src/fs/rock/RockIoState.h

   1 #ifndef SQUID_FS_ROCK_IO_STATE_H
   2 #define SQUID_FS_ROCK_IO_STATE_H
   3
   4 #include "fs/rock/RockSwapDir.h"
   5 #include "MemBlob.h"
   6
   7 class DiskFile;
   8
   9 namespace Rock
  10 {
  11
  12 class DbCellHeader;
  13 class SwapDir;
  14
  15 /// \ingroup Rock
  16 class IoState: public ::StoreIOState
  17 {
  18 public:
  19     typedef RefCount<IoState> Pointer;
  20
  21     IoState(Rock::SwapDir::Pointer &aDir, StoreEntry *e, StoreIOState::STFNCB *cbFile, StoreIOState::STIOCB *cbIo, void *data);
  22     virtual ~IoState();
  23
  24     void file(const RefCount<DiskFile> &aFile);
  25
  26     // ::StoreIOState API
  27     virtual void read_(char *buf, size_t size, off_t offset, STRCB * callback, void *callback_data);
  28     virtual bool write(char const *buf, size_t size, off_t offset, FREE * free_func);
  29     virtual void close(int how);
  30
  31     /// whether we are still waiting for the I/O results (i.e., not closed)
  32     bool stillWaiting() const { return theFile != NULL; }
  33
  34     /// called by SwapDir::writeCompleted() after the last write and on error
  35     void finishedWriting(const int errFlag);
  36
  37     MEMPROXY_CLASS(IoState);
  38
  39     /* one and only one of these will be set and locked; access via *Anchor() */
  40     const Ipc::StoreMapAnchor *readableAnchor_; ///< starting point for reading
  41     Ipc::StoreMapAnchor *writeableAnchor_; ///< starting point for writing
  42
  43     SlotId sidCurrent; ///< ID of the db slot currently being read or written
  44
  45 private:
  46     const Ipc::StoreMapAnchor &readAnchor() const;
  47     Ipc::StoreMapAnchor &writeAnchor();
  48     const Ipc::StoreMapSlice &currentReadableSlice() const;
  49
  50     void tryWrite(char const *buf, size_t size, off_t offset);
  51     size_t writeToBuffer(char const *buf, size_t size);
  52     void writeToDisk(const SlotId nextSlot);
  53     SlotId reserveSlotForWriting();
  54
  55     void callBack(int errflag);
  56
  57     Rock::SwapDir::Pointer dir; ///< swap dir that initiated I/O
  58     const size_t slotSize; ///< db cell size
  59     int64_t objOffset; ///< object offset for current db slot
  60
  61     RefCount<DiskFile> theFile; // "file" responsible for this I/O
  62     MemBlob theBuf; // use for write content accumulation only
  63 };
  64
  65 MEMPROXY_CLASS_INLINE(IoState);
  66
  67 } // namespace Rock
  68
  69 #endif /* SQUID_FS_ROCK_IO_STATE_H */