src/fs/rock/RockSwapDir.h

   1 /*
   2  * Copyright (C) 1996-2015 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/RockDbCell.h"
  15 #include "fs/rock/RockForward.h"
  16 #include "ipc/mem/Page.h"
  17 #include "ipc/mem/PageStack.h"
  18 #include "ipc/StoreMap.h"
  19 #include "SwapDir.h"
  20
  21 class DiskIOStrategy;
  22 class ReadRequest;
  23 class WriteRequest;
  24
  25 namespace Rock
  26 {
  27
  28 /// \ingroup Rock
  29 class SwapDir: public ::SwapDir, public IORequestor, public Ipc::StoreMapCleaner
  30 {
  31 public:
  32     typedef RefCount<SwapDir> Pointer;
  33     typedef Ipc::StoreMap DirMap;
  34
  35     SwapDir();
  36     virtual ~SwapDir();
  37
  38     /* public ::SwapDir API */
  39     virtual void reconfigure();
  40     virtual StoreSearch *search(String const url, HttpRequest *);
  41     virtual StoreEntry *get(const cache_key *key);
  42     virtual void get(String const, STOREGETCLIENT, void * cbdata);
  43     virtual void markForUnlink(StoreEntry &e);
  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 swappedOut(const StoreEntry &e);
  49     virtual void create();
  50     virtual void parse(int index, char *path);
  51
  52     // temporary path to the shared memory map of first slots of cached entries
  53     SBuf inodeMapPath() const;
  54     // temporary path to the shared memory stack of free slots
  55     const char *freeSlotsPath() const;
  56
  57     int64_t entryLimitAbsolute() const { return SwapFilenMax+1; } ///< Core limit
  58     int64_t entryLimitActual() const; ///< max number of possible entries in db
  59     int64_t slotLimitAbsolute() const; ///< Rock store implementation limit
  60     int64_t slotLimitActual() const; ///< total number of slots in this db
  61
  62     /// removes a slot from a list of free slots or returns false
  63     bool useFreeSlot(Ipc::Mem::PageId &pageId);
  64     /// whether the given slot ID may point to a slot in this db
  65     bool validSlotId(const SlotId slotId) const;
  66     /// purges one or more entries to make full() false and free some slots
  67     void purgeSome();
  68
  69     int64_t diskOffset(Ipc::Mem::PageId &pageId) const;
  70     int64_t diskOffset(int filen) const;
  71     void writeError(StoreEntry &e);
  72
  73     /* StoreMapCleaner API */
  74     virtual void noteFreeMapSlice(const Ipc::StoreMapSliceId fileno);
  75
  76     uint64_t slotSize; ///< all db slots are of this size
  77
  78 protected:
  79     /* Store API */
  80     virtual bool anchorCollapsed(StoreEntry &collapsed, bool &inSync);
  81     virtual bool updateCollapsed(StoreEntry &collapsed);
  82
  83     /* protected ::SwapDir API */
  84     virtual bool needsDiskStrand() const;
  85     virtual void init();
  86     virtual ConfigOption *getOptionTree() const;
  87     virtual bool allowOptionReconfigure(const char *const option) const;
  88     virtual bool canStore(const StoreEntry &e, int64_t diskSpaceNeeded, int &load) const;
  89     virtual StoreIOState::Pointer createStoreIO(StoreEntry &, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
  90     virtual StoreIOState::Pointer openStoreIO(StoreEntry &, StoreIOState::STFNCB *, StoreIOState::STIOCB *, void *);
  91     virtual void maintain();
  92     virtual void diskFull();
  93     virtual void reference(StoreEntry &e);
  94     virtual bool dereference(StoreEntry &e, bool);
  95     virtual bool unlinkdUseful() const;
  96     virtual void unlink(StoreEntry &e);
  97     virtual void statfs(StoreEntry &e) const;
  98
  99     /* IORequestor API */
 100     virtual void ioCompletedNotification();
 101     virtual void closeCompleted();
 102     virtual void readCompleted(const char *buf, int len, int errflag, RefCount< ::ReadRequest>);
 103     virtual void writeCompleted(int errflag, size_t len, RefCount< ::WriteRequest>);
 104
 105     void parseSize(const bool reconfiguring); ///< parses anonymous cache_dir size option
 106     void validateOptions(); ///< warns of configuration problems; may quit
 107     bool parseTimeOption(char const *option, const char *value, int reconfiguring);
 108     void dumpTimeOption(StoreEntry * e) const;
 109     bool parseRateOption(char const *option, const char *value, int reconfiguring);
 110     void dumpRateOption(StoreEntry * e) const;
 111     bool parseSizeOption(char const *option, const char *value, int reconfiguring);
 112     void dumpSizeOption(StoreEntry * e) const;
 113
 114     void rebuild(); ///< starts loading and validating stored entry metadata
 115
 116     bool full() const; ///< no more entries can be stored without purging
 117     void trackReferences(StoreEntry &e); ///< add to replacement policy scope
 118     void ignoreReferences(StoreEntry &e); ///< delete from repl policy scope
 119
 120     int64_t diskOffsetLimit() const;
 121
 122     void anchorEntry(StoreEntry &e, const sfileno filen, const Ipc::StoreMapAnchor &anchor);
 123     bool updateCollapsedWith(StoreEntry &collapsed, const Ipc::StoreMapAnchor &anchor);
 124
 125     friend class Rebuild;
 126     friend class IoState;
 127     const char *filePath; ///< location of cache storage file inside path/
 128     DirMap *map; ///< entry key/sfileno to MaxExtras/inode mapping
 129
 130 private:
 131     void createError(const char *const msg);
 132
 133     DiskIOStrategy *io;
 134     RefCount<DiskFile> theFile; ///< cache storage for this cache_dir
 135     Ipc::Mem::Pointer<Ipc::Mem::PageStack> freeSlots; ///< all unused slots
 136     Ipc::Mem::PageId *waitingForPage; ///< one-page cache for a "hot" free slot
 137
 138     /* configurable options */
 139     DiskFile::Config fileConfig; ///< file-level configuration options
 140
 141     static const int64_t HeaderSize; ///< on-disk db header size
 142 };
 143
 144 /// initializes shared memory segments used by Rock::SwapDir
 145 class SwapDirRr: public Ipc::Mem::RegisteredRunner
 146 {
 147 public:
 148     /* ::RegisteredRunner API */
 149     virtual ~SwapDirRr();
 150
 151 protected:
 152     /* Ipc::Mem::RegisteredRunner API */
 153     virtual void create();
 154
 155 private:
 156     std::vector<SwapDir::DirMap::Owner *> mapOwners;
 157     std::vector< Ipc::Mem::Owner<Ipc::Mem::PageStack> *> freeSlotsOwners;
 158 };
 159
 160 } // namespace Rock
 161
 162 #endif /* SQUID_FS_ROCK_SWAP_DIR_H */
 163