, bool &inSync);
  86     virtual bool updateAnchored(StoreEntry &);
  87
  88     /* protected ::SwapDir API */
  89     virtual bool needsDiskStrand() const;
  90     virtual void init();
  91     virtual ConfigOption *getOptionTree() const;
  92     virtual bool allowOptionReconfigure(const char *const option) const;
  93     virtual bool canStore(const StoreEntry &e, int64_t diskSpaceNeeded, int &load) const;
  94     virtual StoreIOState::Pointer createStoreIO(StoreEntry &, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
  95     virtual StoreIOState::Pointer openStoreIO(StoreEntry &, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
  96     virtual void maintain();
  97     virtual void diskFull();
  98     virtual void reference(StoreEntry &e);
  99     virtual bool dereference(StoreEntry &e);
 100     virtual void updateHeaders(StoreEntry *e);
 101     virtual bool unlinkdUseful() const;
 102     virtual void statfs(StoreEntry &e) const;
 103
 104     /* IORequestor API */
 105     virtual void ioCompletedNotification();
 106     virtual void closeCompleted();
 107     virtual void readCompleted(const char *buf, int len, int errflag, RefCount< ::ReadRequest>);
 108     virtual void writeCompleted(int errflag, size_t len, RefCount< ::WriteRequest>);
 109
 110     void parseSize(const bool reconfiguring); ///< parses anonymous cache_dir size option
 111     void validateOptions(); ///< warns of configuration problems; may quit
 112     bool parseTimeOption(char const *option, const char *value, int reconfiguring);
 113     void dumpTimeOption(StoreEntry * e) const;
 114     bool parseRateOption(char const *option, const char *value, int reconfiguring);
 115     void dumpRateOption(StoreEntry * e) const;
 116     bool parseSizeOption(char const *option, const char *value, int reconfiguring);
 117     void dumpSizeOption(StoreEntry * e) const;
 118
 119     void rebuild(); ///< starts loading and validating stored entry metadata
 120
 121     bool full() const; ///< no more entries can be stored without purging
 122     void trackReferences(StoreEntry &e); ///< add to replacement policy scope
 123     void ignoreReferences(StoreEntry &e); ///< delete from repl policy scope
 124
 125     int64_t diskOffsetLimit() const;
 126
 127     void updateHeadersOrThrow(Ipc::StoreMapUpdate &update);
 128     StoreIOState::Pointer createUpdateIO(const Ipc::StoreMapUpdate &update, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
 129
 130     void anchorEntry(StoreEntry &e, const sfileno filen, const Ipc::StoreMapAnchor &anchor);
 131     bool updateAnchoredWith(StoreEntry &, const Ipc::StoreMapAnchor &);
 132
 133     friend class Rebuild;
 134     friend class IoState;
 135     friend class HeaderUpdater;
 136     const char *filePath; ///< location of cache storage file inside path/
 137     DirMap *map; ///< entry key/sfileno to MaxExtras/inode mapping
 138
 139 private:
 140     void createError(const char *const msg);
 141     void handleWriteCompletionSuccess(const WriteRequest &request);
 142     void handleWriteCompletionProblem(const int errflag, const WriteRequest &request);
 143
 144     DiskIOStrategy *io;
 145     RefCount<DiskFile> theFile; ///< cache storage for this cache_dir
 146     Ipc::Mem::Pointer<Ipc::Mem::PageStack> freeSlots; ///< all unused slots
 147     Ipc::Mem::PageId *waitingForPage; ///< one-page cache for a "hot" free slot
 148
 149     /* configurable options */
 150     DiskFile::Config fileConfig; ///< file-level configuration options
 151
 152     static const int64_t HeaderSize; ///< on-disk db header size
 153 };
 154
 155 /// initializes shared memory segments used by Rock::SwapDir
 156 class SwapDirRr: public Ipc::Mem::RegisteredRunner
 157 {
 158 public:
 159     /* ::RegisteredRunner API */
 160     virtual ~SwapDirRr();
 161
 162 protected:
 163     /* Ipc::Mem::RegisteredRunner API */
 164     virtual void create();
 165
 166 private:
 167     std::vector<SwapDir::DirMap::Owner *> mapOwners;
 168     std::vector< Ipc::Mem::Owner<Ipc::Mem::PageStack> *> freeSlotsOwners;
 169 };
 170
 171 } // namespace Rock
 172
 173 #endif /* SQUID_FS_ROCK_SWAP_DIR_H */
 174