ceph/src/librbd/cache/PassthroughImageCache.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #ifndef CEPH_LIBRBD_CACHE_PASSTHROUGH_IMAGE_CACHE
   5 #define CEPH_LIBRBD_CACHE_PASSTHROUGH_IMAGE_CACHE
   6
   7 #include "ImageCache.h"
   8 #include "ImageWriteback.h"
   9
  10 namespace librbd {
  11
  12 struct ImageCtx;
  13
  14 namespace cache {
  15
  16 /**
  17  * Example passthrough client-side, image extent cache
  18  */
  19 template <typename ImageCtxT = librbd::ImageCtx>
  20 class PassthroughImageCache : public ImageCache {
  21 public:
  22   PassthroughImageCache(ImageCtx &image_ctx);
  23
  24   /// client AIO methods
  25   void aio_read(Extents&& image_extents, ceph::bufferlist *bl,
  26                 int fadvise_flags, Context *on_finish) override;
  27   void aio_write(Extents&& image_extents, ceph::bufferlist&& bl,
  28                  int fadvise_flags, Context *on_finish) override;
  29   void aio_discard(uint64_t offset, uint64_t length,
  30                    bool skip_partial_discard, Context *on_finish);
  31   void aio_flush(Context *on_finish) override;
  32   void aio_writesame(uint64_t offset, uint64_t length,
  33                      ceph::bufferlist&& bl,
  34                      int fadvise_flags, Context *on_finish) override;
  35   void aio_compare_and_write(Extents&& image_extents,
  36                              ceph::bufferlist&& cmp_bl, ceph::bufferlist&& bl,
  37                              uint64_t *mismatch_offset,int fadvise_flags,
  38                              Context *on_finish) override;
  39
  40   /// internal state methods
  41   void init(Context *on_finish) override;
  42   void shut_down(Context *on_finish) override;
  43
  44   void invalidate(Context *on_finish) override;
  45   void flush(Context *on_finish) override;
  46
  47 private:
  48   ImageCtxT &m_image_ctx;
  49   ImageWriteback<ImageCtxT> m_image_writeback;
  50
  51 };
  52
  53 } // namespace cache
  54 } // namespace librbd
  55
  56 extern template class librbd::cache::PassthroughImageCache<librbd::ImageCtx>;
  57
  58 #endif // CEPH_LIBRBD_CACHE_PASSTHROUGH_IMAGE_CACHE