initial code repo

[stor4nfv.git] / src / ceph / src / librbd / io / ReadResult.h

diff --git a/src/ceph/src/librbd/io/ReadResult.h b/src/ceph/src/librbd/io/ReadResult.h
new file mode 100644 (file)
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+++ b/src/ceph/src/librbd/io/ReadResult.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_IO_READ_RESULT_H
+#define CEPH_LIBRBD_IO_READ_RESULT_H
+
+#include "include/int_types.h"
+#include "include/buffer_fwd.h"
+#include "include/Context.h"
+#include "librbd/io/Types.h"
+#include "osdc/Striper.h"
+#include <sys/uio.h>
+#include <boost/variant/variant.hpp>
+
+struct CephContext;
+
+namespace librbd {
+namespace io {
+
+struct AioCompletion;
+template <typename> struct ObjectReadRequest;
+
+class ReadResult {
+private:
+  struct C_ReadRequest : public Context {
+    AioCompletion *aio_completion;
+    bufferlist bl;
+
+    C_ReadRequest(AioCompletion *aio_completion);
+
+    void finish(int r) override;
+  };
+
+public:
+
+  struct C_ImageReadRequest : public C_ReadRequest {
+    Extents image_extents;
+
+    C_ImageReadRequest(AioCompletion *aio_completion,
+                       const Extents image_extents)
+      : C_ReadRequest(aio_completion), image_extents(image_extents) {
+    }
+
+    void finish(int r) override;
+  };
+
+  struct C_SparseReadRequestBase : public C_ReadRequest {
+    C_SparseReadRequestBase(AioCompletion *aio_completion)
+      : C_ReadRequest(aio_completion) {
+    }
+
+    using C_ReadRequest::finish;
+    void finish(ExtentMap &extent_map, const Extents &buffer_extents,
+                uint64_t offset, size_t length, bufferlist &bl, int r);
+  };
+
+  template <typename ImageCtxT>
+  struct C_SparseReadRequest : public C_SparseReadRequestBase {
+    ObjectReadRequest<ImageCtxT> *request;
+
+    C_SparseReadRequest(AioCompletion *aio_completion)
+      : C_SparseReadRequestBase(aio_completion) {
+    }
+
+    void finish(int r) override {
+      C_SparseReadRequestBase::finish(request->get_extent_map(),
+                                      request->get_buffer_extents(),
+                                      request->get_offset(),
+                                      request->get_length(), request->data(),
+                                      r);
+    }
+  };
+
+  ReadResult();
+  ReadResult(char *buf, size_t buf_len);
+  ReadResult(const struct iovec *iov, int iov_count);
+  ReadResult(ceph::bufferlist *bl);
+
+  void set_clip_length(size_t length);
+  void assemble_result(CephContext *cct);
+
+private:
+  struct Empty {
+  };
+
+  struct Linear {
+    char *buf;
+    size_t buf_len;
+
+    Linear(char *buf, size_t buf_len) : buf(buf), buf_len(buf_len) {
+    }
+  };
+
+  struct Vector {
+    const struct iovec *iov;
+    int iov_count;
+
+    Vector(const struct iovec *iov, int iov_count)
+      : iov(iov), iov_count(iov_count) {
+    }
+  };
+
+  struct Bufferlist {
+    ceph::bufferlist *bl;
+
+    Bufferlist(ceph::bufferlist *bl) : bl(bl) {
+    }
+  };
+
+  typedef boost::variant<Empty,
+                         Linear,
+                         Vector,
+                         Bufferlist> Buffer;
+  struct SetClipLengthVisitor;
+  struct AssembleResultVisitor;
+
+  Buffer m_buffer;
+  Striper::StripedReadResult m_destriper;
+
+};
+
+} // namespace io
+} // namespace librbd
+
+#endif // CEPH_LIBRBD_IO_READ_RESULT_H
+