src/fs/rock/RockRebuild.h

   1 /*
   2  * Copyright (C) 1996-2017 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_REBUILD_H
  10 #define SQUID_FS_ROCK_REBUILD_H
  11
  12 #include "base/AsyncJob.h"
  13 #include "cbdata.h"
  14 #include "fs/rock/forward.h"
  15 #include "MemBuf.h"
  16 #include "store_rebuild.h"
  17
  18 namespace Rock
  19 {
  20
  21 class LoadingEntry;
  22 class LoadingSlot;
  23 class LoadingParts;
  24
  25 /// \ingroup Rock
  26 /// manages store rebuild process: loading meta information from db on disk
  27 class Rebuild: public AsyncJob
  28 {
  29     CBDATA_CHILD(Rebuild);
  30
  31 public:
  32     Rebuild(SwapDir *dir);
  33     virtual ~Rebuild() override;
  34
  35 protected:
  36     /* AsyncJob API */
  37     virtual void start() override;
  38     virtual bool doneAll() const override;
  39     virtual void swanSong() override;
  40
  41     bool doneLoading() const;
  42     bool doneValidating() const;
  43
  44 private:
  45     void checkpoint();
  46     void steps();
  47     void loadingSteps();
  48     void validationSteps();
  49     void loadOneSlot();
  50     void validateOneEntry(const sfileno fileNo);
  51     void validateOneSlot(const SlotId slotId);
  52     bool importEntry(Ipc::StoreMapAnchor &anchor, const sfileno slotId, const DbCellHeader &header);
  53     void freeBadEntry(const sfileno fileno, const char *eDescription);
  54
  55     void failure(const char *msg, int errNo = 0);
  56
  57     LoadingEntry loadingEntry(const sfileno fileNo);
  58     void startNewEntry(const sfileno fileno, const SlotId slotId, const DbCellHeader &header);
  59     void primeNewEntry(Ipc::StoreMapAnchor &anchor, const sfileno fileno, const DbCellHeader &header);
  60     void finalizeOrFree(const sfileno fileNo, LoadingEntry &le);
  61     void finalizeOrThrow(const sfileno fileNo, LoadingEntry &le);
  62     void addSlotToEntry(const sfileno fileno, const SlotId slotId, const DbCellHeader &header);
  63     void useNewSlot(const SlotId slotId, const DbCellHeader &header);
  64
  65     LoadingSlot loadingSlot(const SlotId slotId);
  66     void mapSlot(const SlotId slotId, const DbCellHeader &header);
  67     void freeUnusedSlot(const SlotId slotId, const bool invalid);
  68     void freeSlot(const SlotId slotId, const bool invalid);
  69
  70     template <class SlotIdType>
  71     void chainSlots(SlotIdType &from, const SlotId to);
  72
  73     bool sameEntry(const sfileno fileno, const DbCellHeader &header) const;
  74
  75     SwapDir *sd;
  76     LoadingParts *parts; ///< parts of store entries being loaded from disk
  77
  78     int64_t dbSize;
  79     int dbSlotSize; ///< the size of a db cell, including the cell header
  80     int dbSlotLimit; ///< total number of db cells
  81     int dbEntryLimit; ///< maximum number of entries that can be stored in db
  82
  83     int fd; // store db file descriptor
  84     int64_t dbOffset;
  85     sfileno loadingPos; ///< index of the db slot being loaded from disk now
  86     sfileno validationPos; ///< index of the loaded db slot being validated now
  87     MemBuf buf; ///< space to load current db slot (and entry metadata) into
  88
  89     StoreRebuildData counts;
  90
  91     static void Steps(void *data);
  92 };
  93
  94 } // namespace Rock
  95
  96 #endif /* SQUID_FS_ROCK_REBUILD_H */
  97