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     /// forwards read data to the reader that initiated this I/O
  35     void callReaderBack(const char *buf, int rlen);
  36
  37     /// called by SwapDir::writeCompleted() after the last write and on error
  38     void finishedWriting(const int errFlag);
  39
  40     MEMPROXY_CLASS(IoState);
  41
  42     /* one and only one of these will be set and locked; access via *Anchor() */
  43     const Ipc::StoreMapAnchor *readableAnchor_; ///< starting point for reading
  44     Ipc::StoreMapAnchor *writeableAnchor_; ///< starting point for writing
  45
  46     SlotId sidCurrent; ///< ID of the db slot currently being read or written
  47
  48 private:
  49     const Ipc::StoreMapAnchor &readAnchor() const;
  50     Ipc::StoreMapAnchor &writeAnchor();
  51     const Ipc::StoreMapSlice &currentReadableSlice() const;
  52
  53     void tryWrite(char const *buf, size_t size, off_t offset);
  54     size_t writeToBuffer(char const *buf, size_t size);
  55     void writeToDisk(const SlotId nextSlot);
  56     void writeBufToDisk(const SlotId nextSlot, const bool eof);
  57     SlotId reserveSlotForWriting();
  58
  59     void callBack(int errflag);
  60
  61     Rock::SwapDir::Pointer dir; ///< swap dir that initiated I/O
  62     const size_t slotSize; ///< db cell size
  63     int64_t objOffset; ///< object offset for current db slot
  64
  65     RefCount<DiskFile> theFile; // "file" responsible for this I/O
  66     MemBlob theBuf; // use for write content accumulation only
  67 };
  68
  69 MEMPROXY_CLASS_INLINE(IoState);
  70
  71 } // namespace Rock
  72
  73 #endif /* SQUID_FS_ROCK_IO_STATE_H */