1 files changed, 77 insertions, 0 deletions
diff --git a/src/librbd/cache/ImageWriteback.h b/src/librbd/cache/ImageWriteback.h
new file mode 100644
index 000000000..3f62391e4
--- /dev/null
+++ b/src/librbd/cache/ImageWriteback.h
@@ -0,0 +1,77 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_CACHE_IMAGE_WRITEBACK
+#define CEPH_LIBRBD_CACHE_IMAGE_WRITEBACK
+
+#include "include/buffer_fwd.h"
+#include "include/int_types.h"
+#include "librbd/io/Types.h"
+#include <vector>
+
+class Context;
+
+namespace librbd {
+
+struct ImageCtx;
+
+namespace cache {
+
+class ImageWritebackInterface {
+public:
+  typedef std::vector<std::pair<uint64_t,uint64_t> > Extents;
+  virtual ~ImageWritebackInterface() {
+  }
+  virtual void aio_read(Extents &&image_extents, ceph::bufferlist *bl,
+                        int fadvise_flags, Context *on_finish) = 0;
+  virtual void aio_write(Extents &&image_extents, ceph::bufferlist&& bl,
+                         int fadvise_flags, Context *on_finish) = 0;
+  virtual void aio_discard(uint64_t offset, uint64_t length,
+                           uint32_t discard_granularity_bytes, Context *on_finish) = 0;
+  virtual void aio_flush(io::FlushSource flush_source, Context *on_finish) = 0 ;
+  virtual void aio_writesame(uint64_t offset, uint64_t length,
+                             ceph::bufferlist&& bl,
+                             int fadvise_flags, Context *on_finish) = 0;
+  virtual void aio_compare_and_write(Extents &&image_extents,
+                                     ceph::bufferlist&& cmp_bl,
+                                     ceph::bufferlist&& bl,
+                                     uint64_t *mismatch_offset,
+                                     int fadvise_flags, Context *on_finish) = 0;
+};
+
+/**
+ * client-side, image extent cache writeback handler
+ */
+template <typename ImageCtxT = librbd::ImageCtx>
+class ImageWriteback : public ImageWritebackInterface {
+public:
+  using ImageWritebackInterface::Extents;
+
+  explicit ImageWriteback(ImageCtxT &image_ctx);
+
+  void aio_read(Extents &&image_extents, ceph::bufferlist *bl,
+                int fadvise_flags, Context *on_finish);
+  void aio_write(Extents &&image_extents, ceph::bufferlist&& bl,
+                 int fadvise_flags, Context *on_finish);
+  void aio_discard(uint64_t offset, uint64_t length,
+                   uint32_t discard_granularity_bytes, Context *on_finish);
+  void aio_flush(io::FlushSource flush_source, Context *on_finish);
+  void aio_writesame(uint64_t offset, uint64_t length,
+                     ceph::bufferlist&& bl,
+                     int fadvise_flags, Context *on_finish);
+  void aio_compare_and_write(Extents &&image_extents,
+                             ceph::bufferlist&& cmp_bl,
+                             ceph::bufferlist&& bl,
+                             uint64_t *mismatch_offset,
+                             int fadvise_flags, Context *on_finish);
+private:
+  ImageCtxT &m_image_ctx;
+
+};
+
+} // namespace cache
+} // namespace librbd
+
+extern template class librbd::cache::ImageWriteback<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_CACHE_IMAGE_WRITEBACK